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°. 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. [Key words: acceleration, change of velocity, equivalent barrier speed, gravitation, perturbations, whiplash] Spine 1994;19: 1285–1290
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From *Simon Fraser University, Burnaby, British Columbia, †Weir-JonesEngineering, Vancouver British Columbia, and ‡Finders University,Adelaide, Australia.
Accepted for publication December 15, 1992.