Linear Acceleration Is a Primary Risk Factor for Concussion and a Target for Prevention

Area of Science:

• Biomechanics
• Sports Medicine
• Neurology

Background:

• Concussion is a common injury resulting from head impacts.
• The precise biomechanical factors causing concussion remain uncertain.
• Rotational acceleration has been historically considered the primary injury mechanism.

Purpose of the Study:

• To directly test the hypothesis that rotational acceleration causes concussion.
• To identify the most precise kinematic predictors of concussion.
• To evaluate the effectiveness of interventions targeting linear acceleration.

Main Methods:

• Instrumented mouthguards were used to record head kinematics during diagnosed concussions.
• Injury risk functions were developed based on measured linear and rotational accelerations.
• The impact of a liquid-filled helmet pad designed to attenuate linear acceleration was simulated.

Main Results:

• Linear acceleration was a more precise predictor of concussion than rotational acceleration.
• Rotational velocity provided additional predictive value for concussion.
• A liquid-filled helmet pad reduced predicted concussion risk by up to 52%.

Conclusions:

• Effective concussion prevention strategies must target linear acceleration.
• Current prevention methods focusing solely on rotational forces may be insufficient.
• Reducing linear acceleration is a promising approach for mitigating concussion risk in sports.