Having elbow pain throwing in baseball. which ligaments are usually the problem?

Ulnar collateral: The ligament that is placed through the most strain is the ulnar collateral ligament. This ligament keeps the elbow from opening along the inside of the arm. It is stressed and pulled upon with every throw. A strain or partial tear in the ulnar collateral ligament can sometimes heal on its own. For high level throwers that require a return to throwing, we may offer a "tommy john" reconstruction.

MCL: The throwing motion places the medial ulnar collateral ligament under significant strain. The ligament may stretch over time, leading to medial elbow pain. Sometimes, it may tear away from the bone acutely. If this occurs in a thrower, surgery maybe necessary to reconstruct the incompetent ligament. It is commonly referred to as "tommy john surgery".