DiagnosticTree/FrontOfArm: Difference between revisions

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   "model": "bayesian_lr_scoring",
   "model": "bayesian_lr_scoring",
   "version": "1.0",
   "version": "1.0",
   "region_label": "Volar Forearm Pain",
   "region_label": "Front of Arm Pain",
   "description": "Probabilistic scoring model for pain on the volar (palm-side) forearm. Two muscles generate it locally: the palmaris longus, with its distinctive prickling, needle-like pain in the distal volar forearm and central palm; and the pronator teres, a deep volar-forearm ache that can compress the median nerve between its two heads (pronator syndrome) and mimic carpal tunnel. Two refer from a distance: the serratus anterior (side of chest to the medial arm and palm, with a respiratory component) and the triceps brachii, whose deep medial-head trigger point refers to the medial epicondyle and the inner forearm from an origin in the posterior arm. Structural and neurological differential led by the proximal median-nerve entrapments (pronator teres syndrome and its siblings, and anterior interosseous syndrome), carpal tunnel syndrome as the distal contrast, forearm fracture with Monteggia/Galeazzi, and the can't-miss forearm compartment syndrome (Dididze et al. 2023; Akhondi et al.; Brukner & Khan 2006, Ch.18).",
   "description": "Probabilistic scoring model for front-of-arm pain using Bayesian likelihood ratio updating with Thurstonian pairwise tiebreakers. Muscles drawn from T&S Vol.1 Ch.18 (Overview: Upper Back, Shoulder, and Arm) and individual chapters. Bold muscles carry higher priors (0.12); regular-weight muscles carry lower priors (0.08). Triceps TrP5 = medial head, referring to medial epicondyle and medial forearm.",
   "thresholds": {
   "thresholds": {
     "early_exit_posterior": 0.55,
     "early_exit_posterior": 0.55,
     "early_exit_gap": 0.18,
     "early_exit_gap": 0.18,
     "pairwise_trigger": 0.15
     "pairwise_trigger": 0.22
   },
   },
   "muscles": {
   "muscles": {
     "palmaris_longus": {
     "biceps": {
       "label": "Palmaris Longus",
       "label": "Biceps Brachii",
       "prior": 0.25,
       "prior": 0.12,
       "page": "Muscle:Palmaris_Longus",
       "page": "Muscle:Biceps_Brachii",
       "key_trp_note": "Unique among the forearm muscles in referring a PRICKLING, needle-like sensation - fine needles in the distal volar forearm and the centre of the palm - rather than the deep aching of other myofascial referrals; this quality is the key diagnostic feature. Activated by pressing or holding a tool (screwdriver, trowel, chisel, racquet butt, angular cane) forcibly in the cupped palm. The tendon stands out at the wrist on vigorous palm-cupping - and the muscle is congenitally ABSENT in up to 20% of people, so confirm it exists before blaming it. Active trigger points commonly accompany Dupuytren's contracture; anomalous variants can themselves entrap the median nerve at the wrist.",
       "key_trp_note": "Infraspinatus TrPs are the most important key TrP source driving satellite biceps TrPs. Inactivating infraspinatus is essential for sustained biceps relief and may alone resolve the biceps TrPs. With prolonged biceps TrP activity, expect secondary TrPs in brachialis, supinator, and triceps (in that sequence).",
       "subtitle": "A distinctive PRICKLING, needle-like pain in the lower (distal) front of the forearm and the centre of the palm - not a deep ache; brought on by pressing a tool handle into the cupped palm"
       "subtitle": "Superficial anterior shoulder aching; can lie on affected side; can reach behind waist"
     },
     },
     "pronator_teres": {
     "brachialis": {
       "label": "Pronator Teres",
       "label": "Brachialis",
       "prior": 0.25,
       "prior": 0.08,
       "page": "Muscle:Hand_and_Finger_Flexors",
       "page": "Muscle:Brachialis",
       "key_trp_note": "A proximal volar-forearm muscle referring a deep ache along the volar forearm to the radial wrist. The median nerve passes between its two heads in most people, so a taut or hypertrophied pronator teres can compress it (pronator teres syndrome), producing median-territory paraesthesia that - unlike carpal tunnel syndrome - INCLUDES the thenar eminence (the palmar cutaneous branch leaves the median nerve proximal to the carpal tunnel but distal to the pronator teres), is worse on resisted pronation, and lacks the nocturnal predominance of carpal tunnel syndrome. A positive Tinel sign over the proximal edge of the muscle is typical. Distinguish the trigger point and pronator syndrome from true carpal tunnel syndrome and from the sibling proximal-median entrapments. Examine with the other volar forearm flexors.",
       "key_trp_note": "Brachialis TrPs are almost always co-active with biceps brachii TrPs. In the tennis elbow pattern, the supinator is the primary TrP; brachialis develops secondarily. The almond-shaped lateral border TrP specifically compresses the sensory radial nerve branch \u2014 causing dorsal thumb dysesthesia alongside the referred aching.",
       "subtitle": "A deep ache in the front of the forearm running toward the radial side of the wrist; worse on turning the palm down against resistance; often with tingling of the thumb, index, and middle fingers (a carpal-tunnel mimic that also affects the ball of the thumb)"
       "subtitle": "Thumb base and dorsal web of thumb; thumb hurts not elbow; passive elbow extension worsens pain"
     },
     },
     "serratus_anterior": {
     "scalene": {
       "label": "Serratus Anterior",
       "label": "Scalene",
       "prior": 0.25,
       "prior": 0.12,
       "page": "Muscle:Serratus_Anterior",
       "page": "Muscle:Scalene",
       "key_trp_note": "A lateral chest-wall muscle whose essential pain is at the anterolateral midchest (with an interscapular patch), spilling down the medial arm and forearm to the palm and ring finger - which is how it reaches this region. Its signature is respiratory: a 'stitch in the side' on running, air hunger, and inability to finish a sentence without pausing for breath. Activated by fast or prolonged running, push-ups, severe coughing, and the torsional stress of wrenching the body around. The trigger point sits in the midaxillary line over the fifth or sixth rib. Left-sided pain must not be called myofascial until cardiac disease has been excluded.",
       "key_trp_note": "Scalene TrPs drive satellite TrPs in biceps brachii, pectoralis major/minor, serratus posterior superior, and upper trapezius. Treat scalenes before their satellites. SCM should be treated concurrently.",
       "subtitle": "Pain on the SIDE of the chest (and a patch between the shoulder blades) spilling down the inner arm and forearm to the palm; a 'stitch in the side', breathlessness, or pain on taking a deep breath; brought on by hard running or wrenching the body around"
       "subtitle": "Anterior chest and arm symptoms; nocturnal arm aching; must hang arm over bed for relief"
     },
     },
     "triceps_brachii": {
     "scalenus_minimus": {
       "label": "Triceps Brachii",
      "label": "Scalenus Minimus",
       "prior": 0.25,
      "prior": 0.12,
      "page": "Muscle:Scalene",
      "key_trp_note": "Scalenus minimus (when present) is anatomically positioned to compress the lower trunk of the brachial plexus against the first rib. Its TrPs produce a distinct radial-hand pattern extending to the thumb and index finger. Treat as part of the scalene group in the same session.",
      "subtitle": "Posterior arm to radial hand/thumb; lower brachial plexus compression pattern"
    },
    "subclavius": {
      "label": "Subclavius",
      "prior": 0.12,
      "page": "Muscle:Pectoralis_Major",
      "key_trp_note": "Subclavius TrPs almost always coexist with clavicular pectoralis major TrPs. Subclavius shortening draws the clavicle down toward the subclavian neurovascular structures \u2014 vascular thoracic outlet syndrome. Treat clavicular pectoralis major first.",
      "subtitle": "Radial forearm and hand SKIPPING the elbow and wrist; thumb, index, and middle fingers"
    },
    "triceps_trp5": {
       "label": "Triceps \u2014 Medial Head (TrP5)",
       "prior": 0.12,
       "page": "Muscle:Triceps_Brachii",
       "page": "Muscle:Triceps_Brachii",
       "key_trp_note": "Enters this region through its deep medial-head trigger point (the deep, medial portion just above the medial epicondyle), which refers to the medial epicondyle and may extend along the INNER side of the forearm and to the volar surface of the fourth and fifth digits, the adjacent palm, and sometimes the middle finger. Unlike the local volar-forearm muscles, the PAIN ORIGINATES IN THE POSTERIOR ARM and is provoked by forceful or resisted ELBOW EXTENSION (and reproduced by passive elbow flexion). Often mistaken for medial epicondylitis ('golfer's elbow') - but resisted wrist flexion is negative here, and the tender point is in the triceps, not the common flexor origin. A satellite of latissimus dorsi and serratus posterior superior trigger points, which must be inactivated first for lasting relief.",
       "key_trp_note": "Triceps TrP5 (medial head) refers to the medial epicondyle and medial forearm \u2014 the front-of-arm pattern that distinguishes it from TrP1 (posterior arm, long head) and TrP3 (lateral head, radial nerve zone). Scalene TrPs drive triceps long head satellite TrPs; the medial head may be activated independently by direct overload or antagonist cramping from biceps/brachialis treatment.",
       "subtitle": "A deep ache that starts in the back of the upper arm and reaches the INNER side of the forearm and the medial epicondyle (the 'funny bone' bump), sometimes the palm side of the ring and little fingers; brought on by straightening the elbow against resistance"
      "subtitle": "Medial epicondyle and medial forearm pain from anterior arm; antagonist cramping after biceps treatment"
    },
    "infraspinatus": {
      "label": "Infraspinatus",
      "prior": 0.08,
      "page": "Muscle:Infraspinatus",
      "key_trp_note": "Infraspinatus is the key TrP source driving satellite biceps brachii TrPs. Inactivating infraspinatus first is essential \u2014 biceps TrPs may resolve without direct treatment once infraspinatus is addressed. Primary infraspinatus presentation is deep anterior joint pain; when it appears in a front-of-arm algorithm it usually reflects the satellite biceps being masked by the primary source.",
      "subtitle": "Deep inside anterior shoulder joint; cannot sleep either side; cannot reach behind back"
    },
    "supraspinatus": {
      "label": "Supraspinatus",
      "prior": 0.08,
      "page": "Muscle:Supraspinatus",
      "key_trp_note": "Supraspinatus TrPs refer to the mid-deltoid and lateral upper arm. Infraspinatus TrPs often drive supraspinatus satellites. With prolonged biceps TrP activity, supraspinatus eventually develops secondary TrPs. Inactivating supraspinatus usually resolves middle deltoid satellite TrPs without direct treatment.",
      "subtitle": "Lateral shoulder to lateral upper arm; lateral epicondyle referral; painful arc 60\u2013120\u00b0"
    },
    "deltoid_anterior": {
      "label": "Anterior Deltoid",
      "prior": 0.08,
      "page": "Muscle:Deltoid",
       "key_trp_note": "Anterior deltoid TrPs are almost always satellites of infraspinatus, supraspinatus, or pectoralis major key TrPs \u2014 the anterior deltoid lies in the pain reference zone of all three. Treat the key TrP source first; anterior deltoid TrPs usually resolve without direct treatment.",
      "subtitle": "Local anterior shoulder surface only; no arm or hand referral; history of direct impact or injection"
    },
    "sternalis": {
      "label": "Sternalis",
      "prior": 0.08,
      "page": "Muscle:Sternalis",
      "key_trp_note": "Sternalis TrPs are almost always co-active with pectoralis major TrPs. SCM sternal division (lower end) may refer pain downward over the sternum and activate sternalis as a satellite. Present in only ~4\u20135% of the population. Treat pectoralis major and SCM before or alongside sternalis.",
      "subtitle": "Deep substernal ache; movement-independent; cardiac mimic; may extend to front of shoulder and upper arm"
     }
     }
   },
   },
   "questions": [
   "questions": [
     {
     {
       "id": "q_zone",
       "id": "q_dominant_pain_zone",
       "text": "Where is the pain mainly felt, and where does it seem to start?",
       "text": "Where is the front-of-arm pain most concentrated?",
       "sublabel": "The origin of the whole pattern",
      "sublabel": "Choose the single best description of the dominant pain zone",
      "type": "choice",
      "answers": [
        {
          "id": "anterior_shoulder_surface",
          "label": "Surface of the ANTERIOR SHOULDER \u2014 front of the shoulder bulge; superficial aching",
          "sublabel": "Superficial aching over the front of the shoulder and deltoid region; NOT deep inside the joint",
          "lr": {
            "biceps": 8.0,
            "deltoid_anterior": 5.0,
            "supraspinatus": 2.0,
            "scalene": 1.5,
            "infraspinatus": 0.3,
            "brachialis": 0.5,
            "subclavius": 1.0,
            "scalenus_minimus": 0.8,
            "triceps_trp5": 0.5,
            "sternalis": 0.5
          }
        },
        {
          "id": "deep_inside_joint",
          "label": "DEEP INSIDE the front of the shoulder joint \u2014 patient places hand over the anterior shoulder",
          "sublabel": "The pain is felt inside the joint itself, not on the surface",
          "lr": {
            "infraspinatus": 10.0,
            "biceps": 1.0,
            "deltoid_anterior": 0.3,
            "supraspinatus": 1.0,
            "scalene": 0.7,
            "brachialis": 0.3,
            "subclavius": 0.4,
            "scalenus_minimus": 0.4,
            "triceps_trp5": 0.3,
            "sternalis": 0.3
          }
        },
        {
          "id": "biceps_belly_antecubital",
          "label": "BICEPS MUSCLE BELLY or ANTECUBITAL SPACE \u2014 front of the upper arm or elbow crease",
          "sublabel": "The arm itself hurts, not just the shoulder; the antecubital fossa may also ache",
          "lr": {
            "biceps": 5.0,
            "brachialis": 6.0,
            "scalene": 1.5,
            "triceps_trp5": 2.0,
            "infraspinatus": 0.5,
            "supraspinatus": 0.8,
            "deltoid_anterior": 0.4,
            "subclavius": 0.8,
            "scalenus_minimus": 0.8,
            "sternalis": 0.4
          }
        },
        {
          "id": "substernal_chest",
          "label": "SUBSTERNAL or anterior chest \u2014 behind the breastbone or across the front of the chest",
          "sublabel": "The dominant pain is in the chest, not in the arm itself",
          "lr": {
            "sternalis": 12.0,
            "scalene": 2.0,
            "subclavius": 1.5,
            "scalenus_minimus": 1.0,
            "biceps": 0.3,
            "brachialis": 0.2,
            "infraspinatus": 0.2,
            "supraspinatus": 0.2,
            "deltoid_anterior": 0.3,
            "triceps_trp5": 0.3
          }
        }
      ]
    },
    {
      "id": "q_thumb_pain",
      "text": "Is the thumb affected \u2014 specifically pain or soreness at the BASE of the thumb or dorsal web space of the thumb?",
       "sublabel": "The thumb hurts at its base (carpometacarpal joint area) or on the back of the thumb web; this is the dominant or a prominent complaint",
      "type": "binary",
      "answers": [
        {
          "id": "yes",
          "label": "Yes \u2014 thumb base or dorsal thumb web is painful or sore",
          "lr": {
            "brachialis": 12.0,
            "subclavius": 3.0,
            "scalenus_minimus": 3.0,
            "scalene": 1.5,
            "biceps": 0.4,
            "infraspinatus": 0.4,
            "supraspinatus": 0.3,
            "deltoid_anterior": 0.2,
            "triceps_trp5": 0.3,
            "sternalis": 0.2
          }
        },
        {
          "id": "no",
          "label": "No \u2014 thumb is not specifically affected",
          "lr": {
            "brachialis": 0.15,
            "subclavius": 0.7,
            "scalenus_minimus": 0.7,
            "scalene": 0.9,
            "biceps": 1.2,
            "infraspinatus": 1.2,
            "supraspinatus": 1.2,
            "deltoid_anterior": 1.3,
            "triceps_trp5": 1.2,
            "sternalis": 1.2
          }
        }
      ]
    },
    {
      "id": "q_thumb_vs_elbow",
      "text": "Regarding pain when moving the arm or thumb: which hurts more?",
      "sublabel": "A key brachialis dissociation test \u2014 the thumb hurts with use; the elbow does not",
      "type": "choice",
      "condition": {
        "q_thumb_pain": "yes"
      },
      "answers": [
        {
          "id": "thumb_hurts_elbow_ok",
          "label": "Active thumb movement HURTS; active elbow movement does NOT hurt",
          "sublabel": "Using the thumb causes pain; bending or straightening the elbow does not",
          "lr": {
            "brachialis": 14.0,
            "subclavius": 1.5,
            "scalenus_minimus": 1.5,
            "scalene": 0.8,
            "biceps": 0.3,
            "infraspinatus": 0.3,
            "supraspinatus": 0.3,
            "deltoid_anterior": 0.3,
            "triceps_trp5": 0.3,
            "sternalis": 0.2
          }
        },
        {
          "id": "elbow_also_hurts",
          "label": "Both the thumb AND the elbow hurt with movement",
          "sublabel": "Elbow movement is also painful, not just the thumb",
          "lr": {
            "brachialis": 2.0,
            "subclavius": 2.0,
            "scalenus_minimus": 2.0,
            "scalene": 1.5,
            "biceps": 1.5,
            "infraspinatus": 0.5,
            "supraspinatus": 0.5,
            "deltoid_anterior": 0.4,
            "triceps_trp5": 1.5,
            "sternalis": 0.3
          }
        }
      ]
    },
    {
      "id": "q_sleep",
      "text": "How does the arm pain affect sleep?",
      "sublabel": "Which sleeping position is tolerated?",
       "type": "choice",
       "type": "choice",
       "answers": [
       "answers": [
         {
         {
           "id": "distal_volar_palm",
           "id": "neither_side",
           "label": "The LOWER front of the forearm and the centre of the PALM",
           "label": "Cannot sleep on EITHER side \u2014 may sleep upright or propped in a chair",
           "sublabel": "Distal volar forearm / palm",
           "sublabel": "Even the unaffected side causes pain; every lying position wakes the patient",
           "lr": {
           "lr": {
             "palmaris_longus": 6.5,
             "infraspinatus": 10.0,
             "pronator_teres": 1.0,
            "scalene": 2.0,
             "serratus_anterior": 0.5,
             "biceps": 1.0,
             "triceps_brachii": 0.5
             "brachialis": 0.5,
            "supraspinatus": 0.5,
             "deltoid_anterior": 0.3,
            "subclavius": 0.4,
            "scalenus_minimus": 0.4,
            "triceps_trp5": 0.4,
            "sternalis": 0.5
           }
           }
         },
         },
         {
         {
           "id": "proximal_volar_to_wrist",
           "id": "not_affected_side",
           "label": "The front of the forearm running down toward the RADIAL wrist",
           "label": "Cannot sleep on the AFFECTED side only",
          "sublabel": "Volar forearm to radial wrist",
          "sublabel": "Lying on the painful arm wakes the patient; other positions are tolerated",
          "lr": {
            "biceps": 5.0,
            "deltoid_anterior": 3.0,
            "supraspinatus": 2.5,
            "brachialis": 2.0,
            "triceps_trp5": 2.0,
            "scalene": 1.0,
            "subclavius": 1.0,
            "scalenus_minimus": 0.8,
            "infraspinatus": 0.4,
            "sternalis": 1.0
          }
        },
        {
          "id": "sleep_ok",
          "label": "Sleep is largely unaffected or only mildly disturbed",
          "sublabel": "The patient finds a comfortable position without significant waking",
          "lr": {
            "sternalis": 3.0,
            "subclavius": 2.0,
            "scalenus_minimus": 1.5,
            "scalene": 1.5,
            "deltoid_anterior": 1.5,
            "supraspinatus": 1.0,
            "brachialis": 1.0,
            "biceps": 0.5,
            "infraspinatus": 0.2,
            "triceps_trp5": 1.2
          }
        }
      ]
    },
    {
      "id": "q_behind_back",
      "text": "Can the patient reach comfortably behind the back?",
      "sublabel": "Test: reaching the arm behind the back to the hip pocket or brassiere hooks",
      "type": "binary",
      "answers": [
        {
          "id": "restricted",
          "label": "Painful or restricted \u2014 cannot reach behind the back fully",
           "lr": {
           "lr": {
             "palmaris_longus": 1.0,
             "infraspinatus": 8.0,
             "pronator_teres": 6.5,
            "biceps": 3.0,
             "serratus_anterior": 0.5,
            "supraspinatus": 2.0,
             "triceps_brachii": 0.5
            "brachialis": 1.5,
            "scalene": 1.0,
             "deltoid_anterior": 0.6,
            "subclavius": 0.5,
             "scalenus_minimus": 0.4,
            "triceps_trp5": 0.5,
             "sternalis": 0.4
           }
           }
         },
         },
         {
         {
           "id": "side_of_chest",
           "id": "normal",
           "label": "The SIDE of the CHEST (and maybe between the shoulder blades), spilling down the inner arm",
           "label": "Full behind-back reach \u2014 no restriction",
           "sublabel": "Lateral chest source",
          "lr": {
            "infraspinatus": 0.2,
            "biceps": 0.5,
            "supraspinatus": 0.7,
            "brachialis": 0.9,
            "scalene": 1.0,
            "deltoid_anterior": 1.4,
            "subclavius": 1.4,
            "scalenus_minimus": 1.4,
            "triceps_trp5": 1.3,
            "sternalis": 1.4
          }
        }
      ]
    },
    {
      "id": "q_elbow_extension_test",
      "text": "Does PASSIVELY straightening (extending) the elbow increase pain in the arm, antecubital space, or thumb?",
      "sublabel": "With the arm relaxed, the examiner gently straightens the elbow fully \u2014 does this increase pain?",
      "type": "binary",
      "answers": [
        {
          "id": "yes",
           "label": "Yes \u2014 passively extending the elbow worsens pain",
           "lr": {
           "lr": {
             "palmaris_longus": 0.5,
             "brachialis": 10.0,
             "pronator_teres": 0.5,
            "biceps": 4.0,
             "serratus_anterior": 7.0,
            "triceps_trp5": 1.5,
             "triceps_brachii": 0.6
            "scalene": 0.8,
            "infraspinatus": 0.5,
             "supraspinatus": 0.5,
             "deltoid_anterior": 0.4,
            "subclavius": 0.5,
            "scalenus_minimus": 0.5,
             "sternalis": 0.3
           }
           }
         },
         },
         {
         {
           "id": "back_of_arm_inner_forearm",
           "id": "no",
           "label": "The BACK of the UPPER ARM, reaching the INNER forearm and the 'funny bone' bump",
           "label": "No \u2014 elbow extension does not worsen pain",
          "sublabel": "Posterior arm / inner forearm",
           "lr": {
           "lr": {
             "palmaris_longus": 0.5,
             "brachialis": 0.2,
             "pronator_teres": 0.5,
             "biceps": 0.6,
             "serratus_anterior": 0.6,
             "triceps_trp5": 1.0,
             "triceps_brachii": 7.0
            "scalene": 1.1,
            "infraspinatus": 1.2,
            "supraspinatus": 1.2,
            "deltoid_anterior": 1.3,
            "subclavius": 1.2,
            "scalenus_minimus": 1.2,
             "sternalis": 1.2
           }
           }
         }
         }
Line 93: Line 383:
     },
     },
     {
     {
       "id": "q_quality",
       "id": "q_supination_vs_pronation",
       "text": "What is the pain like?",
       "text": "Is arm pain or weakness worse when the forearm is SUPINATED (palm up) compared to PRONATED (palm down) during elbow flexion?",
       "sublabel": "The prickling quality is near-unique to one muscle",
       "sublabel": "Test: flex the elbow with palm facing up, then repeat with palm facing down \u2014 which position is more painful or weak?",
       "type": "choice",
       "type": "choice",
       "answers": [
       "answers": [
         {
         {
           "id": "prickling",
           "id": "supination_worse",
           "label": "PRICKLING or needle-like, like fine needles in the forearm and palm",
           "label": "Supination (palm up) is more painful or weak than pronation (palm down)",
           "sublabel": "Prickling / needle-like",
           "sublabel": "Lifting with palm up hurts more than lifting with palm down",
           "lr": {
           "lr": {
             "palmaris_longus": 7.5,
             "biceps": 8.0,
             "pronator_teres": 0.5,
            "scalene": 1.5,
             "serratus_anterior": 0.5,
            "infraspinatus": 1.0,
             "triceps_brachii": 0.5
            "brachialis": 0.4,
            "supraspinatus": 0.8,
            "deltoid_anterior": 0.7,
            "subclavius": 0.8,
             "scalenus_minimus": 0.8,
             "triceps_trp5": 0.5,
             "sternalis": 0.5
           }
           }
         },
         },
         {
         {
           "id": "deep_ache_local",
           "id": "equal_both",
           "label": "A DEEP ACHE in the forearm or arm itself",
           "label": "Both positions are equally painful or weak",
           "sublabel": "Deep local ache",
           "sublabel": "No difference between palm up and palm down during elbow flexion",
           "lr": {
           "lr": {
             "palmaris_longus": 0.6,
             "brachialis": 6.0,
             "pronator_teres": 4.0,
            "triceps_trp5": 2.0,
             "serratus_anterior": 0.7,
            "scalene": 1.5,
             "triceps_brachii": 4.0
            "scalenus_minimus": 1.5,
            "subclavius": 1.5,
            "sternalis": 1.5,
            "infraspinatus": 1.0,
             "supraspinatus": 1.0,
             "biceps": 0.4,
             "deltoid_anterior": 1.0
           }
           }
         },
         },
         {
         {
           "id": "referred_distance",
           "id": "no_difference_painless",
           "label": "A spillover from an ache that really lives in the chest or upper arm",
           "label": "No pain with either position \u2014 elbow flexion is not a trigger",
           "sublabel": "Referred from a distance",
           "sublabel": "Bending the elbow does not provoke the arm pain",
           "lr": {
           "lr": {
             "palmaris_longus": 0.5,
             "infraspinatus": 2.0,
             "pronator_teres": 0.6,
            "deltoid_anterior": 2.0,
             "serratus_anterior": 4.5,
            "sternalis": 2.0,
             "triceps_brachii": 3.0
            "subclavius": 1.5,
             "scalenus_minimus": 1.5,
            "scalene": 1.5,
             "supraspinatus": 1.5,
             "biceps": 0.4,
            "brachialis": 0.3,
            "triceps_trp5": 1.0
           }
           }
         }
         }
Line 134: Line 442:
     },
     },
     {
     {
       "id": "q_provocation",
       "id": "q_arm_referral",
       "text": "Which activity most reliably brings on the pain?",
       "text": "Does the arm pain extend to the forearm or hand?",
       "sublabel": "Choose the single strongest aggravator",
       "sublabel": "Choose the best description of the distal referral",
       "type": "choice",
       "type": "choice",
       "answers": [
       "answers": [
         {
         {
           "id": "tool_in_palm",
           "id": "radial_skip",
           "label": "Pressing a tool handle (or cane/racquet butt) into the cupped palm",
           "label": "Radial forearm and/or thumb/index/middle fingers \u2014 SKIPPING the elbow and wrist",
           "sublabel": "Tool pressed in palm",
           "sublabel": "The radial side of the forearm and/or the thumb, index, or middle finger hurt; the elbow joint area is pain-free",
           "lr": {
           "lr": {
             "palmaris_longus": 7.0,
             "subclavius": 10.0,
             "pronator_teres": 0.7,
             "scalenus_minimus": 6.0,
             "serratus_anterior": 0.5,
            "brachialis": 3.0,
             "triceps_brachii": 0.5
            "scalene": 2.0,
             "biceps": 0.5,
             "infraspinatus": 0.8,
            "supraspinatus": 0.5,
            "deltoid_anterior": 0.2,
            "triceps_trp5": 0.4,
            "sternalis": 0.3
           }
           }
         },
         },
         {
         {
           "id": "resisted_pronation",
           "id": "medial_epicondyle",
           "label": "Turning the palm down against resistance, or repetitive twisting (hammering, ladling, wringing cloths)",
           "label": "Medial epicondyle (inner elbow) and/or medial forearm",
           "sublabel": "Resisted pronation",
           "sublabel": "The inner bump of the elbow and/or the medial forearm is part of the pain",
           "lr": {
           "lr": {
             "palmaris_longus": 0.8,
             "triceps_trp5": 9.0,
             "pronator_teres": 6.5,
            "scalene": 2.0,
             "serratus_anterior": 0.5,
             "brachialis": 1.5,
             "triceps_brachii": 0.6
             "biceps": 1.0,
            "scalenus_minimus": 1.0,
            "infraspinatus": 0.5,
             "supraspinatus": 0.4,
            "subclavius": 0.4,
            "deltoid_anterior": 0.3,
            "sternalis": 0.3
           }
           }
         },
         },
         {
         {
           "id": "resisted_elbow_extension",
           "id": "ulnar_forearm_hand",
           "label": "Straightening the elbow against resistance (push-ups, pushing, a tennis backhand)",
           "label": "Ulnar forearm and/or ring and little fingers",
           "sublabel": "Resisted elbow extension",
           "sublabel": "The inner forearm and/or the two ulnar digits hurt",
           "lr": {
           "lr": {
             "palmaris_longus": 0.6,
             "scalene": 4.0,
             "pronator_teres": 0.6,
            "scalenus_minimus": 2.0,
             "serratus_anterior": 0.6,
             "sternalis": 2.0,
             "triceps_brachii": 7.0
            "brachialis": 1.0,
             "biceps": 0.5,
             "triceps_trp5": 1.5,
            "subclavius": 0.5,
            "infraspinatus": 0.5,
            "supraspinatus": 0.4,
            "deltoid_anterior": 0.3
           }
           }
         },
         },
         {
         {
           "id": "running_cough_torsion",
           "id": "suprascapular_spillover",
           "label": "Hard running, coughing, or wrenching the body around (turning a heavy steering wheel)",
           "label": "Pain skips upward to the suprascapular region \u2014 above the scapular spine",
           "sublabel": "Running / cough / torsion",
           "sublabel": "The area above the shoulder blade also aches, almost as if the pain jumps over the shoulder",
           "lr": {
           "lr": {
             "palmaris_longus": 0.6,
             "biceps": 7.0,
             "pronator_teres": 0.6,
            "scalene": 2.0,
             "serratus_anterior": 7.0,
            "infraspinatus": 1.5,
             "triceps_brachii": 0.7
            "supraspinatus": 1.5,
            "scalenus_minimus": 1.0,
            "brachialis": 0.5,
             "deltoid_anterior": 0.4,
             "subclavius": 0.5,
            "triceps_trp5": 0.4,
            "sternalis": 0.4
          }
        },
        {
          "id": "lateral_arm_epicondyle",
          "label": "Lateral upper arm or lateral epicondyle \u2014 outer elbow region",
          "sublabel": "The outer side of the upper arm or the outer elbow bump is included in the pain",
          "lr": {
            "supraspinatus": 7.0,
             "biceps": 1.0,
            "scalene": 1.5,
            "infraspinatus": 1.5,
            "brachialis": 0.5,
            "deltoid_anterior": 0.8,
            "subclavius": 0.5,
            "scalenus_minimus": 0.5,
            "triceps_trp5": 0.5,
            "sternalis": 0.3
          }
        },
        {
          "id": "no_distal_referral",
          "label": "No forearm or hand referral \u2014 pain stays in the shoulder and upper arm",
          "sublabel": "Pain does not travel below the elbow",
          "lr": {
            "deltoid_anterior": 3.0,
            "sternalis": 3.0,
            "infraspinatus": 1.5,
            "biceps": 1.0,
            "supraspinatus": 1.0,
            "brachialis": 0.5,
            "scalene": 0.5,
            "subclavius": 0.4,
            "scalenus_minimus": 0.4,
            "triceps_trp5": 0.5
           }
           }
         }
         }
Line 186: Line 552:
     },
     },
     {
     {
       "id": "q_median_tingle",
       "id": "q_nocturnal_arm",
       "text": "Is there tingling or numbness of the THUMB, INDEX, and MIDDLE fingers - INCLUDING the ball of the thumb (thenar eminence)?",
       "text": "Is the patient woken at night by arm aching or numbness \u2014 requiring the arm to hang over the side of the bed or be shaken for relief?",
       "sublabel": "Median-territory symptoms that include the thenar eminence point to a proximal (pronator-level) median compression rather than the local muscles; carpal tunnel syndrome characteristically SPARES the thenar skin",
       "sublabel": "Nocturnal arm symptoms specifically relieved by hanging the arm over the bed edge",
       "type": "binary",
       "type": "binary",
       "answers": [
       "answers": [
         {
         {
           "id": "yes",
           "id": "yes",
           "label": "Yes - median-territory tingling that includes the ball of the thumb",
           "label": "Yes \u2014 woken at night; arm must hang over bed side for relief",
           "lr": {
           "lr": {
             "palmaris_longus": 0.8,
             "scalene": 9.0,
             "pronator_teres": 5.0,
            "scalenus_minimus": 5.0,
             "serratus_anterior": 0.7,
            "subclavius": 2.0,
             "triceps_brachii": 0.7
             "brachialis": 0.5,
            "biceps": 0.5,
            "infraspinatus": 0.5,
            "supraspinatus": 0.4,
            "deltoid_anterior": 0.3,
             "triceps_trp5": 0.4,
             "sternalis": 0.3
           }
           }
         },
         },
         {
         {
           "id": "no",
           "id": "no",
           "label": "No - aching/prickling pain only, or no thenar involvement",
           "label": "No \u2014 no nocturnal arm hanging symptom",
           "lr": {
           "lr": {
             "palmaris_longus": 1.1,
             "scalene": 0.25,
             "pronator_teres": 0.4,
            "scalenus_minimus": 0.35,
             "serratus_anterior": 1.05,
            "subclavius": 0.8,
             "triceps_brachii": 1.05
            "brachialis": 1.1,
             "biceps": 1.1,
            "infraspinatus": 1.1,
            "supraspinatus": 1.1,
            "deltoid_anterior": 1.2,
             "triceps_trp5": 1.1,
             "sternalis": 1.1
           }
           }
         }
         }
Line 214: Line 592:
     },
     },
     {
     {
       "id": "q_respiratory",
       "id": "q_movement_independence",
       "text": "Is there a 'stitch in the side', breathlessness, or pain clearly worse on taking a deep breath?",
       "text": "Is the arm or chest pain MOVEMENT-INDEPENDENT \u2014 present at rest and NOT worsened by any specific shoulder or arm movement?",
       "sublabel": "Serratus anterior signature - a respiratory symptom complex distinguishes it from the other sources",
       "sublabel": "No position, movement, or activity clearly makes the pain better or worse",
       "type": "binary",
       "type": "binary",
       "answers": [
       "answers": [
         {
         {
           "id": "yes",
           "id": "yes",
           "label": "Yes - a stitch in the side, breathlessness, or pain on deep breathing",
           "label": "Yes \u2014 pain present at rest, unchanged by movement",
           "lr": {
           "lr": {
             "palmaris_longus": 0.6,
             "sternalis": 10.0,
             "pronator_teres": 0.6,
            "scalene": 2.0,
             "serratus_anterior": 7.0,
            "scalenus_minimus": 1.5,
             "triceps_brachii": 0.6
             "biceps": 0.5,
             "brachialis": 0.4,
            "infraspinatus": 0.5,
            "supraspinatus": 0.4,
            "deltoid_anterior": 0.5,
            "subclavius": 0.5,
             "triceps_trp5": 0.5
           }
           }
         },
         },
         {
         {
           "id": "no",
           "id": "no",
           "label": "No - breathing does not affect it",
           "label": "No \u2014 pain varies with position, activity, or movement",
           "lr": {
           "lr": {
             "palmaris_longus": 1.05,
             "sternalis": 0.2,
             "pronator_teres": 1.05,
            "scalene": 0.9,
             "serratus_anterior": 0.3,
            "scalenus_minimus": 0.9,
             "triceps_brachii": 1.05
            "biceps": 1.2,
            "brachialis": 1.2,
            "infraspinatus": 1.2,
             "supraspinatus": 1.2,
             "deltoid_anterior": 1.2,
            "subclavius": 1.1,
             "triceps_trp5": 1.1
           }
           }
         }
         }
Line 242: Line 632:
     },
     },
     {
     {
       "id": "q_palpation",
       "id": "q_painful_arc",
       "text": "Where does firm palpation most precisely reproduce the familiar forearm pain?",
       "text": "Is there a painful arc during shoulder abduction \u2014 pain appearing between 60\u00b0 and 120\u00b0 of raising the arm sideways, then diminishing above that?",
       "sublabel": "The reproducing tender point - the most specific localiser",
      "sublabel": "Pain appears then disappears as the arm reaches overhead",
      "type": "binary",
      "answers": [
        {
          "id": "yes",
          "label": "Yes \u2014 painful arc between 60\u00b0 and 120\u00b0 of abduction",
          "lr": {
            "supraspinatus": 8.0,
            "deltoid_anterior": 2.0,
            "biceps": 0.8,
            "infraspinatus": 0.7,
            "brachialis": 0.4,
            "scalene": 0.5,
            "scalenus_minimus": 0.4,
            "subclavius": 0.4,
            "triceps_trp5": 0.4,
            "sternalis": 0.3
          }
        },
        {
          "id": "no",
          "label": "No \u2014 no arc pattern; abduction is uniformly painful or pain-free",
          "lr": {
            "supraspinatus": 0.2,
            "deltoid_anterior": 0.9,
            "biceps": 1.1,
            "infraspinatus": 1.1,
            "brachialis": 1.2,
            "scalene": 1.1,
            "scalenus_minimus": 1.1,
            "subclavius": 1.1,
            "triceps_trp5": 1.2,
            "sternalis": 1.2
          }
        }
      ]
    },
    {
      "id": "q_onset",
      "text": "How did the front-of-arm pain begin?",
       "sublabel": "Choose the onset pattern that best describes this episode",
       "type": "choice",
       "type": "choice",
       "answers": [
       "answers": [
         {
         {
           "id": "mid_volar_forearm",
           "id": "sustained_flexion_load",
           "label": "In the middle of the front of the forearm, over the central tendon that pops up on cupping the palm (palmaris longus)",
           "label": "Sustained elbow flexion under load \u2014 carrying groceries, using power tools at elbow height, ironing, violin playing",
           "sublabel": "Palmaris longus location",
           "sublabel": "Pain crept in over repeated sessions of forearm flexion activity",
           "lr": {
           "lr": {
             "palmaris_longus": 7.0,
             "brachialis": 8.0,
             "pronator_teres": 0.6,
            "biceps": 5.0,
             "serratus_anterior": 0.4,
            "triceps_trp5": 2.0,
             "triceps_brachii": 0.4
            "scalene": 1.0,
            "infraspinatus": 0.5,
            "supraspinatus": 0.5,
            "deltoid_anterior": 0.5,
             "subclavius": 0.7,
             "scalenus_minimus": 0.7,
             "sternalis": 0.4
           }
           }
         },
         },
         {
         {
           "id": "proximal_volar_forearm",
           "id": "acute_overstretch",
           "label": "In the upper front of the forearm just below the elbow crease (pronator teres)",
           "label": "Acute overstretch \u2014 catching a fall, reaching backward suddenly, lifting at arm\u2019s length",
           "sublabel": "Pronator teres location",
           "sublabel": "A specific sudden event the patient can recall",
           "lr": {
           "lr": {
             "palmaris_longus": 0.6,
             "biceps": 6.0,
             "pronator_teres": 7.0,
            "infraspinatus": 5.0,
             "serratus_anterior": 0.4,
            "brachialis": 2.0,
             "triceps_brachii": 0.4
            "deltoid_anterior": 3.0,
            "supraspinatus": 2.0,
             "scalene": 1.0,
             "subclavius": 0.7,
            "scalenus_minimus": 0.7,
            "triceps_trp5": 1.0,
             "sternalis": 0.5
           }
           }
         },
         },
         {
         {
           "id": "midaxillary_ribs",
           "id": "gradual_postural",
           "label": "On the side of the chest over the ribs, in line with the armpit (serratus anterior)",
           "label": "Gradual onset without clear incident \u2014 prolonged desk work, sustained sitting, poor posture",
           "sublabel": "Serratus anterior location",
           "sublabel": "Pain developed insidiously over weeks without a specific event",
           "lr": {
           "lr": {
             "palmaris_longus": 0.4,
             "scalene": 4.0,
             "pronator_teres": 0.4,
            "scalenus_minimus": 3.0,
             "serratus_anterior": 7.0,
             "subclavius": 3.0,
             "triceps_brachii": 0.5
            "sternalis": 2.5,
            "biceps": 1.5,
            "brachialis": 1.0,
             "infraspinatus": 0.5,
            "supraspinatus": 0.8,
             "deltoid_anterior": 1.0,
            "triceps_trp5": 1.5
           }
           }
         },
         },
         {
         {
           "id": "posterior_arm_medial",
           "id": "post_cardiac",
           "label": "Deep in the back of the upper arm, toward the inner side just above the 'funny bone' (triceps, medial head)",
           "label": "During or after a cardiac event \u2014 myocardial infarction or sustained angina",
           "sublabel": "Triceps brachii location",
           "sublabel": "Chest and arm pain began or intensified around the time of a cardiac event",
           "lr": {
           "lr": {
             "palmaris_longus": 0.4,
             "sternalis": 9.0,
             "pronator_teres": 0.4,
            "scalene": 1.5,
             "serratus_anterior": 0.5,
             "scalenus_minimus": 1.0,
             "triceps_brachii": 7.0
            "subclavius": 0.8,
            "biceps": 0.3,
             "brachialis": 0.3,
            "infraspinatus": 0.3,
            "supraspinatus": 0.3,
             "deltoid_anterior": 0.3,
            "triceps_trp5": 0.3
           }
           }
         }
         }
Line 296: Line 750:
   "pairwise": [
   "pairwise": [
     {
     {
       "id": "pw_pl_pt",
       "id": "pw_brachialis_biceps",
      "pair": [
        "brachialis",
        "biceps"
      ],
      "text": "Tiebreaker \u2014 Brachialis vs Biceps Brachii",
      "question": "Does elbow flexion pain differ between palm-up and palm-down positions?",
      "answers": [
        {
          "id": "equal_both_positions",
          "label": "Equally painful or weak in both palm-up and palm-down flexion",
          "lr": {
            "brachialis": 5.0,
            "biceps": 0.25
          }
        },
        {
          "id": "worse_palm_up",
          "label": "Worse with palm-up (supinated) flexion than palm-down",
          "lr": {
            "brachialis": 0.25,
            "biceps": 5.0
          }
        }
      ]
    },
    {
      "id": "pw_scalene_scalenus_minimus",
       "pair": [
       "pair": [
         "palmaris_longus",
         "scalene",
         "pronator_teres"
         "scalenus_minimus"
       ],
       ],
       "text": "Tiebreaker - Palmaris Longus vs Pronator Teres",
       "text": "Tiebreaker \u2014 Scalene vs Scalenus Minimus",
       "question": "Is the pain a PRICKLING, needle-like sensation in the distal forearm and central palm (palmaris longus), or a DEEP ACHE in the upper forearm running to the radial wrist, often with median-finger tingling and worse on resisted pronation (pronator teres)?",
       "question": "Which arm symptom pattern dominates?",
      "sublabel": "The two local volar-forearm sources",
       "answers": [
       "answers": [
         {
         {
           "id": "pl",
           "id": "nocturnal_ulnar",
           "label": "Prickling, needle-like, distal forearm/palm - palmaris longus",
           "label": "Nocturnal arm aching (hanging over bed) OR posterior arm and ulnar hand symptoms dominate",
           "lr": {
           "lr": {
             "palmaris_longus": 6.0,
             "scalene": 4.0,
             "pronator_teres": 0.4
             "scalenus_minimus": 0.3
           }
           }
         },
         },
         {
         {
           "id": "pt",
           "id": "radial_thumb_plexus",
           "label": "Deep ache to radial wrist, median tingling, resisted pronation - pronator teres",
           "label": "Radial forearm, thumb, or lower brachial plexus compression symptoms dominate",
           "lr": {
           "lr": {
             "palmaris_longus": 0.4,
             "scalene": 0.3,
             "pronator_teres": 6.0
             "scalenus_minimus": 4.0
           }
           }
         }
         }
Line 324: Line 804:
     },
     },
     {
     {
       "id": "pw_pt_tri",
       "id": "pw_subclavius_scalenus_minimus",
       "pair": [
       "pair": [
         "pronator_teres",
         "subclavius",
         "triceps_brachii"
         "scalenus_minimus"
       ],
       ],
       "text": "Tiebreaker - Pronator Teres vs Triceps Brachii",
       "text": "Tiebreaker \u2014 Subclavius vs Scalenus Minimus",
       "question": "Does the forearm ache run to the RADIAL wrist and worsen with resisted PRONATION, often with median tingling (pronator teres)? Or does it start in the BACK OF THE UPPER ARM, reach the INNER forearm and medial epicondyle, and worsen with resisted ELBOW EXTENSION (triceps)?",
       "question": "Does arm abduction worsen the radial forearm and hand symptoms (Wright position), OR is the nocturnal arm pattern more prominent?",
      "sublabel": "Both give a deep forearm ache but from opposite sides and mechanisms",
       "answers": [
       "answers": [
         {
         {
           "id": "pt",
           "id": "wright_worsens",
           "label": "Radial wrist, resisted pronation, median tingling - pronator teres",
           "label": "Arm raised and rotated outward (Wright position) worsens symptoms",
           "lr": {
           "lr": {
             "pronator_teres": 5.5,
             "subclavius": 4.0,
             "triceps_brachii": 0.4
             "scalenus_minimus": 0.3
           }
           }
         },
         },
         {
         {
           "id": "tri",
           "id": "nocturnal_lower_plexus",
           "label": "Posterior arm to inner forearm, resisted elbow extension - triceps brachii",
           "label": "Nocturnal arm symptoms OR lower plexus compression features dominate \u2014 Wright position not specifically positive",
           "lr": {
           "lr": {
             "pronator_teres": 0.4,
             "subclavius": 0.3,
             "triceps_brachii": 5.5
             "scalenus_minimus": 4.0
           }
           }
         }
         }
Line 352: Line 831:
     },
     },
     {
     {
       "id": "pw_sant_tri",
       "id": "pw_infraspinatus_biceps",
       "pair": [
       "pair": [
         "serratus_anterior",
         "infraspinatus",
         "triceps_brachii"
         "biceps"
       ],
       ],
       "text": "Tiebreaker - Serratus Anterior vs Triceps Brachii",
       "text": "Tiebreaker \u2014 Infraspinatus vs Biceps Brachii",
       "question": "Is the source a SIDE-OF-CHEST pain with a respiratory component - stitch in the side, breathlessness (serratus anterior), or a BACK-OF-THE-UPPER-ARM ache reaching the inner forearm, worse on straightening the elbow (triceps)?",
       "question": "Is the primary pain DEEP INSIDE the shoulder joint, OR is it a superficial surface ache over the anterior shoulder?",
      "sublabel": "Two distant referrers reaching the forearm",
       "answers": [
       "answers": [
         {
         {
           "id": "sant",
           "id": "deep_joint",
           "label": "Side of chest with stitch/breathlessness - serratus anterior",
           "label": "Deep inside the joint \u2014 the patient covers the anterior joint",
           "lr": {
           "lr": {
             "serratus_anterior": 5.5,
             "infraspinatus": 5.0,
             "triceps_brachii": 0.4
             "biceps": 0.2
           }
           }
         },
         },
         {
         {
           "id": "tri",
           "id": "surface_ache",
           "label": "Back of upper arm to inner forearm, resisted elbow extension - triceps brachii",
           "label": "Superficial surface ache \u2014 can lie comfortably on the affected side",
           "lr": {
           "lr": {
             "serratus_anterior": 0.4,
             "infraspinatus": 0.2,
             "triceps_brachii": 5.5
             "biceps": 5.0
           }
           }
         }
         }
Line 380: Line 858:
     },
     },
     {
     {
       "id": "pw_pl_sant",
       "id": "pw_supraspinatus_biceps",
       "pair": [
       "pair": [
         "palmaris_longus",
         "supraspinatus",
         "serratus_anterior"
         "biceps"
       ],
       ],
       "text": "Tiebreaker - Palmaris Longus vs Serratus Anterior",
       "text": "Tiebreaker \u2014 Supraspinatus vs Biceps Brachii",
       "question": "Is the pain a local PRICKLING in the distal forearm and palm from a forearm tender point (palmaris longus), or a SIDE-OF-CHEST/respiratory pattern spilling down the inner arm to the palm (serratus anterior)?",
       "question": "Is there a painful arc between 60\u00b0 and 120\u00b0 of shoulder abduction, OR is the arm pain primarily at the anterior shoulder without an arc pattern?",
      "sublabel": "Local prickling source vs distant respiratory source",
       "answers": [
       "answers": [
         {
         {
           "id": "pl",
           "id": "painful_arc",
           "label": "Prickling, distal forearm/palm, forearm tender point - palmaris longus",
           "label": "Painful arc between 60\u00b0 and 120\u00b0 of abduction",
           "lr": {
           "lr": {
             "palmaris_longus": 5.5,
             "supraspinatus": 5.0,
             "serratus_anterior": 0.4
             "biceps": 0.2
           }
           }
         },
         },
         {
         {
           "id": "sant",
           "id": "anterior_shoulder_no_arc",
           "label": "Side of chest, stitch/breathlessness, inner-arm spillover - serratus anterior",
           "label": "Anterior shoulder aching without a painful arc pattern",
           "lr": {
           "lr": {
             "palmaris_longus": 0.4,
             "supraspinatus": 0.2,
             "serratus_anterior": 5.5
            "biceps": 4.0
          }
        }
      ]
    },
    {
      "id": "pw_sternalis_scalene",
      "pair": [
        "sternalis",
        "scalene"
      ],
      "text": "Tiebreaker \u2014 Sternalis vs Scalene",
      "question": "Is the chest pain completely unaffected by any shoulder or arm movement, OR do arm or hand symptoms accompany it?",
      "answers": [
        {
          "id": "movement_independent",
          "label": "Completely movement-independent \u2014 no position or activity changes the pain",
          "lr": {
             "sternalis": 5.0,
            "scalene": 0.3
          }
        },
        {
          "id": "arm_symptoms_present",
          "label": "Arm or hand symptoms accompany the chest pain",
          "lr": {
            "sternalis": 0.3,
            "scalene": 4.0
          }
        }
      ]
    },
    {
      "id": "pw_triceps_trp5_brachialis",
      "pair": [
        "triceps_trp5",
        "brachialis"
      ],
      "text": "Tiebreaker \u2014 Triceps Medial Head vs Brachialis",
      "question": "Is the medial epicondyle the dominant distal referral, OR is the thumb base the dominant distal referral?",
      "answers": [
        {
          "id": "medial_epicondyle_dominant",
          "label": "Medial epicondyle (inner elbow) or medial forearm is the dominant distal referral",
          "lr": {
            "triceps_trp5": 5.0,
            "brachialis": 0.25
          }
        },
        {
          "id": "thumb_base_dominant",
          "label": "Thumb base or dorsal web of the thumb is the dominant distal referral",
          "lr": {
            "triceps_trp5": 0.25,
            "brachialis": 5.0
           }
           }
         }
         }
Line 411: Line 942:
     "edges": [
     "edges": [
       {
       {
         "from": "palmaris_longus",
         "from": "infraspinatus",
         "to": "pronator_teres",
         "to": "biceps",
        "type": "key_satellite",
        "label": "Infraspinatus is the most important key TrP driving satellite biceps TrPs \u2014 treat infraspinatus first; biceps may resolve without direct treatment"
      },
      {
        "from": "biceps",
        "to": "brachialis",
         "type": "functional_unit",
         "type": "functional_unit",
         "label": "Palmaris longus and pronator teres are adjacent volar-forearm flexors overloaded together by gripping and pronation; examine and treat together, and check the median nerve for a pronator component"
         "label": "Biceps and brachialis are the primary elbow flexor pair \u2014 examine and treat together in the same session"
       },
       },
       {
       {
         "from": "serratus_anterior",
         "from": "scalene",
         "to": "triceps_brachii",
         "to": "biceps",
         "type": "key_satellite",
         "type": "key_satellite",
         "label": "Serratus posterior superior and latissimus dorsi drive satellite triceps trigger points; the shoulder-girdle/trunk drivers must be inactivated before the triceps will resolve"
         "label": "Scalene TrPs drive biceps brachii satellite TrPs"
       },
       },
       {
       {
         "from": "triceps_brachii",
         "from": "scalene",
         "to": "pronator_teres",
         "to": "scalenus_minimus",
         "type": "secondary_load",
         "type": "functional_unit",
         "label": "Triceps is a posterior-arm referrer reaching the inner forearm; address it when local volar-forearm treatment gives incomplete relief"
         "label": "Scalenus minimus (when present) is part of the scalene group \u2014 treat in the same session"
      },
      {
        "from": "biceps",
        "to": "triceps_trp5",
        "type": "antagonist_risk",
        "label": "\u26a0 Triceps (medial head) may reactively cramp when biceps is released \u2014 spray triceps after biceps release; treat in alternating partial cycles if both are active"
      },
      {
        "from": "infraspinatus",
        "to": "supraspinatus",
        "type": "functional_unit",
        "label": "Infraspinatus-supraspinatus team \u2014 almost always active together; treat in the same session"
      },
      {
        "from": "infraspinatus",
        "to": "deltoid_anterior",
        "type": "key_satellite",
        "label": "Infraspinatus is the most important key TrP driving anterior deltoid satellite TrPs"
      },
      {
        "from": "supraspinatus",
        "to": "deltoid_anterior",
        "type": "key_satellite",
        "label": "Supraspinatus TrPs drive anterior and middle deltoid satellite TrPs"
       },
       },
       {
       {
         "from": "serratus_anterior",
         "from": "subclavius",
         "to": "pronator_teres",
         "to": "scalene",
         "type": "secondary_load",
         "type": "secondary_load",
         "label": "Serratus anterior is a distant trunk referrer; treat it when local forearm treatment is incomplete and a respiratory pattern is present"
         "label": "Subclavius shortening draws the clavicle down, increasing load on the scalene group \u2014 treat together"
       }
       }
     ],
     ],
     "edge_type_labels": {
     "edge_type_labels": {
       "key_satellite": "Treat first - key TrP driving satellite",
       "key_satellite": "Treat first \u2014 key TrP driving satellites",
       "functional_unit": "Treat concurrently in same session",
       "functional_unit": "Treat concurrently in same session",
       "secondary_load": "Treat after primary resolves",
       "secondary_load": "Treat after primary resolves",
       "antagonist_risk": "Treat in alternating cycles - reactive activation risk"
       "antagonist_risk": "\u26a0 Treat in alternating cycles \u2014 reactive activation risk"
     }
     }
   },
   },
Line 445: Line 1,006:
     {
     {
       "id": "rf-e1",
       "id": "rf-e1",
       "label": "Acute forearm compartment syndrome",
       "label": "Acute coronary syndrome / cardiac ischaemia",
       "question": "Surgical emergency. Severe forearm pain OUT OF PROPORTION to the injury, worsening and unrelieved by analgesia, with PAIN ON PASSIVE STRETCH of the fingers (the earliest sign) and a tense, wood-like forearm? After a fracture, crush, reperfusion, tight cast, bleeding (anticoagulation), or strenuous exertion (kayakers, rowers, weight-trainers)? The volar compartments are most often affected and the median and ulnar nerves run within them. Pallor, pulselessness, paraesthesia, and paralysis are LATE. Confirm with compartment pressures if needed (delta-p within 30 mmHg of diastolic, or absolute >30 mmHg) but do not delay - fasciotomy within about 6 hours gives near-complete recovery; later, irreversible necrosis and Volkmann's contracture follow.",
       "question": "Cardiac emergency \u2014 consider FIRST with any anterior-chest or left-arm pain. Central/left chest pressure or tightness radiating to inner arm, neck, or jaw, with sweating, nausea, breathlessness, or rest/exertional onset; often atypical in women, the elderly, and diabetics. Sternalis TrP mimics cardiac pain and TrP relief does NOT exclude ACS. 12-lead ECG within 10 min + troponins before any myofascial label.",
       "source": "Forearm Compartment Syndrome StatPearls (NBK556130); Brukner & Khan Ch.18"
       "source": "Acute Coronary Syndrome StatPearls (NBK459157); Chest Pain: Evaluation and Exclusion of MI and Angina StatPearls (NBK557672); T&S (sternalis cardiac mimicry)"
     },
     },
     {
     {
       "id": "rf-e2",
       "id": "rf-e2",
       "label": "Acute coronary syndrome / cardiac ischaemia",
       "label": "Acute compartment syndrome of the arm",
       "question": "Left-sided or central chest pressure, tightness, or constriction radiating to the inner arm and forearm, especially with exertion, breathlessness, sweating, nausea, or a cardiac history? The left serratus anterior (and pectoral) trigger-point patterns mimic cardiac pain - and relief by trigger-point treatment does NOT exclude cardiac disease. Establish cardiac status independently and urgently when this pattern is present.",
       "question": "Surgical limb emergency. Arm pain OUT OF PROPORTION, unrelieved by analgesia, worse on PASSIVE finger/elbow stretch (earliest sign), with a tense, swollen arm \u2014 after fracture, crush, tight cast, bleeding/anticoagulation, or hard exertion. Pulselessness, paraesthesia, and paralysis are LATE. Immediate surgical referral; fasciotomy within ~6 h.",
       "source": "T&S Ch.46 (serratus anterior cardiac mimicry)"
      "source": "Acute Compartment Syndrome StatPearls; Brukner & Khan Ch.18 [VERIFY against your Ch.18 copy + add exact StatPearls NBK id]"
    },
    {
      "id": "rf-e3",
      "label": "Septic glenohumeral arthritis",
      "question": "Joint emergency \u2014 rapid cartilage destruction. Acute, constant, severe deep shoulder pain with pain on ALL movement (active AND passive), often warm or swollen. Fever may be absent or low-grade (only ~17\u201342% of cases) \u2014 a normal temperature does NOT exclude it. Risk: diabetes, immunosuppression, IV drug use, recent injection, prosthesis, bacteraemia. Urgent WBC/ESR/CRP + joint aspiration; drainage + IV antibiotics.",
       "source": "Evaluation and Management of Septic Arthritis in the ED (PMC6404712); Septic Arthritis of the Glenohumeral Joint (PubMed 9653429); Septic Arthritis evidence-based review (AJR 2021, AJR.20.22773)"
     }
     }
   ],
   ],
Line 459: Line 1,026:
     {
     {
       "id": "rf-u1",
       "id": "rf-u1",
       "label": "Forearm fracture with Monteggia or Galeazzi pattern",
       "label": "Posterior glenohumeral dislocation",
       "question": "Forearm pain, deformity, or marked tenderness after a fall or direct blow? Both bones usually break together; a single-bone forearm fracture must prompt a search for an associated joint dislocation - the Monteggia injury (ulnar fracture with radial-head dislocation at the elbow) and the Galeazzi injury (radial fracture with distal-ulnar/DRUJ dislocation at the wrist). These are usually displaced, need orthopaedic referral and internal fixation, and the dislocation is easily missed if the whole forearm (elbow AND wrist) is not imaged.",
       "question": "Easily missed \u2014 often invisible on the AP X-ray. After a seizure, electric shock, or a fall on an internally rotated arm: arm locked in INTERNAL ROTATION/adduction with marked loss of EXTERNAL ROTATION (cardinal sign). Needs an axillary/true-lateral view and timely reduction.",
       "source": "Brukner & Khan Ch.18"
       "source": "Brukner & Khan Ch.17 (posterior dislocation of the glenohumeral joint)"
     },
     },
     {
     {
       "id": "rf-u2",
       "id": "rf-u2",
       "label": "Anterior interosseous nerve (AIN) syndrome",
       "label": "Proximal humerus (humeral neck) fracture",
       "question": "Forearm pain with WEAKNESS but NO sensory loss - specifically difficulty bending the tip of the thumb and index finger so the patient cannot make a normal 'OK' sign (the pulps flatten and pinch instead)? The anterior interosseous nerve is the pure-motor terminal branch of the median nerve (flexor pollicis longus, flexor digitorum profundus to the index/middle, pronator quadratus). Often a transient neuritis but compression and trauma occur; needs electrodiagnostic confirmation and timely specialist assessment because motor recovery is the concern.",
       "question": "After a fall on the outstretched hand or a direct blow (esp. older/osteoporotic): shoulder pain, tenderness, swelling, can't use the arm. >2 fragments, displacement >1 cm, angulation, or associated dislocation \u2192 orthopaedic referral. Check axillary-nerve sensation (lateral shoulder) and distal neurovascular status.",
       "source": "Anterior Interosseous Syndrome StatPearls (NBK525956)"
       "source": "Brukner & Khan Ch.17 (fracture of the neck of the humerus; axillary nerve injury)"
     },
     },
     {
     {
       "id": "rf-u3",
       "id": "rf-u3",
       "label": "Pronator teres syndrome / proximal median nerve entrapment",
       "label": "Acute massive rotator cuff tear",
       "question": "Volar forearm pain worse on resisted pronation, with median-territory paraesthesia that INCLUDES the thenar eminence (unlike carpal tunnel) and a positive Tinel over the proximal pronator teres? Consider the sibling entrapments: ligament of Struthers (worse on supination and elbow extension, possibly a reduced radial pulse), lacertus fibrosus (worse on resisted elbow flexion in supination), and the flexor digitorum superficialis sublimis bridge (worse on resisted middle-finger PIP flexion). Progressive motor or sensory deficit warrants nerve studies and surgical release.",
       "question": "Sudden loss of active elevation or external rotation after trauma (or acute-on-chronic in older adults), with night pain and weakness but PRESERVED passive range (pseudoparalysis) and positive impingement signs. Timely US/MRI and surgical referral \u2014 early repair improves outcome. TrPs don't cause true power loss with preserved passive motion.",
       "source": "Pronator Teres Syndrome StatPearls (Dididze et al. 2023)"
       "source": "Brukner & Khan Ch.17 (rotator cuff strains/tears); JOSPT 2009 LHBT review (associated cuff disease)"
     },
     },
     {
     {
       "id": "rf-u4",
       "id": "rf-u4",
       "label": "Forearm stress fracture",
       "label": "Long head of biceps (LHB) tendon rupture",
       "question": "Activity-related forearm pain that builds with loading and eases with rest, in an upper-limb sport (gymnastics, throwing, racquet sports, weight-training), with focal bony tenderness? A radius or ulnar stress fracture needs activity modification and imaging (it may be occult on early plain films); missed, it can progress to a complete fracture.",
       "question": "Sudden 'pop' in the front of the arm on a lift, then a 'Popeye' bulge low in the arm (worse on elbow flexion), with bruising, little residual pain, and near-normal strength. Examine the cuff/subscapularis (commonly associated). Older/low-demand: reassurance + rehab; refer younger patients, laborers, or athletes for tenodesis/tenotomy.",
       "source": "Brukner & Khan Ch.18"
      "source": "Long Head of the Biceps Tendon JOSPT 2009 (Nho et al.); Proximal Biceps Tendinitis and Tendinopathy StatPearls (Varacallo & Mair); Brukner & Khan Ch.17 (rupture of the long head of the biceps)"
    },
    {
      "id": "rf-u5",
      "label": "Distal biceps tendon rupture",
      "question": "Sudden tearing at the FRONT OF THE ELBOW on a forceful eccentric load (catching a heavy object): antecubital pain, bruising, palpable defect, muscle belly retracts PROXIMALLY (reverse-Popeye), positive hook test, weak supination. Refer for EARLY repair (~2\u20133 weeks). TrP pain has no defect/retraction and normal strength.",
      "source": "Brukner & Khan Ch.18 (distal biceps rupture) [VERIFY against your Ch.18 copy]"
    },
    {
      "id": "rf-u6",
      "label": "Humeral shaft stress fracture / spiral fracture (throwers)",
      "question": "Throwing-related upper-arm pain that builds with load, with focal bony tenderness at the mid/lower shaft \u2014 or a sudden SPIRAL fracture on a hard throw. Risks RADIAL NERVE injury (test wrist/finger/thumb extension and dorsal first-web sensation). Stop activity and image (a stress fracture may be occult early). Myofascial pain lacks focal bony tenderness.",
      "source": "Brukner & Khan Ch.17 (throwing fracture of the humeral shaft); Ch.18 [VERIFY arm/elbow detail against your Ch.18 copy]"
    },
    {
      "id": "rf-u7",
      "label": "Vascular thoracic outlet syndrome / subclavian effort thrombosis (Paget-Schroetter)",
      "question": "ARTERIAL: pallor, coolness, claudication, or a lost radial pulse on arm elevation/abduction-ER (cervical rib) \u2014 limb-threatening. VENOUS (Paget-Schroetter): sudden swelling, bluish discoloration, and a heavy WHOLE arm with prominent veins after heavy overhead activity. Duplex/venography; venous needs anticoagulation \u00b1 thrombolysis + TOS work-up. NEUROGENIC TOS (paraesthesia, nocturnal arm-hang) is NOT urgent \u2014 see [[Differential:ThoracicOutletSyndrome]].",
       "source": "Brukner & Khan Ch.17 (thoracic outlet syndrome; axillary vein 'effort' thrombosis / Paget-von Schrotter syndrome)"
     }
     }
   ],
   ],
Line 485: Line 1,070:
     {
     {
       "id": "bd-1",
       "id": "bd-1",
       "condition": "Carpal tunnel syndrome (median neuropathy at the wrist)",
       "condition": "Subacromial impingement / rotator cuff tendinopathy",
       "confidence": "common",
       "confidence": "common",
       "mimics": "Median-territory hand symptoms and volar forearm aching - overlaps the pronator teres referral and is the chief distal contrast",
       "mimics": "Anterior and lateral shoulder pain with overhead activity and a painful arc \u2014 overlaps the supraspinatus, anterior deltoid, and biceps anterior-shoulder patterns",
       "distinguishing_feature": "Burning volar wrist/hand pain with median-distribution paraesthesia (thumb, index, middle, radial ring finger) that is characteristically NOCTURNAL and can radiate proximally up the forearm; positive Phalen and Tinel at the wrist; late thenar wasting. Crucially, the thenar SKIN is SPARED (the palmar cutaneous branch leaves the median nerve proximal to the carpal tunnel), pronation is unaffected, and night symptoms predominate - the opposite of pronator teres syndrome, where the thenar eminence is involved, pronation provokes the pain, and night symptoms are usually absent. Because the two coexist, a proximal pronator syndrome is easily missed when carpal tunnel syndrome is found - rule it out before carpal tunnel surgery.",
       "distinguishing_feature": "Pain on overhead activity with a painful arc of abduction (roughly 70\u2013120\u00b0), positive Neer and Hawkins-Kennedy impingement signs, and pain on resisted supraspinatus testing ('empty can'). Strength that IMPROVES with scapular retraction points to scapular dyskinesis driving the cuff rather than a true tear. Impingement is a clinical SIGN with several underlying causes (subacromial spur, cuff disease, instability, GIRD, scapular dyskinesis), not a stand-alone diagnosis. Trigger-point referral from supraspinatus/infraspinatus/deltoid is reproduced by muscle palpation and lacks the structural impingement signs.",
       "action": "Phalen/Tinel at the wrist vs resisted pronation and proximal Tinel; thenar sensory testing; nerve conduction studies confirm and localise (distal latencies are normal in pure pronator syndrome). Night splinting, activity modification, injection, decompression for motor loss. Treat coexisting pronator teres and forearm-flexor trigger points.",
       "action": "Neer/Hawkins-Kennedy, painful-arc and empty-can testing, and the scapular assistance test; assess scapular control and posterior-capsule tightness. Relative rest, activity/technique modification, rotator-cuff and periscapular strengthening; consider subacromial corticosteroid injection or imaging (US/MRI) if refractory or a tear is suspected. Treat coexisting cuff and deltoid trigger points.",
       "source": "Pronator Teres Syndrome StatPearls; Shehab & Mirabelli 2013; Brukner & Khan Ch.19"
       "source": "Brukner & Khan Ch.17 (impingement; rotator cuff tendinopathy)"
     },
     },
     {
     {
       "id": "bd-2",
       "id": "bd-2",
       "condition": "Proximal median nerve entrapments (ligament of Struthers, lacertus fibrosus, FDS sublimis bridge)",
       "condition": "Long head of biceps tendinopathy / bicipital groove pathology",
       "confidence": "uncommon",
       "confidence": "common",
       "mimics": "Volar forearm pain with median paraesthesia - the same picture as pronator teres syndrome, with which they are grouped",
       "mimics": "Anterior shoulder pain localised to the bicipital groove, radiating down the front of the arm \u2014 the structural counterpart of the biceps myofascial pattern",
       "distinguishing_feature": "All produce forearm pain and median-digit paraesthesia, separated by the provocative posture: the ligament of Struthers is worse on forearm SUPINATION and elbow EXTENSION (and may reduce the radial pulse, as the brachial artery runs with the nerve under the ligament from a supracondylar bony spur); lacertus fibrosus (bicipital aponeurosis) is worse on resisted ELBOW FLEXION with the forearm supinated; the FDS sublimis bridge is worse on resisted FLEXION of the middle-finger PIP joint. Trigger-point referral has no fixed sensory deficit and is reproduced by muscle palpation.",
       "distinguishing_feature": "Point tenderness over the bicipital groove that rotates laterally and medially with arm rotation (distinguishing it from fixed superficial tenderness), with pain on resisted forward flexion (Speed's) and resisted supination (Yergason's). Usually SECONDARY to impingement, cuff disease, or instability rather than isolated. A positive O'Brien (active compression) test raises a SLAP/biceps-anchor lesion. Biceps brachii trigger-point pain is a surface ache reproduced by belly palpation, without groove-specific tenderness or positive provocative tendon tests.",
       "action": "Targeted provocative testing for each site; nerve conduction studies (often normal); ultrasound or MRI can show the compressing structure. Conservative care (rest, activity modification, splinting, NSAIDs) for at least 6 weeks; surgical release of all compressive structures if motor/sensory deficit or failure of conservative treatment.",
       "action": "Palpate the groove with rotation; Speed's, Yergason's, and O'Brien tests; screen the cuff and for biceps instability (clunk on abduction-external rotation). Relative rest, NSAIDs, rehabilitation focused on dynamic stability; intra-articular or sheath injection and surgical options (tenodesis/tenotomy) for refractory or structural cases. No treatment reliably benefits isolated biceps fraying \u2014 address the primary driver.",
       "source": "Pronator Teres Syndrome StatPearls (Dididze et al. 2023)"
       "source": "Long Head of the Biceps Tendon JOSPT 2009; Proximal Biceps Tendinitis StatPearls (Varacallo & Mair); Brukner & Khan Ch.17"
     },
     },
     {
     {
       "id": "bd-3",
       "id": "bd-3",
       "condition": "Anterior interosseous nerve syndrome",
       "condition": "SLAP lesion / glenohumeral instability",
       "confidence": "uncommon",
       "confidence": "uncommon",
       "mimics": "Forearm pain - but the hallmark is motor weakness without sensory change, distinguishing it from the muscular sources",
       "mimics": "Deep anterior shoulder pain with catching, popping, or a 'dead arm', often in overhead athletes \u2014 overlaps the biceps (anchor) and deep-joint presentations",
       "distinguishing_feature": "Poorly localised forearm/cubital-fossa pain with a PURE MOTOR deficit and NO sensory loss: weakness of flexor pollicis longus and flexor digitorum profundus to the index (and middle) finger, so the patient cannot flex the distal joints to make a normal 'OK' sign (the pinch flattens - a positive pinch-grip/Froment sign), plus pronator quadratus weakness on resisted pronation with the elbow flexed. Often a transient neuritis (may follow viral illness, like a forme fruste of neuralgic amyotrophy). Trigger-point pain has full strength and no pincer deficit.",
       "distinguishing_feature": "Poorly localised deep shoulder pain aggravated by overhead and behind-the-back motion, with popping/catching and sometimes episodes of subluxation or 'dead arm' (transient numbness/weakness). Apprehension in abduction-external rotation relieved by posterior relocation indicates anterior instability; positive O'Brien, crank, or anterior-slide tests suggest a superior labral (SLAP) lesion, which involves the biceps anchor. Generalized ligamentous laxity (sulcus sign) supports multidirectional instability. Trigger-point pain has no apprehension, instability, or labral provocation signs.",
       "action": "Test FPL, FDP (index/middle), and pronator quadratus individually; the OK-sign/pinch test screens at the bedside. Nerve conduction studies and EMG confirm and localise. Many recover spontaneously over months; persistent or compressive cases are referred for decompression or tendon transfer.",
       "action": "Apprehension-augmentation-relocation, load-and-shift, sulcus sign, and SLAP tests (O'Brien, crank, anterior slide) used in combination; MR arthrography for labral detail. Rehabilitation emphasising rotator-cuff and scapular stabilisers and avoidance of provocative positions; arthroscopic stabilisation/labral repair for unstable lesions or failed conservative care.",
       "source": "Anterior Interosseous Syndrome StatPearls (NBK525956); Pronator Teres Syndrome StatPearls"
       "source": "Brukner & Khan Ch.17 (glenoid labral injuries; shoulder instability)"
     },
     },
     {
     {
       "id": "bd-4",
       "id": "bd-4",
       "condition": "Medial epicondylitis (flexor/pronator tendinopathy, 'golfer's elbow')",
       "condition": "Acromioclavicular (AC) joint pathology",
       "confidence": "common",
       "confidence": "common",
       "mimics": "Medial elbow and proximal volar forearm pain - overlaps the pronator teres origin and the triceps TrP5 medial-epicondyle referral",
       "mimics": "Well-localised anterosuperior shoulder pain \u2014 can be mistaken for anterior deltoid or supraspinatus referral over the front of the shoulder",
       "distinguishing_feature": "Tenderness localised at or just below the MEDIAL EPICONDYLE at the common flexor-pronator origin, with pain on RESISTED WRIST FLEXION and resisted forearm pronation (reverse Mills' test), especially with passive stretch of the tendon. Seen in golfers and in tennis players with heavy topspin forehands. Distinguish from a pronator teres trigger point (belly tenderness, deep forearm ache to the wrist) and from triceps TrP5 (medial-epicondyle pain that is NEGATIVE on resisted wrist flexion and reproduced from the posterior arm). The ulnar nerve may be caught in adjacent scar.",
       "distinguishing_feature": "Pain localised precisely to the AC joint at the top of the shoulder, often after a fall onto the point of the shoulder (sprain/separation) or from chronic overuse/osteolysis (weightlifters doing bench press). Reproduced by AC joint compression (Paxinos test) and by cross-body (horizontal) adduction, with possible palpable step deformity in higher-grade separations. Anterior deltoid trigger-point pain sits over the deltoid bulge, not the AC joint, and is not provoked by cross-arm adduction.",
       "action": "Localise tenderness to the common flexor origin; resisted wrist flexion and pronation reproduce it. Relative rest, technique correction, eccentric loading, bracing, corticosteroid injection if refractory; treat coexisting pronator teres trigger points. Check the ulnar nerve.",
       "action": "Localise tenderness to the AC joint; Paxinos and cross-arm adduction tests; X-ray for separation grade or osteolysis/osteoarthritis. Most sprains and many type III separations are managed conservatively (sling, activity modification, strengthening); local anesthetic/corticosteroid injection is diagnostic and therapeutic; distal clavicle excision for persistent cases.",
       "source": "Brukner & Khan Ch.18; Hand and Finger Flexors (Ch.38)"
       "source": "Brukner & Khan Ch.17 (acromioclavicular joint injuries; chronic AC joint pain)"
     },
     },
     {
     {
       "id": "bd-5",
       "id": "bd-5",
       "condition": "Cervical radiculopathy (C6-C7) / brachial plexopathy / neuralgic amyotrophy",
       "condition": "Adhesive capsulitis (frozen shoulder)",
       "confidence": "uncommon",
       "confidence": "common",
       "mimics": "Volar forearm pain with median-territory or motor symptoms referred from the neck or plexus - overlaps the proximal-median and AIN pictures",
       "mimics": "Diffuse shoulder pain with stiffness and difficulty reaching behind the back or sleeping on the shoulder \u2014 overlaps the infraspinatus 'cannot reach behind back / cannot sleep either side' pattern",
       "distinguishing_feature": "Neck pain radiating to the arm, dermatomal sensory change, reflex loss, and weakness in muscles OUTSIDE the median territory point to a root (C6-C7) or plexus lesion rather than a forearm entrapment; a positive Spurling's supports radiculopathy. Neuralgic amyotrophy (Parsonage-Turner) typically begins with severe SHOULDER pain, then patchy multi-nerve weakness (it can present as an AIN-like palsy) and usually improves over 6-12 months. Trigger-point referral and isolated forearm entrapments produce no root-level deficit. When a median muscle is abnormal, test muscles of the same myotome supplied by other nerves to exclude a proximal lesion.",
       "distinguishing_feature": "Global restriction of glenohumeral motion \u2014 the hallmark is loss of PASSIVE external rotation with the elbow at the side (with the scapula stabilised), which trigger-point pain does NOT cause. Typically ages 40\u201360, insidious or post-immobilisation onset, associated with diabetes and thyroid disease; passes through painful, stiff, and thawing phases over months. Myofascial restriction is movement- and direction-specific and improves with trigger-point release, whereas capsulitis is a true passive-ROM block.",
       "action": "Full neurological and upper-quarter examination with Spurling's; MRI cervical spine and electrodiagnostics where root/plexus signs are present; consider neuralgic amyotrophy when severe shoulder pain precedes patchy weakness. Treat coexisting scalene/shoulder-girdle and forearm trigger points concurrently.",
       "action": "Examine passive external rotation with the scapula stabilised; exclude glenohumeral arthritis radiographically. Reassurance about the self-limiting course; analgesia, intra-articular corticosteroid in the painful phase, supervised range-of-motion program; arthroscopic capsular release for refractory cases (less effective in diabetes).",
       "source": "Pronator Teres Syndrome StatPearls (differential); Brukner & Khan Ch.18 (referred pain)"
       "source": "Brukner & Khan Ch.17 (shoulder stiffness / adhesive capsulitis)"
     },
     },
     {
     {
       "id": "bd-6",
       "id": "bd-6",
       "condition": "Chronic exertional forearm compartment syndrome",
       "condition": "Cervical radiculopathy (C5\u2013C6) / referred cervicothoracic pain",
      "confidence": "common",
      "mimics": "Neck pain referring to the shoulder and arm with dermatomal sensory or motor change \u2014 overlaps the scalene/scalenus minimus and biceps anterior-arm patterns",
      "distinguishing_feature": "Neck pain radiating into the shoulder and arm with dermatomal paraesthesia, reflex change (e.g. diminished biceps/brachioradialis reflex), and weakness in muscles of a single myotome including ones OUTSIDE the front-of-arm myofascial group; a positive Spurling's (neck extension-rotation reproducing arm symptoms) supports it. The cervical and upper-thoracic spine commonly refer to the shoulder even without prominent neck pain. Scalene/myofascial referral has no fixed dermatomal deficit, normal reflexes, and is reproduced by muscle palpation; test the upper-quarter neurology to separate them.",
      "action": "Full upper-quarter neurological exam with Spurling's and an upper-limb neural tension test; reassess shoulder symptoms after treating any hypomobile cervical/thoracic segment. MRI cervical spine and electrodiagnostics where root signs persist or progress. Treat coexisting scalene and shoulder-girdle trigger points concurrently.",
      "source": "Brukner & Khan Ch.17 (referred pain from cervical/thoracic spine)"
    },
    {
      "id": "bd-7",
      "condition": "Neurogenic thoracic outlet syndrome",
       "confidence": "uncommon",
       "confidence": "uncommon",
       "mimics": "Activity-related volar forearm pain and tightness - overlaps the local muscular sources during loading",
       "mimics": "Arm/forearm aching and paraesthesia with the nocturnal arm-hanging pattern \u2014 directly overlaps the scalene, scalenus minimus, and subclavius presentations the model scores",
       "distinguishing_feature": "Aching, tightness, and sometimes paraesthesia in the flexor (volar) forearm that builds predictably with sustained gripping or repetitive loading and is RELIEVED BY REST, in rowers, kayakers/canoeists, motorcyclists, and weight-trainers (and rock climbers). Distinct from the ACUTE compartment syndrome emergency - the chronic form is exertional and reversible. Compartment-pressure testing during/after exercise confirms it. Trigger-point pain is reproduced by palpation and is not strictly load-threshold dependent.",
       "distinguishing_feature": "Compression of the brachial plexus (usually the lower trunk) in the costoclavicular space producing arm/forearm aching, ulnar-side paraesthesia, easy fatigue, and symptoms worsened by overhead or sustained arm positions; provoked by the Roos hyperabduction/external-rotation (EAST) and Wright maneuvers, and associated with drooping posture, tight scalene/pectoralis minor, and scapular dyskinesis. Distinguished from the VASCULAR TOS emergency (limb swelling, discoloration, pulse change) by the absence of acute vascular signs. This is the myofascially-entangled, NON-emergent subtype.",
       "action": "History of strict activity-related onset and rapid relief with rest; dynamic compartment-pressure measurement is diagnostic. Activity and technique modification first; fasciotomy for refractory cases. Address coexisting forearm-flexor trigger points.",
       "action": "Cross-linked to the dedicated page \u2014 see [[Differential:ThoracicOutletSyndrome]] for full assessment and management; this entry exists to flag overlap with the scalene/subclavius muscles and to keep the canonical content in one place. In brief: posture and scalene/pectoralis-minor work, scapular stabilisation, and trigger-point treatment; nerve studies and surgical referral for progressive neurological deficit.",
       "source": "Brukner & Khan Ch.18; Forearm Compartment Syndrome StatPearls"
       "source": "Brukner & Khan Ch.17 (thoracic outlet syndrome); cross-link [[Differential:ThoracicOutletSyndrome]]"
     },
     },
     {
     {
       "id": "bd-7",
       "id": "bd-8",
       "condition": "Pronator quadratus / distal volar forearm strain and flexor tenosynovitis",
       "condition": "Suprascapular neuropathy",
       "confidence": "uncommon",
       "confidence": "uncommon",
       "mimics": "Distal volar forearm pain on gripping and rotation - overlaps the palmaris longus and pronator referral",
       "mimics": "Deep, poorly localised posterior/lateral shoulder pain with shoulder weakness \u2014 overlaps the infraspinatus and supraspinatus contributions to a front-of-shoulder picture",
       "distinguishing_feature": "Localised distal volar-forearm pain and tenderness from a flexor or pronator-quadratus strain or a flexor tenosynovitis, worse on resisted gripping or pronation, sometimes with crepitus or swelling along the tendons. Trigger-point pain (especially the palmaris prickling quality) is reproduced by muscle-belly palpation and lacks tendon-sheath swelling or crepitus, though they can coexist.",
       "distinguishing_feature": "Deep, poorly localised shoulder pain (often felt posterolaterally or referred to the arm/upper anterior chest) with weakness of abduction and external rotation and visible wasting of supraspinatus and/or infraspinatus. Entrapment at the suprascapular notch affects BOTH muscles; entrapment at the spinoglenoid notch causes ISOLATED infraspinatus wasting (seen in volleyball 'float' servers and from a paralabral cyst arising off a SLAP tear). Trigger-point pain produces no true muscle wasting or denervation weakness.",
       "action": "Examine the flexor tendons and resisted pronation; ultrasound for tenosynovitis. Relative rest, splinting, activity modification, anti-inflammatories; treat coexisting forearm trigger points.",
      "action": "Inspect for supra-/infraspinatus wasting; test external-rotation and abduction strength; palpate the suprascapular notch. EMG/nerve conduction confirm and localise; MRI to seek a paralabral/spinoglenoid cyst. Usually non-operative (rehabilitation, load management); surgical decompression or cyst excision for progressive weakness or a compressive cyst.",
       "source": "Brukner & Khan Ch.18/Ch.19; Hand and Finger Flexors (Ch.38)"
      "source": "Brukner & Khan Ch.17 (suprascapular nerve entrapment)"
    },
    {
      "id": "bd-9",
      "condition": "Costochondritis / Tietze syndrome / anterior chest-wall pain",
      "confidence": "common",
      "mimics": "Anterior chest pain that can extend toward the front of the shoulder \u2014 the benign musculoskeletal counterpart to the sternalis substernal pattern, and the key contrast to cardiac pain",
      "distinguishing_feature": "Localised anterior chest-wall pain REPRODUCED BY PALPATION of the costochondral/costosternal junctions (Tietze syndrome adds visible/palpable swelling, classically of the 2nd\u20133rd costal cartilage), often worse with deep breathing, coughing, or trunk movement. Reproducibility on palpation and a clear positional/respiratory component point to the chest wall \u2014 but palpable reproducibility does NOT by itself exclude cardiac disease, which must be ruled out first when risk factors or red-flag features are present. Sternalis trigger-point pain is a deep substernal ache reproduced by sternalis/pectoralis palpation and is characteristically movement-INDEPENDENT.",
       "action": "Palpate the costochondral junctions and reproduce the pain; assess respiratory/positional provocation; exclude ACS (see emergency tier) before settling on a chest-wall diagnosis. Reassurance, analgesia/NSAIDs, activity modification; treat coexisting sternalis and pectoralis trigger points.",
       "source": "Chest Pain: Evaluation and Exclusion of MI and Angina StatPearls (NBK557672); Coronary Artery Disease StatPearls (NBK564304, costochondritis as MSK mimic)"
     }
     }
   ]
   ]
}
}

Latest revision as of 21:45, 12 June 2026

{ 

 "model": "bayesian_lr_scoring",
 "version": "1.0",
 "region_label": "Front of Arm Pain",
 "description": "Probabilistic scoring model for front-of-arm pain using Bayesian likelihood ratio updating with Thurstonian pairwise tiebreakers. Muscles drawn from T&S Vol.1 Ch.18 (Overview: Upper Back, Shoulder, and Arm) and individual chapters. Bold muscles carry higher priors (0.12); regular-weight muscles carry lower priors (0.08). Triceps TrP5 = medial head, referring to medial epicondyle and medial forearm.",
 "thresholds": {
   "early_exit_posterior": 0.55,
   "early_exit_gap": 0.18,
   "pairwise_trigger": 0.22
 },
 "muscles": {
   "biceps": {
     "label": "Biceps Brachii",
     "prior": 0.12,
     "page": "Muscle:Biceps_Brachii",
     "key_trp_note": "Infraspinatus TrPs are the most important key TrP source driving satellite biceps TrPs. Inactivating infraspinatus is essential for sustained biceps relief and may alone resolve the biceps TrPs. With prolonged biceps TrP activity, expect secondary TrPs in brachialis, supinator, and triceps (in that sequence).",
     "subtitle": "Superficial anterior shoulder aching; can lie on affected side; can reach behind waist"
   },
   "brachialis": {
     "label": "Brachialis",
     "prior": 0.08,
     "page": "Muscle:Brachialis",
     "key_trp_note": "Brachialis TrPs are almost always co-active with biceps brachii TrPs. In the tennis elbow pattern, the supinator is the primary TrP; brachialis develops secondarily. The almond-shaped lateral border TrP specifically compresses the sensory radial nerve branch \u2014 causing dorsal thumb dysesthesia alongside the referred aching.",
     "subtitle": "Thumb base and dorsal web of thumb; thumb hurts not elbow; passive elbow extension worsens pain"
   },
   "scalene": {
     "label": "Scalene",
     "prior": 0.12,
     "page": "Muscle:Scalene",
     "key_trp_note": "Scalene TrPs drive satellite TrPs in biceps brachii, pectoralis major/minor, serratus posterior superior, and upper trapezius. Treat scalenes before their satellites. SCM should be treated concurrently.",
     "subtitle": "Anterior chest and arm symptoms; nocturnal arm aching; must hang arm over bed for relief"
   },
   "scalenus_minimus": {
     "label": "Scalenus Minimus",
     "prior": 0.12,
     "page": "Muscle:Scalene",
     "key_trp_note": "Scalenus minimus (when present) is anatomically positioned to compress the lower trunk of the brachial plexus against the first rib. Its TrPs produce a distinct radial-hand pattern extending to the thumb and index finger. Treat as part of the scalene group in the same session.",
     "subtitle": "Posterior arm to radial hand/thumb; lower brachial plexus compression pattern"
   },
   "subclavius": {
     "label": "Subclavius",
     "prior": 0.12,
     "page": "Muscle:Pectoralis_Major",
     "key_trp_note": "Subclavius TrPs almost always coexist with clavicular pectoralis major TrPs. Subclavius shortening draws the clavicle down toward the subclavian neurovascular structures \u2014 vascular thoracic outlet syndrome. Treat clavicular pectoralis major first.",
     "subtitle": "Radial forearm and hand SKIPPING the elbow and wrist; thumb, index, and middle fingers"
   },
   "triceps_trp5": {
     "label": "Triceps \u2014 Medial Head (TrP5)",
     "prior": 0.12,
     "page": "Muscle:Triceps_Brachii",
     "key_trp_note": "Triceps TrP5 (medial head) refers to the medial epicondyle and medial forearm \u2014 the front-of-arm pattern that distinguishes it from TrP1 (posterior arm, long head) and TrP3 (lateral head, radial nerve zone). Scalene TrPs drive triceps long head satellite TrPs; the medial head may be activated independently by direct overload or antagonist cramping from biceps/brachialis treatment.",
     "subtitle": "Medial epicondyle and medial forearm pain from anterior arm; antagonist cramping after biceps treatment"
   },
   "infraspinatus": {
     "label": "Infraspinatus",
     "prior": 0.08,
     "page": "Muscle:Infraspinatus",
     "key_trp_note": "Infraspinatus is the key TrP source driving satellite biceps brachii TrPs. Inactivating infraspinatus first is essential \u2014 biceps TrPs may resolve without direct treatment once infraspinatus is addressed. Primary infraspinatus presentation is deep anterior joint pain; when it appears in a front-of-arm algorithm it usually reflects the satellite biceps being masked by the primary source.",
     "subtitle": "Deep inside anterior shoulder joint; cannot sleep either side; cannot reach behind back"
   },
   "supraspinatus": {
     "label": "Supraspinatus",
     "prior": 0.08,
     "page": "Muscle:Supraspinatus",
     "key_trp_note": "Supraspinatus TrPs refer to the mid-deltoid and lateral upper arm. Infraspinatus TrPs often drive supraspinatus satellites. With prolonged biceps TrP activity, supraspinatus eventually develops secondary TrPs. Inactivating supraspinatus usually resolves middle deltoid satellite TrPs without direct treatment.",
     "subtitle": "Lateral shoulder to lateral upper arm; lateral epicondyle referral; painful arc 60\u2013120\u00b0"
   },
   "deltoid_anterior": {
     "label": "Anterior Deltoid",
     "prior": 0.08,
     "page": "Muscle:Deltoid",
     "key_trp_note": "Anterior deltoid TrPs are almost always satellites of infraspinatus, supraspinatus, or pectoralis major key TrPs \u2014 the anterior deltoid lies in the pain reference zone of all three. Treat the key TrP source first; anterior deltoid TrPs usually resolve without direct treatment.",
     "subtitle": "Local anterior shoulder surface only; no arm or hand referral; history of direct impact or injection"
   },
   "sternalis": {
     "label": "Sternalis",
     "prior": 0.08,
     "page": "Muscle:Sternalis",
     "key_trp_note": "Sternalis TrPs are almost always co-active with pectoralis major TrPs. SCM sternal division (lower end) may refer pain downward over the sternum and activate sternalis as a satellite. Present in only ~4\u20135% of the population. Treat pectoralis major and SCM before or alongside sternalis.",
     "subtitle": "Deep substernal ache; movement-independent; cardiac mimic; may extend to front of shoulder and upper arm"
   }
 },
 "questions": [
   {
     "id": "q_dominant_pain_zone",
     "text": "Where is the front-of-arm pain most concentrated?",
     "sublabel": "Choose the single best description of the dominant pain zone",
     "type": "choice",
     "answers": [
       {
         "id": "anterior_shoulder_surface",
         "label": "Surface of the ANTERIOR SHOULDER \u2014 front of the shoulder bulge; superficial aching",
         "sublabel": "Superficial aching over the front of the shoulder and deltoid region; NOT deep inside the joint",
         "lr": {
           "biceps": 8.0,
           "deltoid_anterior": 5.0,
           "supraspinatus": 2.0,
           "scalene": 1.5,
           "infraspinatus": 0.3,
           "brachialis": 0.5,
           "subclavius": 1.0,
           "scalenus_minimus": 0.8,
           "triceps_trp5": 0.5,
           "sternalis": 0.5
         }
       },
       {
         "id": "deep_inside_joint",
         "label": "DEEP INSIDE the front of the shoulder joint \u2014 patient places hand over the anterior shoulder",
         "sublabel": "The pain is felt inside the joint itself, not on the surface",
         "lr": {
           "infraspinatus": 10.0,
           "biceps": 1.0,
           "deltoid_anterior": 0.3,
           "supraspinatus": 1.0,
           "scalene": 0.7,
           "brachialis": 0.3,
           "subclavius": 0.4,
           "scalenus_minimus": 0.4,
           "triceps_trp5": 0.3,
           "sternalis": 0.3
         }
       },
       {
         "id": "biceps_belly_antecubital",
         "label": "BICEPS MUSCLE BELLY or ANTECUBITAL SPACE \u2014 front of the upper arm or elbow crease",
         "sublabel": "The arm itself hurts, not just the shoulder; the antecubital fossa may also ache",
         "lr": {
           "biceps": 5.0,
           "brachialis": 6.0,
           "scalene": 1.5,
           "triceps_trp5": 2.0,
           "infraspinatus": 0.5,
           "supraspinatus": 0.8,
           "deltoid_anterior": 0.4,
           "subclavius": 0.8,
           "scalenus_minimus": 0.8,
           "sternalis": 0.4
         }
       },
       {
         "id": "substernal_chest",
         "label": "SUBSTERNAL or anterior chest \u2014 behind the breastbone or across the front of the chest",
         "sublabel": "The dominant pain is in the chest, not in the arm itself",
         "lr": {
           "sternalis": 12.0,
           "scalene": 2.0,
           "subclavius": 1.5,
           "scalenus_minimus": 1.0,
           "biceps": 0.3,
           "brachialis": 0.2,
           "infraspinatus": 0.2,
           "supraspinatus": 0.2,
           "deltoid_anterior": 0.3,
           "triceps_trp5": 0.3
         }
       }
     ]
   },
   {
     "id": "q_thumb_pain",
     "text": "Is the thumb affected \u2014 specifically pain or soreness at the BASE of the thumb or dorsal web space of the thumb?",
     "sublabel": "The thumb hurts at its base (carpometacarpal joint area) or on the back of the thumb web; this is the dominant or a prominent complaint",
     "type": "binary",
     "answers": [
       {
         "id": "yes",
         "label": "Yes \u2014 thumb base or dorsal thumb web is painful or sore",
         "lr": {
           "brachialis": 12.0,
           "subclavius": 3.0,
           "scalenus_minimus": 3.0,
           "scalene": 1.5,
           "biceps": 0.4,
           "infraspinatus": 0.4,
           "supraspinatus": 0.3,
           "deltoid_anterior": 0.2,
           "triceps_trp5": 0.3,
           "sternalis": 0.2
         }
       },
       {
         "id": "no",
         "label": "No \u2014 thumb is not specifically affected",
         "lr": {
           "brachialis": 0.15,
           "subclavius": 0.7,
           "scalenus_minimus": 0.7,
           "scalene": 0.9,
           "biceps": 1.2,
           "infraspinatus": 1.2,
           "supraspinatus": 1.2,
           "deltoid_anterior": 1.3,
           "triceps_trp5": 1.2,
           "sternalis": 1.2
         }
       }
     ]
   },
   {
     "id": "q_thumb_vs_elbow",
     "text": "Regarding pain when moving the arm or thumb: which hurts more?",
     "sublabel": "A key brachialis dissociation test \u2014 the thumb hurts with use; the elbow does not",
     "type": "choice",
     "condition": {
       "q_thumb_pain": "yes"
     },
     "answers": [
       {
         "id": "thumb_hurts_elbow_ok",
         "label": "Active thumb movement HURTS; active elbow movement does NOT hurt",
         "sublabel": "Using the thumb causes pain; bending or straightening the elbow does not",
         "lr": {
           "brachialis": 14.0,
           "subclavius": 1.5,
           "scalenus_minimus": 1.5,
           "scalene": 0.8,
           "biceps": 0.3,
           "infraspinatus": 0.3,
           "supraspinatus": 0.3,
           "deltoid_anterior": 0.3,
           "triceps_trp5": 0.3,
           "sternalis": 0.2
         }
       },
       {
         "id": "elbow_also_hurts",
         "label": "Both the thumb AND the elbow hurt with movement",
         "sublabel": "Elbow movement is also painful, not just the thumb",
         "lr": {
           "brachialis": 2.0,
           "subclavius": 2.0,
           "scalenus_minimus": 2.0,
           "scalene": 1.5,
           "biceps": 1.5,
           "infraspinatus": 0.5,
           "supraspinatus": 0.5,
           "deltoid_anterior": 0.4,
           "triceps_trp5": 1.5,
           "sternalis": 0.3
         }
       }
     ]
   },
   {
     "id": "q_sleep",
     "text": "How does the arm pain affect sleep?",
     "sublabel": "Which sleeping position is tolerated?",
     "type": "choice",
     "answers": [
       {
         "id": "neither_side",
         "label": "Cannot sleep on EITHER side \u2014 may sleep upright or propped in a chair",
         "sublabel": "Even the unaffected side causes pain; every lying position wakes the patient",
         "lr": {
           "infraspinatus": 10.0,
           "scalene": 2.0,
           "biceps": 1.0,
           "brachialis": 0.5,
           "supraspinatus": 0.5,
           "deltoid_anterior": 0.3,
           "subclavius": 0.4,
           "scalenus_minimus": 0.4,
           "triceps_trp5": 0.4,
           "sternalis": 0.5
         }
       },
       {
         "id": "not_affected_side",
         "label": "Cannot sleep on the AFFECTED side only",
         "sublabel": "Lying on the painful arm wakes the patient; other positions are tolerated",
         "lr": {
           "biceps": 5.0,
           "deltoid_anterior": 3.0,
           "supraspinatus": 2.5,
           "brachialis": 2.0,
           "triceps_trp5": 2.0,
           "scalene": 1.0,
           "subclavius": 1.0,
           "scalenus_minimus": 0.8,
           "infraspinatus": 0.4,
           "sternalis": 1.0
         }
       },
       {
         "id": "sleep_ok",
         "label": "Sleep is largely unaffected or only mildly disturbed",
         "sublabel": "The patient finds a comfortable position without significant waking",
         "lr": {
           "sternalis": 3.0,
           "subclavius": 2.0,
           "scalenus_minimus": 1.5,
           "scalene": 1.5,
           "deltoid_anterior": 1.5,
           "supraspinatus": 1.0,
           "brachialis": 1.0,
           "biceps": 0.5,
           "infraspinatus": 0.2,
           "triceps_trp5": 1.2
         }
       }
     ]
   },
   {
     "id": "q_behind_back",
     "text": "Can the patient reach comfortably behind the back?",
     "sublabel": "Test: reaching the arm behind the back to the hip pocket or brassiere hooks",
     "type": "binary",
     "answers": [
       {
         "id": "restricted",
         "label": "Painful or restricted \u2014 cannot reach behind the back fully",
         "lr": {
           "infraspinatus": 8.0,
           "biceps": 3.0,
           "supraspinatus": 2.0,
           "brachialis": 1.5,
           "scalene": 1.0,
           "deltoid_anterior": 0.6,
           "subclavius": 0.5,
           "scalenus_minimus": 0.4,
           "triceps_trp5": 0.5,
           "sternalis": 0.4
         }
       },
       {
         "id": "normal",
         "label": "Full behind-back reach \u2014 no restriction",
         "lr": {
           "infraspinatus": 0.2,
           "biceps": 0.5,
           "supraspinatus": 0.7,
           "brachialis": 0.9,
           "scalene": 1.0,
           "deltoid_anterior": 1.4,
           "subclavius": 1.4,
           "scalenus_minimus": 1.4,
           "triceps_trp5": 1.3,
           "sternalis": 1.4
         }
       }
     ]
   },
   {
     "id": "q_elbow_extension_test",
     "text": "Does PASSIVELY straightening (extending) the elbow increase pain in the arm, antecubital space, or thumb?",
     "sublabel": "With the arm relaxed, the examiner gently straightens the elbow fully \u2014 does this increase pain?",
     "type": "binary",
     "answers": [
       {
         "id": "yes",
         "label": "Yes \u2014 passively extending the elbow worsens pain",
         "lr": {
           "brachialis": 10.0,
           "biceps": 4.0,
           "triceps_trp5": 1.5,
           "scalene": 0.8,
           "infraspinatus": 0.5,
           "supraspinatus": 0.5,
           "deltoid_anterior": 0.4,
           "subclavius": 0.5,
           "scalenus_minimus": 0.5,
           "sternalis": 0.3
         }
       },
       {
         "id": "no",
         "label": "No \u2014 elbow extension does not worsen pain",
         "lr": {
           "brachialis": 0.2,
           "biceps": 0.6,
           "triceps_trp5": 1.0,
           "scalene": 1.1,
           "infraspinatus": 1.2,
           "supraspinatus": 1.2,
           "deltoid_anterior": 1.3,
           "subclavius": 1.2,
           "scalenus_minimus": 1.2,
           "sternalis": 1.2
         }
       }
     ]
   },
   {
     "id": "q_supination_vs_pronation",
     "text": "Is arm pain or weakness worse when the forearm is SUPINATED (palm up) compared to PRONATED (palm down) during elbow flexion?",
     "sublabel": "Test: flex the elbow with palm facing up, then repeat with palm facing down \u2014 which position is more painful or weak?",
     "type": "choice",
     "answers": [
       {
         "id": "supination_worse",
         "label": "Supination (palm up) is more painful or weak than pronation (palm down)",
         "sublabel": "Lifting with palm up hurts more than lifting with palm down",
         "lr": {
           "biceps": 8.0,
           "scalene": 1.5,
           "infraspinatus": 1.0,
           "brachialis": 0.4,
           "supraspinatus": 0.8,
           "deltoid_anterior": 0.7,
           "subclavius": 0.8,
           "scalenus_minimus": 0.8,
           "triceps_trp5": 0.5,
           "sternalis": 0.5
         }
       },
       {
         "id": "equal_both",
         "label": "Both positions are equally painful or weak",
         "sublabel": "No difference between palm up and palm down during elbow flexion",
         "lr": {
           "brachialis": 6.0,
           "triceps_trp5": 2.0,
           "scalene": 1.5,
           "scalenus_minimus": 1.5,
           "subclavius": 1.5,
           "sternalis": 1.5,
           "infraspinatus": 1.0,
           "supraspinatus": 1.0,
           "biceps": 0.4,
           "deltoid_anterior": 1.0
         }
       },
       {
         "id": "no_difference_painless",
         "label": "No pain with either position \u2014 elbow flexion is not a trigger",
         "sublabel": "Bending the elbow does not provoke the arm pain",
         "lr": {
           "infraspinatus": 2.0,
           "deltoid_anterior": 2.0,
           "sternalis": 2.0,
           "subclavius": 1.5,
           "scalenus_minimus": 1.5,
           "scalene": 1.5,
           "supraspinatus": 1.5,
           "biceps": 0.4,
           "brachialis": 0.3,
           "triceps_trp5": 1.0
         }
       }
     ]
   },
   {
     "id": "q_arm_referral",
     "text": "Does the arm pain extend to the forearm or hand?",
     "sublabel": "Choose the best description of the distal referral",
     "type": "choice",
     "answers": [
       {
         "id": "radial_skip",
         "label": "Radial forearm and/or thumb/index/middle fingers \u2014 SKIPPING the elbow and wrist",
         "sublabel": "The radial side of the forearm and/or the thumb, index, or middle finger hurt; the elbow joint area is pain-free",
         "lr": {
           "subclavius": 10.0,
           "scalenus_minimus": 6.0,
           "brachialis": 3.0,
           "scalene": 2.0,
           "biceps": 0.5,
           "infraspinatus": 0.8,
           "supraspinatus": 0.5,
           "deltoid_anterior": 0.2,
           "triceps_trp5": 0.4,
           "sternalis": 0.3
         }
       },
       {
         "id": "medial_epicondyle",
         "label": "Medial epicondyle (inner elbow) and/or medial forearm",
         "sublabel": "The inner bump of the elbow and/or the medial forearm is part of the pain",
         "lr": {
           "triceps_trp5": 9.0,
           "scalene": 2.0,
           "brachialis": 1.5,
           "biceps": 1.0,
           "scalenus_minimus": 1.0,
           "infraspinatus": 0.5,
           "supraspinatus": 0.4,
           "subclavius": 0.4,
           "deltoid_anterior": 0.3,
           "sternalis": 0.3
         }
       },
       {
         "id": "ulnar_forearm_hand",
         "label": "Ulnar forearm and/or ring and little fingers",
         "sublabel": "The inner forearm and/or the two ulnar digits hurt",
         "lr": {
           "scalene": 4.0,
           "scalenus_minimus": 2.0,
           "sternalis": 2.0,
           "brachialis": 1.0,
           "biceps": 0.5,
           "triceps_trp5": 1.5,
           "subclavius": 0.5,
           "infraspinatus": 0.5,
           "supraspinatus": 0.4,
           "deltoid_anterior": 0.3
         }
       },
       {
         "id": "suprascapular_spillover",
         "label": "Pain skips upward to the suprascapular region \u2014 above the scapular spine",
         "sublabel": "The area above the shoulder blade also aches, almost as if the pain jumps over the shoulder",
         "lr": {
           "biceps": 7.0,
           "scalene": 2.0,
           "infraspinatus": 1.5,
           "supraspinatus": 1.5,
           "scalenus_minimus": 1.0,
           "brachialis": 0.5,
           "deltoid_anterior": 0.4,
           "subclavius": 0.5,
           "triceps_trp5": 0.4,
           "sternalis": 0.4
         }
       },
       {
         "id": "lateral_arm_epicondyle",
         "label": "Lateral upper arm or lateral epicondyle \u2014 outer elbow region",
         "sublabel": "The outer side of the upper arm or the outer elbow bump is included in the pain",
         "lr": {
           "supraspinatus": 7.0,
           "biceps": 1.0,
           "scalene": 1.5,
           "infraspinatus": 1.5,
           "brachialis": 0.5,
           "deltoid_anterior": 0.8,
           "subclavius": 0.5,
           "scalenus_minimus": 0.5,
           "triceps_trp5": 0.5,
           "sternalis": 0.3
         }
       },
       {
         "id": "no_distal_referral",
         "label": "No forearm or hand referral \u2014 pain stays in the shoulder and upper arm",
         "sublabel": "Pain does not travel below the elbow",
         "lr": {
           "deltoid_anterior": 3.0,
           "sternalis": 3.0,
           "infraspinatus": 1.5,
           "biceps": 1.0,
           "supraspinatus": 1.0,
           "brachialis": 0.5,
           "scalene": 0.5,
           "subclavius": 0.4,
           "scalenus_minimus": 0.4,
           "triceps_trp5": 0.5
         }
       }
     ]
   },
   {
     "id": "q_nocturnal_arm",
     "text": "Is the patient woken at night by arm aching or numbness \u2014 requiring the arm to hang over the side of the bed or be shaken for relief?",
     "sublabel": "Nocturnal arm symptoms specifically relieved by hanging the arm over the bed edge",
     "type": "binary",
     "answers": [
       {
         "id": "yes",
         "label": "Yes \u2014 woken at night; arm must hang over bed side for relief",
         "lr": {
           "scalene": 9.0,
           "scalenus_minimus": 5.0,
           "subclavius": 2.0,
           "brachialis": 0.5,
           "biceps": 0.5,
           "infraspinatus": 0.5,
           "supraspinatus": 0.4,
           "deltoid_anterior": 0.3,
           "triceps_trp5": 0.4,
           "sternalis": 0.3
         }
       },
       {
         "id": "no",
         "label": "No \u2014 no nocturnal arm hanging symptom",
         "lr": {
           "scalene": 0.25,
           "scalenus_minimus": 0.35,
           "subclavius": 0.8,
           "brachialis": 1.1,
           "biceps": 1.1,
           "infraspinatus": 1.1,
           "supraspinatus": 1.1,
           "deltoid_anterior": 1.2,
           "triceps_trp5": 1.1,
           "sternalis": 1.1
         }
       }
     ]
   },
   {
     "id": "q_movement_independence",
     "text": "Is the arm or chest pain MOVEMENT-INDEPENDENT \u2014 present at rest and NOT worsened by any specific shoulder or arm movement?",
     "sublabel": "No position, movement, or activity clearly makes the pain better or worse",
     "type": "binary",
     "answers": [
       {
         "id": "yes",
         "label": "Yes \u2014 pain present at rest, unchanged by movement",
         "lr": {
           "sternalis": 10.0,
           "scalene": 2.0,
           "scalenus_minimus": 1.5,
           "biceps": 0.5,
           "brachialis": 0.4,
           "infraspinatus": 0.5,
           "supraspinatus": 0.4,
           "deltoid_anterior": 0.5,
           "subclavius": 0.5,
           "triceps_trp5": 0.5
         }
       },
       {
         "id": "no",
         "label": "No \u2014 pain varies with position, activity, or movement",
         "lr": {
           "sternalis": 0.2,
           "scalene": 0.9,
           "scalenus_minimus": 0.9,
           "biceps": 1.2,
           "brachialis": 1.2,
           "infraspinatus": 1.2,
           "supraspinatus": 1.2,
           "deltoid_anterior": 1.2,
           "subclavius": 1.1,
           "triceps_trp5": 1.1
         }
       }
     ]
   },
   {
     "id": "q_painful_arc",
     "text": "Is there a painful arc during shoulder abduction \u2014 pain appearing between 60\u00b0 and 120\u00b0 of raising the arm sideways, then diminishing above that?",
     "sublabel": "Pain appears then disappears as the arm reaches overhead",
     "type": "binary",
     "answers": [
       {
         "id": "yes",
         "label": "Yes \u2014 painful arc between 60\u00b0 and 120\u00b0 of abduction",
         "lr": {
           "supraspinatus": 8.0,
           "deltoid_anterior": 2.0,
           "biceps": 0.8,
           "infraspinatus": 0.7,
           "brachialis": 0.4,
           "scalene": 0.5,
           "scalenus_minimus": 0.4,
           "subclavius": 0.4,
           "triceps_trp5": 0.4,
           "sternalis": 0.3
         }
       },
       {
         "id": "no",
         "label": "No \u2014 no arc pattern; abduction is uniformly painful or pain-free",
         "lr": {
           "supraspinatus": 0.2,
           "deltoid_anterior": 0.9,
           "biceps": 1.1,
           "infraspinatus": 1.1,
           "brachialis": 1.2,
           "scalene": 1.1,
           "scalenus_minimus": 1.1,
           "subclavius": 1.1,
           "triceps_trp5": 1.2,
           "sternalis": 1.2
         }
       }
     ]
   },
   {
     "id": "q_onset",
     "text": "How did the front-of-arm pain begin?",
     "sublabel": "Choose the onset pattern that best describes this episode",
     "type": "choice",
     "answers": [
       {
         "id": "sustained_flexion_load",
         "label": "Sustained elbow flexion under load \u2014 carrying groceries, using power tools at elbow height, ironing, violin playing",
         "sublabel": "Pain crept in over repeated sessions of forearm flexion activity",
         "lr": {
           "brachialis": 8.0,
           "biceps": 5.0,
           "triceps_trp5": 2.0,
           "scalene": 1.0,
           "infraspinatus": 0.5,
           "supraspinatus": 0.5,
           "deltoid_anterior": 0.5,
           "subclavius": 0.7,
           "scalenus_minimus": 0.7,
           "sternalis": 0.4
         }
       },
       {
         "id": "acute_overstretch",
         "label": "Acute overstretch \u2014 catching a fall, reaching backward suddenly, lifting at arm\u2019s length",
         "sublabel": "A specific sudden event the patient can recall",
         "lr": {
           "biceps": 6.0,
           "infraspinatus": 5.0,
           "brachialis": 2.0,
           "deltoid_anterior": 3.0,
           "supraspinatus": 2.0,
           "scalene": 1.0,
           "subclavius": 0.7,
           "scalenus_minimus": 0.7,
           "triceps_trp5": 1.0,
           "sternalis": 0.5
         }
       },
       {
         "id": "gradual_postural",
         "label": "Gradual onset without clear incident \u2014 prolonged desk work, sustained sitting, poor posture",
         "sublabel": "Pain developed insidiously over weeks without a specific event",
         "lr": {
           "scalene": 4.0,
           "scalenus_minimus": 3.0,
           "subclavius": 3.0,
           "sternalis": 2.5,
           "biceps": 1.5,
           "brachialis": 1.0,
           "infraspinatus": 0.5,
           "supraspinatus": 0.8,
           "deltoid_anterior": 1.0,
           "triceps_trp5": 1.5
         }
       },
       {
         "id": "post_cardiac",
         "label": "During or after a cardiac event \u2014 myocardial infarction or sustained angina",
         "sublabel": "Chest and arm pain began or intensified around the time of a cardiac event",
         "lr": {
           "sternalis": 9.0,
           "scalene": 1.5,
           "scalenus_minimus": 1.0,
           "subclavius": 0.8,
           "biceps": 0.3,
           "brachialis": 0.3,
           "infraspinatus": 0.3,
           "supraspinatus": 0.3,
           "deltoid_anterior": 0.3,
           "triceps_trp5": 0.3
         }
       }
     ]
   }
 ],
 "pairwise": [
   {
     "id": "pw_brachialis_biceps",
     "pair": [
       "brachialis",
       "biceps"
     ],
     "text": "Tiebreaker \u2014 Brachialis vs Biceps Brachii",
     "question": "Does elbow flexion pain differ between palm-up and palm-down positions?",
     "answers": [
       {
         "id": "equal_both_positions",
         "label": "Equally painful or weak in both palm-up and palm-down flexion",
         "lr": {
           "brachialis": 5.0,
           "biceps": 0.25
         }
       },
       {
         "id": "worse_palm_up",
         "label": "Worse with palm-up (supinated) flexion than palm-down",
         "lr": {
           "brachialis": 0.25,
           "biceps": 5.0
         }
       }
     ]
   },
   {
     "id": "pw_scalene_scalenus_minimus",
     "pair": [
       "scalene",
       "scalenus_minimus"
     ],
     "text": "Tiebreaker \u2014 Scalene vs Scalenus Minimus",
     "question": "Which arm symptom pattern dominates?",
     "answers": [
       {
         "id": "nocturnal_ulnar",
         "label": "Nocturnal arm aching (hanging over bed) OR posterior arm and ulnar hand symptoms dominate",
         "lr": {
           "scalene": 4.0,
           "scalenus_minimus": 0.3
         }
       },
       {
         "id": "radial_thumb_plexus",
         "label": "Radial forearm, thumb, or lower brachial plexus compression symptoms dominate",
         "lr": {
           "scalene": 0.3,
           "scalenus_minimus": 4.0
         }
       }
     ]
   },
   {
     "id": "pw_subclavius_scalenus_minimus",
     "pair": [
       "subclavius",
       "scalenus_minimus"
     ],
     "text": "Tiebreaker \u2014 Subclavius vs Scalenus Minimus",
     "question": "Does arm abduction worsen the radial forearm and hand symptoms (Wright position), OR is the nocturnal arm pattern more prominent?",
     "answers": [
       {
         "id": "wright_worsens",
         "label": "Arm raised and rotated outward (Wright position) worsens symptoms",
         "lr": {
           "subclavius": 4.0,
           "scalenus_minimus": 0.3
         }
       },
       {
         "id": "nocturnal_lower_plexus",
         "label": "Nocturnal arm symptoms OR lower plexus compression features dominate \u2014 Wright position not specifically positive",
         "lr": {
           "subclavius": 0.3,
           "scalenus_minimus": 4.0
         }
       }
     ]
   },
   {
     "id": "pw_infraspinatus_biceps",
     "pair": [
       "infraspinatus",
       "biceps"
     ],
     "text": "Tiebreaker \u2014 Infraspinatus vs Biceps Brachii",
     "question": "Is the primary pain DEEP INSIDE the shoulder joint, OR is it a superficial surface ache over the anterior shoulder?",
     "answers": [
       {
         "id": "deep_joint",
         "label": "Deep inside the joint \u2014 the patient covers the anterior joint",
         "lr": {
           "infraspinatus": 5.0,
           "biceps": 0.2
         }
       },
       {
         "id": "surface_ache",
         "label": "Superficial surface ache \u2014 can lie comfortably on the affected side",
         "lr": {
           "infraspinatus": 0.2,
           "biceps": 5.0
         }
       }
     ]
   },
   {
     "id": "pw_supraspinatus_biceps",
     "pair": [
       "supraspinatus",
       "biceps"
     ],
     "text": "Tiebreaker \u2014 Supraspinatus vs Biceps Brachii",
     "question": "Is there a painful arc between 60\u00b0 and 120\u00b0 of shoulder abduction, OR is the arm pain primarily at the anterior shoulder without an arc pattern?",
     "answers": [
       {
         "id": "painful_arc",
         "label": "Painful arc between 60\u00b0 and 120\u00b0 of abduction",
         "lr": {
           "supraspinatus": 5.0,
           "biceps": 0.2
         }
       },
       {
         "id": "anterior_shoulder_no_arc",
         "label": "Anterior shoulder aching without a painful arc pattern",
         "lr": {
           "supraspinatus": 0.2,
           "biceps": 4.0
         }
       }
     ]
   },
   {
     "id": "pw_sternalis_scalene",
     "pair": [
       "sternalis",
       "scalene"
     ],
     "text": "Tiebreaker \u2014 Sternalis vs Scalene",
     "question": "Is the chest pain completely unaffected by any shoulder or arm movement, OR do arm or hand symptoms accompany it?",
     "answers": [
       {
         "id": "movement_independent",
         "label": "Completely movement-independent \u2014 no position or activity changes the pain",
         "lr": {
           "sternalis": 5.0,
           "scalene": 0.3
         }
       },
       {
         "id": "arm_symptoms_present",
         "label": "Arm or hand symptoms accompany the chest pain",
         "lr": {
           "sternalis": 0.3,
           "scalene": 4.0
         }
       }
     ]
   },
   {
     "id": "pw_triceps_trp5_brachialis",
     "pair": [
       "triceps_trp5",
       "brachialis"
     ],
     "text": "Tiebreaker \u2014 Triceps Medial Head vs Brachialis",
     "question": "Is the medial epicondyle the dominant distal referral, OR is the thumb base the dominant distal referral?",
     "answers": [
       {
         "id": "medial_epicondyle_dominant",
         "label": "Medial epicondyle (inner elbow) or medial forearm is the dominant distal referral",
         "lr": {
           "triceps_trp5": 5.0,
           "brachialis": 0.25
         }
       },
       {
         "id": "thumb_base_dominant",
         "label": "Thumb base or dorsal web of the thumb is the dominant distal referral",
         "lr": {
           "triceps_trp5": 0.25,
           "brachialis": 5.0
         }
       }
     ]
   }
 ],
 "treatment_dag": {
   "edges": [
     {
       "from": "infraspinatus",
       "to": "biceps",
       "type": "key_satellite",
       "label": "Infraspinatus is the most important key TrP driving satellite biceps TrPs \u2014 treat infraspinatus first; biceps may resolve without direct treatment"
     },
     {
       "from": "biceps",
       "to": "brachialis",
       "type": "functional_unit",
       "label": "Biceps and brachialis are the primary elbow flexor pair \u2014 examine and treat together in the same session"
     },
     {
       "from": "scalene",
       "to": "biceps",
       "type": "key_satellite",
       "label": "Scalene TrPs drive biceps brachii satellite TrPs"
     },
     {
       "from": "scalene",
       "to": "scalenus_minimus",
       "type": "functional_unit",
       "label": "Scalenus minimus (when present) is part of the scalene group \u2014 treat in the same session"
     },
     {
       "from": "biceps",
       "to": "triceps_trp5",
       "type": "antagonist_risk",
       "label": "\u26a0 Triceps (medial head) may reactively cramp when biceps is released \u2014 spray triceps after biceps release; treat in alternating partial cycles if both are active"
     },
     {
       "from": "infraspinatus",
       "to": "supraspinatus",
       "type": "functional_unit",
       "label": "Infraspinatus-supraspinatus team \u2014 almost always active together; treat in the same session"
     },
     {
       "from": "infraspinatus",
       "to": "deltoid_anterior",
       "type": "key_satellite",
       "label": "Infraspinatus is the most important key TrP driving anterior deltoid satellite TrPs"
     },
     {
       "from": "supraspinatus",
       "to": "deltoid_anterior",
       "type": "key_satellite",
       "label": "Supraspinatus TrPs drive anterior and middle deltoid satellite TrPs"
     },
     {
       "from": "subclavius",
       "to": "scalene",
       "type": "secondary_load",
       "label": "Subclavius shortening draws the clavicle down, increasing load on the scalene group \u2014 treat together"
     }
   ],
   "edge_type_labels": {
     "key_satellite": "Treat first \u2014 key TrP driving satellites",
     "functional_unit": "Treat concurrently in same session",
     "secondary_load": "Treat after primary resolves",
     "antagonist_risk": "\u26a0 Treat in alternating cycles \u2014 reactive activation risk"
   }
 },
 "emergency": [
   {
     "id": "rf-e1",
     "label": "Acute coronary syndrome / cardiac ischaemia",
     "question": "Cardiac emergency \u2014 consider FIRST with any anterior-chest or left-arm pain. Central/left chest pressure or tightness radiating to inner arm, neck, or jaw, with sweating, nausea, breathlessness, or rest/exertional onset; often atypical in women, the elderly, and diabetics. Sternalis TrP mimics cardiac pain and TrP relief does NOT exclude ACS. 12-lead ECG within 10 min + troponins before any myofascial label.",
     "source": "Acute Coronary Syndrome StatPearls (NBK459157); Chest Pain: Evaluation and Exclusion of MI and Angina StatPearls (NBK557672); T&S (sternalis cardiac mimicry)"
   },
   {
     "id": "rf-e2",
     "label": "Acute compartment syndrome of the arm",
     "question": "Surgical limb emergency. Arm pain OUT OF PROPORTION, unrelieved by analgesia, worse on PASSIVE finger/elbow stretch (earliest sign), with a tense, swollen arm \u2014 after fracture, crush, tight cast, bleeding/anticoagulation, or hard exertion. Pulselessness, paraesthesia, and paralysis are LATE. Immediate surgical referral; fasciotomy within ~6 h.",
     "source": "Acute Compartment Syndrome StatPearls; Brukner & Khan Ch.18 [VERIFY against your Ch.18 copy + add exact StatPearls NBK id]"
   },
   {
     "id": "rf-e3",
     "label": "Septic glenohumeral arthritis",
     "question": "Joint emergency \u2014 rapid cartilage destruction. Acute, constant, severe deep shoulder pain with pain on ALL movement (active AND passive), often warm or swollen. Fever may be absent or low-grade (only ~17\u201342% of cases) \u2014 a normal temperature does NOT exclude it. Risk: diabetes, immunosuppression, IV drug use, recent injection, prosthesis, bacteraemia. Urgent WBC/ESR/CRP + joint aspiration; drainage + IV antibiotics.",
     "source": "Evaluation and Management of Septic Arthritis in the ED (PMC6404712); Septic Arthritis of the Glenohumeral Joint (PubMed 9653429); Septic Arthritis evidence-based review (AJR 2021, AJR.20.22773)"
   }
 ],
 "urgent": [
   {
     "id": "rf-u1",
     "label": "Posterior glenohumeral dislocation",
     "question": "Easily missed \u2014 often invisible on the AP X-ray. After a seizure, electric shock, or a fall on an internally rotated arm: arm locked in INTERNAL ROTATION/adduction with marked loss of EXTERNAL ROTATION (cardinal sign). Needs an axillary/true-lateral view and timely reduction.",
     "source": "Brukner & Khan Ch.17 (posterior dislocation of the glenohumeral joint)"
   },
   {
     "id": "rf-u2",
     "label": "Proximal humerus (humeral neck) fracture",
     "question": "After a fall on the outstretched hand or a direct blow (esp. older/osteoporotic): shoulder pain, tenderness, swelling, can't use the arm. >2 fragments, displacement >1 cm, angulation, or associated dislocation \u2192 orthopaedic referral. Check axillary-nerve sensation (lateral shoulder) and distal neurovascular status.",
     "source": "Brukner & Khan Ch.17 (fracture of the neck of the humerus; axillary nerve injury)"
   },
   {
     "id": "rf-u3",
     "label": "Acute massive rotator cuff tear",
     "question": "Sudden loss of active elevation or external rotation after trauma (or acute-on-chronic in older adults), with night pain and weakness but PRESERVED passive range (pseudoparalysis) and positive impingement signs. Timely US/MRI and surgical referral \u2014 early repair improves outcome. TrPs don't cause true power loss with preserved passive motion.",
     "source": "Brukner & Khan Ch.17 (rotator cuff strains/tears); JOSPT 2009 LHBT review (associated cuff disease)"
   },
   {
     "id": "rf-u4",
     "label": "Long head of biceps (LHB) tendon rupture",
     "question": "Sudden 'pop' in the front of the arm on a lift, then a 'Popeye' bulge low in the arm (worse on elbow flexion), with bruising, little residual pain, and near-normal strength. Examine the cuff/subscapularis (commonly associated). Older/low-demand: reassurance + rehab; refer younger patients, laborers, or athletes for tenodesis/tenotomy.",
     "source": "Long Head of the Biceps Tendon JOSPT 2009 (Nho et al.); Proximal Biceps Tendinitis and Tendinopathy StatPearls (Varacallo & Mair); Brukner & Khan Ch.17 (rupture of the long head of the biceps)"
   },
   {
     "id": "rf-u5",
     "label": "Distal biceps tendon rupture",
     "question": "Sudden tearing at the FRONT OF THE ELBOW on a forceful eccentric load (catching a heavy object): antecubital pain, bruising, palpable defect, muscle belly retracts PROXIMALLY (reverse-Popeye), positive hook test, weak supination. Refer for EARLY repair (~2\u20133 weeks). TrP pain has no defect/retraction and normal strength.",
     "source": "Brukner & Khan Ch.18 (distal biceps rupture) [VERIFY against your Ch.18 copy]"
   },
   {
     "id": "rf-u6",
     "label": "Humeral shaft stress fracture / spiral fracture (throwers)",
     "question": "Throwing-related upper-arm pain that builds with load, with focal bony tenderness at the mid/lower shaft \u2014 or a sudden SPIRAL fracture on a hard throw. Risks RADIAL NERVE injury (test wrist/finger/thumb extension and dorsal first-web sensation). Stop activity and image (a stress fracture may be occult early). Myofascial pain lacks focal bony tenderness.",
     "source": "Brukner & Khan Ch.17 (throwing fracture of the humeral shaft); Ch.18 [VERIFY arm/elbow detail against your Ch.18 copy]"
   },
   {
     "id": "rf-u7",
     "label": "Vascular thoracic outlet syndrome / subclavian effort thrombosis (Paget-Schroetter)",
     "question": "ARTERIAL: pallor, coolness, claudication, or a lost radial pulse on arm elevation/abduction-ER (cervical rib) \u2014 limb-threatening. VENOUS (Paget-Schroetter): sudden swelling, bluish discoloration, and a heavy WHOLE arm with prominent veins after heavy overhead activity. Duplex/venography; venous needs anticoagulation \u00b1 thrombolysis + TOS work-up. NEUROGENIC TOS (paraesthesia, nocturnal arm-hang) is NOT urgent \u2014 see Differential:ThoracicOutletSyndrome.",
     "source": "Brukner & Khan Ch.17 (thoracic outlet syndrome; axillary vein 'effort' thrombosis / Paget-von Schrotter syndrome)"
   }
 ],
 "broad_differential": [
   {
     "id": "bd-1",
     "condition": "Subacromial impingement / rotator cuff tendinopathy",
     "confidence": "common",
     "mimics": "Anterior and lateral shoulder pain with overhead activity and a painful arc \u2014 overlaps the supraspinatus, anterior deltoid, and biceps anterior-shoulder patterns",
     "distinguishing_feature": "Pain on overhead activity with a painful arc of abduction (roughly 70\u2013120\u00b0), positive Neer and Hawkins-Kennedy impingement signs, and pain on resisted supraspinatus testing ('empty can'). Strength that IMPROVES with scapular retraction points to scapular dyskinesis driving the cuff rather than a true tear. Impingement is a clinical SIGN with several underlying causes (subacromial spur, cuff disease, instability, GIRD, scapular dyskinesis), not a stand-alone diagnosis. Trigger-point referral from supraspinatus/infraspinatus/deltoid is reproduced by muscle palpation and lacks the structural impingement signs.",
     "action": "Neer/Hawkins-Kennedy, painful-arc and empty-can testing, and the scapular assistance test; assess scapular control and posterior-capsule tightness. Relative rest, activity/technique modification, rotator-cuff and periscapular strengthening; consider subacromial corticosteroid injection or imaging (US/MRI) if refractory or a tear is suspected. Treat coexisting cuff and deltoid trigger points.",
     "source": "Brukner & Khan Ch.17 (impingement; rotator cuff tendinopathy)"
   },
   {
     "id": "bd-2",
     "condition": "Long head of biceps tendinopathy / bicipital groove pathology",
     "confidence": "common",
     "mimics": "Anterior shoulder pain localised to the bicipital groove, radiating down the front of the arm \u2014 the structural counterpart of the biceps myofascial pattern",
     "distinguishing_feature": "Point tenderness over the bicipital groove that rotates laterally and medially with arm rotation (distinguishing it from fixed superficial tenderness), with pain on resisted forward flexion (Speed's) and resisted supination (Yergason's). Usually SECONDARY to impingement, cuff disease, or instability rather than isolated. A positive O'Brien (active compression) test raises a SLAP/biceps-anchor lesion. Biceps brachii trigger-point pain is a surface ache reproduced by belly palpation, without groove-specific tenderness or positive provocative tendon tests.",
     "action": "Palpate the groove with rotation; Speed's, Yergason's, and O'Brien tests; screen the cuff and for biceps instability (clunk on abduction-external rotation). Relative rest, NSAIDs, rehabilitation focused on dynamic stability; intra-articular or sheath injection and surgical options (tenodesis/tenotomy) for refractory or structural cases. No treatment reliably benefits isolated biceps fraying \u2014 address the primary driver.",
     "source": "Long Head of the Biceps Tendon JOSPT 2009; Proximal Biceps Tendinitis StatPearls (Varacallo & Mair); Brukner & Khan Ch.17"
   },
   {
     "id": "bd-3",
     "condition": "SLAP lesion / glenohumeral instability",
     "confidence": "uncommon",
     "mimics": "Deep anterior shoulder pain with catching, popping, or a 'dead arm', often in overhead athletes \u2014 overlaps the biceps (anchor) and deep-joint presentations",
     "distinguishing_feature": "Poorly localised deep shoulder pain aggravated by overhead and behind-the-back motion, with popping/catching and sometimes episodes of subluxation or 'dead arm' (transient numbness/weakness). Apprehension in abduction-external rotation relieved by posterior relocation indicates anterior instability; positive O'Brien, crank, or anterior-slide tests suggest a superior labral (SLAP) lesion, which involves the biceps anchor. Generalized ligamentous laxity (sulcus sign) supports multidirectional instability. Trigger-point pain has no apprehension, instability, or labral provocation signs.",
     "action": "Apprehension-augmentation-relocation, load-and-shift, sulcus sign, and SLAP tests (O'Brien, crank, anterior slide) used in combination; MR arthrography for labral detail. Rehabilitation emphasising rotator-cuff and scapular stabilisers and avoidance of provocative positions; arthroscopic stabilisation/labral repair for unstable lesions or failed conservative care.",
     "source": "Brukner & Khan Ch.17 (glenoid labral injuries; shoulder instability)"
   },
   {
     "id": "bd-4",
     "condition": "Acromioclavicular (AC) joint pathology",
     "confidence": "common",
     "mimics": "Well-localised anterosuperior shoulder pain \u2014 can be mistaken for anterior deltoid or supraspinatus referral over the front of the shoulder",
     "distinguishing_feature": "Pain localised precisely to the AC joint at the top of the shoulder, often after a fall onto the point of the shoulder (sprain/separation) or from chronic overuse/osteolysis (weightlifters doing bench press). Reproduced by AC joint compression (Paxinos test) and by cross-body (horizontal) adduction, with possible palpable step deformity in higher-grade separations. Anterior deltoid trigger-point pain sits over the deltoid bulge, not the AC joint, and is not provoked by cross-arm adduction.",
     "action": "Localise tenderness to the AC joint; Paxinos and cross-arm adduction tests; X-ray for separation grade or osteolysis/osteoarthritis. Most sprains and many type III separations are managed conservatively (sling, activity modification, strengthening); local anesthetic/corticosteroid injection is diagnostic and therapeutic; distal clavicle excision for persistent cases.",
     "source": "Brukner & Khan Ch.17 (acromioclavicular joint injuries; chronic AC joint pain)"
   },
   {
     "id": "bd-5",
     "condition": "Adhesive capsulitis (frozen shoulder)",
     "confidence": "common",
     "mimics": "Diffuse shoulder pain with stiffness and difficulty reaching behind the back or sleeping on the shoulder \u2014 overlaps the infraspinatus 'cannot reach behind back / cannot sleep either side' pattern",
     "distinguishing_feature": "Global restriction of glenohumeral motion \u2014 the hallmark is loss of PASSIVE external rotation with the elbow at the side (with the scapula stabilised), which trigger-point pain does NOT cause. Typically ages 40\u201360, insidious or post-immobilisation onset, associated with diabetes and thyroid disease; passes through painful, stiff, and thawing phases over months. Myofascial restriction is movement- and direction-specific and improves with trigger-point release, whereas capsulitis is a true passive-ROM block.",
     "action": "Examine passive external rotation with the scapula stabilised; exclude glenohumeral arthritis radiographically. Reassurance about the self-limiting course; analgesia, intra-articular corticosteroid in the painful phase, supervised range-of-motion program; arthroscopic capsular release for refractory cases (less effective in diabetes).",
     "source": "Brukner & Khan Ch.17 (shoulder stiffness / adhesive capsulitis)"
   },
   {
     "id": "bd-6",
     "condition": "Cervical radiculopathy (C5\u2013C6) / referred cervicothoracic pain",
     "confidence": "common",
     "mimics": "Neck pain referring to the shoulder and arm with dermatomal sensory or motor change \u2014 overlaps the scalene/scalenus minimus and biceps anterior-arm patterns",
     "distinguishing_feature": "Neck pain radiating into the shoulder and arm with dermatomal paraesthesia, reflex change (e.g. diminished biceps/brachioradialis reflex), and weakness in muscles of a single myotome including ones OUTSIDE the front-of-arm myofascial group; a positive Spurling's (neck extension-rotation reproducing arm symptoms) supports it. The cervical and upper-thoracic spine commonly refer to the shoulder even without prominent neck pain. Scalene/myofascial referral has no fixed dermatomal deficit, normal reflexes, and is reproduced by muscle palpation; test the upper-quarter neurology to separate them.",
     "action": "Full upper-quarter neurological exam with Spurling's and an upper-limb neural tension test; reassess shoulder symptoms after treating any hypomobile cervical/thoracic segment. MRI cervical spine and electrodiagnostics where root signs persist or progress. Treat coexisting scalene and shoulder-girdle trigger points concurrently.",
     "source": "Brukner & Khan Ch.17 (referred pain from cervical/thoracic spine)"
   },
   {
     "id": "bd-7",
     "condition": "Neurogenic thoracic outlet syndrome",
     "confidence": "uncommon",
     "mimics": "Arm/forearm aching and paraesthesia with the nocturnal arm-hanging pattern \u2014 directly overlaps the scalene, scalenus minimus, and subclavius presentations the model scores",
     "distinguishing_feature": "Compression of the brachial plexus (usually the lower trunk) in the costoclavicular space producing arm/forearm aching, ulnar-side paraesthesia, easy fatigue, and symptoms worsened by overhead or sustained arm positions; provoked by the Roos hyperabduction/external-rotation (EAST) and Wright maneuvers, and associated with drooping posture, tight scalene/pectoralis minor, and scapular dyskinesis. Distinguished from the VASCULAR TOS emergency (limb swelling, discoloration, pulse change) by the absence of acute vascular signs. This is the myofascially-entangled, NON-emergent subtype.",
     "action": "Cross-linked to the dedicated page \u2014 see Differential:ThoracicOutletSyndrome for full assessment and management; this entry exists to flag overlap with the scalene/subclavius muscles and to keep the canonical content in one place. In brief: posture and scalene/pectoralis-minor work, scapular stabilisation, and trigger-point treatment; nerve studies and surgical referral for progressive neurological deficit.",
     "source": "Brukner & Khan Ch.17 (thoracic outlet syndrome); cross-link Differential:ThoracicOutletSyndrome"
   },
   {
     "id": "bd-8",
     "condition": "Suprascapular neuropathy",
     "confidence": "uncommon",
     "mimics": "Deep, poorly localised posterior/lateral shoulder pain with shoulder weakness \u2014 overlaps the infraspinatus and supraspinatus contributions to a front-of-shoulder picture",
     "distinguishing_feature": "Deep, poorly localised shoulder pain (often felt posterolaterally or referred to the arm/upper anterior chest) with weakness of abduction and external rotation and visible wasting of supraspinatus and/or infraspinatus. Entrapment at the suprascapular notch affects BOTH muscles; entrapment at the spinoglenoid notch causes ISOLATED infraspinatus wasting (seen in volleyball 'float' servers and from a paralabral cyst arising off a SLAP tear). Trigger-point pain produces no true muscle wasting or denervation weakness.",
     "action": "Inspect for supra-/infraspinatus wasting; test external-rotation and abduction strength; palpate the suprascapular notch. EMG/nerve conduction confirm and localise; MRI to seek a paralabral/spinoglenoid cyst. Usually non-operative (rehabilitation, load management); surgical decompression or cyst excision for progressive weakness or a compressive cyst.",
     "source": "Brukner & Khan Ch.17 (suprascapular nerve entrapment)"
   },
   {
     "id": "bd-9",
     "condition": "Costochondritis / Tietze syndrome / anterior chest-wall pain",
     "confidence": "common",
     "mimics": "Anterior chest pain that can extend toward the front of the shoulder \u2014 the benign musculoskeletal counterpart to the sternalis substernal pattern, and the key contrast to cardiac pain",
     "distinguishing_feature": "Localised anterior chest-wall pain REPRODUCED BY PALPATION of the costochondral/costosternal junctions (Tietze syndrome adds visible/palpable swelling, classically of the 2nd\u20133rd costal cartilage), often worse with deep breathing, coughing, or trunk movement. Reproducibility on palpation and a clear positional/respiratory component point to the chest wall \u2014 but palpable reproducibility does NOT by itself exclude cardiac disease, which must be ruled out first when risk factors or red-flag features are present. Sternalis trigger-point pain is a deep substernal ache reproduced by sternalis/pectoralis palpation and is characteristically movement-INDEPENDENT.",
     "action": "Palpate the costochondral junctions and reproduce the pain; assess respiratory/positional provocation; exclude ACS (see emergency tier) before settling on a chest-wall diagnosis. Reassurance, analgesia/NSAIDs, activity modification; treat coexisting sternalis and pectoralis trigger points.",
     "source": "Chest Pain: Evaluation and Exclusion of MI and Angina StatPearls (NBK557672); Coronary Artery Disease StatPearls (NBK564304, costochondritis as MSK mimic)"
   }
 ]

}

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