DiagnosticTree/DorsalFinger
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{
"model": "bayesian_lr_scoring",
"version": "1.0",
"region_label": "Dorsal Finger Pain",
"description": "Probabilistic scoring model for dorsal finger pain. The primary referrers are local and intrinsic - extensor digitorum (to the specific finger), the first dorsal interosseous, and abductor digiti minimi - together with the scaleni, which seed satellite extensor trigger points and drive a C8 hand pattern. Four proximal shoulder-girdle and chest muscles (pectoralis major, pectoralis minor, latissimus dorsi, subclavius) refer to the fingers as spillover, mostly in an ulnar distribution - except the subclavius, which reaches the radial three digits while skipping the elbow and wrist. Structural differential from the finger-injury and emergent hand/wrist literature, T&S Chapter 40, and the WikiMSK hand list.",
"thresholds": {
"early_exit_posterior": 0.55,
"early_exit_gap": 0.18,
"pairwise_trigger": 0.15
},
"muscles": {
"extensor_digitorum": {
"label": "Extensor Digitorum",
"prior": 0.15,
"page": "Muscle:Extensor_Digitorum",
"key_trp_note": "The principal myofascial source of dorsal finger pain. Refers down the dorsum of the hand into the specific finger served by the involved fibres - the pain follows the finger. The middle and ring finger fibres are most often involved. Provoked by resisted finger extension and firm gripping. Driven by scalene trigger points as satellites - examine the neck for lasting resolution.",
"subtitle": "Pain down the back of the hand INTO one specific finger (following that finger's line), worse on resisted finger extension and gripping; the most common myofascial source of dorsal finger pain"
},
"first_dorsal_interosseous": {
"label": "First Dorsal Interosseous",
"prior": 0.15,
"page": "Muscle:Interossei",
"key_trp_note": "The largest interosseous, filling the dorsal thumb web. Refers strongly down the radial side of the index finger and deeply through both the dorsum and palm, and may extend along the dorsal and ulnar sides of the little finger. Pain is most intense at the index finger end joint, where a Heberden's node may appear and serve as a guide to the trigger point. Activated by sustained or repetitive pincer grasp (sewing, sculpting, model-making, a tight golf grip). Patients typically complain of 'arthritis pain' and finger stiffness.",
"subtitle": "Pain strongly down the radial side of the INDEX finger and deeply through the dorsum and palm; a Heberden's node at the index finger end joint is a guide; brought on by sustained pinch or pincer grip"
},
"abductor_digiti_minimi": {
"label": "Abductor Digiti Minimi",
"prior": 0.15,
"page": "Muscle:Interossei",
"key_trp_note": "The intrinsic muscle of the ulnar border of the hand; functionally the equivalent of the dorsal interosseous to the little finger. Refers pain along the outer aspect of the little finger to which it attaches. When its trigger points dominate, the differential includes a thoracic outlet syndrome. Activated by sustained or repetitive forceful finger use. Examine with the interossei - they share the Chapter 40 intrinsic-hand pattern.",
"subtitle": "Pain along the outer (ulnar) border of the LITTLE finger to which it attaches; finger stiffness and awkwardness; brought on by sustained pinch or repetitive finger use"
},
"scaleni": {
"label": "Scaleni",
"prior": 0.15,
"page": "Muscle:Scalene",
"key_trp_note": "The scalene complex refers pain down the arm to the hand, characteristically in a C8 / ulnar pattern reaching the ring and little fingers, and can produce hand and finger oedema and a lower-trunk thoracic-outlet picture. Critically, scalene trigger points are a key driver of satellite trigger points throughout the finger-extensor group - so they must always be examined when a dorsal-finger extensor trigger point is found, since treating the hand without addressing the scalene driver leads to recurrence.",
"subtitle": "Neck-origin pain extending down the arm to the hand in an ULNAR (ring and little finger) pattern, sometimes with hand/finger swelling; a key driver of satellite finger-extensor trigger points; examine the neck"
},
"pectoralis_major": {
"label": "Pectoralis Major",
"prior": 0.1,
"page": "Muscle:Pectoralis_Major",
"key_trp_note": "The sternal section refers from the anterior chest down the medial arm and volar forearm to the ulnar hand, including the last two to two-and-a-half digits. CRITICAL: the left-sided sternal pattern mimics angina/myocardial ischaemia in exact detail, and relief of the pain by trigger-point treatment does NOT exclude cardiac disease - the two coexist and cardiac status must be established independently. Driven by round-shouldered posture; the subclavius and pectoralis minor are almost always co-active.",
"subtitle": "Anterior chest pain extending down the inner arm and forearm to the ULNAR hand and last two to three fingers; the LEFT sternal pattern mimics cardiac pain - relief by trigger-point treatment does NOT exclude heart disease"
},
"pectoralis_minor": {
"label": "Pectoralis Minor",
"prior": 0.1,
"page": "Muscle:Pectoralis_Minor",
"key_trp_note": "A deep anterior chest muscle whose pain spills along the ulnar arm, elbow, forearm, and hand to the last three fingers, closely mimicking the pectoralis major clavicular pattern and also able to mimic cardiac pain. Its taut fibres can entrap the brachial plexus medial cord, producing 4th/5th digit numbness and paraesthesia (but typically not hand oedema, unlike the scalenus anterior). Almost never found active without pectoralis major - examine and treat the two together.",
"subtitle": "Anterior deltoid / front-of-chest pain spilling down the ulnar arm and forearm to the last three fingers; can compress the brachial plexus (4th/5th finger numbness); almost never active without pectoralis major"
},
"latissimus_dorsi": {
"label": "Latissimus Dorsi",
"prior": 0.1,
"page": "Muscle:Latissimus_Dorsi",
"key_trp_note": "Refers from the inferior scapular angle and mid-back down the posterior arm to the ulnar forearm and hand, including the ring and little fingers, reaching the fingers as distal spillover. One of the four pseudo-thoracic-outlet muscles (with pectoralis major, teres major, and subscapularis). Suspect it when dorsal-finger pain is accompanied by mid-back or posterior axillary-fold pain.",
"subtitle": "Mid-back and inferior scapular pain spilling down the back of the arm to the ulnar forearm and hand (ring and little fingers); a member of the pseudo-thoracic-outlet group"
},
"subclavius": {
"label": "Subclavius",
"prior": 0.1,
"page": "Muscle:Subclavius",
"key_trp_note": "A small muscle beneath the clavicle whose referral runs down the radial side of the arm and forearm, characteristically SKIPPING the elbow and wrist, and reappears on the radial hand at the thumb, index, and middle fingers (dorsal and volar). Its shortening draws the clavicle toward the subclavian vessels, a VASCULAR entrapment mechanism (reduced radial pulse in provocative positions) - distinct from the neurological ulnar pattern of the scaleni. Routinely overlooked because it is palpated through the pectoralis major; almost always co-active with the pectoralis major clavicular section.",
"subtitle": "Front-of-shoulder pain running down the RADIAL arm and forearm, SKIPPING the elbow and wrist, reappearing on the thumb, index, and middle fingers; may reduce the radial pulse (vascular pattern); almost always with pectoralis major"
}
},
"questions": [
{
"id": "q_which_finger",
"text": "Which finger or fingers hurt?",
"sublabel": "The distribution across the digits is the strongest single clue",
"type": "choice",
"answers": [
{
"id": "index_radial",
"label": "The INDEX finger (radial side) and thumb web",
"sublabel": "Index / radial",
"lr": {
"extensor_digitorum": 1.2,
"first_dorsal_interosseous": 6.5,
"abductor_digiti_minimi": 0.4,
"scaleni": 0.6,
"pectoralis_major": 0.4,
"pectoralis_minor": 0.4,
"latissimus_dorsi": 0.4,
"subclavius": 2.0
}
},
{
"id": "little_only",
"label": "The LITTLE finger (outer/ulnar border) on its own",
"sublabel": "Little finger, isolated",
"lr": {
"extensor_digitorum": 1.0,
"first_dorsal_interosseous": 1.0,
"abductor_digiti_minimi": 6.5,
"scaleni": 1.5,
"pectoralis_major": 0.6,
"pectoralis_minor": 0.8,
"latissimus_dorsi": 0.8,
"subclavius": 0.4
}
},
{
"id": "ring_little",
"label": "The RING and LITTLE fingers / ulnar side of the hand",
"sublabel": "Ulnar fingers (4th/5th)",
"lr": {
"extensor_digitorum": 1.2,
"first_dorsal_interosseous": 0.7,
"abductor_digiti_minimi": 1.5,
"scaleni": 4.0,
"pectoralis_major": 2.5,
"pectoralis_minor": 3.0,
"latissimus_dorsi": 3.0,
"subclavius": 0.4
}
},
{
"id": "single_specific",
"label": "One specific finger (often middle or ring), following that finger's line down the back of the hand",
"sublabel": "Single finger ray",
"lr": {
"extensor_digitorum": 6.5,
"first_dorsal_interosseous": 1.0,
"abductor_digiti_minimi": 0.6,
"scaleni": 1.0,
"pectoralis_major": 0.6,
"pectoralis_minor": 0.6,
"latissimus_dorsi": 0.8,
"subclavius": 0.7
}
},
{
"id": "thumb_index_middle",
"label": "The THUMB, INDEX, and MIDDLE fingers (radial three), with the arm pain skipping the elbow and wrist",
"sublabel": "Radial three, skip pattern",
"lr": {
"extensor_digitorum": 0.7,
"first_dorsal_interosseous": 1.2,
"abductor_digiti_minimi": 0.4,
"scaleni": 0.6,
"pectoralis_major": 0.6,
"pectoralis_minor": 0.5,
"latissimus_dorsi": 0.5,
"subclavius": 6.5
}
}
]
},
{
"id": "q_zone",
"text": "Where does the overall pain seem to come from?",
"sublabel": "The dominant origin of the whole pattern",
"type": "choice",
"answers": [
{
"id": "hand_itself",
"label": "The HAND and fingers themselves",
"sublabel": "Local / intrinsic source",
"lr": {
"extensor_digitorum": 3.0,
"first_dorsal_interosseous": 4.0,
"abductor_digiti_minimi": 4.0,
"scaleni": 0.5,
"pectoralis_major": 0.4,
"pectoralis_minor": 0.4,
"latissimus_dorsi": 0.4,
"subclavius": 0.6
}
},
{
"id": "neck",
"label": "The NECK, spreading down the arm to the fingers",
"sublabel": "Neck source",
"lr": {
"extensor_digitorum": 0.8,
"first_dorsal_interosseous": 0.5,
"abductor_digiti_minimi": 0.5,
"scaleni": 7.0,
"pectoralis_major": 0.5,
"pectoralis_minor": 0.5,
"latissimus_dorsi": 0.6,
"subclavius": 0.8
}
},
{
"id": "front_chest_shoulder",
"label": "The FRONT of the chest or shoulder, extending down the arm",
"sublabel": "Anterior chest / shoulder source",
"lr": {
"extensor_digitorum": 0.4,
"first_dorsal_interosseous": 0.4,
"abductor_digiti_minimi": 0.5,
"scaleni": 0.6,
"pectoralis_major": 5.0,
"pectoralis_minor": 5.0,
"latissimus_dorsi": 0.6,
"subclavius": 4.0
}
},
{
"id": "mid_back",
"label": "The MID-BACK or behind the shoulder, wrapping down the arm",
"sublabel": "Posterior thorax source",
"lr": {
"extensor_digitorum": 0.6,
"first_dorsal_interosseous": 0.5,
"abductor_digiti_minimi": 0.6,
"scaleni": 1.0,
"pectoralis_major": 0.6,
"pectoralis_minor": 0.6,
"latissimus_dorsi": 6.5,
"subclavius": 0.6
}
}
]
},
{
"id": "q_provocation",
"text": "Which activity most reliably brings on the pain?",
"sublabel": "Choose the single strongest aggravator",
"type": "choice",
"answers": [
{
"id": "resisted_finger_ext",
"label": "Straightening the fingers against resistance, or gripping",
"sublabel": "Resisted finger extension",
"lr": {
"extensor_digitorum": 6.5,
"first_dorsal_interosseous": 0.8,
"abductor_digiti_minimi": 0.8,
"scaleni": 0.8,
"pectoralis_major": 0.5,
"pectoralis_minor": 0.5,
"latissimus_dorsi": 0.6,
"subclavius": 0.6
}
},
{
"id": "pincer_grip",
"label": "Sustained fine pinch or pincer grip (sewing, writing, small tools, tight club grip)",
"sublabel": "Pincer-grip overload",
"lr": {
"extensor_digitorum": 0.8,
"first_dorsal_interosseous": 6.0,
"abductor_digiti_minimi": 4.0,
"scaleni": 0.6,
"pectoralis_major": 0.5,
"pectoralis_minor": 0.5,
"latissimus_dorsi": 0.5,
"subclavius": 0.5
}
},
{
"id": "shoulder_arm_load",
"label": "Reaching, lifting, or carrying with the arm; round-shouldered posture",
"sublabel": "Shoulder-girdle load / posture",
"lr": {
"extensor_digitorum": 0.5,
"first_dorsal_interosseous": 0.5,
"abductor_digiti_minimi": 0.6,
"scaleni": 0.8,
"pectoralis_major": 4.5,
"pectoralis_minor": 4.0,
"latissimus_dorsi": 3.5,
"subclavius": 3.5
}
},
{
"id": "neck_movement",
"label": "Neck movement, or carrying a heavy bag/strap on the shoulder",
"sublabel": "Neck / lower-trunk load",
"lr": {
"extensor_digitorum": 0.8,
"first_dorsal_interosseous": 0.6,
"abductor_digiti_minimi": 0.7,
"scaleni": 6.0,
"pectoralis_major": 0.7,
"pectoralis_minor": 1.0,
"latissimus_dorsi": 0.8,
"subclavius": 1.0
}
},
{
"id": "breathing_cough",
"label": "Deep breathing, coughing, or after a respiratory illness",
"sublabel": "Respiratory overload",
"lr": {
"extensor_digitorum": 0.5,
"first_dorsal_interosseous": 0.5,
"abductor_digiti_minimi": 0.5,
"scaleni": 3.5,
"pectoralis_major": 1.2,
"pectoralis_minor": 3.0,
"latissimus_dorsi": 0.7,
"subclavius": 1.0
}
}
]
},
{
"id": "q_heberden",
"text": "Is there a hard tender knob at a finger end-joint (a Heberden's node), or a complaint of 'arthritis' pain and finger stiffness?",
"sublabel": "Intrinsic-hand (interosseous / abductor digiti minimi) signature - trigger points are associated with these nodes and finger stiffness",
"type": "binary",
"answers": [
{
"id": "yes",
"label": "Yes - a tender end-joint node and/or 'arthritis' stiffness in the finger",
"lr": {
"extensor_digitorum": 0.8,
"first_dorsal_interosseous": 5.0,
"abductor_digiti_minimi": 3.5,
"scaleni": 0.6,
"pectoralis_major": 0.6,
"pectoralis_minor": 0.6,
"latissimus_dorsi": 0.6,
"subclavius": 0.6
}
},
{
"id": "no",
"label": "No - no end-joint node and no arthritis-type stiffness",
"lr": {
"extensor_digitorum": 1.2,
"first_dorsal_interosseous": 0.6,
"abductor_digiti_minimi": 0.7,
"scaleni": 1.1,
"pectoralis_major": 1.1,
"pectoralis_minor": 1.1,
"latissimus_dorsi": 1.1,
"subclavius": 1.1
}
}
]
},
{
"id": "q_skip_radial",
"text": "Does the arm pain SKIP the elbow and wrist - present in the arm and again in the radial fingers, but not at the elbow or wrist?",
"sublabel": "The radial skip pattern of the subclavius",
"type": "binary",
"answers": [
{
"id": "yes",
"label": "Yes - the elbow and wrist are spared while the arm and radial fingers hurt",
"lr": {
"extensor_digitorum": 0.6,
"first_dorsal_interosseous": 0.8,
"abductor_digiti_minimi": 0.6,
"scaleni": 0.7,
"pectoralis_major": 0.9,
"pectoralis_minor": 0.9,
"latissimus_dorsi": 0.8,
"subclavius": 7.0
}
},
{
"id": "no",
"label": "No - the pain includes the elbow or wrist, or follows the hand continuously",
"lr": {
"extensor_digitorum": 1.2,
"first_dorsal_interosseous": 1.1,
"abductor_digiti_minimi": 1.1,
"scaleni": 1.1,
"pectoralis_major": 1.0,
"pectoralis_minor": 1.0,
"latissimus_dorsi": 1.0,
"subclavius": 0.3
}
}
]
},
{
"id": "q_chest_cardiac",
"text": "Is there anterior chest pain, or a pressure/constriction in the chest (especially left-sided) accompanying the finger pain?",
"sublabel": "Pectoral source screen. IMPORTANT: a left-sided chest-and-ulnar-arm pattern can mimic cardiac pain - relief by trigger-point treatment does NOT exclude heart disease; establish cardiac status independently.",
"type": "binary",
"answers": [
{
"id": "yes",
"label": "Yes - anterior chest pain or constriction accompanies the finger pain",
"lr": {
"extensor_digitorum": 0.4,
"first_dorsal_interosseous": 0.4,
"abductor_digiti_minimi": 0.5,
"scaleni": 0.8,
"pectoralis_major": 6.0,
"pectoralis_minor": 5.0,
"latissimus_dorsi": 0.7,
"subclavius": 1.5
}
},
{
"id": "no",
"label": "No - no chest pain or constriction",
"lr": {
"extensor_digitorum": 1.2,
"first_dorsal_interosseous": 1.2,
"abductor_digiti_minimi": 1.1,
"scaleni": 1.1,
"pectoralis_major": 0.3,
"pectoralis_minor": 0.4,
"latissimus_dorsi": 1.0,
"subclavius": 0.9
}
}
]
},
{
"id": "q_neck_swelling",
"text": "Is there neck pain or tightness with the finger pain, or swelling/puffiness of the hand and fingers?",
"sublabel": "Scalene screen - scalene trigger points give a C8 ulnar pattern with hand oedema and drive satellite finger-extensor trigger points",
"type": "binary",
"answers": [
{
"id": "yes",
"label": "Yes - neck involvement and/or hand and finger swelling",
"lr": {
"extensor_digitorum": 0.9,
"first_dorsal_interosseous": 0.6,
"abductor_digiti_minimi": 0.7,
"scaleni": 6.5,
"pectoralis_major": 0.7,
"pectoralis_minor": 0.9,
"latissimus_dorsi": 0.9,
"subclavius": 0.9
}
},
{
"id": "no",
"label": "No - no neck component and no hand swelling",
"lr": {
"extensor_digitorum": 1.1,
"first_dorsal_interosseous": 1.1,
"abductor_digiti_minimi": 1.1,
"scaleni": 0.3,
"pectoralis_major": 1.0,
"pectoralis_minor": 1.0,
"latissimus_dorsi": 1.0,
"subclavius": 1.0
}
}
]
},
{
"id": "q_palpation",
"text": "Where does firm palpation most precisely reproduce the familiar finger pain?",
"sublabel": "The reproducing tender point - the most specific localiser",
"type": "choice",
"answers": [
{
"id": "mid_extensor_forearm",
"label": "In the dorsal forearm extensor mass (mid-forearm)",
"sublabel": "Extensor digitorum location",
"lr": {
"extensor_digitorum": 7.0,
"first_dorsal_interosseous": 0.5,
"abductor_digiti_minimi": 0.5,
"scaleni": 0.6,
"pectoralis_major": 0.4,
"pectoralis_minor": 0.4,
"latissimus_dorsi": 0.4,
"subclavius": 0.4
}
},
{
"id": "thumb_web_muscle",
"label": "In the muscle of the dorsal thumb web (between thumb and index metacarpals)",
"sublabel": "First dorsal interosseous location",
"lr": {
"extensor_digitorum": 0.5,
"first_dorsal_interosseous": 7.0,
"abductor_digiti_minimi": 0.6,
"scaleni": 0.5,
"pectoralis_major": 0.4,
"pectoralis_minor": 0.4,
"latissimus_dorsi": 0.4,
"subclavius": 0.4
}
},
{
"id": "ulnar_border_hand",
"label": "Along the muscle on the ulnar border of the palm, below the little finger",
"sublabel": "Abductor digiti minimi location",
"lr": {
"extensor_digitorum": 0.5,
"first_dorsal_interosseous": 0.6,
"abductor_digiti_minimi": 7.0,
"scaleni": 0.6,
"pectoralis_major": 0.4,
"pectoralis_minor": 0.4,
"latissimus_dorsi": 0.4,
"subclavius": 0.4
}
},
{
"id": "side_of_neck",
"label": "In the side of the neck (scalene muscles)",
"sublabel": "Scaleni location",
"lr": {
"extensor_digitorum": 0.6,
"first_dorsal_interosseous": 0.5,
"abductor_digiti_minimi": 0.5,
"scaleni": 7.0,
"pectoralis_major": 0.5,
"pectoralis_minor": 0.5,
"latissimus_dorsi": 0.5,
"subclavius": 0.8
}
},
{
"id": "anterior_chest_pincer",
"label": "In the chest muscle, pinched at the front of the armpit fold",
"sublabel": "Pectoralis major location",
"lr": {
"extensor_digitorum": 0.4,
"first_dorsal_interosseous": 0.4,
"abductor_digiti_minimi": 0.4,
"scaleni": 0.5,
"pectoralis_major": 7.0,
"pectoralis_minor": 1.5,
"latissimus_dorsi": 0.5,
"subclavius": 1.0
}
},
{
"id": "deep_under_pec",
"label": "Deep under the chest muscle toward the coracoid (front of shoulder)",
"sublabel": "Pectoralis minor location",
"lr": {
"extensor_digitorum": 0.4,
"first_dorsal_interosseous": 0.4,
"abductor_digiti_minimi": 0.4,
"scaleni": 0.5,
"pectoralis_major": 1.5,
"pectoralis_minor": 7.0,
"latissimus_dorsi": 0.5,
"subclavius": 1.0
}
},
{
"id": "posterior_axillary_fold",
"label": "In the posterior axillary fold / side of the back (latissimus dorsi)",
"sublabel": "Latissimus dorsi location",
"lr": {
"extensor_digitorum": 0.4,
"first_dorsal_interosseous": 0.4,
"abductor_digiti_minimi": 0.4,
"scaleni": 0.5,
"pectoralis_major": 0.6,
"pectoralis_minor": 0.5,
"latissimus_dorsi": 7.0,
"subclavius": 0.5
}
},
{
"id": "beneath_clavicle",
"label": "Deep beneath the collarbone (through the chest muscle)",
"sublabel": "Subclavius location",
"lr": {
"extensor_digitorum": 0.4,
"first_dorsal_interosseous": 0.4,
"abductor_digiti_minimi": 0.4,
"scaleni": 0.6,
"pectoralis_major": 1.2,
"pectoralis_minor": 1.0,
"latissimus_dorsi": 0.5,
"subclavius": 7.0
}
}
]
}
],
"pairwise": [
{
"id": "pw_fdi_adm",
"pair": [
"first_dorsal_interosseous",
"abductor_digiti_minimi"
],
"text": "Tiebreaker - First Dorsal Interosseous vs Abductor Digiti Minimi",
"question": "Is the pain at the radial INDEX finger and thumb web, or along the ULNAR border of the little finger?",
"sublabel": "Index-web intrinsic vs little-finger-border intrinsic",
"answers": [
{
"id": "index",
"label": "Index finger / thumb web - first dorsal interosseous",
"lr": {
"first_dorsal_interosseous": 6.0,
"abductor_digiti_minimi": 0.3
}
},
{
"id": "little",
"label": "Little-finger border - abductor digiti minimi",
"lr": {
"first_dorsal_interosseous": 0.3,
"abductor_digiti_minimi": 6.0
}
}
]
},
{
"id": "pw_ed_scal",
"pair": [
"extensor_digitorum",
"scaleni"
],
"text": "Tiebreaker - Extensor Digitorum vs Scaleni",
"question": "Is the pain reproduced by resisted finger extension and palpation of the dorsal forearm, or does it come from the neck with an ulnar (ring/little) hand pattern?",
"sublabel": "Local finger extensor vs neck driver",
"answers": [
{
"id": "forearm",
"label": "Resisted finger extension, forearm tender point - extensor digitorum",
"lr": {
"extensor_digitorum": 6.0,
"scaleni": 0.3
}
},
{
"id": "neck",
"label": "Neck origin, ulnar hand pattern - scaleni",
"lr": {
"extensor_digitorum": 0.3,
"scaleni": 6.0
}
}
]
},
{
"id": "pw_pmaj_pmin",
"pair": [
"pectoralis_major",
"pectoralis_minor"
],
"text": "Tiebreaker - Pectoralis Major vs Pectoralis Minor",
"question": "Is the tender point superficial in the chest muscle / front of the armpit fold, or deeper toward the coracoid at the front of the shoulder?",
"sublabel": "Both refer to the ulnar fingers and mimic cardiac pain; they almost always coexist - separate by depth",
"answers": [
{
"id": "superficial",
"label": "Superficial chest muscle / axillary fold - pectoralis major",
"lr": {
"pectoralis_major": 5.0,
"pectoralis_minor": 0.5
}
},
{
"id": "deep",
"label": "Deep toward the coracoid - pectoralis minor",
"lr": {
"pectoralis_major": 0.5,
"pectoralis_minor": 5.0
}
}
]
},
{
"id": "pw_scal_pmaj",
"pair": [
"scaleni",
"pectoralis_major"
],
"text": "Tiebreaker - Scaleni vs Pectoralis Major",
"question": "Does the ulnar finger pain come from the NECK (with hand swelling), or from the FRONT OF THE CHEST (with chest pain or constriction)?",
"sublabel": "Both give an ulnar hand pattern - separate by neck vs chest origin",
"answers": [
{
"id": "neck",
"label": "Neck origin, hand swelling - scaleni",
"lr": {
"scaleni": 5.5,
"pectoralis_major": 0.4
}
},
{
"id": "chest",
"label": "Front of chest, chest pain/constriction - pectoralis major",
"lr": {
"scaleni": 0.4,
"pectoralis_major": 5.5
}
}
]
},
{
"id": "pw_scal_latd",
"pair": [
"scaleni",
"latissimus_dorsi"
],
"text": "Tiebreaker - Scaleni vs Latissimus Dorsi",
"question": "Does the ulnar arm/finger pain originate at the NECK, or at the MID-BACK / posterior axillary fold?",
"sublabel": "Neck source vs posterior thorax source",
"answers": [
{
"id": "neck",
"label": "Neck origin - scaleni",
"lr": {
"scaleni": 5.0,
"latissimus_dorsi": 0.4
}
},
{
"id": "back",
"label": "Mid-back / posterior axillary fold - latissimus dorsi",
"lr": {
"scaleni": 0.4,
"latissimus_dorsi": 5.0
}
}
]
}
],
"treatment_dag": {
"edges": [
{
"from": "scaleni",
"to": "extensor_digitorum",
"type": "key_satellite",
"label": "Scalene trigger points seed satellite finger-extensor trigger points; treat the neck first"
},
{
"from": "first_dorsal_interosseous",
"to": "abductor_digiti_minimi",
"type": "functional_unit",
"label": "Intrinsic hand muscles (Chapter 40) - examine and treat the involved interossei and abductor digiti minimi together"
},
{
"from": "pectoralis_major",
"to": "pectoralis_minor",
"type": "functional_unit",
"label": "Pectoralis minor is almost never active without pectoralis major; treat the major first, then reassess the minor"
},
{
"from": "pectoralis_major",
"to": "subclavius",
"type": "functional_unit",
"label": "Subclavius is almost always co-active with the clavicular section; treat the pectoralis major first, then the residual subclavius"
},
{
"from": "pectoralis_major",
"to": "latissimus_dorsi",
"type": "functional_unit",
"label": "Pseudo-thoracic-outlet group - examine pectoralis major, latissimus, teres major, and subscapularis together"
},
{
"from": "scaleni",
"to": "abductor_digiti_minimi",
"type": "secondary_load",
"label": "When abductor digiti minimi dominates, exclude a thoracic outlet picture; scalene drivers may coexist"
}
],
"edge_type_labels": {
"key_satellite": "Treat first - key TrP driving satellite",
"functional_unit": "Treat concurrently in same session",
"secondary_load": "Treat after primary resolves",
"antagonist_risk": "Treat in alternating cycles - reactive activation risk"
}
},
"emergency": [
{
"id": "rf-e1",
"label": "Flexor (suppurative) tenosynovitis",
"question": "A surgical emergency. Look for the four Kanavel signs: (1) fusiform swelling of the WHOLE finger ('sausage digit'); (2) the finger held semi-flexed at rest; (3) tenderness along the length of the flexor tendon sheath in the palm; and (4) severe pain on PASSIVE EXTENSION of the finger. Usually follows a penetrating injury or bite. Fever or spreading erythema? Requires urgent hand-surgery referral, IV antibiotics, and drainage - delay risks tendon necrosis and spread to the deep palmar spaces or wrist.",
"source": "Standard hand-infection emergency criteria (Kanavel)"
},
{
"id": "rf-e2",
"label": "Septic arthritis of a finger joint / deep hand-space infection",
"question": "An acutely hot, red, swollen, exquisitely tender finger joint with severe pain on any movement, after a bite, puncture, or wound (including a clenched-fist 'fight bite' over a knuckle)? Fever or systemic upset? Needs urgent washout and antibiotics.",
"source": "Sanderson, Mohr & Abraham 2020 (open fractures/infections); standard joint-sepsis screen"
},
{
"id": "rf-e3",
"label": "Compartment syndrome of the hand / digit, or neurovascular compromise",
"question": "Severe, disproportionate, worsening hand pain after a crush, high-energy injury, or tight dressing, with a tense hand, pain on passive finger movement, or pallor/paraesthesia? Any open fracture, or a dusky/pulseless finger? Emergent injuries - compartment syndrome, neurovascular compromise, and open fractures - require immediate referral.",
"source": "Sanderson, Mohr & Abraham 2020"
}
],
"urgent": [
{
"id": "rf-u1",
"label": "Mallet finger (extensor avulsion at the end joint)",
"question": "After a finger was forcibly bent at the tip (a ball or object striking an extended fingertip), is the end joint dropped and unable to actively straighten, with tenderness over the back of the end joint? Bony avulsion is present in about a third of cases. Needs continuous extension splinting of the end joint for six weeks (the clock restarts if the joint is allowed to flex); refer if an avulsion involves more than ~30% of the joint or full passive extension is not possible.",
"source": "AFP Finger Injuries; Sanderson, Mohr & Abraham 2020"
},
{
"id": "rf-u2",
"label": "Central slip injury / evolving boutonniere deformity",
"question": "After the middle finger joint was forcibly bent while actively straightening (or a volar dislocation), is there tenderness over the back of the middle joint and inability to actively straighten it (with passive extension still possible)? Untreated, a boutonniere deformity develops over weeks. Splint the middle joint in full extension for six weeks; refer if full passive extension is not possible.",
"source": "AFP Finger Injuries"
},
{
"id": "rf-u3",
"label": "Jersey finger (flexor digitorum profundus avulsion)",
"question": "After a fingertip was forcibly straightened while gripping (catching on a jersey/clothing), is the patient unable to actively bend the END joint, with tenderness (and perhaps a tender fullness from a retracted tendon) on the palm side? The ring finger accounts for ~75%. All confirmed or suspected cases need prompt referral to a hand surgeon (repair within 7-10 days).",
"source": "AFP Finger Injuries; Sanderson, Mohr & Abraham 2020"
},
{
"id": "rf-u4",
"label": "Phalangeal fracture with rotational deformity, or unstable ligament/volar-plate injury",
"question": "After trauma, is there a finger fracture with malrotation (the flexed fingers cross/scissor, or the nails do not lie in the same plane), an unstable joint on stress testing, or a large avulsion fragment? Rotational deformity needs prompt reduction; unstable joints and large fragments need referral. A low threshold for referral applies to collateral-ligament injuries in children (growth plate involvement).",
"source": "AFP Finger Injuries; Sanderson, Mohr & Abraham 2020"
}
],
"broad_differential": [
{
"id": "bd-1",
"condition": "Heberden's node / interphalangeal osteoarthritis",
"confidence": "common",
"mimics": "A tender bony knob at the finger end joint with 'arthritis' pain and stiffness - directly overlaps the interosseous and abductor digiti minimi referral, which are associated with these nodes",
"distinguishing_feature": "A Heberden's node is a firm enlargement (sometimes partly bony) on the dorsal margin of the end joint, classically on the index and middle fingers; brief morning stiffness and gradual loss of motion. Trigger points in the corresponding interosseous muscle are frequently associated and may be the source of the node's tenderness - inactivating the trigger point typically abolishes node tenderness at once even though the node itself persists. Bouchard's nodes are the equivalent at the middle joint (seen in ~25% of those with Heberden's nodes).",
"action": "Clinical diagnosis; radiographs if joint destruction or an alternative diagnosis is suspected. Treat the associated interosseous trigger points and perpetuating pincer-grip overload; node tenderness usually settles even though the bony node remains. Address the osteoarthritis on its own merits.",
"source": "T&S Ch.40; WikiMSK (finger OA)"
},
{
"id": "bd-2",
"condition": "Finger extensor tendon injuries (mallet, central slip/boutonniere, sagittal band)",
"confidence": "common",
"mimics": "Dorsal finger pain and difficulty straightening a finger - overlaps the extensor digitorum referral",
"distinguishing_feature": "Mallet finger: dropped end joint, cannot actively extend it, dorsal end-joint tenderness. Central slip: cannot actively extend the middle joint, dorsal middle-joint tenderness, evolving boutonniere. Sagittal band rupture: the extensor tendon subluxes off the knuckle on making a fist, with pain over the knuckle. Trigger-point pain is reproduced by forearm-muscle palpation and does not produce a true extensor lag or tendon subluxation.",
"action": "Examine each joint in isolation for an active extension lag; radiographs (AP, true lateral, oblique) for avulsion fractures. Splint per the specific injury (continuous extension splinting for mallet and central slip); refer extensor lag with a large avulsion, irreducible subluxation, or failure to maintain extension.",
"source": "AFP Finger Injuries; WikiMSK"
},
{
"id": "bd-3",
"condition": "Finger flexor tendon injuries (jersey finger, pulley injury, trigger finger)",
"confidence": "common",
"mimics": "Finger pain with catching or difficulty bending - can be confused with intrinsic-muscle stiffness",
"distinguishing_feature": "Jersey finger: cannot actively flex the end joint after a forced-extension-while-gripping injury. Pulley injury (rock climbers): volar pain and bowstringing of the flexor tendon. Trigger finger: painful catching/locking of the finger in flexion with a palpable nodule at the base of the finger on the palm. Trigger-point finger stiffness has no true flexor lag, no locking, and no palpable A1-pulley nodule.",
"action": "Test active end-joint flexion in isolation; ultrasound or MRI confirms a flexor avulsion or pulley rupture. Refer jersey finger promptly (repair within 7-10 days). Trigger finger: splinting, corticosteroid injection, or release if refractory.",
"source": "AFP Finger Injuries; Sanderson, Mohr & Abraham 2020; WikiMSK"
},
{
"id": "bd-4",
"condition": "Collateral ligament / volar plate injury ('jammed finger')",
"confidence": "common",
"mimics": "Localised finger-joint pain and stiffness after a jamming injury - overlaps intrinsic-muscle finger pain",
"distinguishing_feature": "Collateral ligament injury: maximal tenderness at one side of a joint (usually the middle joint), with pain or laxity on side-to-side stress tested at 30 degrees of flexion. Volar plate injury: maximal tenderness on the palmar aspect after a hyperextension injury, sometimes with a small avulsion fragment. Trigger-point pain is not localised to a collateral ligament and shows no stress laxity.",
"action": "Stress test for stability; radiographs for avulsion fragments. Stable injuries: buddy taping or a short course of extension-block splinting. Refer unstable joints, large avulsion fragments, and ligament injuries in children (growth-plate involvement).",
"source": "AFP Finger Injuries"
},
{
"id": "bd-5",
"condition": "Phalangeal and metacarpal fractures / dislocations",
"confidence": "common",
"mimics": "Post-traumatic finger pain, swelling, and deformity",
"distinguishing_feature": "Focal bony tenderness, deformity, or malrotation after trauma. Rotational deformity is a clinical sign - the flexed fingers scissor or the nails do not lie in one plane - and needs reduction. Distal-phalanx tuft fractures often accompany nail-bed injury. Trigger-point pain has no bony tenderness, deformity, or malrotation.",
"action": "Radiographs (AP, true lateral, oblique). Reduce rotational deformity; splint per fracture (gutter splint for proximal/middle phalanx, extension splint for distal-phalanx avulsions). Refer open, displaced, intra-articular, or malrotated fractures and base-of-thumb fractures (Bennett/Rolando).",
"source": "Sanderson, Mohr & Abraham 2020; AFP Finger Injuries"
},
{
"id": "bd-6",
"condition": "Cervical radiculopathy (C6-C8) / thoracic outlet syndrome",
"confidence": "uncommon",
"mimics": "Finger pain and numbness referred from the neck - overlaps the scalene, pectoral, and latissimus spillover, and the abductor digiti minimi (ulnar) pattern",
"distinguishing_feature": "Dermatomal sensory deficit, reflex change, or myotomal weakness with neck pain and a positive Spurling test point to radiculopathy; positive EAST/Roos and ulnar-sided symptoms with possible vascular change point to thoracic outlet syndrome. Trigger-point referral produces no reflex change or true dermatomal deficit and IS reproduced by muscle palpation - and scalene/pectoral trigger points frequently coexist with and drive a thoracic-outlet picture.",
"action": "Full neurological and upper-quarter examination; Spurling, EAST, neurodynamic tests. MRI cervical spine and EMG/NCS if neurological signs. Treat coexisting scalene and shoulder-girdle trigger points concurrently - they may be the dominant or driving source.",
"source": "T&S Ch.40 (differential); WikiMSK"
},
{
"id": "bd-7",
"condition": "Digital nerve entrapment / peripheral neuropathy",
"confidence": "uncommon",
"mimics": "Numbness or pain along one side of a finger - can be mimicked by an interosseous trigger point entrapping a digital nerve",
"distinguishing_feature": "True digital nerve entrapment gives sensory change confined to one side of one finger, sometimes after local trauma or a tight ring; a diffuse glove-distribution change suggests a peripheral neuropathy (e.g. diabetic). An interosseous trigger point can entrap a digital nerve and produce one-sided finger numbness that resolves completely when the trigger point is inactivated. Establish whether the deficit is fixed or reversible.",
"action": "Map the sensory deficit; screen for systemic causes of neuropathy where the pattern is diffuse. Inactivate the corresponding interosseous trigger point and reassess - resolution confirms a myofascial entrapment rather than structural nerve disease.",
"source": "T&S Ch.40 (entrapment); WikiMSK"
},
{
"id": "bd-8",
"condition": "Dupuytren disease / CRPS / dorsal ganglion and other masses",
"confidence": "uncommon",
"mimics": "Finger or hand pain, stiffness, or a palpable lump not explained by a muscular source",
"distinguishing_feature": "Dupuytren disease: a palmar cord and progressive flexion contracture of the ring/little fingers, usually painless. Complex regional pain syndrome: disproportionate burning pain with swelling, colour/temperature change, and stiffness after an injury. A dorsal ganglion or giant-cell tumour presents as a localised lump. None of these is reproduced by a muscular trigger point, and the palpable structural finding distinguishes them.",
"action": "Clinical diagnosis; imaging (ultrasound/MRI) for masses; recognise CRPS early and refer for multidisciplinary management. Treat any coexisting myofascial trigger points on their own merits, but do not attribute the structural finding to them.",
"source": "WikiMSK (Dupuytren, CRPS, ganglion)"
}
]
}