Wrist drop is due to injury to -

Ans. is 'a' i.e.. Radial nerve Clinical features of radial nerve palsyo Clinical features depend upon the site of lesion.If lesion is highWrist drop, thumb drop and finger drop.Inability to extend elbow, wTist, thumb & fingers (MP joint)Patient can extend interphalangeal joints due to action of lumbricals and interossei.Sensory' loss over posterior surface of arm & forearm and Iowrer lateral half of forearm.If lesion is lowType IWrist drop, thumb drop and finger drop.Elbow extension is preserved.Sensory loss over the dorsum of first web space.Type IIThumb drop and finger dropElbow' and wrist extension is preservedSensory loss over the dorsum of first web space.