The wrist is among the most complicated joints in the human body, made up of many muscles, tendons, ligaments, and small bones that connect the hand to the forearm and allow it to move and rotate.
The eight carpal bones, four of which are located at the bottom of the hand and four at the top of the wrist, are collectively referred to as the carpus. Where the carpus meets the two bones of the forearm (the radius and ulna) is where the “wrist” as we think of it is formed. Technically, the wrist is not one single joint, but several, where two or more bones meet and create movement.
The many wrist bones are connected by ligaments, strong connective tissues that hold them together. There are four major ligaments in the wrist, running on both sides from the radius and ulna through the various bones of the carpus; some aid the movement of the wrist itself while others support the movement of the hand. Ligaments are not only connective: they also help to make the joint more stable, ensure that the hand follows the forearm when they move, and prevent the thumbs and fingers from bending backward.
Tendons are tough connective tissues that connect muscle to bone; this allows the muscles to move the bones with them. There are six major groups of tendons in the wrist and hand: some pass through the palm, others the back of the hand, and they connect the bones of the fingers and thumbs to those in the forearm. Tendons work with muscles to allow the wrist and hand to extend, flex, and rotate.
Three nerves also run through the wrist and hand, supplied with blood by the nearby ulnar and radial arteries. Nerves allow you to feel sensations such as pain and touch.