A recent study showed that, in case of impact, the brain followed the skull motion up to 200 Hz and was motionless over this frequency. A new mass-spring model which differentiated the brain mass from the other head components has been proposed. The present study uses this model to calculate the skull to brain velocity ratios. This velocity ratio varied with frequency which showed a critical area ranging from 100 to 200 Hz. This result produced to analyze the tolerance curves given in the literature, in the frequency field. Expressing the total energy and energy ranging from 0 to 100 Hz for limit impacts, as a function of their spectrum maximal frequency, showed different injury mechanisms considered by various authors. The study yielded the first elements of a tolerance curve in the frequency field for specific injuries. (A)
Abstract