Conditions & Treatments - Cubital Tunnel Syndrome

Cubital tunnel syndrome (ulnar nerve entrapment) is the second most common peripheral nerve entrapment neuropathy in the upper limb behind carpal tunnel syndrome (1, 2). At the elbow the ulnar nerve traverses behind the medial epicondyle in a groove that is converted into an osseofibrous canal, the cubital tunnel, by the arcuate ligament (aponeurosis which connects the ulnar and humeral heads of the flexor carpi ulnaris) which runs from the medial epicondyle to the olecranon process (1). When the elbow is flexed at 90 degrees the arcuate ligament is taut and when the elbow is extended it is laxed (1). This unusual anatomy of the cubital tunnel along with the increase intraneural pressure associated with elbow flexion are believed to contributing factors to the development of cubital tunnel syndrome (2).

Causes and Symptoms
Entrapment or irritation of the ulnar nerve at the elbow may be associated with 1) osseous degenerative changes 2) compression caused by a thickened retinaculum or hypertrophied flexor carpi ulnaris muscle 3) recurrent subluxations or dislocation 4) direct trauma and 5) traction caused by an increase laxity of the medial complex that causes a compressive force on the nerve resulting in a tension neuropathy (1).

Entrapment neuropathy of the ulnar nerve is common especially after prolonged sitting, overuse of the elbow, or repeated microtrauma from occupations that involve leaning on the elbow (1, 2). It is generally found in throwing athletes, racquet sports enthusiasts, weight lifters and manual laborers (1, 2).

Symptoms which are associated with cubital tunnel syndrome include pain or paresthesias in the sensory distribution of the ulnar nerve, clumsiness of the hand as a result of weakness, hyperesthesia, complaints of muscle cramping, dull ache after activity or rest, aggravation of symptoms with activity and pain which may radiate up the forearm to the elbow and as far as the shoulder (1, 2).

Examination / Findings for Cubital Tunnel Syndrome (3)
1) Tenderness over the course of the ulnar nerve
2) Abnormal Tinel sign over the ulnar nerve as it passes through the cubital tunnel
3) Ulnar nerve compression test abnormal
4) Elbow flexion test abnormal (variable)
5) Abnormal sensation (two point discrimination or light touch), little finger (fifth finger); ulnar aspect of ring finger (fourth finger); ulnar aspect of hand (variable)
6) Weakness and atrophy of the ulnar-innervated intrinsic muscles of the hand (variable)
7) Weakness of flexor digitorum profundus to the little finger (variable)
8) Signs of concomitant ulnar nerve instability, elbow instability, or elbow deformity (occasionally)

Cubital Tunnel Syndrome Treatment Options for a PT
• Rest
• Night splint
• ROM exercises
• Stretching
• Strengthening / Stabilization
• Manual Therapy
• Nerve Gliding
• Postural Training
• Modalities (ice, ultrasound, phonophoresis, iontophoresis)
• Functional training / Work place modification

Last revised: December 21, 2014
by Chai Rasavong, MPT, COMT, MBA

References
1) Hertling D & Kessler R. Management of Common Musculoskeletal Disorders: Physical Therapy Principles and Methods. Fourth Edition. Lippincot Williams & Wilkins. 2006;226, 230, 379.
2) Cutts S. Cubital Tunnel Syndrome. Postgraduate Medical Journal. Jan 2007; 83(975): 28-31.
3) Brotzman S.B., Wilk K. Clinical Orthopaedic Rehabilitation. Philadelphia, PA: Mosby. 2003; 88.