Hand Nerve Examination

Commonly Tested

Hand nerve examination requires systematic assessment of the three main nerves: median, ulnar, and radial. Examiners expect you to know the motor and sensory distributions of each nerve, perform provocative tests correctly, and differentiate between high and low nerve lesions.

Exam day cheat sheet

Hand Nerve Examination Summary

Median Nerve

Motor: Thenar muscles (APB key), lumbricals 1-2
Sensory: Palmar thumb, index, middle, radial half ring
Tests: Phalen's, Tinel's, Durkan's
Carpal tunnel most common entrapment

Ulnar Nerve

Motor: Interossei, hypothenars, adductor pollicis
Sensory: Little finger, ulnar half ring
Tests: Froment's, Wartenberg, elbow flexion test
Cubital tunnel second most common entrapment

Radial Nerve

Motor: Wrist/finger extensors (PIN)
Sensory: Dorsal first web space (SRN)
Minimal hand motor function
Wrist drop with high lesion

Key Tests

Phalen's: Wrist flexion 60 sec
Tinel's: Percussion over nerve
Froment's: Paper grip (ulnar)
OK sign: AIN (median)

Anatomy Overview

Nerve Distributions

Median Nerve (C6-T1):

Enters hand through carpal tunnel
Motor: APB, opponens pollicis, FPB superficial head, lumbricals 1-2
Sensory: Palmar thumb, index, middle, radial half ring finger
Anterior interosseous nerve (AIN): No sensory, pure motor (FPL, FDP 1-2, PQ)

Ulnar Nerve (C8-T1):

Enters hand through Guyon's canal
Motor: All interossei, hypothenar muscles, adductor pollicis, FPB deep head, lumbricals 3-4
Sensory: Little finger, ulnar half ring finger (dorsal and palmar)
Dorsal cutaneous branch: Dorsal ulnar hand (leaves proximal to wrist)

Radial Nerve (C5-T1):

No intrinsic hand muscles
Posterior interosseous nerve (PIN): No sensory, pure motor (finger/thumb extensors)
Superficial radial nerve (SRN): Sensory to dorsal first web space, dorsum of hand

Key Concept

Memory Aid - "LOAF" Muscles (Median Nerve):

Lumbricals 1 and 2
Opponens pollicis
Abductor pollicis brevis (most important/first affected)
Flexor pollicis brevis (superficial head)

Everything else in the hand is ULNAR!

Median Nerve Examination

Motor Testing

Abductor Pollicis Brevis (APB):

Most important muscle to test (first affected in CTS)
Place palm up, thumb pointing to ceiling
Ask patient to lift thumb straight up against resistance
Observe and palpate thenar eminence

Opposition:

Touch thumb tip to little finger tip
Make a complete circle (pulp-to-pulp contact)
Test against resistance

Anterior Interosseous Nerve (AIN):

"OK Sign" test
Patient makes circle with thumb and index finger
Should be round circle (FPL and FDP to index)
Pinch test: Abnormal pinch = flat (uses EPL and FDS compensation)

Sensory Testing

Distribution:

Palmar thumb
Palmar index finger
Palmar middle finger
Radial half of ring finger (palmar)

Best Test Area:

Tip of index finger (most reliable)
Autonomous zone = volar index finger tip

Note: Palm is spared in carpal tunnel syndrome (palmar cutaneous branch exits proximal to tunnel)

Carpal Tunnel Provocative Tests

Special test

Phalen's Test

Carpal tunnel syndrome

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Technique

1Patient holds wrists in full flexion (back of hands together)
2Maintain for 60 seconds
3Ask about paresthesias

Positive Sign

Tingling or numbness in median nerve distribution within 60 seconds

Indicates

Carpal tunnel syndrome - wrist flexion increases pressure in carpal tunnel

Diagnostic Accuracy

Sensitivity68%

Ability to detect true positives

Specificity73%

Ability to exclude false positives

Special test

Tinel's Sign (Wrist)

Carpal tunnel syndrome

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Technique

1Tap over the carpal tunnel at the wrist crease
2Use finger or reflex hammer
3Ask about radiating symptoms

Positive Sign

Paresthesias radiating into median nerve territory (thumb, index, middle finger)

Indicates

Carpal tunnel syndrome - demyelination/regeneration at compression site

Diagnostic Accuracy

Sensitivity50%

Ability to detect true positives

Specificity77%

Ability to exclude false positives

Special test

Durkan's Test (Carpal Compression)

Carpal tunnel syndrome

Technique

1Apply direct pressure over the carpal tunnel with thumbs
2Maintain for 30 seconds
3Ask about paresthesias

Positive Sign

Reproduction of median nerve paresthesias within 30 seconds

Indicates

Carpal tunnel syndrome - most sensitive provocation test

Diagnostic Accuracy

Sensitivity87%

Ability to detect true positives

Specificity90%

Ability to exclude false positives

Special test

Reverse Phalen's Test (Prayer Sign)

Carpal tunnel syndrome

Technique

1Hold wrists in full extension (palms together in prayer position)
2Maintain for 60 seconds

Positive Sign

Paresthesias in median nerve distribution

Indicates

Carpal tunnel syndrome (alternative to Phalen's)

Diagnostic Accuracy

Sensitivity61%

Ability to detect true positives

Specificity83%

Ability to exclude false positives

Ulnar Nerve Examination

Motor Testing

First Dorsal Interosseous (FDI):

Place palm flat on table
Abduct index finger (spread away from middle finger)
Resist abduction
Palpate muscle bulk in first web space

Finger Abduction/Adduction:

"Spread your fingers apart" (interossei)
"Squeeze fingers together" (interossei)
Note first dorsal interosseous wasting

Adductor Pollicis:

Froment's test (see below)

Hypothenar Muscles:

Abduct little finger (ADM)
Compare bulk with contralateral side

Sensory Testing

Distribution:

Little finger (both dorsal and palmar)
Ulnar half of ring finger

Best Test Area:

Tip of little finger
Autonomous zone = volar little finger tip

Key Point:

Dorsal sensation preserved if lesion distal to dorsal cutaneous branch (which exits proximal to wrist)

Ulnar Nerve Provocative Tests

Special test

Froment's Sign

Ulnar nerve palsy

Technique

1Patient holds paper between thumb and side of index finger
2Examiner pulls paper away
3Observe thumb position

Positive Sign

Flexion of thumb IP joint (uses FPL instead of weak adductor pollicis)

Indicates

Ulnar nerve palsy with adductor pollicis weakness - compensatory FPL activation

Diagnostic Accuracy

Sensitivity82%

Ability to detect true positives

Specificity98%

Ability to exclude false positives

Key Concept

Froment's Sign Explained:

Normal: Pinch with extended IP joint (adductor pollicis)
Positive: Thumb IP flexes (using FPL - median nerve - to compensate)
Indicates adductor pollicis weakness (ulnar nerve)
May also see hypothenar and interosseous wasting

Special test

Wartenberg's Sign

Ulnar nerve palsy

Technique

1Ask patient to hold fingers extended and adducted together
2Observe little finger position

Positive Sign

Little finger remains abducted (cannot adduct with other fingers)

Indicates

Ulnar nerve palsy - weak third palmar interosseous, unopposed EDM

Diagnostic Accuracy

Sensitivity76%

Ability to detect true positives

Specificity96%

Ability to exclude false positives

Special test

Elbow Flexion Test

Cubital tunnel syndrome

Technique

1Fully flex elbow with forearm supinated
2May add wrist extension to increase tension
3Hold for 60 seconds

Positive Sign

Paresthesias in ulnar nerve distribution (ring and little finger)

Indicates

Cubital tunnel syndrome - elbow flexion increases pressure in cubital tunnel

Diagnostic Accuracy

Sensitivity75%

Ability to detect true positives

Specificity99%

Ability to exclude false positives

Special test

Tinel's Sign (Elbow)

Cubital tunnel syndrome

Technique

1Tap over the ulnar nerve in the cubital tunnel
2Located behind the medial epicondyle

Positive Sign

Paresthesias radiating into ulnar nerve territory (ring and little finger)

Indicates

Cubital tunnel syndrome - ulnar nerve irritability

Diagnostic Accuracy

Sensitivity70%

Ability to detect true positives

Specificity98%

Ability to exclude false positives

Radial Nerve Examination

Motor Testing

Wrist Extension (ECRL, ECRB, ECU):

Patient extends wrist against resistance
With high radial nerve palsy = wrist drop

Finger Extension (EDC):

Extend MCP joints against resistance
Note: IP extension preserved (interossei, lumbricals)

Thumb Extension (EPL):

Extend thumb IP joint against resistance
Place palm flat, lift thumb off table

Posterior Interosseous Nerve (PIN):

Pure motor branch
Finger and thumb extension weakness
Wrist extension preserved (ECRL takes off proximal to PIN)
"Finger drop" with preserved wrist extension

Sensory Testing

Superficial Radial Nerve (SRN):

Dorsal first web space (autonomous zone)
Dorsum of thumb, index, and middle finger (proximal phalanx)
Radial half of dorsum of hand

Note:

SRN palsy = sensory loss only (no motor)
PIN palsy = motor only (no sensory)

Special test

Finkelstein's Test

De Quervain's (affects SRN region)

Technique

1Patient makes fist with thumb inside fingers
2Ulnar deviate the wrist

Positive Sign

Pain over radial styloid (first dorsal compartment)

Indicates

De Quervain's tenosynovitis (note: SRN may be tender in Wartenberg syndrome)

Diagnostic Accuracy

Sensitivity81%

Ability to detect true positives

Specificity50%

Ability to exclude false positives

Claw Hand Deformity

Ulnar Claw Assessment

Classic Ulnar Claw:

MCP hyperextension (loss of lumbrical MCP flexion)
IP flexion (unopposed FDP)
Ring and little fingers affected (lumbricals 3-4 are ulnar)

Ulnar Paradox:

LOW ulnar lesion = MORE obvious claw (FDP intact, working)
HIGH ulnar lesion = LESS obvious claw (FDP also paralyzed)

Bouvier's Test:

Block MCP hyperextension passively
Can patient now extend IP joints?
If yes: Simple claw (lumbricals only)
If no: Complex claw (intrinsic tightness, other pathology)

Differentiating Lesion Levels

High Median

motor: FPL, FDP 1-2, pronators, FCR, all LOAF
sensory: Full median territory
clinicalSign: Can't make OK sign, weak pinch

Low Median (CTS)

motor: APB, opponens, FPB, lumbricals 1-2
sensory: Spares palm (cutaneous branch)
clinicalSign: Thenar wasting, weak opposition

AIN (Median)

motor: FPL, FDP 1-2, pronator quadratus
sensory: None (pure motor)
clinicalSign: Flat OK sign, no sensory loss

High Ulnar

motor: FDP 3-4 + all hand intrinsics
sensory: Full ulnar territory
clinicalSign: Less obvious claw (ulnar paradox)

Low Ulnar (Guyon's)

motor: Hand intrinsics only
sensory: May spare dorsum (DCB)
clinicalSign: More obvious claw, Froment's

High Radial

motor: Wrist + finger + thumb extensors
sensory: Full radial territory
clinicalSign: Wrist drop

PIN (Radial)

motor: Finger + thumb extensors only
sensory: None (pure motor)
clinicalSign: Finger drop, wrist extension OK

nerve	motor	sensory	clinicalSign
High Median	FPL, FDP 1-2, pronators, FCR, all LOAF	Full median territory	Can't make OK sign, weak pinch
Low Median (CTS)	APB, opponens, FPB, lumbricals 1-2	Spares palm (cutaneous branch)	Thenar wasting, weak opposition
AIN (Median)	FPL, FDP 1-2, pronator quadratus	None (pure motor)	Flat OK sign, no sensory loss
High Ulnar	FDP 3-4 + all hand intrinsics	Full ulnar territory	Less obvious claw (ulnar paradox)
Low Ulnar (Guyon's)	Hand intrinsics only	May spare dorsum (DCB)	More obvious claw, Froment's
High Radial	Wrist + finger + thumb extensors	Full radial territory	Wrist drop
PIN (Radial)	Finger + thumb extensors only	None (pure motor)	Finger drop, wrist extension OK

Summary Presentation

Viva scenarioStandard

Presenting Your Findings

Clinical prompt

“54-year-old woman with numbness and tingling in her right hand, waking her at night.”

Examination Sequence

Systematic Approach

Observation: Thenar/hypothenar wasting, interosseous wasting, claw deformity
Median Motor: APB (thumb abduction), opposition, OK sign (AIN)
Median Sensory: Index finger tip
Median Provocative: Phalen's, Tinel's, Durkan's
Ulnar Motor: FDI, finger abduction, Froment's
Ulnar Sensory: Little finger tip
Ulnar Provocative: Elbow flexion test, Tinel's at elbow
Radial Motor: Wrist extension, finger extension
Radial Sensory: First web space dorsally
Compare with contralateral side

Examiner Tips

Exam day cheat sheet

Scoring High in Hand Nerve Examination

Do

Test APB specifically for median nerve
Know LOAF muscles (median) vs all else (ulnar)
Perform Froment's test correctly
Check for thenar and hypothenar wasting
Compare sensation using fingertip as autonomous zones

Don't

Confuse median and ulnar distributions
Forget AIN has no sensory component
Miss ulnar claw deformity
Neglect to test radial nerve
Forget proximal causes (cervical radiculopathy)