Clinical and Biomechanical Evaluation of the Softball Pitcher: A Review of Current Concepts and Clinical Commentary.

BACKGROUND: The windmill softball pitch (WSP) is a vastly understudied human motion relative to its counterpart the overhand baseball pitch (OBP). A large body of research has been conducted to understand the kinematics and kinetics of the OBP. Better understanding of the kinematics and kinetics of the WSP may help provide better pitch volume guidelines, physical performance preparation, and injury prevention programs. EVIDENCE ACQUISITION: A comprehensive review of the literature was performed to gain a full understanding of all currently available biomechanical and clinical evidence surrounding the WSP and related softball injuries. STUDY DESIGN: Clinical Review. LEVEL OF EVIDENCE: Level 5. RESULTS: The softball pitch is a highly complex series of coordinated movements, in which the force generated by the large muscles of the lower extremity and trunk during the wind-up and stride phases are transferred to the ball through the shoulder and arm. Biomechanical evidence has demonstrated relatively equivocal distraction forces at the shoulder for both the softball pitch and baseball pitch. CONCLUSIONS: Altered pitching biomechanics, high pitch velocity, elevated pitch counts, decreased rest between outings, and increased pitcher fatigue may increase tissue stress on the upper extremity of a softball pitcher. There is convincing evidence that each of these variables have a compounding effect on injury risk for a softball pitcher. Therefore, coaches and clinicians need more research to promote upper extremity health in the softball pitcher at all levels of competition including pitch volume guidelines and injury prevention strategies.

Youth Baseball Pitching Stride Length: Normal Values and Correlation With Field Testing.

BACKGROUND: Pitching biomechanical analysis has been recommended as an important component of performance, injury prevention, and rehabilitation. Normal values for youth pitching stride length have not been established, leading to application of normative values found among professional pitchers to youth pitchers. HYPOTHESES: The average youth pitching stride length will be significantly less than that of college and professional pitchers. There will be a positive correlation between stride length, lower extremity power, balance, and pitching experience. STUDY DESIGN: Prospective cohort study. LEVEL OF EVIDENCE: Level 3. METHODS: Ninety-two youth baseball pitchers (aged 9-14 years) met the inclusion/exclusion criteria and completed the study. Stride length was recorded using a Dartfish video system over 3 maximal effort pitches. Both intra- and interrater reliability was calculated for the assessment of stride length. Double-leg vertical jump, single-leg stance time, leg length, weight, age, and pitching experience were also recorded. RESULTS: Mean (SD) stride length was 66.0% (7.1%) of height. Stride length was correlated ( P < 0.01) with vertical jump (0.38), pitching experience (0.36), and single-leg balance (0.28), with excellent intra- and interrater reliability (0.985 or higher). No significant correlations between stride length and body weight, leg length, or age existed. CONCLUSIONS: There was a significant difference between youth pitching stride length and the current published norms for older and more elite throwers. There was a positive correlation between stride length and lower extremity power, pitching experience, and single-leg balance. CLINICAL RELEVANCE: Two-dimensional analysis of stride length allows for the assessment of pitching biomechanics in a practical manner. These values can be used for return to pitching parameters after an injury and designing injury prevention and performance programs.