Citation

Withnall C, Shewchenko N, Wonnacott M, Dvorak J. Br. J. Sports Med. 2005; 39(Suppl 1): i40-8; discussion i48.

Affiliation

Biokinetics and Associates Ltd, Ontario, Canada. withnall@biokinetics.com

Copyright

(Copyright © 2005, BMJ Publishing Group)

DOI

10.1136/bjsm.2005.019174

PMID

16046355

PMCID

PMC1765314

Abstract

OBJECTIVES: Commercial headgear is currently being used by football players of all ages and skill levels to provide protection from heading and direct impact. The clinical and biomechanical effectiveness of the headgear in attenuating these types of impact is not well defined or understood. This study was conducted to determine whether football headgear has an effect on head impact responses. METHODS: Controlled laboratory tests were conducted with a human volunteer and surrogate head/neck system. The impact attenuation of three commercial headgears during ball impact speeds of 6-30 m/s and in head to head contact with a closing speed of 2-5 m/s was quantified. The human subject, instrumented to measure linear and angular head accelerations, was exposed to low severity impacts during heading in the unprotected and protected states. High severity heading contact and head to head impacts were studied with a biofidelic surrogate headform instrumented to measure linear and angular head responses. Subject and surrogate responses were compared with published injury assessment functions associated with mild traumatic brain injury (MTBI). RESULTS: For ball impacts, none of the headgear provided attenuation over the full range of impact speeds. Head responses with or without headgear were not significantly different (p>0.05) and remained well below levels associated with MTBI. In head to head impact tests the headgear provided an overall 33% reduction in impact response. CONCLUSION: The football headgear models tested did not provide benefit during ball impact. This is probably because of the large amount of ball deformation relative to headband thickness. However, the headgear provided measurable benefit during head to head impacts.