Individual factors associated with baseball pitching performance: scoping review

Background Ball velocity, accuracy and game statistics represent three methods used to measure pitching performance. However, individual determinants of pitching performance are more elusive. Objectives The aims of this study were to classify the performance factors associated with baseball pitchers, to identify the methods used to quantify their abilities through all features of the game and to document relationships between performance factors and indicators. Design Scoping review. Data sources Electronic searches of MEDLINE, Academic Search Complete, CINAHL, SportDiscus, PubMed, PsycINFO, Cochrane and of grey literature were undertaken from inception to January 2019. Eligibility criteria for selecting studies Cross-sectional studies that investigated the relationship between performance indicators and individual performance factors in healthy baseball pitchers were selected. Results Thirty-four cross-sectional studies investigating individual potential factors of pitching performance met the inclusion criteria. The primary performance factors investigated were kinematic, kinetic, timing outcomes, personal characteristics, physical tests and range of motion. Shoulder horizontal adduction (SHA), upper torso forward flexion, maximal shoulder external rotation, upper torso rotation angle, upper torso lateral flexion, lead knee flexion (LKF) and forward trunk tilt (FTT) were identified as key kinematic features associated with increased ball velocity. Shoulder proximal force and peak elbow proximal forces were associated with greater ball velocity. Individual performances in jumping tests and body weight (BW) are also associated with pitching performance. Summary/conclusion Based on studies presenting low and moderate risk of bias, we conclude that BW, age and kinematics, such as FTT, LKF, SHA and lateral trunk tilt, are associated with pitching performance.