Helmet retention system types as a risk factor to properly attach the chin strap

This study aimed to determine the factors associated with the incorrect use of a helmet retention system (loose or open) and how often this happens.

This was an observational transversal study conducted in Curitiba, Brazil. Trained observers positioned at traffic lights collected information about the helmet fixation mode, the helmet model (full-face, open-face, modular, half), and the helmet retention system model (micrometric, double-D, fast-release). Additional data including position on the motorcycle, gender, and function of the motorcycle (as a work vehicle) were collected. The observers, collection site, and periods were randomly selected by lots.

From a total of 3,050 motorcyclists, 1,807 (59.2%) had their helmets fastened correctly, 907 (29.7%) had the retention system fastened loosely, and in 336 (11.0%), the retention system was completely open. Increased odds of incorrect use were observed for the fast-release and double-D buckles compared to the micrometrics buckles, with a fixed odds ratio (OR) of 4.62 (95% confidence interval [CI], 3.89-5.51) and 3.54 (95% CI, 2.46-5.09), respectively (P <.0001). Full-face helmets had a higher chance of incorrect use (P <.0001), and passengers had a higher incidence of incorrect use of the helmet than drivers (P <.0001).

An important risk factor related to the incorrect use of the helmet was the type of retention system. The helmet model and being a passenger had a secondary influence on incorrect use of helmets.