Date of Award

Spring 2018

Document Type


Degree Name

Master of Science (MS) in Physical Education: Exercise Science


Physical Education, Health and Recreation


Research investigating baseball position players has been limited primarily to pitchers. The current study examined several kinematic variables and their relationship with ball velocity in middle and high school-aged baseball players using two-dimensional (2D) motion analysis. The purpose of this study was to investigate these relationships using 2D motion analysis and compare these results to those reported in the literature using 3D analysis. Thirteen baseball players (15.31 ± 1.25 yrs., 72.29 ± 10.79 kg and 177.09 ± 5.59 cm tall) participated in the study. A video camera was used to record three throwing trials for each participant. Four reflective markers were placed on the participants to identify anatomical landmarks of interest on the players. Video trials were digitized in 2D using commercially available Dartfish software. Trunk side bend and knee flexion angle at foot contact, and trunk flexion, knee flexion, and knee extension velocity at ball release were calculated. Intra-rater reliability of ten re-digitized trials using Pearson’s inter-item correlation was very high (r = 0.99, p < 0.001). Of the five kinematic variables analyzed, only trunk side-bend at foot contact achieved a significant correlation with ball velocity (r = 0.527, p < 0.001). 2D motion analysis may be a viable option for the analysis of throwing kinematics when expensive 3D systems are not available, however they are limited in the types of variables that can be related to ball velocity.