POSTERIOR INTEROSSEOUS NERVE PALSY

Eleven patients with non-traumatic paralysis of posterior interosseous innervated muscles were divided into three types, and the association between the type of paralysis and sites of compression was investigat ed. Type 1 (drop finger and thumb) showed a simultaneous compression o f the recurrent branch and the descending branch at the entrance point and within the supinator. Type 2 (drop fingers) had compression of th e recurrent branch alone, and Type 3 (drop thumb) had compression of t he descending branch alone. The exit point from the supinator is consi dered to be the site of compression in Types 2 and 3.