(9) USING THE IMPULSE MOMENTUM EQUATION TO EVALUATE MAJOR LEAGUE BASEBALL POSITIONAL DIFFERENCES IN MOMENTUM, VELOCITY, AND POWER DURING SPRINTING

Sprint performance data of Major League Baseball (MLB) players has become publicly available in recent years via MLB’s Statcast database. This data can be used to calculate mean velocity or velocity (V) at specific intervals. When combined with publicly available body mass data, linear momentum (L) can then be calculated. The impulse-momentum equation then creates an opportunity to calculate the force (F) applied during sprints. Subsequently, power (P) can then be calculated as the product of force and velocity. Positional differences likely exist in each of these variables.

Purpose: The purpose of this investigation was to determine if there are positional differences in V, L, and P in MLB players.

Methods: This study examined publicly available sprint and body mass data in 249 MLB players from the 2022 season. The sprint performance data includes times at specific intervals from 0 to 27.4 m (90 ft), which was used to calculate V. This was multiplied by each athlete’s body mass resulting in L. Knowing both the L and sprint time, F applied was calculated with the impulse-momentum equation (F*Δt=m*ΔV). P was calculated as the product of F & V. All data preparation and analyses were completed in R. Data were non-normally distributed, thus, Kruskal-Wallis ANOVAs were used to evaluate the presence of statistical differences (p< 0.05) by position for V, L, & P. When necessary, post hoc comparisons were completed via Welch tests with a Holm-Bonferroni correction and effect sizes (ω²) were included.

Results: All 3 variables resulted in statistical and practical differences (V ω² = 0.65, L ω² = 0.25, P ω² = 0.33) between positions. There were many statistically significant positional differences in V, and they are shown in Figure 1. Designated hitters produced statistically greater L than short stops (p = 0.01). Both right fielders (p < 0.000) and center fielders (p < 0.000) showed statistically greater power than catchers.

Conclusions: To the current authors’ knowledge, this is the first investigation to utilize the impulse-momentum equation to evaluate sprinting performance in MLB players. Traditional sprint testing generally only utilizes time for a set distance, but calculating V, L, and P are relatively easy when body mass is known. L and P are likely more robust measures of performance as they quantify more than speed alone. Results demonstrated that positional differences exist, and practitioners may find this useful when evaluating athletes or for setting target training goals. PRACTICAL APPLICATIONS: Coaches and sport scientists should consider using impulse-momentum derived variables when quantifying and evaluating sprint performance. L and P are more informative than sprint time alone. At the same time, positional and sport related differences likely exist, and the production of normative data will prove useful when evaluating athlete performance.

Acknowledgements: none