Finger abduction (spread fingers against resistance)
Grip card between little and ring fingers with hands held vertically. Examiner tries to pull card away. (Tests adduction of little finger.)
Grip card between thumb and index fingers with hands held vertically. Examiner tries to pull card away. (If adductor pollicis is weak, patient will flex their thumb to grip the card – ‘Froment’s sign’.)
Radial (commonest causes: humeral shaft fracture, compression over spiral groove/Saturday night palsy)
Finger extension (all together at MCP joint) – posterior interosseous nerve
Thumb extension (with hand vertical, point thumb to ceiling – ‘Don’t let me push it down’)
Sensory (light touch)
Palm facing up
Over DIP joint of index finger (median nerve)
Over DIP joint of little finger (ulnar nerve)
Palm facing down
Anatomical snuffbox (radial nerve)
Special tests for carpal tunnel syndrome
Test: reverse prayer sign for 1 minute
Positive test: causes pain and paraesthesia in median nerve distribution.
Test: tap median nerve at its course in wrist
Positive test: worsening paraesthesia
Function: test pincer grip; prayer sign; carry out everyday tasks (e.g. undo buttons, write a sentence, hold cup, turn key)
Summarise and suggest further investigations you would consider after a full history
You need to know which muscles are supplied by which nerve
Which hand muscles does the median nerve supply?
Which hand muscles does the ulnar nerve supply?
Which hand muscles does the radial nerve supply?
Here’s a couple more questions
What can cause damage to the ulnar nerve and how would this present?
What are the different management options for carpal tunnel syndrome?