Photo Quiz: Nerve Damage from Soft Tissue Injury to the Forearm

摘要

The ulnar nerve originates from the brachial plexus and contains motor and sensory fibers from the C8 and T1 roots.1, 2 It innervates many intrinsic muscles of the hand, as well as extrinsic muscles for flexion of the ring and little fingers to allow for the power grip.3 When the patient extends his fingers, the MCP, PIP, and DIP joints remain flexed. The median nerve innervates the thenar compartment, allowing for fine control of the pincer grip.2,3 Damage to the median nerve causes motor and sensory loss to the thumb, index finger, and middle finger.