Response of the Seated Human Cadaver to Acceleration and Jerk with and without Seat Cushions 1

Abstract

Human cadavers were subjected to seat-to-head accelerations to a maximum acceleration and jerk (rate of change of acceleration) of 18 g and 2600 g/sec, respectively, with six different types of seat cushions. Strain gages were cemented to the vertebral column and accelerometers were attached to bone at several levels of the body. The object of the experiments was to observe the effects of varying magnitude of acceleration, jerk, and seat cushions on the strain and acceleration response of the cadaver. Results indicate that dynamic load factor (ratio of peak to mean response) increases with jerk at low jerk levels to a maximum and thereafter remains relatively independent of jerk; increases with mean or terminal acceleration in the range of these tests; and increases for all types of cushions used in these tests. Strains measured on the body of vertebrae, particularly in the lumbar region, correspond closely to body accelerations, but strains measured on the rear of vertebrae were not related to body accelerations.