The Wrist

The wrist can refer to multiple anatomical connections around the hand.

1. The connection between the radius and the carpal bones (the overall radiocarpal joint and commonly used term).
2. The connection between all of the eight little carpal bones.
3. Or the connection between the bones of the forearm, eight carpal bones, and the metacarpals of the hand.

Note: For this wiki the last definition will be used focusing on the overall movement of the wrist in terms of martial arts.

Bones: Radius, ulnar, eight carpals composed into two rows, the metacarpals.

Cartilage: There is an articular disc between the radius and the carpal bones.

Ligaments: There are intrinsic ligaments that connect only between (to and from) the carpal bones. There are also extrinsic ligaments that connect the carpals to the radius and ulnar or the metacarpals.

Tendons: There are a number of long thing tendons that run about a third of the forearm from the wrist, these connect to the bones and help bend the wrist. They are most prevalent on the bottom of the wrist where if relaxed can easily be felt.

Muscles: There are three little flexor muscles on the underside of the forearm that contract and pull the hand down downwards. There are also three little extensor muscles on the top of the forearm that contract and pull the hand upwards. A combination of extensors and flexors is used to deviate the wrist from side to side.

Range of motion: The wrist is able to flex downwards at roughly an 80 degree angle. With extension the hand is able to bend upwards about 70 degrees. The wrist is capable of deviating to the side towards the radius at roughly 20 degrees and towards the ulnar at roughly 40 degrees.

Manipulation: The wrist is very nice starting point for securing an attacker. Many wrist locks start with the locker grabbing the attacker's hand and wrapping their fingers around the metacarpal of the thumb and the locker's thumb between the metacarpal of the index and middle finger. The reason for this being is that immediate pressure is put on the (radial) carpal bones. Additional pressure will start to rip intrinsic and extrinsic ligaments and then put pressure on the tendons of the flexors and extensors. With a twist pressure can be channeled to the supinators and the pronators of the forearm as well as pressure on the elbow.

The overall mechanics of these locks on the wrist can be simple but the forces the exert on all the bones, muscles, ligaments, and tendons can be quite complex. For some nice wrist examples please look at the the Hapkido Joint Locks page.

Injury: The main concern for injury with applied pressure being damage to the tendons and ligaments around the wrist. Falling on palm of the hand is likely fracture one of the small carpal bones which can take 8 to 12 weeks to heal.

Stretching: Due to the pressure on the wrist it is best for martial artists to stretch their wrists, which would give them additional room for their wrist to bend giving them the needed second to get out of the hold. This stretching will also slightly decrease the pain of the beginning of a wrist lock. For more on stretching the wrist please visit the Wrist Stretches page.

For information on additional joints please refer back to the Joints page.