Date of Award

Spring 5-2021

Document Type


Degree Name

Master of Science (MS)



First Advisor

David Szymanski


Jump tests are effective, valid, and reliable methods to examine lower body power and possibly influence ground reaction forces (GRFs) in baseball pitching. Purpose: To determine relationships between drive leg and stride leg GRFs and fastball velocities while pitching from the wind-up and stretch to 1) drive leg and stride leg GRFs of unilateral countermovement jumps (UCMJ) and bilateral countermovement jumps (BCMJ), 2) BCMJ, and drive and stride leg UCMJ height as well as bilateral broad jump (BBJ) and drive and stride leg unilateral lateral to medial jump (ULMJ) distances, and 3) BBJ estimated peak power. Methods: Nineteen Division I collegiate baseball pitchers (age 19.9 ± 1.5 years, height 1.86 ± .06 m, body mass 90.7 ± 13.8 kg) completed six multi-directional jump tests and threw fastballs from a pitching mound with embedded force plates. Results: Three moderate and one moderately high statistically significant relationships were observed for BCMJ and UCMJ heights to pitching GRFs, p < 0.05. Stride leg UCMJ height was significantly greater than drive leg UCMJ height, p < 0.01. Wind-up and stretch GRFs were statistically similar. Fastball velocities had statistically moderately high relationships to wind-up and stretch drive leg GRFs. Fastball velocities were statistically similar between both deliveries. Conclusion: Collegiate pitcher’s jumped higher and had more power displayed by their stride leg compared to their drive leg, and produced more power vertically when summing drive and stride leg UCMJ forces compared to BCMJ force. Both wind-up and stretch drive leg forces had moderately high associations to fastball velocities.

Keywords: baseball pitching, fastball velocity, ground reaction forces, multi-directional jumps

Included in

Kinesiology Commons