<prompt> Injury to radial nerve in lower pa of spiral groove:Spares nerve supply to extensor carpi radialis longusResults in paralysis of anconeus muscleLeaves extensions at elbow joint intactWeakens pronation movement  <response>: 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 