Cross-Sectional Analysis of Ground Reaction Forces During Jumps in Professional Baseball Players

Abstract Amonette, WE, Vazquez, J, and Coleman, AE. Cross-sectional analysis of ground reaction forces during jumps in professional baseball players. J Strength Cond Res 37(8): 1616–1622, 2023—This study described and compared force plate kinetics in major (MLB) and minor (MiLB) baseball players while performing vertical jumps (CMVJ), squat jumps (SSJ), and depth jumps (DJ). Second, comparisons were made between playing positions. Data were collected on 101 professional baseball players. Peak force, eccentric and concentric impulses, peak power, and jump height were determined from each test. Reactive strength index was computed from the DJ. Data were compared using factorial analysis of variances, alpha was set at p ≤ 0.05, and effect sizes were reported using Cohen's d. During CMVJ, MiLB players generated more force (p = 0.04; d = 0.48), power (p = 0.02; d = 0.42), and jumped higher (p = 0.03; d = 0.32) than MLB players. Pitchers generated higher propulsive impulses than catchers (p = 0.004; d = 0.93). Outfielders generated more power (p = 0.02; d = 0.98) and jumped higher (p = 0.049; d = 1.08) than catchers and infielders (p = 0.025; d = 0.32). Minor league baseball players generated more force (p = 0.002; d = 0.62), power (p = 0.001; d = 0.84), and jumped higher (p = 0.02; d = 0.48) than MLB players in SSJ. No differences were observed by position in SSJ. Minor league baseball players jumped higher than MLB players in the DJ (p = 0.01; d = 0.57) and outfielders generated more power in the DJ than pitchers (p = 0.05; d = 0.43) and catchers (p = 0.007; d = 1.61). Reactive strength index was greater in outfielders compared with catchers (p = 0.01; d = 1.20). These data indicate that MiLB players were generally more powerful and jumped higher than MLB players in the 3 performance tasks. The difference observed by playing level were likely related to physical preparedness at the beginning of spring training; positional differences were the result of athletic skill sets required for tactical excellence at each position.