Internal rotation loss, external rotation gain may increase medial UCL injury risk in pitchers
Results showed glenohumeral internal rotation loss, glenohumeral external rotation gain and total rotational motion deficit may be related to increased medial ulnar collateral ligament injury risk among baseball pitchers.
Rafael F. Escamilla, PhD, PT, CSCS, and colleagues matched 108 male high school, college and professional baseball pitchers with medial UCL injury with 108 baseball pitchers without medial UCL injury according to number, level of play and age. Researchers measured bilateral shoulder passive internal rotation/external rotation and calculated glenohumeral internal rotation loss, glenohumeral external rotation gain, total rotational motion and total rotational motion deficit.
Results showed pitchers with medial UCL injury had more glenohumeral internal rotation loss, glenohumeral external rotation gain and total rotational motion deficit. Researchers found a glenohumeral internal rotation loss greater than 18° in approximately 60% of pitchers in the medial UCL injury group vs. approximately 30% of pitchers in the control group for all pitching levels. Approximately 60% of pitchers in the medial UCL injury group and approximately 50% of pitchers in the control group had total rotational motion deficit greater than 5°, according to results. For glenohumeral internal rotation loss, glenohumeral external rotation gain, total rotational motion deficit and throwing shoulder external rotation, internal rotation and total rotational motion, researchers found no differences among high school, college and professional pitchers.
“Greater [glenohumeral internal rotation loss] GIRLoss and [total rotational motion deficit] TRMD in [medial UCL] MUCL-injured pitchers compared to uninjured pitchers implies these variables may be related to increased MUCL injury risk, especially since GIRLoss greater than 18° and TRMD greater than 5° demonstrate an increased MUCL injury risk,” Escamilla told Healio.com/Orthopedics. “Shoulder rotational motion and deficits do not vary among [high school] HS, [college] COLL and [professional] PRO levels of pitchers.” – by Casey Tingle
Disclosures: The authors report no relevant financial disclosures.