Baseball Players Diagnosed With Ulnar Collateral Ligament Tears Demonstrate Decreased Balance Compared to Healthy Controls

STUDY DESIGN: Cross-sectional. OBJECTIVES: To compare lower extremity balance and shoulder range of motion in baseball players with ulnar collateral ligament (UCL) tears to a healthy cohort. BACKGROUND: Throwing is a complex motion that requires balance and coordination to effectively transfer energy through the kinetic chain. In theory, poorer balance could negatively affect throwing mechanics and lead to injury. METHODS: Thirty baseball players (mean +/- SD age, 18.5 +/- 1.9 years) with a diagnosis of a UCL tear of their throwing arm were compared to 30 players (age, 19.0 +/- 1.1 years) without a UCL tear. All participants were competing at either the high school or collegiate level and reported an average SD of 13.5 +/- 1.7 years of playing experience. The Y Balance Test composite scores were calculated for the stance and lead lower extremities of all players. Shoulder range of motion was used to calculate glenohumeral internal rotation deficit and side-to-side differences in total rotational motion. Group comparisons were made between participants with and without UCL tears using independent t tests. RESULTS: Baseball players with UCL tears scored significantly lower on the Y Balance Test for both the stance (P<.001) and lead (P<.001) lower extremities compared to the noninjured cohort. No between-group differences were noted in glenohumeral internal rotation deficit (P =.453), whereas the mean SD side-to-side difference in total rotational motion was -6.0 degrees 9.6 degrees for the injured group, compared to 0.4 degrees 9.6 degrees for the control group (P =.028). CONCLUSION: Participants with a UCL tear demonstrated decreased performance for their stance and lead lower extremities during the Y Balance Test. These data are consistent with a clinical hypothesis of a potential association between impaired balance and UCL tears in high school and collegiate baseball players. The lower total rotational motion of the dominant shoulder in participants with UCL tears needs to be considered in the interpretation of those results.