<prompt> Which muscle will be paralyzed when radial nerve is injured in just below be spiral groove ?Lateral head of tricepsMedial head of tricepsLong head of tricepsECRL  <response>: Ans. is d i.e., ECRLRadial nerve injury Radial nerve injury may be high or low. 1. High radial nerve palsyInjury is before the spiral grooveAll muscles supplied by radial nerve are paralysed. 2. Low radial nerve palsyInjury is after the spiral groove.Low radial nerve palsy may be of two types.Injury occurs between the spiral groove and elbow joint. Muscles involvement is : ?Elbow extensors Triceps, anconeus are spared.Wrist, elbow and finger extensors are paralysed.Sensory loss in first web space on dorsal sideInjury occurs below the elbow joint.Elbow extensors triceps, anconeus and wrist extensors ECRL are spared.Finger extensors extensor digitorum, extensor digiti minimi, extensor indicis and thumb extensors extensor pollicis longus brevis are paralysed.Sensory loss in first web space on dorsal side. 