The wrist is a surprisingly complicated joint, with multiple bones and soft tissues—tendons, ligaments, and muscles—to enable the hands to be both flexible and strong. Some experts speculate that it’s the most complex joint in the body.
In fact, it may be argued that there’s no such thing as a single “wrist joint” since the wrist contains many joints that articulate to allow movement.
This article reviews the complex makeup of the wrist and how it is susceptible to injury and painful conditions.
The Many Bones in and Around the Wrist
The wrist is made up of several small bones that are interconnected with tendons and ligaments, allowing movement and rotation in all directions.
There are two long parallel bones in the forearm that run from the elbow to the wrist: the larger bone, the radius, is on the same side as the thumb, and the smaller bone, the ulna, is on the pinky finger side. Most wrist fractures are the result of a break in the radius bone near the end closest to the wrist—known as distal radius fractures.
At the wrist end of the radius and ulna are two rows of small round bones—four in each row—known as the carpal bones:
- The row closest to the forearm are the proximal carpals
- The row closer to the fingers are the distal carpals
In This Article:
- Guide to Wrist Anatomy
- Ligaments, Tendons, and Nerves of the Wrist
The carpal bone most susceptible to fracture is called the scaphoid bone and is located near the base of the thumb.
The distal carpals connect to the metacarpals, long bones in the hand that connect to the thumb and each finger.
There are two main joints enable the majority of wrist movement: the radiocarpal joint (between the radius and proximal carpals) and ulnocarpal joint (between the ulna and proximal carpals). The carpal bones all have articular cartilage on their surfaces and move slightly in relation to each other, but not much.