Injury to radial nerve in lower pa of spiral groove:
C i.e. Leaves extension at elbow joint intact Triceps, anconeus are supplied by radial nerve above the level of spiral groove; so these are spared in injuries of radial n. at & below spiral groove thus leaving elbow extension intact Q
Spares nerve supply to extensor carpi radialis longus
Results in paralysis of anconeus muscle
Leaves extensions at elbow joint intact
Weakens pronation movement