The effect of motorcycle helmet fit on estimating head impact kinematics from residual liner crush

Stephanie J. Bonin, John C. Gardiner, Arzu Onar-Thomas, Shihab S Asfour, Gunter P. Siegmund

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

Proper helmet fit is important for optimizing head protection during an impact, yet many motorcyclists wear helmets that do not properly fit their heads. The goals of this study are i) to quantify how a mismatch in headform size and motorcycle helmet size affects headform peak acceleration and head injury criteria (HIC), and ii) to determine if peak acceleration, HIC, and impact speed can be estimated from the foam liner's maximum residual crush depth or residual crush volume. Shorty-style helmets (4 sizes of a single model) were tested on instrumented headforms (4 sizes) during linear impacts between 2.0 and 10.5 m/s to the forehead region. Helmets were CT scanned to quantify residual crush depth and volume. Separate linear regression models were used to quantify how the response variables (peak acceleration (g), HIC, and impact speed (m/s)) were related to the predictor variables (maximum crush depth (mm), crush volume (cm3), and the difference in circumference between the helmet and headform (cm)). Overall, we found that increasingly oversized helmets reduced peak headform acceleration and HIC for a given impact speed for maximum residual crush depths less than 7.9 mm and residual crush volume less than 40 cm3. Below these levels of residual crush, we found that peak headform acceleration, HIC, and impact speed can be estimated from a helmet's residual crush. Above these crush thresholds, large variations in headform kinematics are present, possibly related to densification of the foam liner during the impact.

Original languageEnglish (US)
Pages (from-to)315-326
Number of pages12
JournalAccident Analysis and Prevention
Volume106
DOIs
StatePublished - Sep 1 2017

Keywords

  • Acceleration
  • Headform
  • Helmet
  • HIC
  • Impact
  • Size

ASJC Scopus subject areas

  • Human Factors and Ergonomics
  • Safety, Risk, Reliability and Quality
  • Public Health, Environmental and Occupational Health
  • Law

Fingerprint Dive into the research topics of 'The effect of motorcycle helmet fit on estimating head impact kinematics from residual liner crush'. Together they form a unique fingerprint.

Cite this