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

TL;DR

This study demonstrates that linear acceleration is a more accurate predictor of concussion risk than rotational acceleration and that targeting it can significantly reduce injury likelihood.

Contribution

The paper provides direct evidence that linear acceleration is the primary biomechanical factor in concussion risk and introduces a liquid-filled helmet pad to mitigate this acceleration.

Findings

Linear acceleration predicts concussion injury more accurately than rotational acceleration.

Rotational velocity adds some predictive value for injury risk.

A liquid-filled helmet pad can reduce predicted concussion risk by up to 52%.

Abstract

Head impacts can cause concussion, but the precise biomechanical conditions that produce injury remain uncertain. Rotational acceleration has long been posited as the primary cause and has guided concussion prevention strategies. Using instrumented mouthguards to record head kinematics of diagnosed concussions, we directly tested this hypothesis and found that linear acceleration predicted injury with greater precision than rotational acceleration, while rotational velocity provided additional predictive value. Injury risk functions derived from these measurements indicated substantial predicted concussion risk during typical impacts to an American football helmet. Introducing a liquid-filled helmet pad designed to attenuate linear acceleration reduced predicted risk by up to 52%. These results indicate that effective concussion prevention requires targeting linear acceleration.