Carpal Tunnel Syndrome
The carpal tunnel is a narrow passage on the palm side of the wrist, formed by the carpal bones. The tendons that bend the fingers and wrist run through this space, together with a sensory nerve, the median nerve, which supplies the thumb, index finger, middle finger and part of the ring finger. The tunnel is covered by a tough ligament, the flexor retinaculum, which stops the wrist tendons from bowstringing outward when the wrist is bent. There is little or no room for expansion within the carpal tunnel, so any swelling at that site – whatever the cause – compresses the median nerve and interferes with nerve signal conduction.
Carpal tunnel syndrome also falls under the umbrella term RSI (repetitive strain injury), which covers a number of specific tendon-, nerve- and muscle-related conditions of the neck and arm. More recently the term CANS (complaints of arm, neck and/or shoulder) has also come into use, since RSI doesn't distinguish clearly enough between the different conditions it covers. However, RSI is still so established that it remains the most commonly used term.
Symptoms
The complaints are caused by compression of the nerve and consist of a tingling or painful sensation in the hand and fingers, particularly in the area supplied by the median nerve – the thumb, index and middle fingers and part of the ring finger. Numbness in the fingertips can also occur, along with reduced grip strength that makes it easy to drop things. Sometimes the hand can feel as though it is swollen. The pain can radiate up through the forearm and elbow as far as the shoulder…