The number of ulnar collateral ligament (UCL) reconstructive (i.e. “Tommy John”) surgeries performed on youth baseball pitchers have more than doubled since 2000 [1]. Routinely pitching while fatigued is considered a leading factor associated with UCL injuries; adolescent pitchers who had elbow or shoulder surgery were 36 times more likely to have routinely pitched with arm fatigue [1]. MLB/USA Baseball Pitch Smart guidelines limit 9-10 yr. old pitchers to a maximum 75 pitches per game, a figure based on long-term studies related to injury prevention [2]. Several studies have shown that pitching kinematics (e.g. elbow flexion/extension and pronation/supination, scapulothoracic internal-external rotation) may change as adult pitchers reach muscular fatigue [3], and such kinematic changes could result in higher elbow and shoulder rotational torques that may increase injury risk [4]. Several biomechanical studies have been done on ~12 yr. old youth pitchers [5,6] but none have been reported at the 9-10 yr. old level. This study aims to predict elbow and shoulder joint torques throughout a simulated game of 75 pitches for 9-10 yr. old youth pitchers and investigate joint torque correlations with pitch count, pitch speed, and body mass index (BMI; kg/m2).


Biomedical Engineering and Bioengineering

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URL: https://digitalcommons.calpoly.edu/bmed_fac/84