Question

Why can't we fold our elbow backward?

Answer 1

Being a hinge joint, the only movement allowed by the elbow are flexion and extension of the joint and rotation of the radius. The range of motion of the elbow is limited by the olecranon of the ulna, so that the elbow can only extend to around 180 degrees. Flexion of the elbow is limited only by the compression of soft tissues surrounding the joint.