Clinical features of radial nerve palsyClinical features depend upon the site of the lesion.1) 1f lesion is highWrist drop, thumb drop and finger drop. Inability to extend elbow, wrist, thumb & fingers (MP joint) The patient can extend interphalangeal joints due to the action of lubricants and interossei. Sensory loss over posterior surface of arm & forearm and lower lateral half of forearm.2) If the lesion is low a) Type IWrist drop, thumb drop and finger drop. Elbow extension is preserved. Sensory loss over the dorsum of first web space.b) Type IIThumb drop and finger drop Elbow and wrist extension is preserved Sensory loss over the dorsum of first web spaceClinical features of posterior interosseous nerveIt is prone to be injured in injury & operations of radial head- neck. There is no sensory deficit as it is a pure motor nerve. Wrist extension is preserved (i.e. no wrist drop) due to spared extensor carpi radialis longus . Presents with loss of extension of metacarpophalangeal (MP) joints i.e., thumb & finger drop.