<prompt> Injury to radial nerve in the lower part of spiral groove -Spares nerve supply to extensor carpi radialis longusResults in paralysis of anconeus muscleLeaves extensions at elbow joint intactWeakens pronation movement  <response>: Radial nerve injuryRadial nerve injury may be high or low.1 High radial nerve palsyThe injury is before the spiral grooveAll muscles supplied by radial nerve are paralysed.2 Low radial nerve palsyThe injury is after the spiral groove.Low radial nerve palsy may be of two types.i Type I: - Injury occurs between the spiral groove and elbows joint. Muscles involvement is : -aElbow extensors Triceps, anconeus are spared.bWrist, elbow and finger extensors are paralysed.c Sensory loss in first web space on dorsal sideii Type II: - Injury occurs below the elbow joint.a Elbow extensors triceps, anconeus, Brachioradialis and wrist extensors ECRL are spared.b Finger extensors extensor digitorum, extensor digit minimi, extensor indices and thumb extensors extensor pollicis longus brevis are paralysed.c Sensory loss in first web space on dorsal side. 