Extensors and flexors

Extensors and flexors

Asking the patient to grip two of your fingers in their fist tests the power of the extensors of the wrist (radial nerve) because Jules Froment , 1878–1946, Professor of Clinical Medicine, Lyons, France. they are needed to brace the wrist. It also tests the power of the flexors in the forearm (median nerve). Asking the patient then to extend and spread their fingers apart against resistance tests the intrinsic muscles of the hand (mainly the ulnar nerve).

Signi /f_i cance Tests the adequacy of the blood supply to the hand from the radial and ulnar arteries and the arcade between them Identi /f_i es compression of a peripheral nerve Compression of the medial nerve causes paraesthesia A positive test indicated by /f_l exion of the thumb interphalangeal joint suggests weakness of the adductor pollicis muscle supplied by the ulnar nerve. Recruitment of the median nerve-innervated /f_l exor pollicis brevis explains the thumb posture