The most common nerve entrapment syndrome, carpal tunnel syndrome results from compression of the median nerve in the wrist where it passes through the carpal tunnel. (See Locating the carpal tunnel.)

The median nerve controls motions in the forearm, wrist, and hand, such as turning the wrist toward the body, flexing the index and middle fingers, and many thumb movements. It also supplies sensation to the index, middle, and ring fingers. Compression of this nerve causes loss of movement and sensation in the wrist, hand, and fingers.

Carpal tunnel syndrome, which usually occurs in females between ages 30 and 60 and is especially high in postmenopausal females, may pose a serious occupational health problem. It’s one of the three most common work-related injuries, largely because of the increased number of people using computers. However, the syndrome may also occur in people working in other occupations where continuous wrist movement is common—for example, butchers, computer operators, and concert pianists. Any strenuous use of the hands—sustained grasping, twisting, or flexing—aggravates the condition.