The purpose of this study is to help understand the thoracic
response and injury mechanisms in high-energy, limited-stroke,
lateral velocity pulse impacts to the human chest wall. To impart
such impacts, a linear impactor was developed which had a limited
stroke and minimally decreased velocity during impact. The peak
impact velocity was 5.6 ± 0.3 m/s.
A series of BioSID and cadaver tests were conducted to measure
biomechanical response and injury data. The conflicting effects of
padding on increased deflection and decreased acceleration were
demonstrated in tests with BioSID and cadavers. The results of
tests conducted on six cadavers were used to test several proposed
injury criteria for side impact. Linear regression was used to
correlate each injury criterion to the number of rib fractures.
This test methodology captured and supported a contrasting trend
of increased chest deflection and decreased TTI when padding was
introduced. This study suggested that chest deflection or the
energy generated in a lateral velocity pulse impact, correlated
with the number of rib fractures better than acceleration or the
viscous response of the struck-side rib cage. Interestingly,
Favg*Cmax, TTI*Cmax and peak spine acceleration
(T12-y) also correlated well with the number of rib fractures. The
hypothesis for injury assessment using energy concept, Maximum
Stored Energy Criterion (SEC), also was supported by the BioSID and
cadaver test results.