Radius Ulna
The radius and ulna shape the forearm: they lie distal to the elbow and above the carpus (“knee”). These bones are covered on three sides by muscle groups that allow flexion and extension of the distal forelimb. Injury to the radius and ulna is uncommon, but cause a non-weight bearing lameness characterized by a dropped elbow. Physical examination findings include swellings, heat, and pain on palpation of the bone and/or muscle groups. Fractures of the radius and ulna occur infrequently in the horse.