Eleven dynamic fronto-occipital impact tests on helmet-protected cadavers were conducted with a deceleration trolley to which a quasirigid wall was installed. Effective head impact velocity lay between 32 and 45 km/h. The maximum deceleration of the head was on average 136 g x-direction and 105 g z-direction. The deceleration of the vertebral column reached values of 146 g for the 1st thoracic vertebra and 77 g for the 12th thoracic vertebra (average value of the maxima). examination of the vertebral column showed 6 cases of severe compression fractures of the upper and middle thoracic part; signs of strain and flexion could be detected in the form of minor injuries in all cases. Discreet skull injuries were found in only two cases. Injury to the brain could not be detected but cannot be excluded in view of the test object. All the full-faced safety helmets used were of the same type and manufacture. The polycarbonate outer shell did not break in any of the tests. The polystyrole inner liner showed plastic compressions of a maximum of 30 percent of the thickness of the damping liner at contact point. (a)
Samenvatting