Differences in Pitching Kinetics and Kinematics During Various Effort Level Pitching.

Abstract

Background: After a pitching injury, players must go through a return to sports protocol to enable them to get back to competition. However, this should be done while reducing the risk of reinjury. In the early stages of the return to sports protocol, it is important to minimize kinetics while ideally working on pitching mechanics, which may be achieved through interval throwing progressions.

Purpose: To assess the differences in kinetics and kinematics during reduced effort pitching.

Study design: Descriptive laboratory study.

Methods: Collegiate-aged pitchers (n = 19) throw 5 fastballs at each effort level, including 60%, 70%, 80%, 90%, and 100%. Kinetics and kinematics were recorded. Variables of interest included elbow varus torque, shoulder rotation at maximum external rotation (MER), elbow flexion at MER, maximum resultant shoulder force, peak pelvis rotation velocity, peak trunk rotation velocity, peak shoulder internal rotation velocity, peak elbow extension velocity, shoulder abduction at MER, maximum shoulder horizontal abduction, and maximum hand velocity. Once the data were extracted from the Kinatrax database, separate analyses of covariance tests were performed on each set of data, followed by a Tukey Honest Significant Difference post hoc test when the analysis of variance test returned a statistically significant P value (P < .05).

Results: Only elbow varus torque was found to have statistically significant differences between effort levels, and only a statistically significant difference between 100% and 60% effort levels was found. At 100% effort level, elbow varus torque showed a mean value of 92.5 N·m, while 60% effort level pitching showed a mean elbow varus torque of 73.2 (P = .017).

Conclusion/clinical relevance: These results suggest that players can throw at close to half effort to reduce their elbow kinetics while maintaining kinematics that would be occurring at 100% effort pitching.