Ulna - Ulna

Anatomical hierarchy

Translations

The ulna is the caudolateral bone of forearm, divide into three segments:

The development of ulna varies considerably between species due to the evolution of rotation movement in forearm:

In human, the ulna is well developped due to an important rotational movement (pronation and suppination).
In carnivores, the movement is quite limite but the radius and ulna remains separate.
In the pigs, the rotation is prevented by firm soft tissue bridging the interosseous space.
In horses and ox, there is no movement and the two bones are fused.

Text by Antoine Micheau, MD - Copyright IMAIOS