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.
Summary of Background Data.
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