Radial Nerve Anatomy and Function The Radial nerve is the nerve of elbow, wrist and digital extension. Sensation to the skin over the back of the arm, forearm and first web space and the wrist and elbow joints. It arises from C5, C6, C7 , C8 and T1 roots via the posterior cord. The first motor branches are to the triceps, these run along with the radial nerve (having branched from it) through the triangular space. When clinically assessing the Radial nerve remember: • Triceps branches arise from the radial nerve very high; prior to the triangular space & are not usually affected even in a high radial nerve injury. • ECRL extends and radially deviates the wrist and it is lost in a radial nerve injury. • Thus a PIN palsy does not involve a wrist drop: ECRB and ECU are lost (which provide central and ulnarly deviated wrist extension) but ECRL remains leading to a radially deviated wrist when extending. • As a degenerative Radial nerve (or PIN) palsy recovers there is a progressive recovery of function in this order; (BR, ECRL) ECRB, Sup, ECU, EDC, EI, EPB, APL, EPL. by Dr. Tom Quick @TJQPNI via orthohub.xyz @OrthohubXYZ #Radial #Nerve #Anatomy #diagnosis #neurology #orthopedics
