Synonyms
Radiocarpal joint, ulna, radius, carpal bone (Os navicularescaphoideum = scaphoid), triangular bone (Os triquetum) Carpal
Introduction
The wrist is a joint on the hand of mammals, composed of several partial joints. In humans, the wrist is the term used to describe the wrist:
- Proximal wrist: a joint between radius and carpal bone (lat. Articulatio radiocarpalis)
- Distal wrist: The joint between the two rows of carpal bones (lat.
Articulatio mediocarpalis)
- Remaining carpal joints: are also counted as wrist in the broader sense. These are so-called tight joints (amphiarthroses), which support the wrist in its mobility, but are themselves hardly mobile.
The wrist is composed of several bones. The most important bone of the wrist is the spoke (radius).
It forms the thumb-side wrist. On the small finger side, a small part of the wrist is formed by the ulna with its stylus process (Processus styloideus ulnae). On the carpal side, the first row of carpal roots, especially the scaphoid and lunar bone, forms the joint – antagonist.
The wrist is stabilized by a tight capsule-ligament apparatus and limited in its range of motion. On the back of the hand, the so-called extensor tendons run through 6 tendon compartments as a guide rail. On the flexor side, all tendons run together with the median nerve under the carpal ligament (Ligamentum transversum carpi) through the so-called carpal tunnel.
The wrist is a so-called ellipsoid joint (egg joint with two main axes, similar to a ball joint). All partial joints of the wrist function as one unit and enable the complex movements of the wrist. They enable flexion towards the palm of the hand (palmar flexion) by about 80°, and extension towards the back of the hand (dorsal extension) by about 70°.
In addition, the wrist allows spreading movements (abduction) towards the thumb (radial abduction) and towards the little finger (ulnar abduction) by approx. 30 to 40°.
- Ulna (ulna)
- Spoke (radius)
- Wrist
- Stylus process (Processus styloideus ulnae)
- Moon leg (Os lunatum)
- Scaphoid (Os naviculare)
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