DiagnosticTree/VolarWristAndPalmar
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{
"model": "bayesian_lr_scoring",
"version": "1.0",
"region_label": "Volar Wrist and Palmar Pain",
"description": "Probabilistic scoring model for pain on the volar (palm-side) wrist and the palm. Four local muscles generate it at the wrist and forearm: the flexor carpi radialis (radial volar wrist) and flexor carpi ulnaris (ulnar volar wrist), the palmaris longus (a distinctive prickling, needle-like central-palm pain), and the pronator teres (volar forearm to the radial wrist, a carpal-tunnel mimic). Five more refer from a distance: the opponens pollicis (palmar thumb and a radial palmar-wrist spot), and the trunk and shoulder-girdle referrers - pectoralis major and minor (anterior chest to the ulnar hand), latissimus dorsi (mid-back to the ulnar palm), and serratus anterior (side of chest to the palm with a respiratory component). Structural differential led by carpal tunnel syndrome, ulnar nerve compression at Guyon's canal, the hook-of-hamate fracture, the volar wrist-flexor tendinopathies, and Dupuytren's disease (Brukner & Khan 2006, Ch.19; Shehab & Mirabelli 2013).",
"thresholds": {
"early_exit_posterior": 0.55,
"early_exit_gap": 0.18,
"pairwise_trigger": 0.15
},
"muscles": {
"flexor_carpi_radialis": {
"label": "Flexor Carpi Radialis",
"prior": 0.136364,
"page": "Muscle:Hand_and_Finger_Flexors",
"key_trp_note": "The radial wrist flexor; refers a deep aching pain to the volar (palmar) aspect of the wrist on the radial side, occasionally toward the base of the thumb. Provoked by resisted wrist flexion and forceful gripping. Its tendon is a landmark at the wrist (lateral to palmaris longus). A common but overlooked contributor to volar wrist pain; distinguish from a flexor carpi radialis tendinopathy at the trapezial tuberosity and from carpal tunnel syndrome, with which it can coexist. Examine with the other volar wrist flexors, which share the gripping-overload mechanism.",
"subtitle": "Deep aching at the front of the wrist on the RADIAL (thumb) side, sometimes toward the base of the thumb; worse on bending the wrist forward against resistance and on forceful gripping"
},
"flexor_carpi_ulnaris": {
"label": "Flexor Carpi Ulnaris",
"prior": 0.136364,
"page": "Muscle:Hand_and_Finger_Flexors",
"key_trp_note": "The ulnar wrist flexor; refers a deep aching pain to the volar wrist on the ulnar side, around the pisiform. Provoked by resisted wrist flexion and forceful gripping. Its tendon inserts on the pisiform and is the landmark for the ulnar side of the wrist. Distinguish from a flexor carpi ulnaris tendinopathy or pisotriquetral degeneration at the pisiform, and from ulnar nerve symptoms at Guyon's canal (the nerve and artery lie just radial to the tendon). Examine with the other volar wrist flexors.",
"subtitle": "Deep aching at the front of the wrist on the ULNAR (little-finger) side, around the pisiform; worse on bending the wrist forward against resistance and on forceful gripping"
},
"palmaris_longus": {
"label": "Palmaris Longus",
"prior": 0.136364,
"page": "Muscle:Palmaris_Longus",
"key_trp_note": "Unique among the forearm muscles in referring a PRICKLING, needle-like sensation - fine needles in the palm - rather than the deep aching of other myofascial referrals; this quality is the key diagnostic feature. The pain centres on the mid-palm and reaches the thumb base and distal palmar crease but does not enter the digits. 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 and account for much of its palmar tenderness; anomalous variants can themselves entrap the median nerve at the wrist.",
"subtitle": "A distinctive PRICKLING, needle-like pain in the CENTRE of the PALM (not a deep ache), spreading toward the thumb base and the crease across the palm but NOT into the fingers; brought on by pressing a tool handle into the cupped palm"
},
"pronator_teres": {
"label": "Pronator Teres",
"prior": 0.136364,
"page": "Muscle:Hand_and_Finger_Flexors",
"key_trp_note": "A proximal volar-forearm muscle that refers deep aching along the volar forearm to the radial volar wrist. The median nerve passes between its two heads, so a taut pronator teres can compress it (pronator syndrome), producing median-territory paraesthesia that mimics carpal tunnel syndrome - but with forearm aching, pain on resisted pronation, and NO nocturnal predominance. Distinguish a pronator-teres trigger point and pronator syndrome from true carpal tunnel syndrome (where symptoms are at the wrist, nocturnal, and Phalen-positive). Examine with the other volar forearm flexors.",
"subtitle": "Deep aching in the volar forearm running to the RADIAL side of the front of the wrist; worse on turning the palm down against resistance; may be accompanied by tingling in the thumb/index/middle finger (a carpal-tunnel mimic)"
},
"opponens_pollicis": {
"label": "Opponens Pollicis",
"prior": 0.090909,
"page": "Muscle:Adductor_Pollicis_and_Opponens_Pollicis",
"key_trp_note": "An intrinsic thenar muscle that refers pain to the palmar surface of the thumb and, characteristically, to a discrete spot on the radial palmar aspect of the wrist that the patient localises with a fingertip - which is how it enters this region. Thumb opposition is weak or painful. Part of the 'weeder's thumb' picture; usually accompanied by adductor pollicis and first dorsal interosseous trigger points. Distinguish its discrete radial palmar-wrist spot from a flexor carpi radialis ache and from carpal tunnel syndrome.",
"subtitle": "Pain over the PALMAR surface of the thumb and a discrete spot on the RADIAL PALMAR side of the wrist that the patient points to with a fingertip; thumb opposition weak or painful"
},
"pectoralis_major": {
"label": "Pectoralis Major",
"prior": 0.090909,
"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 wrist and hand. CRITICAL: the left-sided sternal pattern mimics angina/myocardial ischaemia in detail, and relief by trigger-point treatment does NOT exclude cardiac disease - cardiac status must be established independently. Driven by round-shouldered posture; pectoralis minor and subclavius are usually co-active.",
"subtitle": "Anterior chest pain extending down the inner arm and forearm to the ULNAR side of the wrist and hand; the LEFT sternal pattern mimics cardiac pain - relief by trigger-point treatment does NOT exclude heart disease"
},
"pectoralis_minor": {
"label": "Pectoralis Minor",
"prior": 0.090909,
"page": "Muscle:Pectoralis_Minor",
"key_trp_note": "A deep anterior chest muscle whose pain spills along the ulnar arm, forearm, and hand, and which can entrap the brachial plexus medial cord (a myofascial thoracic-outlet mechanism) to add ulnar-finger numbness. Almost never active without pectoralis major; examine and treat the two together. Its reach to the volar ulnar wrist/hand is how it enters this region.",
"subtitle": "Front-of-chest / anterior deltoid pain spilling down the ULNAR arm and forearm to the wrist and hand; can compress the brachial plexus (4th/5th-finger numbness); almost never active without pectoralis major"
},
"latissimus_dorsi": {
"label": "Latissimus Dorsi",
"prior": 0.090909,
"page": "Muscle:Latissimus_Dorsi",
"key_trp_note": "Refers from the inferior scapular angle and mid-back down the posterior arm to the ulnar forearm, wrist, and hand, reaching the ulnar palm and the ring and little fingers. The mid-thoracic ache is characteristically constant and unchanged by ordinary movement. One of the pseudo-thoracic-outlet muscles; suspect it when volar ulnar wrist/palm pain accompanies a constant mid-back or posterior axillary-fold ache.",
"subtitle": "A constant MID-BACK ache spilling down the back of the arm to the ULNAR side of the wrist, palm, and the ring and little fingers; unchanged by ordinary movement; a member of the pseudo-thoracic-outlet group"
},
"serratus_anterior": {
"label": "Serratus Anterior",
"prior": 0.090909,
"page": "Muscle:Serratus_Anterior",
"key_trp_note": "A lateral chest-wall muscle whose essential pain is at the anterolateral midchest (with an interscapular patch), with spillover down the medial arm 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/prolonged running, push-ups, severe coughing, and the torsional stress of wrenching the body around. Left-sided pain must not be called myofascial until cardiac disease is excluded.",
"subtitle": "Pain on the SIDE of the chest (and a patch between the shoulder blades) spilling down the inner arm to the PALM and ring finger; a 'stitch in the side', breathlessness, or pain on deep breathing; brought on by hard running or wrenching the body around"
}
},
"questions": [
{
"id": "q_zone",
"text": "Where is the pain mainly felt?",
"sublabel": "The dominant location of the pattern",
"type": "choice",
"answers": [
{
"id": "radial_volar_wrist",
"label": "Front of the wrist on the RADIAL (thumb) side",
"sublabel": "Radial volar wrist",
"lr": {
"flexor_carpi_radialis": 5.5,
"flexor_carpi_ulnaris": 0.6,
"palmaris_longus": 0.8,
"pronator_teres": 3.0,
"opponens_pollicis": 2.5,
"pectoralis_major": 0.4,
"pectoralis_minor": 0.4,
"latissimus_dorsi": 0.4,
"serratus_anterior": 0.4
}
},
{
"id": "ulnar_volar_wrist",
"label": "Front of the wrist on the ULNAR (little-finger) side",
"sublabel": "Ulnar volar wrist",
"lr": {
"flexor_carpi_radialis": 0.6,
"flexor_carpi_ulnaris": 6.0,
"palmaris_longus": 0.7,
"pronator_teres": 0.6,
"opponens_pollicis": 0.5,
"pectoralis_major": 1.5,
"pectoralis_minor": 1.5,
"latissimus_dorsi": 2.0,
"serratus_anterior": 1.0
}
},
{
"id": "central_palm",
"label": "The CENTRE of the PALM",
"sublabel": "Central palm",
"lr": {
"flexor_carpi_radialis": 0.8,
"flexor_carpi_ulnaris": 0.8,
"palmaris_longus": 6.5,
"pronator_teres": 0.6,
"opponens_pollicis": 1.5,
"pectoralis_major": 0.5,
"pectoralis_minor": 0.5,
"latissimus_dorsi": 0.6,
"serratus_anterior": 0.8
}
},
{
"id": "volar_forearm",
"label": "The front of the FOREARM, running down toward the wrist",
"sublabel": "Volar forearm",
"lr": {
"flexor_carpi_radialis": 1.5,
"flexor_carpi_ulnaris": 1.5,
"palmaris_longus": 1.0,
"pronator_teres": 5.5,
"opponens_pollicis": 0.5,
"pectoralis_major": 0.5,
"pectoralis_minor": 0.5,
"latissimus_dorsi": 0.6,
"serratus_anterior": 0.6
}
},
{
"id": "front_chest",
"label": "The FRONT of the CHEST, extending down the arm to the wrist/hand",
"sublabel": "Anterior chest",
"lr": {
"flexor_carpi_radialis": 0.4,
"flexor_carpi_ulnaris": 0.5,
"palmaris_longus": 0.4,
"pronator_teres": 0.4,
"opponens_pollicis": 0.4,
"pectoralis_major": 6.0,
"pectoralis_minor": 5.0,
"latissimus_dorsi": 0.8,
"serratus_anterior": 1.5
}
},
{
"id": "mid_back_or_side_chest",
"label": "The MID-BACK or the SIDE of the chest, spilling down the arm",
"sublabel": "Posterior / lateral thorax",
"lr": {
"flexor_carpi_radialis": 0.4,
"flexor_carpi_ulnaris": 0.5,
"palmaris_longus": 0.4,
"pronator_teres": 0.4,
"opponens_pollicis": 0.4,
"pectoralis_major": 0.8,
"pectoralis_minor": 0.9,
"latissimus_dorsi": 5.0,
"serratus_anterior": 5.0
}
}
]
},
{
"id": "q_quality",
"text": "What is the pain like?",
"sublabel": "The prickling quality is near-unique to one muscle",
"type": "choice",
"answers": [
{
"id": "prickling",
"label": "PRICKLING or needle-like, like fine needles in the palm",
"sublabel": "Prickling / needle-like",
"lr": {
"flexor_carpi_radialis": 0.4,
"flexor_carpi_ulnaris": 0.4,
"palmaris_longus": 7.5,
"pronator_teres": 0.4,
"opponens_pollicis": 0.6,
"pectoralis_major": 0.4,
"pectoralis_minor": 0.4,
"latissimus_dorsi": 0.4,
"serratus_anterior": 0.4
}
},
{
"id": "deep_ache_local",
"label": "A DEEP ACHE in the wrist or forearm itself",
"sublabel": "Deep local ache",
"lr": {
"flexor_carpi_radialis": 3.0,
"flexor_carpi_ulnaris": 3.0,
"palmaris_longus": 0.5,
"pronator_teres": 3.0,
"opponens_pollicis": 1.5,
"pectoralis_major": 0.6,
"pectoralis_minor": 0.6,
"latissimus_dorsi": 0.7,
"serratus_anterior": 0.6
}
},
{
"id": "referred_distance",
"label": "A spillover from an ache that really lives in the chest, back, or upper arm",
"sublabel": "Referred from a distance",
"lr": {
"flexor_carpi_radialis": 0.5,
"flexor_carpi_ulnaris": 0.5,
"palmaris_longus": 0.5,
"pronator_teres": 0.5,
"opponens_pollicis": 0.6,
"pectoralis_major": 3.5,
"pectoralis_minor": 3.5,
"latissimus_dorsi": 3.5,
"serratus_anterior": 3.5
}
}
]
},
{
"id": "q_provocation",
"text": "Which activity most reliably brings on the pain?",
"sublabel": "Choose the single strongest aggravator",
"type": "choice",
"answers": [
{
"id": "resisted_wrist_flexion",
"label": "Bending the wrist forward against resistance, or forceful gripping",
"sublabel": "Resisted wrist flexion / grip",
"lr": {
"flexor_carpi_radialis": 5.0,
"flexor_carpi_ulnaris": 5.0,
"palmaris_longus": 1.0,
"pronator_teres": 1.0,
"opponens_pollicis": 0.6,
"pectoralis_major": 0.5,
"pectoralis_minor": 0.5,
"latissimus_dorsi": 0.6,
"serratus_anterior": 0.6
}
},
{
"id": "tool_in_palm",
"label": "Pressing a tool handle (or cane/racquet butt) into the cupped palm",
"sublabel": "Tool pressed in palm",
"lr": {
"flexor_carpi_radialis": 0.8,
"flexor_carpi_ulnaris": 0.8,
"palmaris_longus": 7.0,
"pronator_teres": 0.6,
"opponens_pollicis": 0.8,
"pectoralis_major": 0.5,
"pectoralis_minor": 0.5,
"latissimus_dorsi": 0.5,
"serratus_anterior": 0.5
}
},
{
"id": "resisted_pronation",
"label": "Turning the palm down against resistance (twisting motions)",
"sublabel": "Resisted pronation",
"lr": {
"flexor_carpi_radialis": 1.0,
"flexor_carpi_ulnaris": 0.8,
"palmaris_longus": 0.7,
"pronator_teres": 6.0,
"opponens_pollicis": 0.6,
"pectoralis_major": 0.5,
"pectoralis_minor": 0.5,
"latissimus_dorsi": 0.6,
"serratus_anterior": 0.6
}
},
{
"id": "pinch_opposition",
"label": "Sustained pinch or thumb opposition (bringing thumb to little finger)",
"sublabel": "Pinch / opposition",
"lr": {
"flexor_carpi_radialis": 0.8,
"flexor_carpi_ulnaris": 0.7,
"palmaris_longus": 0.9,
"pronator_teres": 0.6,
"opponens_pollicis": 6.0,
"pectoralis_major": 0.5,
"pectoralis_minor": 0.5,
"latissimus_dorsi": 0.5,
"serratus_anterior": 0.5
}
},
{
"id": "posture_reach",
"label": "Round-shouldered posture, reaching forward, or loaded reaching/pulling",
"sublabel": "Posture / reaching load",
"lr": {
"flexor_carpi_radialis": 0.6,
"flexor_carpi_ulnaris": 0.6,
"palmaris_longus": 0.6,
"pronator_teres": 0.6,
"opponens_pollicis": 0.7,
"pectoralis_major": 4.0,
"pectoralis_minor": 4.0,
"latissimus_dorsi": 4.0,
"serratus_anterior": 1.5
}
},
{
"id": "running_cough",
"label": "Hard running, coughing, or wrenching the body around (turning a heavy steering wheel)",
"sublabel": "Running / cough / torsion",
"lr": {
"flexor_carpi_radialis": 0.5,
"flexor_carpi_ulnaris": 0.5,
"palmaris_longus": 0.5,
"pronator_teres": 0.5,
"opponens_pollicis": 0.6,
"pectoralis_major": 0.9,
"pectoralis_minor": 1.0,
"latissimus_dorsi": 0.9,
"serratus_anterior": 7.0
}
}
]
},
{
"id": "q_median_tingle",
"text": "Is there tingling or numbness of the THUMB, INDEX, and MIDDLE fingers (the palm side)?",
"sublabel": "Median-territory symptoms - the pronator teres can compress the median nerve (pronator syndrome), mimicking carpal tunnel; the local wrist flexors do not",
"type": "binary",
"answers": [
{
"id": "yes",
"label": "Yes - tingling/numbness of the thumb, index, and middle fingers",
"lr": {
"flexor_carpi_radialis": 0.8,
"flexor_carpi_ulnaris": 0.7,
"palmaris_longus": 0.9,
"pronator_teres": 4.0,
"opponens_pollicis": 1.2,
"pectoralis_major": 0.8,
"pectoralis_minor": 1.0,
"latissimus_dorsi": 0.7,
"serratus_anterior": 0.7
}
},
{
"id": "no",
"label": "No - aching/prickling pain only, no median tingling",
"lr": {
"flexor_carpi_radialis": 1.1,
"flexor_carpi_ulnaris": 1.1,
"palmaris_longus": 1.05,
"pronator_teres": 0.5,
"opponens_pollicis": 1.0,
"pectoralis_major": 1.0,
"pectoralis_minor": 1.0,
"latissimus_dorsi": 1.05,
"serratus_anterior": 1.05
}
}
]
},
{
"id": "q_respiratory",
"text": "Is there a 'stitch in the side', breathlessness, or pain clearly worse on taking a deep breath?",
"sublabel": "Serratus anterior signature - a respiratory symptom complex distinguishes it from the other distant referrers",
"type": "binary",
"answers": [
{
"id": "yes",
"label": "Yes - a stitch in the side, breathlessness, or pain on deep breathing",
"lr": {
"flexor_carpi_radialis": 0.6,
"flexor_carpi_ulnaris": 0.6,
"palmaris_longus": 0.6,
"pronator_teres": 0.6,
"opponens_pollicis": 0.6,
"pectoralis_major": 0.9,
"pectoralis_minor": 1.0,
"latissimus_dorsi": 0.8,
"serratus_anterior": 7.0
}
},
{
"id": "no",
"label": "No - breathing does not affect it",
"lr": {
"flexor_carpi_radialis": 1.05,
"flexor_carpi_ulnaris": 1.05,
"palmaris_longus": 1.05,
"pronator_teres": 1.05,
"opponens_pollicis": 1.05,
"pectoralis_major": 1.0,
"pectoralis_minor": 1.0,
"latissimus_dorsi": 1.05,
"serratus_anterior": 0.3
}
}
]
},
{
"id": "q_chest",
"text": "Is there anterior chest pain, or a pressure/constriction in the chest (especially left-sided) with the arm pain?",
"sublabel": "Pectoral source screen. IMPORTANT: a left-sided chest-and-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 arm pain",
"lr": {
"flexor_carpi_radialis": 0.5,
"flexor_carpi_ulnaris": 0.5,
"palmaris_longus": 0.5,
"pronator_teres": 0.5,
"opponens_pollicis": 0.5,
"pectoralis_major": 6.0,
"pectoralis_minor": 4.5,
"latissimus_dorsi": 0.7,
"serratus_anterior": 1.2
}
},
{
"id": "no",
"label": "No - no chest pain or constriction",
"lr": {
"flexor_carpi_radialis": 1.1,
"flexor_carpi_ulnaris": 1.1,
"palmaris_longus": 1.1,
"pronator_teres": 1.1,
"opponens_pollicis": 1.05,
"pectoralis_major": 0.3,
"pectoralis_minor": 0.4,
"latissimus_dorsi": 1.1,
"serratus_anterior": 1.0
}
}
]
},
{
"id": "q_palpation",
"text": "Where does firm palpation most precisely reproduce the familiar wrist/palm pain?",
"sublabel": "The reproducing tender point - the most specific localiser",
"type": "choice",
"answers": [
{
"id": "fcr_belly",
"label": "In the radial volar forearm (flexor carpi radialis, lateral to the central tendon)",
"sublabel": "Flexor carpi radialis location",
"lr": {
"flexor_carpi_radialis": 7.0,
"flexor_carpi_ulnaris": 0.5,
"palmaris_longus": 0.5,
"pronator_teres": 0.8,
"opponens_pollicis": 0.4,
"pectoralis_major": 0.4,
"pectoralis_minor": 0.4,
"latissimus_dorsi": 0.4,
"serratus_anterior": 0.4
}
},
{
"id": "fcu_belly",
"label": "In the ulnar volar forearm toward the pisiform (flexor carpi ulnaris)",
"sublabel": "Flexor carpi ulnaris location",
"lr": {
"flexor_carpi_radialis": 0.5,
"flexor_carpi_ulnaris": 7.0,
"palmaris_longus": 0.5,
"pronator_teres": 0.5,
"opponens_pollicis": 0.4,
"pectoralis_major": 0.4,
"pectoralis_minor": 0.4,
"latissimus_dorsi": 0.5,
"serratus_anterior": 0.4
}
},
{
"id": "palmaris_belly",
"label": "In the mid-volar forearm over the palmaris longus (the central tendon that pops up on cupping)",
"sublabel": "Palmaris longus location",
"lr": {
"flexor_carpi_radialis": 0.6,
"flexor_carpi_ulnaris": 0.6,
"palmaris_longus": 7.0,
"pronator_teres": 0.6,
"opponens_pollicis": 0.4,
"pectoralis_major": 0.4,
"pectoralis_minor": 0.4,
"latissimus_dorsi": 0.4,
"serratus_anterior": 0.4
}
},
{
"id": "pronator_belly",
"label": "In the proximal volar forearm just below the elbow crease (pronator teres)",
"sublabel": "Pronator teres location",
"lr": {
"flexor_carpi_radialis": 0.7,
"flexor_carpi_ulnaris": 0.6,
"palmaris_longus": 0.6,
"pronator_teres": 7.0,
"opponens_pollicis": 0.4,
"pectoralis_major": 0.4,
"pectoralis_minor": 0.4,
"latissimus_dorsi": 0.4,
"serratus_anterior": 0.4
}
},
{
"id": "thenar_eminence",
"label": "Across the thenar mound at the base of the thumb (opponens pollicis)",
"sublabel": "Opponens pollicis location",
"lr": {
"flexor_carpi_radialis": 0.5,
"flexor_carpi_ulnaris": 0.4,
"palmaris_longus": 0.6,
"pronator_teres": 0.4,
"opponens_pollicis": 7.0,
"pectoralis_major": 0.4,
"pectoralis_minor": 0.4,
"latissimus_dorsi": 0.4,
"serratus_anterior": 0.4
}
},
{
"id": "anterior_chest_pincer",
"label": "In the chest muscle at the front of the armpit fold (pectoralis major)",
"sublabel": "Pectoralis major location",
"lr": {
"flexor_carpi_radialis": 0.4,
"flexor_carpi_ulnaris": 0.4,
"palmaris_longus": 0.4,
"pronator_teres": 0.4,
"opponens_pollicis": 0.4,
"pectoralis_major": 7.0,
"pectoralis_minor": 1.5,
"latissimus_dorsi": 0.5,
"serratus_anterior": 0.5
}
},
{
"id": "deep_under_pec",
"label": "Deep under the chest muscle toward the coracoid (pectoralis minor)",
"sublabel": "Pectoralis minor location",
"lr": {
"flexor_carpi_radialis": 0.4,
"flexor_carpi_ulnaris": 0.4,
"palmaris_longus": 0.4,
"pronator_teres": 0.4,
"opponens_pollicis": 0.4,
"pectoralis_major": 1.5,
"pectoralis_minor": 7.0,
"latissimus_dorsi": 0.5,
"serratus_anterior": 0.5
}
},
{
"id": "posterior_axillary_fold",
"label": "In the back wall of the armpit / side of the back (latissimus dorsi)",
"sublabel": "Latissimus dorsi location",
"lr": {
"flexor_carpi_radialis": 0.4,
"flexor_carpi_ulnaris": 0.5,
"palmaris_longus": 0.4,
"pronator_teres": 0.4,
"opponens_pollicis": 0.4,
"pectoralis_major": 0.5,
"pectoralis_minor": 0.5,
"latissimus_dorsi": 7.0,
"serratus_anterior": 0.8
}
},
{
"id": "midaxillary_ribs",
"label": "On the side of the chest over the ribs, in line with the armpit (serratus anterior)",
"sublabel": "Serratus anterior location",
"lr": {
"flexor_carpi_radialis": 0.4,
"flexor_carpi_ulnaris": 0.4,
"palmaris_longus": 0.4,
"pronator_teres": 0.4,
"opponens_pollicis": 0.4,
"pectoralis_major": 0.5,
"pectoralis_minor": 0.5,
"latissimus_dorsi": 0.8,
"serratus_anterior": 7.0
}
}
]
}
],
"pairwise": [
{
"id": "pw_fcr_fcu",
"pair": [
"flexor_carpi_radialis",
"flexor_carpi_ulnaris"
],
"text": "Tiebreaker - Flexor Carpi Radialis vs Flexor Carpi Ulnaris",
"question": "Is the volar wrist ache on the RADIAL (thumb) side, or on the ULNAR (little-finger) side around the pisiform?",
"sublabel": "The two volar wrist flexors - separate by side",
"answers": [
{
"id": "fcr",
"label": "Radial (thumb) side - flexor carpi radialis",
"lr": {
"flexor_carpi_radialis": 5.5,
"flexor_carpi_ulnaris": 0.4
}
},
{
"id": "fcu",
"label": "Ulnar (little-finger) side, around the pisiform - flexor carpi ulnaris",
"lr": {
"flexor_carpi_radialis": 0.4,
"flexor_carpi_ulnaris": 5.5
}
}
]
},
{
"id": "pw_fcr_pt",
"pair": [
"flexor_carpi_radialis",
"pronator_teres"
],
"text": "Tiebreaker - Flexor Carpi Radialis vs Pronator Teres",
"question": "Is the pain reproduced by resisted WRIST FLEXION at the radial wrist (flexor carpi radialis), or by resisted PRONATION with aching up the volar forearm and possible median tingling (pronator teres)?",
"sublabel": "Both reach the radial volar wrist; pronator teres adds a median-nerve component",
"answers": [
{
"id": "fcr",
"label": "Resisted wrist flexion, radial wrist - flexor carpi radialis",
"lr": {
"flexor_carpi_radialis": 5.5,
"pronator_teres": 0.4
}
},
{
"id": "pt",
"label": "Resisted pronation, forearm aching, median tingling - pronator teres",
"lr": {
"flexor_carpi_radialis": 0.4,
"pronator_teres": 5.5
}
}
]
},
{
"id": "pw_pl_fcr",
"pair": [
"palmaris_longus",
"flexor_carpi_radialis"
],
"text": "Tiebreaker - Palmaris Longus vs Flexor Carpi Radialis",
"question": "Is the pain a PRICKLING, needle-like sensation in the central palm (palmaris longus), or a DEEP ACHE at the radial volar wrist (flexor carpi radialis)?",
"sublabel": "Quality and location separate these adjacent volar muscles",
"answers": [
{
"id": "pl",
"label": "Prickling, needle-like, central palm - palmaris longus",
"lr": {
"palmaris_longus": 6.0,
"flexor_carpi_radialis": 0.4
}
},
{
"id": "fcr",
"label": "Deep ache, radial volar wrist - flexor carpi radialis",
"lr": {
"palmaris_longus": 0.4,
"flexor_carpi_radialis": 6.0
}
}
]
},
{
"id": "pw_fcu_opp",
"pair": [
"flexor_carpi_ulnaris",
"opponens_pollicis"
],
"text": "Tiebreaker - Flexor Carpi Ulnaris vs Opponens Pollicis",
"question": "Is the volar-wrist pain on the ULNAR side near the pisiform (flexor carpi ulnaris), or at a discrete RADIAL palmar-wrist spot with painful thumb opposition (opponens pollicis)?",
"sublabel": "Opposite sides of the volar wrist",
"answers": [
{
"id": "fcu",
"label": "Ulnar side near the pisiform - flexor carpi ulnaris",
"lr": {
"flexor_carpi_ulnaris": 5.5,
"opponens_pollicis": 0.4
}
},
{
"id": "opp",
"label": "Radial palmar-wrist spot, weak/painful opposition - opponens pollicis",
"lr": {
"flexor_carpi_ulnaris": 0.4,
"opponens_pollicis": 5.5
}
}
]
},
{
"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 (pectoralis major), or deeper toward the coracoid at the front of the shoulder with ulnar-finger numbness (pectoralis minor)?",
"sublabel": "Both refer down the ulnar arm to the wrist and coexist",
"answers": [
{
"id": "pmaj",
"label": "Superficial chest muscle / axillary fold - pectoralis major",
"lr": {
"pectoralis_major": 5.0,
"pectoralis_minor": 0.5
}
},
{
"id": "pmin",
"label": "Deep toward the coracoid, ulnar-finger numbness - pectoralis minor",
"lr": {
"pectoralis_major": 0.5,
"pectoralis_minor": 5.0
}
}
]
},
{
"id": "pw_latd_sant",
"pair": [
"latissimus_dorsi",
"serratus_anterior"
],
"text": "Tiebreaker - Latissimus Dorsi vs Serratus Anterior",
"question": "Is the source a constant MID-BACK / posterior axillary ache (latissimus), or a SIDE-OF-CHEST pain with a respiratory component - stitch in the side, breathlessness (serratus anterior)?",
"sublabel": "Two trunk referrers reaching the palm and ulnar wrist",
"answers": [
{
"id": "latd",
"label": "Constant mid-back / posterior axillary fold - latissimus dorsi",
"lr": {
"latissimus_dorsi": 5.5,
"serratus_anterior": 0.4
}
},
{
"id": "sant",
"label": "Side of chest with stitch/breathlessness - serratus anterior",
"lr": {
"latissimus_dorsi": 0.4,
"serratus_anterior": 5.5
}
}
]
}
],
"treatment_dag": {
"edges": [
{
"from": "palmaris_longus",
"to": "flexor_carpi_radialis",
"type": "functional_unit",
"label": "The palmaris longus lies between flexor carpi radialis and ulnaris; treat the volar wrist flexors as a group after releasing the palmaris longus"
},
{
"from": "flexor_carpi_radialis",
"to": "flexor_carpi_ulnaris",
"type": "functional_unit",
"label": "The two volar wrist flexors share the gripping/wrist-flexion load; examine and treat together"
},
{
"from": "pronator_teres",
"to": "flexor_carpi_radialis",
"type": "functional_unit",
"label": "Pronator teres and the radial wrist flexor are adjacent volar-forearm muscles; examine together, and check the median nerve for a pronator component"
},
{
"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": "serratus_anterior",
"to": "latissimus_dorsi",
"type": "functional_unit",
"label": "Serratus anterior and latissimus dorsi are functional antagonists for scapular movement; examine both"
},
{
"from": "latissimus_dorsi",
"to": "flexor_carpi_radialis",
"type": "secondary_load",
"label": "Trunk and shoulder-girdle referrers (pectorals, latissimus, serratus) can refer to the volar wrist and palm; address them when local wrist treatment gives incomplete relief"
},
{
"from": "opponens_pollicis",
"to": "flexor_carpi_radialis",
"type": "secondary_load",
"label": "Opponens pollicis contributes a radial palmar-wrist spot; treat after the primary volar wrist flexors and alongside the thenar group"
}
],
"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": "Acute coronary syndrome / cardiac ischaemia",
"question": "Left-sided or central chest pressure, tightness, or constriction radiating to the ulnar arm and wrist, especially with exertion, breathlessness, sweating, nausea, or a cardiac history? The left pectoralis major (and serratus anterior) trigger-point patterns mimic angina - and relief of the pain by trigger-point treatment does NOT exclude cardiac disease. Establish cardiac status independently and urgently when this pattern is present.",
"source": "T&S Ch.42/Ch.46 (pectoralis major / serratus anterior cardiac mimicry)"
},
{
"id": "rf-e2",
"label": "Flexor (suppurative) tenosynovitis / deep palmar-space infection",
"question": "Surgical emergency. A hot, tensely swollen finger or palm with the four Kanavel signs (fusiform digital swelling, finger held semi-flexed, tenderness along the flexor sheath into the palm, severe pain on PASSIVE EXTENSION), or a hot fluctuant palm after a puncture or bite? Needs urgent hand-surgery referral, IV antibiotics, and drainage.",
"source": "Standard hand-infection emergency criteria (Kanavel); Brukner & Khan Ch.19"
},
{
"id": "rf-e3",
"label": "Acute median or ulnar nerve compromise / acute carpal tunnel",
"question": "Rapidly progressive numbness and weakness in the median (thumb/index/middle) or ulnar (ring/little) distribution after a wrist fracture, dislocation (e.g. anterior lunate dislocation), crush, or tense haematoma, with severe or constant pain? Acute compartment or acute carpal-tunnel compression needs emergent decompression to avoid permanent deficit.",
"source": "Brukner & Khan Ch.19 (lunate dislocation / median nerve)"
},
{
"id": "rf-e4",
"label": "Lunate / perilunate dislocation (carpal dislocation)",
"question": "High-energy wrist trauma or a fall on the outstretched hand with marked swelling, deformity, severe pain, and often median-nerve paraesthesia (radial three-and-a-half digits)? These are the disastrous-if-missed end-stage of severe ligament disruption. The lateral x-ray is key: the 'empty/spilled teacup' sign (capitate no longer seated in the lunate concavity) signals a perilunate dislocation, while a volarly tilted lunate not articulating with the capitate signals a lunate dislocation; on the AP, the 'piece-of-pie/pizza' sign (triangular lunate) and disrupted Gilula's arcs are the clues, with a 'signet-ring' scaphoid indicating scapholunate flexion. Needs emergent reduction and hand-surgery referral.",
"source": "EM Cases Ep.189 (Sayal, Distefano, Helman 2023); Brukner & Khan Ch.19"
}
],
"urgent": [
{
"id": "rf-u1",
"label": "Hook-of-hamate fracture",
"question": "Ulnar-sided volar wrist/palm pain and tenderness over the hypothenar eminence (about 1-2 cm distal and radial to the pisiform) after a fall or a 'club/bat/racquet striking the ground' impact, with reduced grip strength and sometimes ulnar-nerve symptoms in the little finger? Routine radiographs and even the carpal-tunnel view are insensitive - CT or MRI is needed. Many present late as a non-union/stress fracture; missed fractures cause ulnar neuropathy and flexor-tendon rupture.",
"source": "Brukner & Khan Ch.19"
},
{
"id": "rf-u2",
"label": "Scaphoid fracture / scapholunate (volar carpal) instability",
"question": "Wrist pain after a fall on the outstretched hand with snuffbox or volar scaphoid-tubercle tenderness, or recurrent wrist swelling and clicking suggesting carpal instability? A scaphoid fracture is the most commonly missed (and most litigated) fracture and may be invisible on initial films - immobilise and re-image, or obtain MRI. Scapholunate dissociation can also be radiographically silent early.",
"source": "Brukner & Khan Ch.19"
},
{
"id": "rf-u3",
"label": "Ulnar nerve compression at Guyon's canal (with motor loss)",
"question": "Ulnar volar wrist/palm pain with paraesthesia of the little and ulnar ring finger and WEAKNESS or wasting of the hand intrinsics, in a cyclist (handlebar palsy), karate player, or baseball catcher, or after a hook-of-hamate fracture? Progressive motor loss needs electrodiagnostic study and decompression - and a hamate fracture or ganglion must be excluded as the cause.",
"source": "Brukner & Khan Ch.19; Shehab & Mirabelli 2013"
},
{
"id": "rf-u4",
"label": "Carpal tunnel syndrome with motor signs, or pronator syndrome",
"question": "Burning volar wrist pain with median-territory numbness (thumb, index, middle, radial ring finger), nocturnal paraesthesia, positive Phalen/Tinel, and thenar weakness or wasting? Or forearm-predominant median symptoms with pain on resisted pronation (pronator syndrome) rather than nocturnal wrist symptoms? Progressive motor involvement needs nerve conduction studies and decompression; exclude diabetes as a risk factor.",
"source": "Brukner & Khan Ch.19; Shehab & Mirabelli 2013; Hand and Finger Flexors (Ch.38)"
},
{
"id": "rf-u5",
"label": "Distal radioulnar joint (DRUJ) injury, including Galeazzi fracture",
"question": "The 'forgotten joint of the wrist'. Pain on resisted PRONATION and SUPINATION (not just flexion/extension), with point tenderness over the DRUJ (between the distal radius and ulnar styloid) and a positive shuck/ballottement test (excess movement of the ulnar head versus the other side) or piano-key sign? Mechanism is forced pronation/supination (power tools, a fall while carrying a load, gripping a steering wheel in a crash) as well as any fall on the outstretched hand. Often OCCULT on x-ray - look for >2 mm DRUJ widening on the PA and loss of radius-ulna overlap on the lateral. A Galeazzi pattern (distal-third radius fracture with DRUJ dislocation) needs ORIF. Splint in an ABOVE-ELBOW cast with the forearm SUPINATED (a short below-elbow splint is the classic pitfall); a missed DRUJ injury causes chronic supination deficit and pain.",
"source": "EM Cases Ep.189 (Sayal, Distefano, Helman 2023); Hemmati et al. CFP 2024"
},
{
"id": "rf-u6",
"label": "Volar distal radius fracture (Smith's / volar Barton's)",
"question": "Wrist injury from a force to the BACK of the hand (rather than a classic fall on the palm), with a reverse dinner-fork deformity? Volar distal radius fractures - Smith's, and especially the volar (reverse) Barton's, which carries an intra-articular volar-lip fragment with radiocarpal subluxation - are more UNSTABLE than dorsal (Colles) injuries, need early orthopaedic involvement and an above-elbow splint, and the volar Barton's usually needs ORIF. Scrutinise the lateral view (forearm horizontal, thumb down). Caution: do NOT mould a volar fracture as you would a dorsal one - it risks compromising the median nerve.",
"source": "EM Cases Ep.189 (Sayal, Distefano, Helman 2023)"
}
],
"broad_differential": [
{
"id": "bd-1",
"condition": "Carpal tunnel syndrome (median neuropathy at the wrist)",
"confidence": "common",
"mimics": "Volar wrist and palmar pain with median paraesthesia - overlaps the pronator teres, palmaris longus, and flexor referral directly",
"distinguishing_feature": "Burning volar wrist pain with numbness/paraesthesia in the median distribution (thumb, index, middle, radial ring finger), characteristically NOCTURNAL, that can radiate up the forearm; positive Tinel's at the carpal tunnel and Phalen's (>=60 s wrist flexion). The median nerve passes through the carpal tunnel with the flexor digitorum profundus, superficialis, and flexor pollicis longus tendons. Late thenar wasting. Trigger-point referral (palmaris prickling, flexor aching) is reproduced by muscle palpation, lacks nocturnal median paraesthesia, and has a negative Phalen's - though a pronator-teres trigger point can compress the median nerve more proximally (pronator syndrome) and an anomalous palmaris longus can itself entrap it at the wrist.",
"action": "Phalen/Tinel, median sensory testing, thenar assessment; nerve conduction studies confirm and grade it (and predict surgical response); exclude diabetes. Night splinting, activity modification, corticosteroid injection; decompression (open or endoscopic, equivalent) for motor loss. Treat coexisting pronator teres and forearm-flexor trigger points.",
"source": "Brukner & Khan Ch.19; Shehab & Mirabelli 2013; Hand and Finger Flexors (Ch.38)"
},
{
"id": "bd-2",
"condition": "Ulnar nerve compression at Guyon's canal (ulnar tunnel syndrome)",
"confidence": "uncommon",
"mimics": "Ulnar volar wrist and palmar pain with little-finger symptoms - overlaps the flexor carpi ulnaris and the ulnar trunk referrers",
"distinguishing_feature": "Pain and paraesthesia of the little and ulnar ring finger with the ulnar nerve and artery lying between the pisiform and the hook of hamate; weakness develops later. Classically in cyclists (handlebar palsy - deep motor branch), karate players, and baseball catchers from repeated hypothenar trauma. The DORSAL ulnar hand is spared (its branch leaves proximal to the canal), localising the lesion to the wrist. Trigger-point referral produces no fixed deficit. A hook-of-hamate fracture, ganglion, or ulnar artery lesion is the usual structural cause.",
"action": "Define motor vs sensory pattern; radiographs/CT for a hamate fracture, MRI/ultrasound for a ganglion or ulnar artery pathology. Splinting and grip/handlebar modification for mild cases; surgical exploration of Guyon's canal for masses or motor loss. Treat coexisting flexor carpi ulnaris and shoulder-girdle trigger points.",
"source": "Brukner & Khan Ch.19; Shehab & Mirabelli 2013"
},
{
"id": "bd-3",
"condition": "Hook-of-hamate fracture / ulnar artery (hypothenar hammer) lesion",
"confidence": "uncommon",
"mimics": "Ulnar volar wrist/palm pain with reduced grip - overlaps the flexor carpi ulnaris zone",
"distinguishing_feature": "Hypothenar tenderness over the hook of the hamate (1-2 cm distal and radial to the pisiform) and reduced grip strength after a fall or a golf-club/bat/racquet striking the ground (the handle driven against the hook), often with ulnar-nerve symptoms. Plain films and even the carpal-tunnel view are insensitive - CT or MRI confirms it, and many present late as a stress fracture/non-union. Repetitive hypothenar impact can also thrombose the ulnar artery (hypothenar hammer syndrome) with ischaemic ulnar-finger symptoms. Trigger-point pain has no bony tenderness or vascular change.",
"action": "Carpal-tunnel-view radiograph and CT/MRI for the hook; vascular studies if hypothenar hammer syndrome is suspected. Excision of the fractured hook (current practice) for non-union; vascular management for arterial occlusion.",
"source": "Brukner & Khan Ch.19"
},
{
"id": "bd-4",
"condition": "Flexor carpi radialis / flexor carpi ulnaris tendinopathy and pisotriquetral degeneration",
"confidence": "common",
"mimics": "Localised volar wrist pain on the radial or ulnar side - overlaps the FCR and FCU trigger-point referral",
"distinguishing_feature": "Flexor carpi radialis tendinopathy gives tenderness along the tendon toward the trapezial tuberosity at the radial volar wrist, worse with resisted wrist flexion; flexor carpi ulnaris tendinopathy and pisotriquetral degenerative joint disease give ulnar volar-wrist tenderness localised to and around the pisiform, worse with resisted flexion and direct pisiform pressure. Trigger-point pain is reproduced by muscle-belly palpation in the forearm rather than localised to the tendon insertion or the pisotriquetral joint, though they commonly coexist.",
"action": "Tendon/insertion palpation, resisted-flexion testing, pisiform compression; ultrasound for tendinopathy and radiographs for pisotriquetral arthrosis. Relative rest, splinting, eccentric loading, corticosteroid injection; treat coexisting forearm-flexor trigger points.",
"source": "Brukner & Khan Ch.19; Shehab & Mirabelli 2013"
},
{
"id": "bd-5",
"condition": "Dupuytren's disease (palmar fascial contracture)",
"confidence": "uncommon",
"mimics": "A palmar nodule and palmar tenderness - the palmaris longus trigger points commonly coexist and account for much of the tenderness",
"distinguishing_feature": "A firm, initially NONTENDER nodule and longitudinal cord in the palmar aponeurosis (usually beginning on the ulnar side of the palm, short of the distal palmar crease), progressing to a fixed flexion contracture of the metacarpophalangeal and proximal interphalangeal joints that the patient cannot passively straighten. The fascial cord is the lesion; the diffuse palmar tenderness is largely referred from coexisting palmaris longus trigger points (which have the characteristic prickling quality), not from the cord itself.",
"action": "Clinical diagnosis; track the contracture with the tabletop test. Observation while mild; needle aponeurotomy, collagenase, or fasciectomy when contracture limits function. Treat coexisting palmaris longus trigger points to address the palmar tenderness - which may resolve even though the cord persists.",
"source": "Palmaris Longus (Ch.37); general hand-surgery knowledge"
},
{
"id": "bd-6",
"condition": "Volar wrist ganglion",
"confidence": "uncommon",
"mimics": "A volar wrist swelling with aching and reduced movement - overlaps the radial volar-wrist sources",
"distinguishing_feature": "A synovial cyst communicating with a joint, most often at the radial volar wrist near the flexor carpi radialis (or scapholunate space), presenting as intermittent wrist pain and reduced movement; the swelling may be visible only intermittently or not at all, so it should not be relied on for the diagnosis. Transilluminates; confirmed on ultrasound or T2-weighted MRI. Trigger-point pain has no cystic swelling.",
"action": "Ultrasound or MRI to confirm. Reassure (benign); aspiration/corticosteroid for symptomatic cysts, excision if persistent (recurs without complete removal). Distinguish the radial volar ganglion from a flexor carpi radialis trigger point and from de Quervain's.",
"source": "Brukner & Khan Ch.19"
},
{
"id": "bd-7",
"condition": "Scaphoid fracture and scapholunate (carpal) instability",
"confidence": "uncommon",
"mimics": "Radial-sided wrist pain after a fall - overlaps the radial volar-wrist sources and the opponens radial palmar-wrist spot",
"distinguishing_feature": "Snuffbox and volar scaphoid-tubercle tenderness and pain on axial thumb loading after a fall on the outstretched hand; the scaphoid fracture is the most commonly missed (and litigated) carpal fracture and may be invisible on initial radiographs. Recurrent wrist swelling and clicking suggest carpal instability; scapholunate dissociation can be radiographically silent early (a clenched-fist view or MRI may be needed). Trigger-point pain follows no fall and has no bony or scapholunate tenderness.",
"action": "Scaphoid-view radiographs; if negative but clinically suspicious, immobilise and re-image, or obtain MRI/bone scan. Watson's test and clenched-fist views for scapholunate instability. Refer fractures and instability; maintain a high index of suspicion.",
"source": "Brukner & Khan Ch.19"
},
{
"id": "bd-8",
"condition": "Thoracic outlet syndrome / C8-T1 radiculopathy and cardiac referred pain",
"confidence": "uncommon",
"mimics": "Ulnar volar wrist/palm pain referred from the neck, shoulder girdle, or chest - overlaps the pectoral, latissimus, and serratus referrers",
"distinguishing_feature": "Thoracic outlet syndrome gives lower-trunk (C8-T1) symptoms with positional/provocative findings and sometimes vascular signs; C8-T1 radiculopathy adds dermatomal change INCLUDING THE MEDIAL FOREARM (above the wrist) with reflex/motor loss and positive Spurling's. A taut pectoralis minor can compress the medial cord (myofascial pseudo-TOS). And a left-sided chest-and-ulnar-arm pattern can be cardiac - relief by trigger-point treatment does not exclude it. Trigger-point referral produces no objective deficit, spares the medial forearm, and is reproduced by muscle palpation.",
"action": "Provocative TOS tests, full neurological/upper-quarter exam and Spurling's; chest/cervical imaging and electrodiagnostics where indicated; cardiac assessment for any left chest-and-arm pattern. Treat coexisting pectoral, latissimus, serratus, and scalene trigger points concurrently.",
"source": "Differential:ThoracicOutletSyndrome; T&S Ch.42/Ch.46"
},
{
"id": "bd-9",
"condition": "Triangular fibrocartilage complex (TFCC) injury",
"confidence": "uncommon",
"mimics": "Ulnar-sided volar wrist pain, often after a prior wrist injury - overlaps the flexor carpi ulnaris zone and the ulnar trunk referrers",
"distinguishing_feature": "The 'meniscus of the wrist' and primary stabiliser of the distal radioulnar joint. Ulnar-sided pain aggravated by pronation/supination and gripping, often dating to a fall on an extended, pronated, ulnarly deviated wrist recalled as a 'sprain', or following a distal radius fracture. A positive fovea sign (tenderness in the soft-tissue depression between the ulnar styloid and the flexor carpi ulnaris tendon) and a positive TFCC compression test (axial load with the wrist ulnarly deviated reproduces the pain) point to it; assess DRUJ stability with the ballottement test. Trigger-point pain is reproduced by forearm-muscle palpation and lacks the focal foveal tenderness and the pronation/supination aggravation.",
"action": "Fovea sign, TFCC compression and DRUJ ballottement tests; radiographs for ulnar variance (a long ulna predisposes), with MRI or MR arthrography where x-rays are normal and suspicion persists (ultrasound and plain MRI are less reliable on the ulnar side). Splinting (volar wrist or above-elbow if pronosupination must be limited); refer for arthroscopy and repair, or ulnar-shortening osteotomy for positive ulnar variance, if unstable or persistent.",
"source": "Hemmati et al. CFP 2024; EM Cases Ep.189 (Sayal, Distefano, Helman 2023)"
}
]
}