Student Author(s)

Keaton Hamilton, Hope College

Faculty Mentor(s)

Dr. Maureen Dunn, Kinesiology; Dr. Brooke Odle, Engineering

Document Type


Event Date



Current acute stretching programs have been reported to increase shoulder range of motion (ROM) utilizing the cross-body stretch and the sleeper stretch but have not examined how this increase could affect throwing velocity in overhead athletes. Few methods have been found to increase throwing velocity with the exception of various weighted ball and strength training programs, often associated with high rates of injury. The aim of this study was to determine if a nine week stretching protocol would result in improvements in shoulder ROM which may lead to an increase in overhand throwing velocity. It was hypothesized that a 9-week stretching program would increase the ROM of the glenohumeral joint and increase the throwing velocity among collegiate baseball players. Participants baseline shoulder ROM and overhand throwing velocity were assessed manually and using wearable motion capture sensors. Participants were then matched into either a control group (n=8) or an experimental group (n=8). The experimental group then performed four sets of two stretches, 30 seconds each, five times per week for a duration of nine weeks. A significant interaction was observed in the manually recorded velocity data (p=0.014) with the control groups velocity decreasing over the testing period and the stretching groups velocity slightly increasing, however no significant interactions were found between groups from pre to post test, between groups in both active and passive flexion, extension, internal rotation, external rotation, or horizontal abduction (p>0.05). There were main effects over time for both active and passive internal rotation and horizontal abduction. Analysis of the sensor data indicates a significant interaction for extension (p=0.04) and a trend towards interaction in flexion (p=0.054). Further data analysis suggests differences in throwing techniques which may have impacted the results. Future work should focus on throwing technique.


All resources were provided by the Hope College Department of Kinesiology, with exception of the Xsens Motion Capture system which was provided by Technos College. This research was supported by the Constantin Kinesiology Student Research Fund.

Included in

Kinesiology Commons