Injury to radial nerve in lower part of spiral groove-
Spares nerve supply to extensor carpi radialis longus
Results in paralysis of anconeus muscle
Leaves extensions at elbow joint intact
Weakens pronation movement
Radial nerve injury
-        High radial nerve palsy- Injury above the spiral groove.

   Paralysis of all muscles supplied by radial nerve.
   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.

   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.

   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.