Acceleration perturbations of daily living. A comparison to 'whiplash'

This study measured repeated human head accelerations (g) during daily activities. Perturbations of daily living were compared to similar data from low velocity rear-end motor vehicle accidents. Past assumptions suggest that motor vehicle accident severity does not correlate with the degree of sustained injury. Early engineering studies indicated that occupant disturbance in a low velocity motor vehicle accident is minor. Eight volunteers were perturbed with 13 daily activities. Helmets on the heads of volunteers were instrumented with tri-planar accelerometers with output sampling of 500 Hz, sensitivity of 0.02 g, and a range of +/- 20 g. There was wide inter-subject response for various perturbations. Plopping backward into a chair caused maximum peak acceleration horizontally at 5.6 g and vertically at 8.5 g, with force vector of 10.1 g at 54.9 degrees. Mean impulse duration was 0.19 sec. There was no hint of injury in any subject. Perturbations of daily living compared similarly to the jostling expected in low velocity "whiplash"-type motor vehicle accidents.