It is directly inferior to the coronoid fossa anteriorly and to the olecranon fossa posteriorly. Flexor carpi ulnar&colon; originates on the olecranon and inserts on the accessory carpal bone. In the forelimb, the ulna is exceptionally robust with a large olecranon process. The ulna is very robust with an enormous olecranon. It is formed by the olecranon and the coronoid process. The third landmark is the olecranon found at the head of the ulna. In the lower arm the robust ulna has a well-developed olecranon process. The ulna is straight, thick with a well developed olecranon. A unique feature is a lack of the olecranon process on the ulna. It is also proximal to the olecranon fossa. Trauma to the elbow often results in comminuted fractures of the olecranon. These apophyseal centers then fuse during adolescence, with the internal epicondyle and olecranon fusing last. It is inserted posteriorly on the olecranon. Fractures of the olecranon are common injuries. People with olecranon fractures present with intense elbow pain after a direct blow or fall.