Electronic Theses and Dissertations

Date of Award


Document Type


Degree Name

Ph.D. in Health and Kinesiology


Health, Exercise Science, and Recreation Management

First Advisor

Martha Bass

Second Advisor

John C. Garner

Third Advisor

Alberto Del Arco

Relational Format



According to the National Collegiate Athletic Association (NCAA) there are over 50,000 men and women who compete in collegiate baseball and softball. These individuals spend hours improving their ability to swing a bat with the hope of improving his or her batting performance during a game situation typically off a tee in a position of their own choosing. However, during a game situation an athlete may swing a bat through his or her strike zone depending upon the pitch thrown by an opposing pitcher. The strike zone is defined as the space over home plate in a region that is above an athlete’s knee and below the armpit when they set up in their chosen batting stance. To date there is a limited amount of information regarding changes in swing kinematics throughout a person’s strike zone. The purpose of this study investigated changes in swing kinematics throughout an individual’s strike zone in collegiate baseball and softball players. The aims of this study were (1) to investigate the changes in bat kinematics within various regions of an individual’s strike zone, (2) investigate changes in full body kinematics within an individual’s strike zone, (3) investigate changes in EMG activity throughout an individual’s swing and how that changes in different areas of his/ her strike zone. A total of 26 intercollegiate baseball (n=13) and softball (n=13) players between the ages of 18-25 were recruited for the following study. The experimental session analyzed changes in both bat and full body kinematics throughout an individual’s strike zone using a motion capture system. Lower extremity EMG was used to analyze mean muscle activity and percent activation of the stride leg over the nine regions of the strike zone. A series of repeated measures analysis of variance were used to determine differences in bat swing kinematics and lower body EMG. Significant differences were seen in bat swing kinematics for both baseball and softball players across the nine regions of the strike zone (p<.05). Significant differences in stride leg EMG was seen over the three phases of the swing for both groups(p<.05). There were significant changes in full body kinematics when examining elbow flexion angle at bat-ball contact among baseball and softball players (p<.001). Both athlete and sport coach can use this data to work on hitting technique along with bat speed/angle depending on where he or she is deficient in the strike zone. This information can also be used to establish what would be considered an ideal bat angle for both baseball and softball so both sport coaches and athletes can practice achieving the ideal bat angle in a given region of the strike zone not only for collegiate populations, but others as well.

Included in

Kinesiology Commons



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