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WHDL - 00015427

Relationship between Ground Reaction Force Impulse and Throwing Arm Joint Kinetics in Collegiate Baseball Pitchers

Natali Contreras

Resource Types

Academic (Thesis, Dissertation, Etc.)

Resource Languages

English

Institutional Repository

Point Loma Nazarene University

Description / Abstract

Peak ground reaction force (GRF) is one variable that has been studied in the lower extremity to determine the amount of force generated by the drive leg and stride leg of the pitcher. Studies suggest that impulse can be used as a performance measure to determine rapid changes in displacement across a group of athletic individuals. The purpose of this study was to determine how peak GRF and GRF impulse of the drive and stride legs relate to ball speed and joint kinetics in collegiate baseball pitchers. It was hypothesized that collegiate baseball pitchers with peak GRF and GRF impulse at the stride leg will have peak internal rotational torque at the shoulder, peak valgus torque at the elbow, and ball speed. A sample of 20 collegiate pitchers were included in this retrospective study on data collected over the course of two baseball seasons. Ball speed was significantly influenced by stride leg horizontal GRF, stride leg vertical GRF, drive leg horizontal GRF, drive leg medio-lateral impulse, and stride leg medio-lateral impulse (r² = 0.626, p = 0.024), which accounted for 62.6% of variance in ball speed. The significant relationship found between medio-lateral impulse at the drive leg and stride leg and ball speed supports the idea that stabilization and balance in the lower extremity is essential for rotation to occur from the legs to the hips to the shoulder to produce a greater change in momentum for a greater ball speed. Further research can be conducted on this population to examine performance measures from the lower extremity to the upper extremity to correlate values with joint kinetics and ball speed and to understand mechanisms of injury using biomechanical variables such as peak GRF and impulse.