Nerve Entrapments in Arm

Nerve entrapment occurs when a nerve is compressed by surrounding joints, muscles and tendons and results in irritation or injury to the nerve. Common upper extremity nerve entrapments seen in physical therapy include ulnar nerve entrapment (Cubital Tunnel Syndrome; Guyon’s Syndrome) and median nerve entrapment (Carpal Tunnel Syndrome).

Ulnar Nerve Entrapment (Cubital Tunnel Syndrome)
Ulnar nerve entrapment at the elbow, also known as Cubital Tunnel Syndrome, is the second most common nerve entrapment treated in physical therapy. It occurs when the ulnar nerve is compressed as it passes the elbow through the Cubital Tunnel.

Cubital Tunnel Syndrome can occur from trauma (such as elbow dislocations or radial/humeral fractures), excessive swelling or bony abnormalities. It may also occur after extended periods with the elbow bent, such as prolonged sling use.

Signs and symptoms of Cubital Tunnel Syndrome:

• Pain and sensitivity to the inside (ulnar side) of the forearm, wrist or hand
• Numbness and tingling to the pinky and/or ring fingers
• Pain and weakness with gripping
• Severe cases may present with clawing of the pinky and ring fingers (sign of Benediction; when trying to make a fist, the ring and little finger flex but the index and middle finger cannot flex at the metacarpal-phalangeal joint or interphalangeal joint.)

Physical therapy examination of upper extremity nerve entrapments include:

• Extensive history of symptom onset and progression
• Range of motion of the elbow, wrist and fingers
• Strength assessment of affected muscles
• Sensation testing
• Special tests including: Froment’s Sign, Phalen Maneuver, Tinnel’s sign and neurodynamic assessment

The neck and shoulder are also screened to rule out other diagnoses that can refer symptoms to the wrist or elbow.

References:

• Descatha A, Dale AM, Franzblau A, Coomes J, Evanoff B. Diagnostic strategies using physical examination are minimally useful in defining carpal tunnel syndrome in population-based research studies. Occup Environ Med 2010; 67:133–135
• Futterman B. Analysis of the Papal Benediction Sign: the ulnar neuropathy of St. Peter. Clinical Anatomy. 2015 Sep;28(6):696-701.
• Han HH, Kang HW, Lee JL, Jung S. Fascia Wrapping Technique: A Modified Method for the Treatment of Cubital Tunnel Syndrome. The Scientific World Journal. 2014; Article ID 482702, 6 pages. doi:10.1155/2014/482702
• Miller, Theodore T., and William R. Reinus. “Nerve entrapment syndromes of the elbow, forearm, and wrist.” American Journal of Roentgenology 195.3 (2010): 585-594.
• Neuropathy of Ulnar Nerve (Entrapment). MD Guidelines. http://www.mdguidelines.com/neuropathy-of-ulnar-nerve-entrapment/differential-diagnosis. Accessed September 29, 2022.
• Palmer BA, Hughes TB. Cubital Tunnel Syndrome. J Hand Surg. 2010; 35(1): 153–163.
• Ulnar Nerve Entrapment. Physiopedia. https://www.physio-pedia.com/Ulnar_Nerve_Entrapment. Accessed September 29, 2022.
• Lawrence RC, Felson DT, Helmick CG, et al.; National Arthritis Data Workgroup. Estimates of the prevalence of arthritis and other rheumatic conditions in the United States. Part II. Arthritis Rheum 2008; 58:26–35 49. 

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