Gender differences in nonlinear motor performance following concussion

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Human Performance

Background:

• Mild traumatic brain injury (TBI), commonly known as concussion, can lead to persistent neurological deficits.
• Assessing nonlinear dynamics in motor control offers a sensitive method to detect subtle post-concussion impairments.
• Sex-based differences in concussion recovery and symptomology are increasingly recognized.

Purpose of the Study:

• To investigate sex-specific differences in nonlinear performance measures during a visual-motor tracking task.
• To compare individuals with and without a history of mild TBI (concussion).
• To quantify nonlinear aspects of force output in a seated visual-motor tracking task.

Main Methods:

• Seventy-three individuals with a concussion history and 75 without completed a seated visual-motor tracking task.
• Participants applied force with their index finger while tracing a line on a screen.
• Calculated metrics included root-mean-square error (RMSE), sample entropy (SampEn), and average power (AvP) in the 0-12 Hz range.

Main Results:

• Males with 0-1 concussion had higher RMSE (worse performance) than females.
• Females with 2+ concussions showed significantly lower SampEn compared to females with 0 or 1 concussion.
• Females with 2+ concussions exhibited lower 8-12 Hz AvP than males with 2+ concussions.

Conclusions:

• Multiple concussions in females are associated with reduced regularity (SampEn) in motor control output.
• Lower SampEn and reduced 8-12 Hz power suggest persistent deficits in visual processing and predictive motor control.
• Findings highlight potential sex-specific impacts of concussion on sensorimotor integration.