Immediate and Transient Perturbances in EEG Within Seconds Following Controlled Soccer Head Impact

Area of Science:

• Sports Medicine
• Neuroscience
• Biomechanics

Background:

• Contact and collision sports frequently expose athletes to subconcussive head impacts.
• Cumulative effects of repetitive head impacts, even mild ones, are a growing concern for athlete brain health.
• Previous research suggests mild impacts can cause brain deformation and transient neurological effects.

Purpose of the Study:

• To investigate the immediate neurophysiological effects of controlled, mild soccer head impacts.
• To explore the dose-response relationship between head impact kinematics and brain activity.
• To assess potential cumulative effects of repetitive mild head impacts.

Main Methods:

• Healthy participants performed simulated soccer headers at controlled impact levels (6g and 10g) and directions.
• Head kinematics were measured using an inertial measurement unit (IMU) bite bar.
• Brain activity was continuously monitored using electroencephalography (EEG) during and after impacts.

Main Results:

• Soccer head impacts led to statistically significant elevations in relative and absolute delta power in EEG readings.
• These changes recovered within two seconds post-impact.
• Higher impact levels (10g vs. 6g) and oblique impact directions showed distinct patterns of delta power changes.

Conclusions:

• Mild soccer head impacts can induce immediate, transient neurophysiological changes in the brain.
• The observed changes, particularly delta power elevations, suggest a direct biomechanical dose-brain response.
• Further research into cumulative effects is warranted for understanding long-term athlete brain health.