Hand nerve tests: Median, ulnar and radial exam guide

Key takeaways

Hand nerve tests check the median, ulnar, and radial nerves through sensory mapping, motor testing, and provocative maneuvers.

No single provocative test confirms carpal tunnel syndrome, so combine two or three and record what each one reproduced.

Durkan’s compression test scored 87% sensitivity in its original 1991 study, while pooled data from later studies sits near 64%.

Static two-point discrimination under 6mm at the fingertip is normal, and higher values suggest reduced innervation density.

Practice management software like Pabau keeps exam findings in the client record, so the six-week comparison takes seconds.

Nerve compression rarely announces itself. A patient mentions pins and needles at 3am, blames the pillow, and books in months later. By then the thenar eminence has started to flatten, and the window for a clean recovery has narrowed.

A structured hand nerve exam catches it much earlier. It takes about five minutes and needs nothing more than a pin, some cotton wool, and a discriminator. It tells you which nerve is involved and roughly where.

A useful exam comes down to technique and an honest reading of the published accuracy. It also depends on a note someone else can still read six weeks later.

What a hand nerve exam can and can’t tell you

The hand nerve exam tells you which of the three nerves is affected, and at roughly what level. That is usually enough to choose between splinting, referral, and an electrodiagnostic study.

However, the exam does not grade severity objectively, and it does not rule out a second compression higher up.

The median, ulnar, and radial nerves each follow their own course, supply their own muscles, and cover their own patch of skin. Compression anywhere along that route produces a pattern you can recognize on examination.

Early compression is quiet. A patient with tingling in the thumb and index finger may show no wasting at all. A positive Phalen’s test with reduced two-point discrimination flags carpal tunnel syndrome before axons are lost.

Recording those first findings matters as much as producing them, because the follow-up exam only means something next to a baseline. A physical therapy EMR keeps both readings in the same client record.

Work through three domains in a fixed order: sensory, then motor, then provocative. Least provocative first, so you are not reading symptoms you just caused.

Hand muscle innervation: Which nerve owns what

The table below pairs each nerve with its sensory patch, its key muscles, and the deficit you see when it is compressed.

Innervation is rarely this tidy in the room. Anatomical variants, dual innervation zones, and a second compression further up all blur the boundaries. Treat the table as a starting map and expect exceptions.

Median nerve tests: Three ways to load the carpal tunnel

Median testing starts at the carpal tunnel, because that is where most compression sits. Lesions at the elbow, such as pronator syndrome, also produce median deficits, and forearm findings are what tell the two apart.

Three provocative tests cover most presentations.

1. Phalen’s test: hold the flexion for a full minute

Phalen’s test reproduces carpal tunnel symptoms through sustained wrist flexion, which raises pressure inside the tunnel and loads the median nerve.

1. Ask the patient to hold both wrists in full passive flexion, dorsa of the hands together, for up to 60 seconds.
2. A positive result is tingling or numbness in the median territory: thumb, index, middle, and the radial half of the ring finger.
3. Symptoms inside 30 seconds suggest heavier compression. Symptoms only at 60 seconds suggest milder disease.

A systematic review of 60 studies puts Phalen’s at 68% sensitivity and 73% specificity. Individual studies scatter widely either side of that, mostly because they recruited different patients.

2. Tinel’s sign: percuss lightly, and mind the technique

Percuss over the carpal tunnel at the wrist crease with a fingertip or a reflex hammer. A positive sign is tingling or an electric shock running into the median territory.

On the same pooled data, Tinel’s is the weakest of the three at roughly 50% sensitivity and 77% specificity. Percussion force varies a lot between examiners, and that accounts for much of the spread.

3. Durkan’s compression test: 30 seconds of thumb pressure

Apply direct thumb pressure over the carpal tunnel and hold it for 30 seconds. A positive result reproduces the patient’s own symptoms in the median distribution.

The figures here need care. Durkan’s original 1991 study reported 87% sensitivity and 90% specificity in 46 affected hands. Pooled results from later studies land lower, near 64% and 83%. Which provocative test is most sensitive remains unsettled, so no single one deserves your whole diagnosis.

Pre-built assessment templates in occupational therapy software fix which tests get recorded, and in what order. That is what stops the third test being skipped when the appointment overruns.

Ulnar nerve tests: Separate the elbow from the wrist

Ulnar testing has to place the lesion at either the cubital tunnel at the elbow or Guyon’s canal at the wrist. Management differs between the two, so careful motor and sensory mapping earns its time.

Froment’s sign: watch the thumb, not the paper

Froment’s sign tests adductor pollicis, the muscle behind a strong key pinch, supplied by the deep branch of the ulnar nerve.

1. Ask the patient to hold a sheet of paper between thumb and index finger, using key pinch.
2. Pull the paper away.
3. A positive sign is thumb flexion at the IP joint as the patient fights to keep hold.

That IP flexion is the diagnostic feature. The patient is recruiting flexor pollicis longus, a median-supplied muscle, to cover for weak adductor pollicis. A formal pinch grip test puts a number on the same weakness for the record.

Wartenberg’s sign and the interossei

Wartenberg’s sign is a little finger that rests in abduction, caused by weakness of the third palmar interosseous. On its own it points to ulnar involvement of the intrinsic muscles.

Confirm it directly. Test finger abduction and adduction against resistance. Weak spreading, or an inability to grip paper between the ring and little fingers, points at the interossei.

Sensory mapping is what gives you the level

Test the little finger and the ulnar half of the ring finger, on both the palmar and dorsal surfaces. The dorsal reading is the one that decides the level.

Spared dorsal sensation with a palmar deficit suggests Guyon’s canal, below the point where the dorsal cutaneous branch leaves. Loss across both surfaces points higher, at or above the cubital tunnel.

Write the two surfaces down separately. “Reduced ulnar sensation” throws away the only finding that localized the lesion. A predictable SOAP note structure keeps that detail in the same place every visit.

Radial nerve tests: Wrist drop is only half the story

Radial compression happens most often at the spiral groove of the humerus, the Saturday night palsy pattern. The other common site is the proximal forearm, where the posterior interosseous nerve (PIN) passes under the supinator.

Those two patterns look different on examination, and mixing them up changes the referral.

Motor testing: Brachioradialis places the lesion

Test wrist extension against resistance first. A complete radial lesion at the spiral groove gives a wrist drop, with the fingers unable to extend as well.

Then test brachioradialis power as elbow flexion in mid-pronation. Intact brachioradialis alongside a true wrist drop places the lesion below that branch, in the radial nerve trunk or the proximal forearm.

PIN syndrome looks different. It spares wrist extension, because extensor carpi radialis longus keeps working, so the wrist extends with radial deviation rather than dropping. The visible failure is finger drop at the MCP joints. A genuine wrist drop therefore argues against isolated PIN involvement.

Sensory territory and the radial nerve tension test

The radial nerve supplies the dorsal thumb web space. It also covers the dorsal surface of the radial three and a half digits, which varies between patients. Test it with a wisp of cotton wool.

The tension test loads the nerve mechanically. Position the shoulder in internal rotation, the elbow extended, the forearm pronated, and the wrist and fingers flexed. Cervical side-flexion away from the test side adds tension.

Radial-territory symptoms in that position suggest a mechanosensitive nerve rather than a fixed block. Read it next to the motor findings, never on its own.

Sensory testing is the part that gets rushed

Sensory testing gives the most precise localization of the three domains, and it is the one most often cut short. Ten seconds per territory is not a sensory exam.

Light touch and pin-prick

Use cotton wool or a Semmes-Weinstein monofilament for light touch. Map each nerve territory and compare it with the other hand. Asymmetry is the finding, not absolute sensitivity. Shading the result on a hand pain diagram beats describing it in a sentence.

For pin-prick, apply a fresh disposable pin or Neurotip lightly to the skin. Blunted sharpness inside a defined territory confirms sensory loss. Discard the pin straight afterwards.

Two-point discrimination thresholds

Apply two points of a discriminator to the palmar fingertip at the same time, narrowing the distance step by step. Record the smallest separation the patient calls correctly and reliably.

Normal static two-point discrimination at the fingertip is under 6mm. Some sources use 5mm, depending on the instrument and the patient’s age. Readings above 6mm suggest reduced innervation density at the fingertip.

Moving two-point discrimination usually runs 1-2mm better than static, and it picks up early compression sooner.

Use the same instrument and hand position every visit, since a threshold only earns its keep against a comparable earlier reading. Validated cut-offs carry the same weight in other exams, including the Ottawa ankle rules.

How accurate are hand nerve tests on their own?

Not accurate enough to stand alone. Every provocative test for carpal tunnel syndrome misses cases. The published figures also move around, depending on who was recruited and how the diagnosis was confirmed.

Pooled estimates from one systematic review sit in the table below, so the three tests are comparable. Where an original validation study reported something different, both numbers appear.

Two positives are worth more than one. The AAOS clinical practice guideline for carpal tunnel syndrome recommends combining clinical findings rather than resting a diagnosis on any single maneuver.

When to send the patient for nerve conduction studies

Refer when the exam cannot answer the question the next decision rests on. Splinting an obvious mild case does not need a study. A surgical opinion almost always does.

Nerve conduction studies (NCS) measure how fast and how strongly signals travel along a peripheral nerve. That is how severity gets graded objectively rather than described.

Electrodiagnostic testing is the usual reference standard for confirming carpal tunnel syndrome and grading it. It still misses some early cases, so a normal study does not close the door on a convincing history.

Order NCS and EMG when any of these apply:

• Findings are ambiguous, or they do not localize to one nerve or one compression site
• Conservative management has failed, with no improvement after splinting and activity modification
• Surgery is on the table and objective confirmation of severity is needed
• Thenar or intrinsic wasting suggests axonal loss, so a baseline measurement matters
• The differential includes polyneuropathy, double crush syndrome, or cervical radiculopathy

Needle EMG usually runs alongside NCS. It reads the electrical activity of individual muscles, and it detects axonal degeneration that conduction studies alone can miss in early or moderate compression.

The performing provider bills by how many nerves were studied, under codes such as 95911.

Before the referral goes out

A referral that gets triaged quickly carries the exam with it. Check the note holds all five of these:

1. The symptom pattern in the patient’s own words, with duration
2. Which provocative tests were positive, and at what timing
3. MRC grades for thenar abduction and finger abduction, on both hands
4. Two-point discrimination values, with the instrument named
5. What conservative treatment was tried, and for how long

Conservative care carries on while the referral sits in a queue. Splinting, activity changes, and structured hand exercise programs give you a documented trial to point at if surgery is discussed later.

Write the exam up so it still means something in six weeks

A nerve exam note earns its place when a colleague can repeat the exam from it and compare the results. That means numbers, sides, and timings. Adjectives do not survive the six weeks.

Grade with a scale, not adjectives

Grade motor strength on the Medical Research Council (MRC) scale, 0 to 5. Anything at 4 or below in thenar abduction deserves a formal entry and a repeat at follow-up.

For sensation, the Semmes-Weinstein monofilament scale gives an ordinal grade from normal, through diminished light touch, to absent. Standard scoring sheets do the same job in other neurological exams, the NIHSS score sheet being a familiar example.

“Some weakness” cannot be compared with anything at the next visit. A grade of 4 can.

What belongs in every nerve exam note

Capture these five components in the same order every time, so serial comparison is quick:

1. Inspection: thenar or hypothenar wasting, deformity, skin changes
2. Sensory results: light touch, static and moving 2PD, pin-prick by territory, with laterality
3. Motor results: MRC grades for the key muscles of each nerve, against the other hand
4. Provocative tests: which were run, positive or negative, the timing, and the symptoms reproduced
5. Impression: suspected level, differential, and plan, including any NCS or EMG referral

Add symptom duration, occupation, and handedness to the same note. Insurance, employer, and legal reports all ask for those three, and chasing them months later is slow. A reference on safer clinical notes is worth reading before you set up a template.

Mistakes that quietly ruin the record

Five recurring ones, in rough order of how often they turn up in notes:

1. Testing the symptomatic hand only, which leaves no comparison side
2. Writing “Phalen’s positive” with no timing, when 25 seconds and 60 seconds mean different things
3. Recording “reduced ulnar sensation” without saying whether the dorsal surface was involved
4. Skipping two-point discrimination because light touch felt normal to the patient
5. Changing instrument or hand position between visits, which makes the numbers incomparable

How Pabau keeps nerve exam findings comparable between visits

Most practices already know what to record. The friction is where it lands. Findings get typed into free text, monofilament values end up in one clinician’s shorthand, and the follow-up exam is written partly from memory.

Practice management software like Pabau moves the exam into a structured form instead. Digital intake forms collect symptom duration, occupation, and handedness before the appointment starts. The exam fields then sit in the same client record as the photos, the appointment history, and the referral letter.

Dictation is handled too. Pabau Scribe, our AI scribe, turns spoken exam findings into a structured note through AI-assisted documentation, which you review and approve before anything saves.

So at the six-week review, last visit’s MRC grades and 2PD values sit on screen beside today’s. Outcome tracking charts the change between them. The decision to refer or discharge then rests on measurements rather than recall.

Forms do the same work at the front of the visit. Symptom duration, occupation, and handedness arrive before the patient sits down, which leaves the appointment for the exam itself.

Keep every nerve exam finding in one record

Pabau stores structured exam fields, digital forms, and clinical photos in the same client record. Follow-up comparisons and referral letters then take minutes, instead of a hunt through free-text notes.

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Conclusion

Running the tests takes five minutes. Reading a 4/5 thenar abduction and a 7mm two-point discrimination six weeks later is the harder job. That reading depends entirely on how the first exam was written down.

So pick a sequence and keep it. Combine two provocative tests rather than trusting one. Record the numbers with their units and their side. Treat the published sensitivity figures as a range, not a verdict.

Do that and referrals get triaged faster, discharge decisions get easier to defend, and early compression gets caught before the wasting starts. Book a demo to see how Pabau keeps nerve exam findings, forms, and follow-up comparisons in one client record.

Continue your research

Need a number for thumb and finger strength? Pinch grip test covers the grades and cut-offs that back up a positive Froment’s sign.

Looking after arthritic hands as well as compressed nerves? Hand exercises for rheumatoid arthritis sets out a conservative program you can document.

Want a model for scoring a neurological exam? NIHSS score sheet shows how a fixed scoring order keeps serial assessments comparable.

Writing notes that may be read in a legal context? Safer clinical notes covers the documentation habits that protect practitioners later.

Managing musculoskeletal patients back to full function? Return-to-running protocol shows how upper and lower limb testing fits a wider rehab plan.

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