Carpal Tunnel Syndrome (CTS)

Carpal Tunnel Syndrome is a painful and disabling cumulative trauma disorder characterized by inflammation and swelling in the tendons that run through the narrow carpal tunnel in the wrist.

Incidence; Causes and Development

One of the most common of repetitive motion injuries, the World Health Organization categorizes it as a work-related musculoskeletal disorder.  Reportedly responsible for 30-40% of workers' compensation claims in the early 1990s, it afflicts burgeoning numbers of office workers.

Underside of left wrist: The carpal tunnel, passing under the transverse carpal ligament (white), contains tendons and nerves

The carpal tunnel is a narrow channel of fixed diameter that contains tendons and nerves.  Carpal Tunnel Syndrome symptoms occur when there is pressure on the median nerve (center, red in the diagram.)

Carpal Tunnel Syndrome is caused by excessive and unrelieved repetition of movements that in themselves appear harmless, such as cutting vegetables or typing on a computer keyboard.  In addition to high frequency of repetition and lack of rest periods, factors that increase risk of hand-wrist damage include awkward or unnatural working posture, use of excessive force in performing a task, and emotional stress.

Some common conditions that can lead to CTS include obesity, using oral contraceptives, hypothyroidism, arthritis, diabetes, and trauma.

Signs and Symptoms

Numbness, tingling, and pain in the base of the thumb and the first three fingers results from the compression of the median nerve, which shares the carpal tunnel with tendons.

Treatment and Prevention

Treatment includes rest, exercises, wrist splints, anti-inflammatory medications, learning stress-reducing movement techniques, making adjustments to the individual's workstation, and surgery to reduce pressure on the afflicted nerve.