Examining Changes in Bat Swing Kinematics in Different Areas of the Strike Zone in Collegiate Baseball Players

Abstract

Background: According to the National Collegiate Athletic Association (NCAA) there are over 34,000 athletes who compete in baseball at the collegiate level. These individuals spend countless hours training to improve their ability at bat performance by use of a batting tee and their position preference. However, during a game situation an athlete may swing a bat through their strike zone depending on the pitch thrown by an opposing pitcher. Objective: The aim of this investigation was to examine changes in swing kinematics throughout an individual’s strike zone in collegiate baseball players. Variables of interest included resultant velocity at ball contact (RVBC) and the angle of the bat at ball contact (BABC). Methodology: A series of markers were placed on the tee and bat to record swing kinematic variables of interest. Participants completed a brief two-minute on-deck warm-up protocol before being counterbalanced into completing 15 swing trials in various regions of their respective strike zone. A ten-minute washout period was completed followed by another 15 swing trials throughout their strike zone until there was a total of 45 swing trials, having 5 swing trials completed in each of the nine regions of the strike zone. Results: Repeated measures analysis of variance were used to examine swing kinematic variables of interest. Significant differences were found in RVBC along with significant differences in BABC (p<.05). Conclusions: Knowledge of this information can allow both athlete and sport coach to identify areas of weakness when addressing their hitting performance in preparation for an at bat situation during a game.

Examining Changes in Electromyography during Swing Performance in Various Strike Zone Locations of Collegiate Baseball Players

“…Motion capture systems have been shown to be a reliable metric of measuring a variety of movement patterns along with being used in previous bat swing study designs [7, 12, 13, 15-17, 21]. In order to properly distinguish the phases of the swing, a modified, full body Helen Hayes marker system along with two custom models was created for both the bat and tee, used in previous studies, to have a total of 47 retro-reflective markers tracking the movement of each trial [12,13]. Sampling rate recording these movement patterns was set at 200Hz to record each swing trial [12, 13, 16, 17] (Figure 1).…”

“…After each swing trial, a period of 20 seconds elapsed to mimic the period between each pitch and to also allow the investigators to move the tee to another position within their strike zone. Each participant completed 15 swing attempts followed by a tenminute rest period for a total of 45 swing trials (5 swings for each of the nine locations of their strike zone) [12].…”

“…Figure 3: Tee position for inside, middle, and outside zone and swing location for a right-handed batter.Once the strike zone was determined, each participant completed a two-minute on-deck warm-up mimicking what each participant would do prior to an at bat situation[12,13]. Upon completion of their warm-up, participants were given a short rest period to allow investigators time to set up the tee and to allow the participant to get in their respective batting stance for the first swing trial.…”