Wrist Extensor Deficit Detection Test – A Simple Test to Determine Wrist Extension Caused by Digital Extensors in Patients with Extended Upper Brachial Plexus Palsy

Abstract

Motor deficit in patients with extended upper brachial plexus palsy is variable. A patient with only thumb and finger extensors may seem to have active wrist extension because of them secondarily acting at wrist and causing wrist extension. To determine the presence of wrist extensors, it is important to block the wrist extension caused by the finger and thumb extensors. Conventional muscle testing is often ineffective in these patients as they learn a variety of trick movements over the time. We describe a simple clinical test to reveal the strength of the wrist extensors only by negating the effect of digital extensors on the wrist. If wrist extensors are absent, a nerve or tendon transfer can be done to address this deficit and improve the functional outcome. Level of Evidence: Level V (Diagnostic)