Measurement of shoulder range of motion, video analysis of pitching, and comparison of shoulder treatments in high-school baseball pitchers with and without shoulder pain
Purpose: The purpose of this study was to evaluate shoulder range of motion, throwing biomechanical differences, and treatment protocols for high school baseball pitchers with and without the presence of throwing-related shoulder pain. Participants: Eighty participants were assessed for shoulder range of motion, 78 for baseball pitching biomechanics, and 38 completed a two-week treatment protocol. Methods: The participants with signed informed consent that met criteria were taken through passive shoulder range of motion measurements for internal and external rotation in the 90/90 position, and video analysis of throwing to measure maximum external rotation, trunk rotation timing, and trunk flexion. The participants reporting the presence of throwing-related shoulder pain were placed in one of four treatment protocols: 1. Self-stretching, 2. Posterior mobilization of the shoulder and manual stretching by a physical therapist, 3. The same treatment as protocol two with the addition of three throwing drills, 4. Only the three throwing drills. Data analysis was performed with SPSS statistical software version 25. A point-biserial correlation and independent samples t-test were run to determine if a relationship existed between shoulder range of motion and the presence of throwing-related shoulder pain. An independent samples t-test was run to determine if there was a difference in throwing mechanics between participants with and without the presence of throwing-related shoulder pain. A split-plot ANOVA was run to determine within subject differences for pre and post measurements and between subject differences for the four treatment groups. Results: This study found that participants reporting the presence of throwing-related shoulder pain had less internal rotation in the 90/90 position. This study also found no differences in baseball pitching biomechanics between high school baseball pitchers with and without the presence of throwing-related shoulder pain. The results of the treatment protocols showed improvement of GIRD, no change in pitching biomechanics, and reduction of pain level in protocols 1-4. Conclusion: GIRD was found in a group of high school baseball pitchers with throwing-related shoulder pain. Treatment with self-stretches and manual therapy showed significant improvement in GIRD and shoulder pain level.