Date of Award


Degree Type

Creative Project

Degree Name

Master of Science (MS)


Kinesiology and Health Science

Committee Chair(s)

Breanna Studenka


Breanna Studenka


David Bolton


Christopher Dakin


Context: There has been minimal examination of the long-term effects of sub-concussive events, particularly related to non-linear aspects of motor performance. Examining the structure of performance, using nonlinear techniques, following sub-concussive events may lend insight into subtle, but significant changes in motor behavior.

Objective: This study examined the effect of performing a bout of headers on visual motor control in a group of female soccer athletes. We specifically examined the amount of error during visual-motor tracking (root mean squared error; RMSE), the regularity of the movement structure (sample entropy; SampEn), and the lag present between the target signal and the participant’s output. Design: Participants were tested before practice, after practice, and 24-hour post practice. This process was done twice, with a heading drill completed at the end of practice during the second round of testing.

Setting: Testing was completed in two private offices within the athletic training facility. Each participant used the same computer for each of her sessions.

Participants: Nine, Division I, female soccer athletes completed the testing sessions. Every subject acted as their own control, completing the first round of testing without the influence of headers and the second round of testing following the soccer heading drill.

Results: RMSE decreased over time for all conditions. Due to potential effects of learning, a projected value for RMSE was calculated for the post and 24-hour post soccer heading sessions. There was a significant increase in RMSE following headers when compared to the projected value. There was, however, no significant effect of headers on the regularity (SampEn) of the waveform produced. Additionally, there was significantly greater lag seen in the waveform with limited visual information compared to the waveform with full visual information. The lag did not change following performance of headers.