Tommy John injury is associated with the medial ulnar collateral ligament (UCL)—most commonly used in reference to pitching in baseball.
While interventions such as platelet rich plasma therapy, physical therapy and surgery have been identified as solutions for repair; there are five fixable risk factors that have the potential to reduce Tommy John injury risk.
What is the ulnar collateral ligament and how is it related to Tommy John injury?
The medial ulnar collateral ligament (UCL) is a ligament that connects the two forearm bones, the humerus and the ulna. It acts as a stabilizing band on the inner side of your elbow and is essential in providing stability when extending your arm.
The UCL is subjected to tensile forces when bending or extending your elbow, which can lead to a UCL sprain or tear if subjected to too much valgus force.
Valgus is defined as an outward twisting or turning of a bone or joint.
When pitching, valgus forces can result in large amounts of tension on the medial elbow (shown above), pulling the forearm bones away from the humerus (but prevented in doing so by the UCL).
The UCL experiences valgus overload from the repetitive stress placed on the elbow seen in throwers.
Is it possible to identify risk factors for Tommy John injury?
Authors of a 2023 study aggregated data from twenty-one studies that evaluated risk factors for UCL injuries in the elbow of baseball players and:
The most consistent modifiable risk factors included:
- Total shoulder range of motion
- Pitch count
- Pitch selection
- Y balance score
- Lateral release position
1. Better shoulder range of motion leads to less risk
Limited range of motion decreases the joint’s ability to move compromising joint stability. (Our recommended shoulder range of motion exercises are shown below.)
2. Increased pitch count both annual and per game
Pitching too much both in a game and over the course of a year is a recipe for an overuse injury—especially during youth and adolescent years.
The pitch smart program from major league baseball is a reference for young pitchers to reduce arm injuries before they happen by providing a comprehensive resource for safe pitching practices.
Following the recommendations within the Pitch Smart program can help prevent injury.
3. Throwing a higher percentage of fastballs and a smaller pitch repertoire
Having a greater variety of pitches thrown utilizes different pitch mechanics as well as reduces muscle fatigue. Having several pitches to use benefits the health of the shoulder.
4. Low Y Balance score
The Y Balance Test is a reliable, repeatable way to measure a person’s upper quarter stability and upper extremity functional testing.
This is an important tool to identify any potential roadblocks to performance and determine if there are any risks for injury.
The results of this 2023 study as well as this 2014 study suggest that those with shoulder impingement syndrome will perform worse on the Upper Quadrant Y Balance Test in the medial and inferolateral directions than healthy controls.
As stated, those with a worse upper quadrant YBT score are at greater risk for tommy john injury, but by identifying this early, exercises can be done to improve this impingement.
5. Lateral Release Position
When compared with controls, the mean pitch release location for pitchers who required UCL reconstruction was 12.2 cm more lateral in the year immediately preceding surgery. Suggesting that a more lateral pitch release location is an independent risk factor for UCL injury and reconstruction.
An interesting point the authors made: pitchers who eventually required UCL surgery started with similar horizontal release locations as the control pitchers, but as they approached UCL rupture the mean release location moved to a more lateral release location.
This could be a critical point to watch out for—if pitchers start to change to a more lateral release position, interventions should be made to correct this to avoid injury in the future.
These risk factors may serve as cues to observe and implement the appropriate corrections to avoid Tommy John injury.
(Pitch velocity was inconsistent in literature, but most studies found this as a risk for injury.)
Regardless of risk for Tommy John injury, it is always recommended to incorporate shoulder range of motion exercises to keep the joint stable and mobile; yielding desired results.
The shoulder range of motion exercises we provided here are an excellent place to start.
It is recommended to do these in the order presented below.