In this poster presentation, it is stated that neck loading to head immersion in water at high speeds produces drag forces which will be transmitted through the neck and cervical spine. To better understand this phenomenon a test was designed to study the effects of neck loading with and without a helmet. Using an instrumented Hybrid III Anthropomorphic Test Dummy (ATD) and 50% head form, physical testing of neck extension moments and shear forces was performed. With a specially designed test apparatus mounted on a boat, testing was done at various speeds to examine the loads applied to the neck. Speeds of 30 mph were obtained. The analytical method allows extrapolation of slower speed empirical test results to loads which may occur during high speed immersions. In addition to testing just a bare head, tests were performed in which a bare head was fitted with a full face helmet and comparison data were measured. In all cases, the helmet increased the drag or shear force on the cervical spine. For the full face helmet the drag force on the lower neck increased 40% at 30 mph. Similarly, the upper neck extension moment increased 160% at 30 mph for the full face helmet compared to the bare head.
Samenvatting