California Self-Insurance Plans (SIP) Practice Exam 2026 - Free SIP Practice Questions and Study Guide

The olecranon is the bony projection of the ulna at the elbow. It’s the large, palpable bump at the back of the elbow and serves as the attachment site for the triceps muscle. When the arm extends, the olecranon fits into the corresponding fossa of the humerus, forming the elbow joint’s hinge mechanism. The radius is the other forearm bone, the humerus is the upper arm bone, and the clavicle is the collarbone, so none of them describe the ulna’s elbow projection.