A volunteer was impacted at velocities up to 4.6m/sec. (15 ft./sec.) with a 10 kg (22.1 lb.), 15.2 cm (6in.) diameter padded impactor. Force-time, deflection-time and force-deflection data are presented for these impacts showing a maximum force of 1.67 kn (376 lbs.) and a maximum skeletal deflection of 4.6 cm (1.80 in.). The maximum chest compression is about the same at 4.4 cm to 4.6 cm (1.72 to 1.80 in.) at all impact velocities. The force-deflection curve reaches a plateau where there is relatively little change in force for a large change in deflection after which there is a large change in force with little change in the maximum deflection. There is considerable hysteresis, and the force drops to zero while there is still appreciable skeletal deflection.
Samenvatting