The Elbow

Motor palsy of the Radial nerve results in paralysis of (the triceps), the supinator and three essential functions of the hand:

extension of the wrist (all three wrist extensors are supplied by the radial nerve)

extension and retroposition of the thumb.

extension of the the metacarpophalangeal joints of the fingers.

All this results in a characteritic "drop hand".

As the fibres, supplying the triceps arise high in the axilla, paralysis of the triceps is rather rare.

Sensory deficit is over the dorsal aspect of the thumb, the radial side of the wrist and arm and the dorsal aspects of the index finger, middle finger and radial side of the ring finger - except for the distal phalanx's of these fingers