Related Experiment Video
Updated: May 30, 2025
A Test Bed to Examine Helmet Fit and Retention and Biomechanical Measures of Head and Neck Injury in Simulated Impact
Published on: September 21, 2017
Measurement and Assessment of Head-to-Helmet Contact Forces
Turner Jennings1, Aidan Tillman2, D'mitra Mukasa2
1Department of Mechanical and Industrial Engineering, Northeastern University, 360 Huntington Avenue, Boston, MA, 02115, USA.
Purpose:
To evaluate the population variation in head-to-helmet contact forces in helmet users.
Methods:
Four different size Kevlar composite helmets were instrumented with contact pressure sensors and chinstrap tension meters. A total number of 89 volunteers (25 female and 64 male volunteers) participated in the study. The length, width, and circumference of their heads were measured and each volunteer was assigned a helmet size. Volunteers were asked to wear the helmet in three different configurations and the chinstrap tension and contact force between the head and each of the seven interior pads were recorded.
Results:
The majority of forces measured on any individual pad were between 0 and 5 N. However, some users exhibited pressure points with forces as high as 30 N. The contact force distribution is non-uniform across the interior of the helmet, with the largest force concentrated at the front. Head shape is a major driver of the observed contact force. There was a statistically significant difference between female and male volunteers, and between groups with different experience levels.
Conclusions:
The fit of helmet systems is highly subject specific. The current metrics used to assign helmet sizes may not accurately predict correct helmet fit.
