Carpal Tunnel Syndrome

Carpal tunnel syndrome (CTS) is one of the most common complaints relating to the upper extremity that affects workers. CTS is poorly understood by clients and the general population. People need to understand what the carpal tunnel is, how they develop CTS, why repetitive tasks like typing are associated with the disorder, and how to relieve their symptoms.

The carpal tunnel is an anatomical structure at the base of the wrist. The carpal bones of the wrist form the floor of the structure while flexor retinaculum or transverse carpal ligament form the roof (Presazzi, Bortolotto, Zacchino, Madonia, & Draghi, 2011). The retinaculum is about 3 cm wide and inserts in the scaphoid tuberosity into the pisiform , and subsequently into the trapezium and the hook of the hamate. Importantly, the carpal tunnel contains nine tendons and a nerve: the flexor pollicis longus, the four flexor digitorum superficialis, and the four flexor digitorum profundus tendons, and the median nerve (Presazzi et al., 2011). The median nerve is vital to understanding CTS.

Scanlon and Maffei (2009) state that any decrease in the space of the carpal tunnel with chronic wrist flexion or extension, increases in mass of the tendons in the tunnel, or external forces compressing the median nerve can elicit CTS. Repetitive use of the wrist with the motions of rotation, flexion, and extension can cause excessive pressure on the nerve (Scanlon & Maffei, 2009). Since the median nerve innervates the forearm wrist, fingers, sufferers of CTS can experience pain and burning in the arm, wrist pain at night, numbness in the fingers, and weakness of the hand muscles. These wrist motions are common in the workplace. Tasks such as cooking, using a computer, and mechanical work all involve complex wrist motions. In a detailed study of occupations, Harris-Adamson et al. (2015) concluded that tasks where the wrist is over extended or flexed greater than 30, tasks where there are forceful hand repetitions, and tasks where a large percentage of time is spent using the wrist and hands may increase a person’s chances of developing CTS. People who spend large amount of time using forceful, repetitive hand and wrist motions at work are at higher risk of developing CTS.

In addition to splinting, local steroidal injections, surgery and anti-inflammatory drugs, therapeutic exercise, called nerve and tendon gliding can help relieve CTS symptoms. During these exercises, pressure is redistributed from the median nerve, which in turn increases venous return from the nerve, which in turn should decrease pressure in the carpal tunnel (Akalin et al., 2002). The five tendon gliding exercises consist of holding the fingers in discrete positions; straight, hook, fist, table top, and straight fist (Akalin et al., 2002). In the nerve gliding exercises there are six positions to make with the wrist; grasping, finger extension, wrist extension, thumb extension, forearm supination, and gentle stretching of the thumb by the opposite hand (Akalin et al., 2002). These exercises were effective in reducing pain associated with CTS.

References

Akalin, E., El, A., Peker, A., Aenocak, A., Tamci, A, Galbahar, S., . . . Ancel, S. (2002). Treatment of carpal tunnel syndrome with nerve and tendon gliding exercises. American Journal of Physical Medicine & Rehabilitation, 81(2), 108-113.

Harris-Adamson, C., Eisen, E. A., Kapellusch, J., Garg, A., Hegmann, K. T., Thiese, M. S., . . . Rempel, D. (2015). Biomechanical risk factors for carpal tunnel syndrome: A pooled study of 2474 workers. Occupational and Environmental Medicine, 72(1), 33-41.

Presazzi, A., Bortolotto, C., Zacchino, M., Madonia, L., & Draghi, F. (2011). Carpal tunnel: Normal anatomy, anatomical variants and ultrasound technique. Journal of Ultrasound, 14(1), 40-46.

Scanlon, A., & Maffei, J. (2009). Carpal tunnel syndrome. The Journal Of Neuroscience Nursing, 41(3), 140-147.