The TuneUp Program

The wrist is comprised of two rows of small irregular shaped bones called carpals that articulate with each other as if they were two individual units. The proximal row also articulates with the forearm (the radius and the radioulnar disk) at the radiocarpal joint while the distal row articulates with long bones in the hand (the metacarpals). Within each of the rows much smaller movements can occur between individual carpals.

The range of motion at the wrist is limited by the shape of these articulating bones. They don't fit together too well. Flexion and extension of the wrist require the two rows slide across each other, eventually locking up due to tension in the connecting ligaments and the individual bones contacting each other.

Flexion of the wrist involves bringing the palm toward the inside of the forearm, like when your fingerpicking. The maximum range is about 85˚. The opposite movement, extension has a range of between 70˚ and 80˚. It can also move from side to side, radial deviation, or movement to the side the thumb is on is about 20˚ to 25˚while ulnar deviation is between 30˚ and 35˚.

The main function of the wrist is to adjust the tension in the muscles that control the hand and fingers. Because they cross the wrist their length and therefore the passive tension in the connective tissue will change as the wrist moves.