TY - CHAP M1 - Book, Section TI - Peripheral Nerve Injury A1 - Breed, Meghan A1 - Fitch, Robert Warne A2 - Knoop, Kevin J. A2 - Stack, Lawrence B. A2 - Storrow, Alan B. A2 - Thurman, R. Jason PY - 2021 T2 - The Atlas of Emergency Medicine, 5e AB - Chronic ulnar nerve injury results in the classic claw-hand (intrinsic minus) deformity due to atrophy and contracture of the lumbrical and interosseus hand muscles. The deformity is formed by MCP joint hyperextension and flexion at the PIP and DIP joints of the 4th and 5th digits. There is wasting of the interosseous and hypothenar muscles, as well as the hypothenar eminence. The acutely injured patient is unable to abduct or adduct the digits. Chronic median nerve damage also results in the claw-hand deformity, but to the 2nd and 3rd digits with associated atrophy of the thenar. Acute and chronic damage to the proximal portion of the median nerve results in weakness of wrist flexion, forearm pronation, thumb apposition, and flexion of the 1st three digits. SN - PB - McGraw-Hill CY - New York, NY Y2 - 2024/03/28 UR - accessemergencymedicine.mhmedical.com/content.aspx?aid=1181041967 ER -