The ulnar collateral ligament (UCL) attaches your upper arm bone to the ulna, one of the bones in your forearm. The UCL supports your elbow and helps you perform certain motions, like throwing a baseball.
Overuse or trauma can cause the UCL to tear, causing elbow pain and instability, making it difficult or impossible to throw a ball.
Tommy John surgery is a UCL tear treatment that gets its name from a baseball pitcher – the first person to undergo a UCL reconstruction procedure and return to play successfully.
