On the inner and outer sides of the elbow, thicker ligaments (collateral ligaments) hold the elbow joint together and prevent dislocation. The ligament on the inside of the elbow is the ulnar collateral ligament (UCL). It runs from the inner side of the humerus to the inner side of the ulna, and must withstand extreme stresses as it stabilizes the elbow during overhand throwing.
Several muscles, nerves, and tendons (connective tissues between muscles and bones) cross at the elbow.The flexor/pronator muscles of the forearm and wrist begin at the elbow, and are also important stabilizers of the elbow during throwing.
The ulnar nerve crosses behind the elbow. It controls the muscles of the hand and provides sensation to the small and ring fingers.