A Study of Impact on Head and Neck Using Human Volunteer Low-Speed Rear Impact Tests

Korean J Leg Med 2013;37:66-72. Korean.

Traffic Engineering Div., Forensic Science Dept., National Forensic Service, Seoul, Korea

Western District Office, National Forensic Service, Jangseong-gun, Jeollanam, Korea, rudany@korea.kr

Traffic Accident Div., Forensic Engineering Research Institute, Seoul, Korea, realityz23@gmail.com

Department of Orthopedic Surgery, Seoul Sky Hospital, Seoul, Korea

Department of Biomedical Engineering, Yonsei University, Wonju-si, Gangwon, Korea

Whiplash injury in low-speed traffic accidents are not objectively verified by medical equipment, thereby creating scope for misuse, which has resulted in huge social losses worldwide. The aim of this study was to examine the influence of low-speed vehicular rear-impact collisions on middle-aged men, and to analyze the head and neck injury criteria for the symptomatic human volunteers. Data was examined from the results of 50 dynamic sled tests, originally performed by Hong et al. (2012). In the previous tests, 50 men aged 30􀅭50 years were exposed to an impulse equivalent to a bumper-to-bumper rear collision under medical supervision, and no resulting whiplash injury was identified. In this study, for 6 subjects who experienced dull aches over their bodies, head injury criteria (HIC15) and neck injury criteria (Nkm) were calculated according to the accelerations, forces, and moments at the occipital condyle measured by motion capture system. Although there were no changes in magnetic resonance imaging findings in all subjects at the pre-/post-test orthopedic examination, 6 subjects revealed mild aches around the shoulder, back, or lumbar area, and their symptoms disappeared within 2 days. The head and neck injury criteria, HIC15 (3.086 ± 2.942) and Nkm (0.077 ± 0.064) were obtained, and the maximum HIC15 and Nkm were found to be significantly lower than the critical injury assessment reference values (HIC15: 700, Nkm: 0.3). Moreover, even though 2 subjects were exposed to the same level of change of velocity (7.9 km/h), each Nkm was significantly different (0.179, 0.057). One can therefore conclude that Nkm can vary according to voluntary movements in the human subject.

Key Words : Whiplash injuries, Human experimentation, Automobiles, Traffic accidents

Original article