Journal of Sport and Health Science
Purpose: To quantify differences in nonlinear aspects of performance on a seated visual-motor tracking task between clinically asymptomatic males and females with and without a self-reported mild traumatic brain injury (mTBI) history.
Methods: Seventy-three individuals with a self-reported concussion history (age: 21.40 ± 2.25 years) and 75 without (age: 21.50 ± 2.00 years) completed the visual-motor tracking task. Participants pressed an index finger against a force sensor, tracing a line across a computer screen (visual-motor tracking). The produced signal's root-mean-square error (RMSE), sample entropy (SampEn, a measure of regularity), and average power (AvP) between 0 and 12 Hz were calculated.
Results: Males with a history of 0 or 1 concussion had greater RMSE (worse performance) than females with 0 (p < 0.0001) and 1 concussion (p = 0.052). Additionally, females with 2+ concussions exhibited lower SampEn than females with no history (p = 0.001) or a history of 1 concussion (p = 0.026). Finally, females with 2+ concussions had lower 8–12 Hz AvP than males with 2+ concussions (p = 0.031). Few differences were observed in the male participants.
Conclusion: Females with a self-reported history of multiple concussions exhibited lower SampEn in the visual-motor tracking-task force output structure as compared to those with no reported history of concussion and their male counterparts. Lower SampEn and lower power between 8 and 12 Hz indicated persistent impairment in visual processing and feed-forward or predictive motor control systems.
Breanna E. Studenka, Adam Raikes, Gender differences in nonlinear motor performance following concussion, Journal of Sport and Health Science (2017), doi: 10.1016/j.jshs.2017.03.006