The thumb action that is totally affected in radial nerve trauma -
Radial nerve injury
-        High radial nerve palsy- Injury above the spiral groove.
o   Paralysis of all muscles supplied by radial nerve.
o   Clinical features

Wrist drop, finger drop, thumb drop
Extension affected of- elbow, wrist, thumb and fingers
Sensation affected of- posterior surface of arm and forearm and lower lateral half of forearm.

-        Low radial nerve palsy- Injury below the spiral groove.
o   Type I- Injury between spiral groove and elbow.

Elbow extensors are spared- Triceps and Anconeus.
Wrist, thumb and finger extensors paralysed- wrist drop, thumb drop, finger drop.
Loss of sensation on dorsal side of first web space.

o   Type II- Injury below the elbow joint.

Elbow and wrist extensors spared
Thumb and finger extensors paralysed.(extensor digitorum, extensor digiti minimi, extensor indicis, extensor pollicis longus, extensor pollicis brevis)- Thumb drop and finger drop.
Loss of sensation on dorsal side of first web space.
Abduction
Adduction
Extension
Flexion