RESEARCH

Wong, R, et. al. Relationship between lower body extremity power and fastball spin rate and ball velocity in professional baseball pitchers. J Strength Cond Res. 37(4):823-828, April 2023.

Lower extremity power has been hypothesized to increase ball spin and velocity during pitching in baseball.

Purpose: The purpose of this study was two-fold:

• To determine the relationship between lower extremity power and fastball spin rate in professional baseball pitchers.

• To determine the relationship between lower extremity power and ball velocity.

Subjects: Fifty-three (53) asymptomatic professional pitchers. Mean age 24.5 ± 3.6 years; 189.9 ± 6.1 cm; 92.6 kg ±10.3 kg).

Procedures: Each athlete performed 3 separate bilateral jump tests on force plates:

• Countermovement jump (CMJ)

• Squat jump (SJ)

• Drop jump (DJ)

Average fastball spin rate and ball velocity for each pitcher was calculated using a 3-dimensional Doppler radar and video system over the course of a competitive season.

Analysis: Standard multiple regression analysis (p ≤ .05).

Results:

• Significant relationships between spin rate and summation of variables for the CMJ (peak force, peak power, rate of power development and jump height (R² = 0.20, F = 3.1, p = 0.03), but no individual variable was significantly associated (p < 0.09).

• A significant amount of variance in ball spin explained by summation of variables for the SJ (peak force, peak power, rate of power development and jump height). (R² = 0.19; F = 2.8, p =0.04).

• Rate of power development was the only variable that significantly predicted ball spin within this model (B = 0.27; 95% confidence interval [CI]: 0.003-0.75, p = 0.050).

• Ball spin was not associated with summation of DJ variables (peak power, rate of power development, jump height, reactive strength index and total power in watts) (R² = 0.18, F = 2.0, p = 0.09).

• Ball velocity was not significantly related to summation of either the CMJ variables (R² = 0.10, p = 0.28 or the SJ variables (R² = 0.07, p = 0.44).

• There was a significant amount of variance in ball velocity explained by summation of variables for the DJ (R² = 0.30, P = 3.93, p = 0.005)

• The reactive strength index was the sole unique contribution to this model (B = 1.18; 95% CI: -10.34 to 2.36, p = 0.002).

• These findings highlight the relevance of increased lower extremity power on increasing fastball spin rate and ball velocity.

 Practical Application:

A professional pitcher who has greater lower extremity power capabilities will have a greater chance of producing increased fastball spin rate and ball velocity. Higher power output during vertical jump testing can be a useful, predictive, and evaluative tool to identify athletes who have the potential or likelihood to express themselves with either higher spin rate or ball velocity. Medical care teams, strength and conditioning staff, and pitching coaches should consider this information to integrate appropriate training programs designed to improve functional power of the neuromuscular system to improve pitch characteristics and sport performance of baseball pitchers. It has been noted that patterned changes were present in drop of 4-seam fastball velocity and decrease in fastball spin rate in 15 games leading up to Tommy John surgery in professional pitchers. Our study supports the concept of completing force plate jump testing regularly, during preseason and in-season, to monitor fatigue and reduction in power output that could negatively affect pitcher game performance. Adding these regular testing measures would not only improve pitcher game performance but also allow the deployment of proactive conservative measures to reduce the risk before a player becomes injured.