DiagnosticTree/Antecubital
{
"model": "bayesian_lr_scoring",
"version": "1.0",
"region": "Antecubital",
"description": "Probabilistic scoring model for antecubital (anterior elbow) pain using Bayesian likelihood ratio updating with Thurstonian pairwise tiebreakers. Muscles drawn from T&S Vol.1 Ch.30 (Biceps Brachii), Ch.31 (Brachialis), Ch.34 (Brachioradialis), Ch.36 (Supinator), Ch.22 (Infraspinatus referred), Ch.20 (Scalenes referred), Ch.29 (Coracobrachialis referred). Brachioradialis and Supinator are bold in the T&S Ch.33 regional overview and carry higher priors (raw 0.15). Brachialis, Biceps Brachii, Infraspinatus, Scalenes, and Coracobrachialis are non-bold in this region and carry lower priors (raw 0.10). All priors normalised to sum to 1.0.",
"thresholds": {
"early_exit_posterior": 0.55,
"early_exit_gap": 0.18,
"pairwise_trigger": 0.22
},
"muscles": {
"brachialis": {
"label": "Brachialis",
"prior": 0.125,
"page": "Muscle:Brachialis",
"key_trp_note": "Brachialis TrPs are almost always found together with biceps brachii TrPs in elbow flexion overload patterns. In the tennis elbow sequence, the supinator is typically the primary TrP activated first, with brachialis and biceps developing secondarily. The brachialis lateral-border TrP can also entrap the sensory branch of the radial nerve, adding dysesthesia on the dorsum of the thumb and web — both components are relieved by brachialis TrP inactivation.",
"subtitle": "Thumb base and dorsal web; antecubital spillover; active thumb hurts, active elbow does not"
},
"biceps": {
"label": "Biceps Brachii",
"prior": 0.125,
"page": "Muscle:Biceps_Brachii",
"key_trp_note": "Infraspinatus TrPs are the most important key TrP source driving satellite biceps TrPs — inactivate infraspinatus first before treating biceps directly. Biceps TrPs drive secondary TrPs in brachialis, supinator, and triceps (early) and anterior deltoid, supraspinatus, upper trapezius, and coracobrachialis (late, chronic). A three-joint muscle: range of motion examination is unreliable unless the biceps is lengthened across all three joints simultaneously (Biceps-extension Test).",
"subtitle": "Anterior shoulder aching; antecubital spillover; can still lie on affected side; cannot reach overhead comfortably"
},
"brachioradialis": {
"label": "Brachioradialis",
"prior": 0.1875,
"page": "Muscle:Brachioradialis",
"key_trp_note": "Brachioradialis TrPs are a primary lateral elbow / tennis-elbow presentation, closely associated with supinator TrPs. Brachioradialis is maximally active during elbow flexion with the forearm in neutral (mid-position between pronation and supination) — the position of greatest pain. Both brachioradialis and supinator must be examined together in any lateral elbow / radial forearm presentation.",
"subtitle": "Lateral elbow to dorsal thumb web; neutral-position elbow flexion aggravates; grip and tool use"
},
"supinator": {
"label": "Supinator",
"prior": 0.1875,
"page": "Muscle:Supinator",
"key_trp_note": "Supinator is the primary TrP in the tennis elbow / radial tunnel pattern — typically activated before brachioradialis, brachialis, and biceps in the elbow flexion overload sequence. Its deep location and the posterior interosseous nerve passing through the arcade of Frohse makes it the main entrapment consideration in lateral elbow pain. Treat supinator TrPs before its satellites (brachioradialis, brachialis, biceps).",
"subtitle": "Lateral epicondyle and dorsal thumb base; pain with resisted supination and gripping; deep to brachioradialis"
},
"infraspinatus": {
"label": "Infraspinatus",
"prior": 0.125,
"page": "Muscle:Infraspinatus",
"key_trp_note": "Infraspinatus TrPs refer pain to the anterior shoulder, and in their full referral pattern extend down the arm, potentially including the antecubital region. Infraspinatus is the most important key TrP source driving satellite biceps TrPs — it must be identified and addressed before biceps will respond durably. The characteristic sleeping posture restriction (cannot lie on either side) and behind-the-back restriction are the strongest clinical differentiators.",
"subtitle": "Deep anterior shoulder + arm referral; CANNOT sleep on either side; behind-the-back reach severely restricted"
},
"scalenes": {
"label": "Scalenes",
"prior": 0.125,
"page": "Muscle:Scalene",
"key_trp_note": "Scalene TrPs refer diffusely down the arm and can produce antecubital area pain as part of a wider brachialgia picture. They are the key TrP source driving pectoralis major/minor, serratus posterior superior, upper trapezius, and triceps long head satellite TrPs. Nocturnal arm aching requiring the arm to hang over the bed side is the most specific symptom. Scalenus minimus (when present) compresses the lower brachial plexus — consider entrapment component and see Differential:ThoracicOutletSyndrome.",
"subtitle": "Diffuse arm aching to antecubital; neck pain; nocturnal arm hanging; upper trapezius tension"
},
"coracobrachialis": {
"label": "Coracobrachialis",
"prior": 0.125,
"page": "Muscle:Coracobrachialis",
"key_trp_note": "Coracobrachialis TrPs are almost always satellites of biceps brachii (short head), anterior deltoid, supraspinatus, and triceps long head key TrPs. They refer pain along the posterior arm skipping the elbow to the dorsal hand — a skip pattern that is highly characteristic. Coracobrachialis is typically the last muscle to be found and treated in a chronic anterior arm pattern, after surrounding muscles have been addressed. Treat all key TrP sources first.",
"subtitle": "Posterior arm and dorsal hand SKIPPING the elbow; residual after surrounding muscles cleared"
}
},
"questions": [
{
"id": "q_pain_location_primary",
"text": "Where in the anterior elbow / antecubital region is the pain most concentrated?",
"sublabel": "Choose the location that best matches where the patient points first",
"type": "choice",
"answers": [
{
"id": "antecubital_fossa",
"label": "In the ANTECUBITAL FOSSA itself — the crease of the elbow, the hollow of the bent arm",
"sublabel": "The centre of the anterior elbow, in the triangular hollow between the two muscle groups",
"lr": {
"brachialis": 6.0,
"biceps": 4.0,
"brachioradialis": 1.5,
"supinator": 1.0,
"infraspinatus": 1.5,
"scalenes": 1.5,
"coracobrachialis": 1.0
}
},
{
"id": "lateral_elbow",
"label": "At the LATERAL EPICONDYLE or just distal to it — outer (thumb-side) bony point of the elbow",
"sublabel": "Tenderness at or just distal to the lateral bony prominence of the elbow",
"lr": {
"brachioradialis": 7.0,
"supinator": 7.0,
"brachialis": 0.5,
"biceps": 0.4,
"infraspinatus": 0.3,
"scalenes": 0.5,
"coracobrachialis": 0.3
}
},
{
"id": "thumb_base_dorsal",
"label": "At the BASE OF THE THUMB or dorsal web of the thumb — pain in the thumb region",
"sublabel": "The dorsal first web space or the CMC joint at the base of the thumb is the most distressing site",
"lr": {
"brachialis": 9.0,
"supinator": 3.0,
"brachioradialis": 4.0,
"biceps": 0.5,
"infraspinatus": 0.4,
"scalenes": 0.5,
"coracobrachialis": 0.3
}
},
{
"id": "anterior_shoulder_arm",
"label": "Anterior SHOULDER spreading into the arm — the front of the shoulder is the dominant complaint",
"sublabel": "Pain is perceived primarily in the anterior shoulder; the antecubital discomfort is secondary",
"lr": {
"biceps": 7.0,
"infraspinatus": 6.0,
"scalenes": 3.0,
"coracobrachialis": 2.0,
"brachialis": 0.5,
"brachioradialis": 0.3,
"supinator": 0.3
}
}
]
},
{
"id": "q_thumb_web_pain",
"text": "Is there pain, deep aching, or sensory change specifically at the BASE OF THE THUMB or dorsal web space?",
"sublabel": "Distinct from radial forearm aching — specifically the dorsal carpometacarpal region or web of thumb",
"type": "binary",
"answers": [
{
"id": "yes",
"label": "Yes — thumb base pain or dorsal web aching, with or without dysesthesia",
"lr": {
"brachialis": 8.0,
"supinator": 2.5,
"brachioradialis": 3.0,
"biceps": 0.5,
"infraspinatus": 0.5,
"scalenes": 0.5,
"coracobrachialis": 0.3
}
},
{
"id": "no",
"label": "No — no thumb base or dorsal web involvement",
"lr": {
"brachialis": 0.25,
"supinator": 0.8,
"brachioradialis": 0.7,
"biceps": 1.3,
"infraspinatus": 1.3,
"scalenes": 1.2,
"coracobrachialis": 1.3
}
}
]
},
{
"id": "q_thumb_elbow_dissociation",
"text": "Does active movement of the THUMB hurt, while active movement of the ELBOW itself does NOT cause pain?",
"sublabel": "The dissociation — thumb use aggravates; active elbow flexion or extension is relatively painless",
"type": "binary",
"answers": [
{
"id": "yes",
"label": "Yes — active thumb use hurts; active elbow motion does not",
"lr": {
"brachialis": 10.0,
"supinator": 1.5,
"brachioradialis": 1.0,
"biceps": 0.4,
"infraspinatus": 0.3,
"scalenes": 0.4,
"coracobrachialis": 0.3
}
},
{
"id": "no",
"label": "No — elbow motion itself is painful, or thumb motion is not differentially worse",
"lr": {
"brachialis": 0.15,
"supinator": 1.0,
"brachioradialis": 1.1,
"biceps": 1.3,
"infraspinatus": 1.2,
"scalenes": 1.2,
"coracobrachialis": 1.2
}
}
]
},
{
"id": "q_supination_aggravation",
"text": "Does RESISTED SUPINATION of the forearm reproduce or markedly worsen the elbow or forearm pain?",
"sublabel": "Test: the examiner resists forearm rotation from pronated to supinated position — does this reproduce pain?",
"type": "choice",
"answers": [
{
"id": "yes_elbow_straight",
"label": "Yes — pain with resisted supination, especially with the ELBOW STRAIGHT (extended)",
"sublabel": "Pain produced by resisted supination when the arm is in extension; diminishes with elbow flexed",
"lr": {
"supinator": 8.0,
"brachioradialis": 2.0,
"biceps": 1.5,
"brachialis": 0.4,
"infraspinatus": 0.4,
"scalenes": 0.5,
"coracobrachialis": 0.4
}
},
{
"id": "yes_elbow_flexed",
"label": "Yes — pain with resisted supination, especially with the ELBOW FLEXED",
"sublabel": "Pain reproduced by resisted supination when elbow is bent; the full biceps-active position",
"lr": {
"biceps": 7.0,
"supinator": 3.0,
"brachioradialis": 1.5,
"brachialis": 0.5,
"infraspinatus": 0.5,
"scalenes": 0.5,
"coracobrachialis": 0.4
}
},
{
"id": "no",
"label": "No — resisted supination does not specifically reproduce the pain",
"lr": {
"brachialis": 2.5,
"brachioradialis": 0.8,
"supinator": 0.2,
"biceps": 0.5,
"infraspinatus": 1.2,
"scalenes": 1.2,
"coracobrachialis": 1.2
}
}
]
},
{
"id": "q_grip_tool_aggravation",
"text": "Is the pain aggravated by GRIPPING, holding a tool, or using a hammer or screwdriver?",
"sublabel": "Sustained grip or rotary tool work specifically triggers or intensifies the arm or elbow pain",
"type": "binary",
"answers": [
{
"id": "yes",
"label": "Yes — gripping and tool use specifically aggravate the pain",
"lr": {
"brachioradialis": 6.0,
"supinator": 5.0,
"brachialis": 2.0,
"biceps": 2.0,
"infraspinatus": 0.7,
"scalenes": 0.7,
"coracobrachialis": 0.5
}
},
{
"id": "no",
"label": "No — grip and tool use are not specific aggravators",
"lr": {
"brachioradialis": 0.3,
"supinator": 0.4,
"brachialis": 0.8,
"biceps": 0.8,
"infraspinatus": 1.2,
"scalenes": 1.2,
"coracobrachialis": 1.2
}
}
]
},
{
"id": "q_flexion_load_pattern",
"text": "Is the pain provoked or worsened by HOLDING THE ELBOW FLEXED UNDER LOAD — carrying a weight with the elbow bent, carrying bags on the forearm, or sustained instrument playing?",
"sublabel": "Activities that sustain elbow flexion against load: carrying groceries, holding tools at elbow height, violin",
"type": "binary",
"answers": [
{
"id": "yes",
"label": "Yes — sustained flexion under load is the primary aggravator",
"lr": {
"brachialis": 7.0,
"biceps": 4.0,
"brachioradialis": 2.0,
"supinator": 1.5,
"infraspinatus": 0.7,
"scalenes": 0.7,
"coracobrachialis": 0.7
}
},
{
"id": "no",
"label": "No — flexion-under-load is not the characteristic aggravator",
"lr": {
"brachialis": 0.3,
"biceps": 0.6,
"brachioradialis": 0.8,
"supinator": 0.9,
"infraspinatus": 1.2,
"scalenes": 1.2,
"coracobrachialis": 1.2
}
}
]
},
{
"id": "q_pronation_insensitivity",
"text": "Is the weakness of elbow flexion EQUALLY PRESENT whether the forearm is SUPINATED or PRONATED?",
"sublabel": "Test: compare elbow flexion strength in supination vs. pronation with the elbow extended — is there a difference?",
"type": "choice",
"answers": [
{
"id": "equal_both",
"label": "Equal weakness in BOTH positions — pronation does not reduce strength or pain",
"sublabel": "Pronating the forearm makes no difference to the elbow flexion weakness or discomfort",
"lr": {
"brachialis": 8.0,
"brachioradialis": 0.3,
"biceps": 0.3,
"supinator": 0.9,
"infraspinatus": 1.0,
"scalenes": 1.0,
"coracobrachialis": 1.0
}
},
{
"id": "worse_supinated",
"label": "WORSE in supination — pronating the forearm reduces the weakness or discomfort",
"sublabel": "Lifting with the thumb pointing down (pronated) feels easier and less painful",
"lr": {
"biceps": 8.0,
"brachialis": 0.3,
"brachioradialis": 1.0,
"supinator": 0.8,
"infraspinatus": 0.8,
"scalenes": 0.9,
"coracobrachialis": 0.8
}
},
{
"id": "worse_neutral",
"label": "WORST in NEUTRAL position — mid-way between pronation and supination",
"sublabel": "Elbow flexion in neutral forearm position (e.g. holding a hammer) is most painful",
"lr": {
"brachioradialis": 8.0,
"brachialis": 1.0,
"biceps": 0.8,
"supinator": 1.5,
"infraspinatus": 0.8,
"scalenes": 0.8,
"coracobrachialis": 0.8
}
}
]
},
{
"id": "q_anterior_shoulder",
"text": "Is ANTERIOR SHOULDER pain a significant or dominant component of the complaint?",
"sublabel": "Superficial aching over the front of the shoulder and deltoid region, in addition to or dominating over the antecubital pain",
"type": "choice",
"answers": [
{
"id": "deep_joint_cannot_lie_either_side",
"label": "Deep INSIDE the front of the shoulder joint AND cannot sleep comfortably on EITHER side",
"sublabel": "Feels inside the joint; even the unaffected side is intolerable for sleeping",
"lr": {
"infraspinatus": 10.0,
"biceps": 0.3,
"brachialis": 0.3,
"brachioradialis": 0.2,
"supinator": 0.2,
"scalenes": 0.7,
"coracobrachialis": 0.4
}
},
{
"id": "surface_shoulder_can_lie_affected",
"label": "Superficial aching OVER the front of the shoulder — CAN lie on the affected side",
"sublabel": "Anterior shoulder ache that is not deep inside the joint; able to sleep on the affected shoulder",
"lr": {
"biceps": 9.0,
"infraspinatus": 0.2,
"scalenes": 2.0,
"coracobrachialis": 2.0,
"brachialis": 0.5,
"brachioradialis": 0.3,
"supinator": 0.3
}
},
{
"id": "no_shoulder",
"label": "NO significant shoulder pain — the complaint is confined to the arm or elbow",
"lr": {
"brachialis": 2.0,
"brachioradialis": 2.5,
"supinator": 2.5,
"biceps": 0.4,
"infraspinatus": 0.2,
"scalenes": 0.6,
"coracobrachialis": 0.5
}
}
]
},
{
"id": "q_neck_involvement",
"text": "Is there associated NECK PAIN, upper trapezius tension, or nocturnal arm aching requiring the arm to hang over the side of the bed for relief?",
"sublabel": "Signs pointing to a cervical or scalene source contributing to the arm/antecubital pain",
"type": "choice",
"answers": [
{
"id": "nocturnal_arm_hang",
"label": "Woken at NIGHT by arm aching — must hang the arm over the bed side for relief",
"sublabel": "Nocturnal brachialgia specifically relieved by bed-hanging; may be associated with neck or upper trapezius tightness",
"lr": {
"scalenes": 9.0,
"infraspinatus": 0.5,
"biceps": 0.6,
"brachialis": 0.5,
"brachioradialis": 0.5,
"supinator": 0.5,
"coracobrachialis": 0.5
}
},
{
"id": "neck_trap_only",
"label": "Neck pain or upper trapezius tightness — NO nocturnal arm hanging",
"sublabel": "Associated cervical stiffness or upper trap tension but the arm pain is primarily a daytime complaint",
"lr": {
"scalenes": 4.0,
"infraspinatus": 1.5,
"biceps": 1.0,
"brachialis": 0.8,
"brachioradialis": 0.7,
"supinator": 0.7,
"coracobrachialis": 0.9
}
},
{
"id": "no_neck",
"label": "No neck pain, no upper trapezius tension, no nocturnal arm hanging",
"lr": {
"scalenes": 0.2,
"brachialis": 1.3,
"biceps": 1.2,
"brachioradialis": 1.3,
"supinator": 1.3,
"infraspinatus": 1.0,
"coracobrachialis": 1.1
}
}
]
},
{
"id": "q_passive_elbow_extension",
"text": "Does PASSIVELY EXTENDING (straightening) the elbow to its full range increase thumb base pain or antecubital discomfort?",
"sublabel": "Clinician passively extends the patient's elbow fully — does this reproduce or increase the characteristic pain?",
"type": "binary",
"answers": [
{
"id": "yes",
"label": "Yes — passive full elbow extension reproduces or increases thumb base or antecubital pain",
"lr": {
"brachialis": 7.0,
"biceps": 3.0,
"brachioradialis": 1.5,
"supinator": 1.0,
"infraspinatus": 0.7,
"scalenes": 0.7,
"coracobrachialis": 0.7
}
},
{
"id": "no",
"label": "No — passive elbow extension does not specifically reproduce the characteristic pain",
"lr": {
"brachialis": 0.3,
"biceps": 0.6,
"brachioradialis": 0.9,
"supinator": 1.0,
"infraspinatus": 1.2,
"scalenes": 1.2,
"coracobrachialis": 1.2
}
}
]
},
{
"id": "q_residual_after_treatment",
"text": "Has the patient already received treatment for surrounding shoulder or arm muscles and THIS arm/elbow pain persists as a residual complaint?",
"sublabel": "Pain that remains unexplained after infraspinatus, biceps, scalenes, and pectorals have already been addressed",
"type": "binary",
"answers": [
{
"id": "yes",
"label": "Yes — this is residual pain after surrounding muscles were treated",
"lr": {
"coracobrachialis": 10.0,
"brachialis": 1.5,
"biceps": 0.4,
"brachioradialis": 1.0,
"supinator": 1.0,
"infraspinatus": 0.7,
"scalenes": 0.7
}
},
{
"id": "no",
"label": "No — this is a first presentation; surrounding muscles have not been cleared",
"lr": {
"coracobrachialis": 0.2,
"brachialis": 1.0,
"biceps": 1.0,
"brachioradialis": 1.0,
"supinator": 1.0,
"infraspinatus": 1.1,
"scalenes": 1.1
}
}
]
}
],
"pairwise": [
{
"id": "pw_brachialis_supinator",
"pair": ["brachialis", "supinator"],
"text": "Tiebreaker — Brachialis vs Supinator",
"question": "Does ACTIVE THUMB MOVEMENT hurt while active ELBOW MOVEMENT does NOT, OR does RESISTED SUPINATION specifically reproduce the pain?",
"answers": [
{
"id": "thumb_hurts_elbow_ok",
"label": "Active thumb use hurts; active elbow flexion/extension does not — the thumb–elbow dissociation",
"lr": {
"brachialis": 6.0,
"supinator": 0.2
}
},
{
"id": "resisted_supination_pain",
"label": "Resisted supination specifically reproduces the lateral elbow or forearm pain",
"lr": {
"brachialis": 0.2,
"supinator": 6.0
}
}
]
},
{
"id": "pw_brachialis_brachioradialis",
"pair": ["brachialis", "brachioradialis"],
"text": "Tiebreaker — Brachialis vs Brachioradialis",
"question": "Is weakness of elbow flexion EQUAL in pronation and supination, OR is it WORST in the NEUTRAL forearm position?",
"answers": [
{
"id": "equal_pronation_supination",
"label": "Equal weakness in both pronated and supinated positions — pronation does not help",
"lr": {
"brachialis": 6.0,
"brachioradialis": 0.2
}
},
{
"id": "worst_neutral",
"label": "Worst in neutral forearm position (mid-way); tool gripping and hammer use most provocative",
"lr": {
"brachialis": 0.2,
"brachioradialis": 6.0
}
}
]
},
{
"id": "pw_biceps_brachialis",
"pair": ["biceps", "brachialis"],
"text": "Tiebreaker — Biceps Brachii vs Brachialis",
"question": "Is the dominant pain in the ANTERIOR SHOULDER with antecubital spillover, OR is it at the THUMB BASE with antecubital spillover?",
"answers": [
{
"id": "anterior_shoulder_dominant",
"label": "Anterior shoulder is the dominant complaint; antecubital discomfort is secondary",
"lr": {
"biceps": 6.0,
"brachialis": 0.2
}
},
{
"id": "thumb_base_dominant",
"label": "Thumb base / dorsal web is the dominant complaint; antecubital fossa is secondary",
"lr": {
"biceps": 0.2,
"brachialis": 6.0
}
}
]
},
{
"id": "pw_biceps_infraspinatus",
"pair": ["biceps", "infraspinatus"],
"text": "Tiebreaker — Biceps Brachii vs Infraspinatus",
"question": "Can the patient LIE COMFORTABLY on the affected side, AND reach behind the waistline without pain — OR is sleeping on either side intolerable and behind-the-back reach severely restricted?",
"answers": [
{
"id": "can_lie_can_reach_behind",
"label": "Can lie on the affected side; can reach behind the waistline — the two biceps-specific positives",
"lr": {
"biceps": 6.0,
"infraspinatus": 0.15
}
},
{
"id": "cannot_lie_cannot_reach",
"label": "Cannot lie on either side; behind-the-back reach is painful or severely restricted",
"lr": {
"biceps": 0.15,
"infraspinatus": 6.0
}
}
]
},
{
"id": "pw_supinator_brachioradialis",
"pair": ["supinator", "brachioradialis"],
"text": "Tiebreaker — Supinator vs Brachioradialis",
"question": "Is the pain reproduced primarily by RESISTED SUPINATION (forearm rotation), OR by GRIPPING and tool use / neutral-position elbow flexion?",
"answers": [
{
"id": "resisted_supination",
"label": "Resisted supination (rotation) is the key provocation — elbow position matters less",
"lr": {
"supinator": 5.0,
"brachioradialis": 0.2
}
},
{
"id": "grip_neutral_flexion",
"label": "Gripping, tool holding, and neutral-forearm elbow flexion are the key provocations",
"lr": {
"supinator": 0.2,
"brachioradialis": 5.0
}
}
]
},
{
"id": "pw_scalenes_infraspinatus",
"pair": ["scalenes", "infraspinatus"],
"text": "Tiebreaker — Scalenes vs Infraspinatus",
"question": "Is NOCTURNAL ARM ACHING (requiring the arm to hang over the bed) the dominant feature, OR is it DEEP GLENOHUMERAL JOINT PAIN with inability to sleep on either side?",
"answers": [
{
"id": "nocturnal_arm_hang",
"label": "Nocturnal arm aching requiring bed-hanging is the dominant feature",
"lr": {
"scalenes": 5.0,
"infraspinatus": 0.3
}
},
{
"id": "deep_joint_neither_side",
"label": "Deep inside the front of the shoulder joint; cannot sleep comfortably on either side",
"lr": {
"scalenes": 0.3,
"infraspinatus": 5.0
}
}
]
},
{
"id": "pw_coracobrachialis_biceps",
"pair": ["coracobrachialis", "biceps"],
"text": "Tiebreaker — Coracobrachialis vs Biceps Brachii",
"question": "Is this pain RESIDUAL AFTER surrounding muscles have been treated AND does it radiate to the POSTERIOR ARM or dorsal hand skipping the elbow — OR is this a fresh presentation with anterior shoulder aching as the dominant feature?",
"answers": [
{
"id": "residual_posterior_arm",
"label": "Residual after treatment; posterior arm or dorsal hand extension; skip pattern over elbow",
"lr": {
"coracobrachialis": 6.0,
"biceps": 0.2
}
},
{
"id": "fresh_anterior_shoulder",
"label": "Fresh presentation; anterior shoulder aching is the dominant feature; no posterior arm referral",
"lr": {
"coracobrachialis": 0.2,
"biceps": 6.0
}
}
]
}
],
"treatment_dag": {
"edges": [
{
"from": "infraspinatus",
"to": "biceps",
"type": "key_satellite",
"label": "Infraspinatus TrPs are the most important key TrP source driving satellite biceps TrPs — inactivate infraspinatus first; biceps TrPs may resolve without direct treatment"
},
{
"from": "supinator",
"to": "brachioradialis",
"type": "key_satellite",
"label": "Supinator is typically the primary TrP in the lateral elbow pattern; brachioradialis develops as a secondary satellite — treat supinator before brachioradialis"
},
{
"from": "supinator",
"to": "brachialis",
"type": "key_satellite",
"label": "In the tennis-elbow sequence, supinator activates first, with brachialis developing secondarily — treat supinator before brachialis"
},
{
"from": "supinator",
"to": "biceps",
"type": "key_satellite",
"label": "Supinator TrPs drive secondary biceps TrPs in the elbow overload sequence — treat supinator before biceps"
},
{
"from": "brachialis",
"to": "biceps",
"type": "functional_unit",
"label": "Brachialis and biceps brachii are synergistic elbow flexors and almost always involved together — examine and treat in the same session"
},
{
"from": "biceps",
"to": "coracobrachialis",
"type": "key_satellite",
"label": "Biceps brachii (short head) TrPs drive coracobrachialis satellite TrPs — treat biceps before coracobrachialis; coracobrachialis is the last muscle to clear"
},
{
"from": "scalenes",
"to": "biceps",
"type": "key_satellite",
"label": "Scalene TrPs can drive satellite biceps TrPs via referred pain overlap — address scalenes before attempting sustained biceps relief"
},
{
"from": "biceps",
"to": "brachialis",
"type": "functional_unit",
"label": "Biceps TrPs drive early secondary brachialis TrPs — treat concurrently in the same session"
},
{
"from": "infraspinatus",
"to": "brachialis",
"type": "antagonist_risk",
"label": "⚠ After infraspinatus release, the biceps and brachialis (its usual satellites) may reactively tighten — spray and stretch the elbow flexors after infraspinatus release"
}
],
"edge_type_labels": {
"key_satellite": "Treat first — key TrP driving satellites",
"functional_unit": "Treat concurrently in the same session",
"secondary_load": "Treat after primary resolves",
"antagonist_risk": "⚠ Treat in alternating cycles — reactive activation risk"
}
},
"red_flags": [
{
"id": "rf_biceps_tendon_rupture",
"label": "Distal biceps tendon rupture",
"description": "Audible or perceived 'pop' in the antecubital fossa with acute onset pain and weakness; palpable gap or 'Popeye' deformity of the distal biceps tendon; marked weakness of forearm supination and elbow flexion. Urgent orthopaedic referral.",
"action": "Refer urgently — surgical repair time-sensitive"
},
{
"id": "rf_radial_tunnel",
"label": "Radial tunnel syndrome / posterior interosseous nerve entrapment",
"description": "Deep aching 4–5 cm distal to the lateral epicondyle (not at the epicondyle); pain worsened by resisted supination and resisted extension of the middle finger; may coexist with brachioradialis and supinator TrPs. No paresthesia. See also Brachialis Entrapment section for sensory radial nerve compression.",
"action": "Examine for supinator TrP with radial tunnel component; if TrP treatment fails, refer for nerve conduction study"
},
{
"id": "rf_lateral_epicondylitis",
"label": "Lateral epicondylitis (tennis elbow)",
"description": "Tenderness at or just distal to the lateral epicondyle; positive Mills' test (passive wrist flexion with elbow extended); positive Cozen's test (resisted wrist extension). Often co-exists with supinator and brachioradialis TrPs — TrP treatment is first-line before other interventions.",
"action": "Examine for supinator and brachioradialis TrPs — myofascial source is common; epicondylitis and TrPs frequently coexist"
},
{
"id": "rf_cubital_tunnel",
"label": "Cubital tunnel syndrome (ulnar nerve)",
"description": "MEDIAL elbow pain; numbness and paresthesia in the ring and little fingers (ulnar 1.5 digits); intrinsic hand weakness in severe cases; positive Tinel's sign at the medial epicondyle. Distinguished from antecubital TrP pain by location (medial vs. anterior) and ulnar digit sensory loss.",
"action": "Refer for electrodiagnostic testing; cubital tunnel is a structural nerve compression and not addressed by TrP treatment"
},
{
"id": "rf_cervical_radiculopathy",
"label": "Cervical radiculopathy — C5 or C6",
"description": "Dermatomal sensory deficit in C5 (lateral upper arm, deltoid patch) or C6 (lateral forearm, thumb, index finger) distribution; biceps reflex depression or absence; motor weakness in C5/C6 myotome. Myofascial TrPs produce pain-inhibited weakness without reflex change or objective sensory deficit. Both conditions can coexist.",
"action": "Neurological examination for reflex change, dermatomal sensory deficit, and myotomal weakness; refer for neuroimaging if positive"
},
{
"id": "rf_vascular",
"label": "Brachial artery aneurysm or vascular mass",
"description": "Pulsatile, expansile mass in the antecubital fossa; bruit on auscultation; Allen test abnormality. Rare but must not be missed before any injection or deep palpation in the fossa.",
"action": "Examine the antecubital fossa for pulsatile mass before any needle procedure; refer vascular surgery if present"
}
],
"broad_differential": [
{
"id": "bd_distal_biceps_rupture",
"label": "Distal biceps tendon rupture",
"note": "Acute pop + palpable gap + supination weakness. Urgent orthopaedic referral (red flag above)."
},
{
"id": "bd_lateral_epicondylitis",
"label": "Lateral epicondylitis (tennis elbow)",
"note": "Positive Mills' and Cozen's tests; epicondyle tenderness. Frequently coexists with supinator and brachioradialis TrPs."
},
{
"id": "bd_medial_epicondylitis",
"label": "Medial epicondylitis (golfer's elbow)",
"note": "MEDIAL epicondyle tenderness; positive Golfer's Elbow test (resisted wrist flexion). Distinct from antecubital/anterior elbow TrP pain."
},
{
"id": "bd_radial_tunnel",
"label": "Radial tunnel syndrome / posterior interosseous nerve entrapment",
"note": "Deep ache 4–5 cm distal to lateral epicondyle; resisted middle-finger extension positive. May coexist with supinator TrPs."
},
{
"id": "bd_cubital_tunnel",
"label": "Cubital tunnel syndrome (ulnar nerve)",
"note": "Medial, ulnar nerve; 4th–5th finger symptoms. Not an antecubital presentation — distinguish by location."
},
{
"id": "bd_anterior_interosseous",
"label": "Anterior interosseous nerve syndrome",
"note": "Weakness of pincer grip (FPL + FDP to index); no sensory loss; no elbow pain at rest. Rare nerve compression."
},
{
"id": "bd_cervical_radiculopathy",
"label": "Cervical radiculopathy — C5/C6",
"note": "Dermatomal sensory deficit; reflex change; myotomal weakness. Can coexist with TrPs and must be excluded when neurological signs are present."
},
{
"id": "bd_tos",
"label": "Thoracic outlet syndrome",
"note": "See Differential:ThoracicOutletSyndrome. Consider when scalene TrPs are prominent and diffuse arm symptoms do not respond to local treatment.",
"wiki_link": "Differential:ThoracicOutletSyndrome"
},
{
"id": "bd_elbow_oa",
"label": "Elbow osteoarthritis / intra-articular pathology",
"note": "Restricted ROM in all planes; crepitus; confirmed by imaging. Joint examination must precede injection in the antecubital fossa."
},
{
"id": "bd_bicipital_tendinopathy",
"label": "Bicipital tendinopathy / partial tear",
"note": "Tenderness at bicipital tendon and groove; Yergason's positive. Frequently coexists with biceps TrPs — inactivate TrPs first and reassess."
},
{
"id": "bd_dequervain",
"label": "De Quervain's tenosynovitis",
"note": "If thumb pain is the chief complaint: Finkelstein's test positive; first dorsal compartment tendon tenderness. Brachialis TrPs produce no Finkelstein's sign."
},
{
"id": "bd_cmc_arthritis",
"label": "First CMC (carpometacarpal) arthritis",
"note": "If thumb base pain is the chief complaint: grind test positive; radiographic changes. Brachialis TrPs produce no CMC joint crepitus or grind-test positivity."
}
]
}