| Humeroulnar joint | |
|---|---|
 Leftelbow-joint, showing anterior andulnar collateral ligaments | |
| Details | |
| Identifiers | |
| Latin | articulatio humeroulnaris |
| TA98 | A03.5.09.002 |
| TA2 | 1773 |
| FMA | 38854 |
| Anatomical terminology | |
Thehumeroulnar joint (ulnohumeral ortrochlear joint[1]) is part of theelbow-joint. It is composed of two bones, thehumerus andulna, and is the junction between thetrochlear notch of ulna and thetrochlea of humerus.[1] It is classified as a simplehinge-joint, which allows for movements offlexion,extension andcircumduction.[2][page needed] Owing to the obliquity of the trochlea of the humerus, this movement does not take place in the antero-posterior plane of thebody of the humerus.
When the forearm is extended andsupinated, the axis of thearm andforearm are not in the same line; the arm forms anobtuse angle with the forearm, known as thecarrying angle. During flexion, however, the forearm and the hand tend to approach the middle line of the body, and thus enable the hand to be easily carried to the face.
The accurate adaptation of the trochlea of the humerus, with its prominences and depressions, to the trochlear notch of the ulna, prevents anylateral movement.
Flexion in the humeroulnar joint is produced by the action of thebiceps brachii andbrachialis,[3] assisted by thebrachioradialis, with a tiny contribution from the muscles arising from themedial epicondyle of the humerus.
Extension in the humeroulnar joint is produced by thetriceps brachii[4] andanconeus muscle, with a tiny contribution from the muscles arising from thelateral epicondyle of the humerus, such as theextensor digitorum muscle.
This article incorporates text in thepublic domain frompage 321 of the 20th edition ofGray's Anatomy(1918)
