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