ORTHOTICS FOR YOUR FEET
BONES OF THE ELBOW
Three bones meet to form the elbow: The humerus, the ulna and the radius. The humerus is the bone in your upper arm, and the part of the humerus that meets the elbow is called the distal humerus. The ulna and the radius are the two bones that make up the forearm.
If you were to hold your hand out with your palm facing upwards, the ulna would be on the inner, or medial, side while the radius would be on the outer, or lateral side. The ulna is the larger of the two forearm bones, with a bony prominence at the elbow called the olecranon. The olecranon and the distal humerus form the hinge-like humeroulnar joint, which allows for bending and straightening movements.
The end of the radius that meets the elbow is called the radial head, and it meets the humerus to form the humeroradial joint, which acts similar to the hinge-like humeroulnar joint. The radial head also articulates with the ulna to form the proximal radioulnar joint, which allows for rotating movements of the forearm, for example when you have your wrists turned down to type.