Functional Hip Characteristics of Baseball Pitchers and Position Players

Background: During the throwing motion, the lower extremity is responsible for creating power that is transmitted through the core to the upper extremity. Research has shown that good hip range of motion and strength in throwing athletes results in greater performance and decreased stress placed on the upper extremity. Although research has investigated bilateral differences in hip characteristics among baseball pitchers, little is known about differences between pitchers and position players. Hypothesis: Pitchers will have decreased passive hip rotation range of motion and gluteus medius strength compared with position players. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Forty professional baseball pitchers and 40 position players with no recent history of lower extremity injury participated. Bilateral hip external and internal rotation range of motion, total arc of motion, and gluteus medius strength were measured with a digital inclinometer and handheld dynamometer. Results: A Hotelling T(2) multivariate analysis of variance showed position players to have significantly more hip internal rotation range of motion (3.1 degrees, P = .01, effect size = .53) and abduction strength (3.5 kg, P = .04, effect size = .53) in the trail leg compared with the pitchers. There were no significant differences for any other hip characteristics between groups (P > .07). Conclusion: The results of this study indicate that baseball pitchers have significantly smaller amounts of hip internal rotation range of motion and abduction strength of the trail leg compared with position players. However, these differences may not be clinically significant. Clinical Relevance: Position players may be able to develop more energy in the lower extremity, while pitchers may rely more on energy created in the core and upper extremity, potentially placing pitchers at an increased risk for upper extremity injury. These descriptive hip characteristics may help clinicians detect inadequacies and provide appropriate prevention, diagnostic, and treatment interventions for such athletes.