Kid Question of the Month ~ Elbow Injuries in Baseball

What is the UCL and Why is it getting injured in pitchers?

This month’s questions from J.C about Elbow Injuries in baseball! 


The Ulnar Collateral Ligament, also known as the UCL, is a ligament that is located on the inside of your elbow (when your palm is up). The UCL consists of three bands of tissue that connect your humerus (bone that goes from your shoulder to your elbow) with your ulna (bone that is on the inside elbow to the wrist, in line with your pinky finger). It prevents your elbow from bending into your body and allows you to throw overhead giving your elbow stability to not dislocate. An injury to the UCL happens when you put tension or stress on the elbow ligament repeatedly, either causing small tears, or even pulling the ligament completely off the bone. This stress happens in the late cocking phase of throwing a baseball.



What are the top 5 risk factors for injuring your UCL when you are a young pitcher?  
  1. Pitching FAST… or referred to as Velocity. 
  2. Pitch Count- too many pitches in a game! 
  3. Innings Pitched (accumulated for the season)- too many pitches over time. 
  4. Days of Rest- not enough days taken off from throwing!
  5. Fatigue- not getting enough rest with your whole body.  
Signs of injury to your UCL/ Elbow: 
  1. Pain with motion or pain when you touch your elbow. Usually, this pain is located on the inside or middle of the elbow joint but can be the outside and back of the elbow. 
  2. Inability to straighten your elbow. Your elbow will feel stiff, especially after playing and when you wake up in the morning.
  3. Feeling loose. Instability is a sign that your elbow may have an injury. With this, you need to stop all throwing activities and get evaluated by a health care professional.
  4. Locking of the elbow. If your elbow is locking up, you will need to be assessed by a health care professional right away.
What do you do if you have elbow pain at your elbow joint?  
  1. Tell your coach and parents immediately- waiting to report injuries and playing through pain is not a way to get better, you can worsen the condition. 
  2. Rest and ice- with the first signs of pain*, ice with an ice pack (and a barrier for skin) when there is no instability or locking. 

*Studies show that injury to the UCL can be present before pain starts so be aware of weakness and changes to your pitching style.  If pain persists, call your pediatrician or pediatric sports medicine physical therapist for an evaluation. We can measure your strength and see how much motion you have in your elbow and refer you on for an orthopedic consult if needed.

How can you prevent injuries while playing baseball? 
  • Monitor the speed of pitches of younger players! 
    Young pitchers throwing high velocity pitches = #1 risk factor for INJURY. 
  • Follow your correct pitch count!
    What is the recommended pitch count for your pitcher? 
    Total Gameday pitches:  Bullpen + Warm-Up + Live Game Pitches 

Follow PitchSmart 
This resource is free and allows both parents and athletes to get information on pitch count, rest days.
Go to: 

  • Listen to your body. Pain is real and changing your mechanics to avoid pain may injure other areas of your body.
  • Get strong everywhere! Legs, core, and arms! Power comes from your ability to transfer energy through your body, not from your arm!
  • Get rest! Try to develop good sleeping habits, you are still growing.
  • Remember, you are not training yet for the MLB! Be a kid!  


Other baseball questions:
Weighted baseball versus lighter baseball training?  

Can Weighted Baseball (WB) programs (when a baseball is heavier than the 5 oz regulation ball) help me throw faster?  

  • Positives with WB: weighted baseballs increase velocity and increase shoulder external rotation. 
  • Negatives: in studies WB programs show a 24% increased incidence of injury in the elbow. 
  • Control groups in the study using only regulation balls had no injuries reported. 

What about Lighter baseball (LB) training?  
Study with (LB) baseballs were 3 and 4 oz, participants in study were 10-17 years old.  

  • No injuries were reported after a 15-week program and the velocity increased in 98% of participants! **  

** inherently increased velocity in young pitchers is #1 risk factor so again, volume and the progression of velocity and speed is important despite what this study showed!

I LOVE baseball!

I hope this helps with your training decisions! 

Wishing you all a healthy and awesome season!
Dr. Robin Bousquet, PT, DPT, SCS, CMP 

References for this article:  

  • Erickson, B. J., Atlee, T. R., Chalmers, P. N., Bassora, R., Inzerillo, C., Beharrie, A., & Romeo, A. A. (2020). Training with lighter baseballs increases velocity without increasing the injury risk. Orthopedic journal of sports medicine, 8(3), 2325967120910503. 
  • Kriz, P. K., Staffa, S. J., Kriz, J. P., & DeFroda, S. (2022). Ulnar Collateral Ligament Tear in Elite Baseball Pitchers: Are High School, Showcase Exposures Associated With Injury?. The American Journal of Sports Medicine, 50(11), 3073-3082. 
  • Manzi, J., Kew, M., Zeitlin, J., Sudah, S. Y., Sandoval, T., Kunze, K. N., … & Dines, J. S. (2023). Increased pitch velocity is associated with throwing arm Kinetics, injury risk, and ulnar collateral ligament reconstruction in adolescent, collegiate, and professional baseball pitchers: a qualitative systematic review. Arthroscopy: The Journal of Arthroscopic & Related Surgery, 39(5), 1330-1344. 
  • Reinold, M. M., Macrina, L. C., Fleisig, G. S., Aune, K., & Andrews, J. R. (2018). Effect of a 6-week weighted baseball throwing program on pitch velocity, pitching arm biomechanics, passive range of motion, and injury rates. Sports health, 10(4), 327-333. 

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