Like other joints, the elbow is held together by strong bands of tissue called "ligaments." On the elbow's inner side is the ulnar collateral ligament complex. We call it the "UCL." It's made of three bands that connect the humerus (the upper arm bone) to the lower arm's ulna. The UCL is the elbow ligament most often injured by baseball pitchers and by other athletes who play throwing sports.
You can injure the UCL if you stress it over and over again. This is called an "overuse" injury. Repeated overhand throwing can weaken, stretch and irritate the ligament. It can partially or completely tear the ligament, or cause one end to pull away from the bone.
A UCL injury causes pain on the inner side of the elbow. Your elbow may feel weak and unstable, and you may not be able to throw as fast as you like. If you tear the UCL, you may feel a pop when it happens. This is painful. It prevents you from throwing. You may also have tingling or numbness in the last two fingers of your hand.
Treatment depends on how badly you've injured the ligament. You may benefit from rest, medications and injections. Physical therapy may help. A complete tear can be fixed with surgery. Your healthcare provider can create a plan that's right for you.
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.