I see a number of people who suffer from carpal tunnel syndrome. Carpal tunnel is a very common condition, often related to repetitive injury at home or in the workplace. It is one of a number of repetitive strain injuries or “RSIs.”
Carpal tunnel symptoms usually include numbness and/or pain in the hand and wrist that may extend up into the arm, shoulder or even neck. The numbness, tingling or pain frequently wakes people during sleep.
To understand the condition, it’s helpful to have a lesson in wrist anatomy (see diagram). There are eight carpal bones that make up the wrist. When you hold your wrist with your palm facing up, these bones form a U-shaped valley. The top of the valley is enclosed by a piece of connective tissue called the transverse carpal ligament. These structures together form the carpal tunnel.
The tunnel is a very cramped space and some very important structures are packed into it. There are nine flexor tendons and the median nerve. The tendons that run through the tunnel connect the muscles in the palm side of the forearm to the bones in the fingers. When the muscles in your forearm contract, the tendons slide through the tunnel and pull on your finger bones, allowing you to make a fist (finger flexion).
The median nerve runs directly under the transverse carpal ligament. This nerve is responsible for the feeling in the thumb, index, middle, and the thumb side of the ring finger. It also controls the muscles in the thumb that allow you to pinch your thumb and index finger together.