Ulnar Stress Fracture occurs when repetitive overuse—most often in athletes like pitchers—leads to a slight cracking of the ulna, the lower arm bone on the pinky side. Unlike traumatic fractures that occur suddenly, stress fractures can develop over a long period of time and be indicated by nothing more than chronic pain upon activity.

Unless the bone is completely broken, an Ulnar Stress Fracture will usually respond to rest, icing and splinting.