Exphysdtr

Prevention of Ulnar Nerve Entrapment (Ulnar Claw)

Ulnar Claw

Ulnar claw (also known as ulnar nerve entrapment, or claw hand) is an abnormal hand position that is caused by problems with the ulnar nerve in the forearm. An ulnar claw hand will have the 4th and 5th fingers flexed at the first knuckles and curled towards the palm at the 2nd and 3rd knuckles. The hand will display “hyper-extension of the metacarpophalangeal joints (MCP) and flexion at the distal and proximal interphalangeal (IP) joints of the 4th and 5th digits (ring and little finger) (Neiman, 683).” The clawing will become most apparent when the patient is asked to straighten their fingers. Patients with ulnar claw are also frequently unable to spread (abduct) or pull together (adduct) the fingers against resistance (Nasim 118). This occurs because the ulnar nerve also innervates the palmar and dorsal interossei of the hand. Patients with this problem will become “increasingly easy to identify over time as the paralyzed first dorsal interosseous muscle atrophies, leaving a prominent hollowing between the thumb and forefinger (Wheeless)”. An ulnar claw may occur after an ulnar nerve lesion which results in the partial or complete denervation of the medial two lumbricals of the hand . Since the lumbricals normally flex the MCP joints, “their denervation causes these joints to become extended by the newly unopposed action of the extensor muscles of the forearm (extensor digitorum and the extensor digiti minimi).” The lumbricals also extend the fingers at the interphalangeal (IP) joints. Their paralysis results in an unopposed flexion from the flexor digitorum profundus at the IP joints. The combination of hyperextension at the MCP and flexion at the IP joints gives the hand its claw like appearance (Wheeless).

Prevention

Prevention of the ulnar claw includes exercise, stretching, proper bodily function, and myofascial release.

Exercises

Exercises must be focused on the forearm muscles including the extensor carpi ulnaris and the extensor digitorum in order to antagonize the flexion of the fingers. They include the rubber band spread and the hand extension.

Stretching

Stretching the muscles around the ulnar nerve includes stretching the flexor carpi ulnaris, and the flexor digitorum profundus. This releases the tightness that may interfere with the innervations of the ulnar nerve.

Proper bodily functions include avoiding repetitive and strenuous activities with the hands, such as those conducted by landscapers, heavy duty mechanics, carpenters, and industrial insulators .” Constant gripping of heavy machinery and tools are a culprit for excessive finger flexion.

Myofascial Release

Myofascial release at the forearm muscles include massaging or foam rolling. This alleviates the tightness, or muscle adhesion, that occurs with the over-exertion of muscle tissue.

Works Cited

Afzal, Suhail, Devgun, and Dinesh Dhar. "Bony Entrapment of Ulnar Nerve After Closed Forearm Fracture." Internet Journal of Orthopedic Surgery. 4.1 (2007): 11.

Nasim Amirjani, Shelley Thompson, Lalith Satkunam, Gary L. W. Lobay and K. Ming Chan. “The Impact of Ulnar Nerve Compression at the Elbow on the Hand Function of Heavy Manual Workers.” Neurorehabil Neural Repair. 2003 17: 118

Neiman, Rafael M.D.; Maiocco, Brian M.D.; Deeney, Vincent F. M.D. “Ulnar Nerve Injury After Closed Forearm Fractures in Children.” Journal of Pediatric Orthopedics. September/October 1998. Volume 18, Issue 5. pp 683-685

Ozbek, B. Bamac, F. Budak, N. Yenigu, T. Colak. “Nerve Conduction Study of Ulnar Nerve in Volleyball Players. Scandinavian Journal of Medicine & Science in Sports. 2006: 16: 197–200.

Taylor, Nathan et al. “The Correction of Ulnar Claw Fingers: A Follow-up Study Comparing the Extensor-to-Flexor with the Palmaris Longus 4-tailed Tendon Transfer in Patients with Leprosy.” Journal of Hand Surgery. July 2004. Vol. 29, Issue 4, Pages 595-604

Wheeless, Clifford. Wheeless’ Textbook of Orthopedics. http://www.wheelessonline.com/ortho/ulnar_nerve