The hand and wrist are composed of multiple bones. In biomechanical studies that do not focus specifically on hand motion, the hand is often considered as a single unit.
The wrist consists of eight carpal bones that form an ellipsoid-type synovial joint, enabling movement in two axes. This joint allows the wrist to flex, extend, adduct, and abduct.
The metacarpals make up the bones of the palm and extend distally from the wrist joint.
Each of the fingers have three phalanges (proximal, middle, and distal) and the thumb has two (proximal and distal).
Many of the muscles that control the movement of the wrist and hand are located in the forearm. On the palm side of the forearm, several long tendons pass through the carpal tunnel on their way to attach to the fingers. These tendons are covered in a sheath that can become inflamed with overuse. Swelling within the carpal tunnel can result in compression of the median nerve that can then lead to carpal tunnel syndrome characterized by pain, numbness, and tingling in the thumb, index and middle fingers.
