The United States ASTM Headgear Committee began the infant/toddler helmet standard development in the year 1990. The primary reason for this standard is to improve the already effective standards, and to foresee the growth of, for instance, bicycle helmet use among this age group. Two test head forms have been developed. The "AA" head form represents a 95th percentile for six month-olds, a 50th percentile for 12 month-olds, and a 5th percentile for 18 month-olds. The second or "A/T" head form represents a 95th percentile for one year-olds, a 50th percentile for two year-olds, and a 5th percentile for a four-year-old child. The "A/T" head form was compared to the existing International Standardization Organization (ISO) "A". It was determined, that in the test area, the two were quite similar. However, the basic plane tilted 15 degrees. Therefore, the ASTM helmet committee decided to develop a new "AA" head form, and to use the existing ISO "A" with the 15 degrees basic plane and redefined test area. The next step is to manufacture tooling in order to produce a ball socket test head form. The paper briefly reports the 1089 helmeted accident study carried out by Bell Sports.
Samenvatting