Bicycle Helmet Size, Adjustment, and Stability
- Authors: Thai, Kim , McIntosh, Andrew , Pang, Toh Yen
- Date: 2015
- Type: Text , Journal article
- Relation: Traffic Injury Prevention Vol. 16, no. 3 (2015), p. 268-275
- Full Text: false
- Reviewed:
- Description: Objectives: One of the main requirements of a protective bicycle helmet is to provide and maintain adequate coverage to the head. A poorly fitting or fastened helmet may be displaced during normal use or even ejected during a crash. The aims of the current study were to identify factors that influence the size of helmet worn, identify factors that influence helmet position and adjustment, and examine the effects of helmet size worn and adjustment on helmet stability. Methods: Recreational and commuter cyclists in Sydney were surveyed to determine how helmet size and/or adjustment affected helmet stability in the real world. Anthropometric characteristics of the head were measured and, to assess helmet stability, a test analogous to the requirements of the Australian bicycle helmet standard was undertaken. Results: Two hundred sixty-seven cyclists were recruited across all age groups and 91% wore an AS/NZS 2063-compliant helmet. The main ethnic group was Europeans (71%) followed by Asians (18%). The circumferences of the cyclists' heads matched well the circumference of the relevant ISO headform for the chosen helmet size, but the head shapes differed with respect to ISO headforms. Age and gender were associated with wearing an incorrectly sized helmet and helmet adjustment. Older males (>55 years) were most likely to wear an incorrectly sized helmet. Adult males in the 35-54 year age group were most likely to wear a correctly adjusted helmet. Using quasistatic helmet stability tests, it was found that the correctness of adjustment, rather than size, head dimensions, or shape, significantly affected helmet stability in all test directions. Conclusions: Bicycle helmets worn by recreational and commuter cyclists are often the wrong size and are often worn and adjusted incorrectly, especially in children and young people. Cyclists need to be encouraged to adjust their helmets correctly. Current headforms used in standards testing may not be representative of cyclists' head shapes. This may create challenges to helmet suppliers if on one hand they optimize the helmet to meet tests on ISO-related headforms while on the other seeking to offer greater range of sizes.
Factors affecting motorcycle helmet use: Size selection, stability, and position
- Authors: Thai, Kim , McIntosh, Andrew , Pang, Toh Yen
- Date: 2015
- Type: Text , Journal article
- Relation: Traffic Injury Prevention Vol. 16, no. 3 (2015), p. 276-282
- Full Text: false
- Reviewed:
- Description: Methods: Observations and measurements of head dimensions, helmet position, adjustment, and stability were made on 216 motorcyclists. Helmet details were recorded. Participants completed a questionnaire on helmet usability and their riding history. Helmet stability was assessed quasistatically. Results: Differences between the dimensions of ISO headforms and equivalent sized motorcyclists’ heads were observed, especially head width. Almost all (94%) of the helmets were labeled to be compliant with AS/NZS 1698 (2006). The majority of riders were satisfied with the comfort, fit, and usability aspects of their helmets. The majority of helmets were deemed to have been worn correctly. Using quasistatic pull tests, it was found that helmet type (open-face or full-face) and the wearing correctness were among factors that affected the loads at which helmets became displaced. The forces required to displace the helmet were low, around 25 N. Conclusions: The size of the in-use motorcycle helmets did not correspond well to the predicted size based on head dimensions, although motorcyclists were generally satisfied with comfort and fit. The in vivo stability tests appear to overpredict that helmets will come off in a crash, based on the measured forces, tangential forces measured in the oblique impact tests, and the actual rate of helmet ejection. Objectives: One of the main requirements of a protective helmet is to provide and maintain appropriate and adequate coverage to the head. A helmet that is poorly fitted or fastened may become displaced during normal use or even ejected during a crash.
Crash characteristics of helmeted motorcyclists
- Authors: Mclntosh, Andrew , Pang, Toh Yen , Thai, Kim , Schilter, Edgar , Rechnitzer, George , Finch, Caroline , McCrory, Paul
- Date: 2010
- Type: Text , Conference paper
- Relation: Proceeding of the Australasian Road Safety Research, Policing and Education Conference
- Full Text: false
- Reviewed:
- Description: The preliminary results of a prospective study ofmotorcycle crashes are reported. Motorcyclists were recruited from three major trauma centres in Sydney and through motorcycle organisations. The main sample criteria were that the cyclist crashed, and that they hit their head while wearing a helmet. Injury andnon-injury cases were collected. Case sampling occurred over a period of l8 months. The response rate through hospitals was approximately l4Yo for those meeting the selection criteria. All motorcyclists were interviewed and the helmets were examined. Characteristics such as environment (road type), vehicle (vehicle damage and interaction) and human factors were recorded. The location of helmet impacts and patterns of helmet damage were recorded. Injuries were documented and rated according to severity. The relationships between the crash characteristics, helmet use and injury will be presented.
Crash characteristics of helmeted pedal cyclists
- Authors: Mclntosh, Andrew , Pang, Toh Yen , Thai, Kim , Schilter, Edgar , Rechnitzer, George , Finch, Caroline , McCrory, Paul
- Date: 2010
- Type: Text , Conference paper
- Relation: Proceeding of the Australasian Road Safety Research, Policing and Education Conference
- Full Text: false
- Reviewed:
- Description: The results of a prospective study of pedal cycle crashes are reported. Cyclists were recruited from three major trauma centres in Sydney and through cycle organisations. The main sample criteria were that the cyclist crashed, and that they hit their head while wearing a helmet. Injury and non-injury cases were collected. Case sampling occurred over a period of 18 months. The response rate through hospitals was approximately 14% for those meeting the selection criteria. All cyclists were interviewed and the helmets were examined. Characteristics such as crash characteristics and injury are reported. The relationships between the crash characteristics, helmet use and injury are presented. The paper reports on 98 cases and excludes fatal cases. Half of the cyclists did not experience a head injury.