A method of evaluating helmet rotational acceleration protection using the Kingston Impact Simulator (KIS Unit).

OBJECTIVE

Helmet use is the primary form of head protection against traumatic brain injury. Although helmet designs have proven to be effective in reducing the incidence of skull fracture and major traumatic brain injury, there is little evidence that helmets protect against concussion. Linear and rotational accelerations are important mechanisms underlying concussion, yet current testing protocols do not account for rotational acceleration. Technical considerations have prevented a valid, accurate, and reproducible testing paradigm. Our objectives were to design a novel helmet-testing methodology that accurately and reliably measures rotational acceleration at injury-relevant impact forces, locations, and planes and to evaluate differences in rotational force protection in commercially available helmets.

SETTING

Laboratory study.

INTERVENTION: The Kingston Impact Simulator (KIS unit) was used to study 10 commercially available hockey helmets. The rotational acceleration force protection was measured in the horizontal, coronal, and sagittal planes at each of 12 predetermined impact locations.

RESULTS

Mean peak unhelmeted and helmeted accelerations at all impact locations and planes ranged from 63 to 28.6 g and from 26.8 to 8.0 g, respectively. The percent reduction in rotational acceleration for all test helmets ranged from 6.4% to 84%. Statistically significant differences in rotational acceleration between manufacturers and within a helmet brand were identified.

CONCLUSIONS

KIS is a novel testing methodology that identifies rotation force protection within and between hockey helmet models and manufacturers at different impact location and planes. This information may be useful in improving future helmet design and construction to provide maximal protection against the forces causing concussion.