Injuries in near-side collisions

This paper examines crash characteristics and the resulting injuries to occupants whose seat position is on the side of impact in a vehicle exposed to a side collision. The databases of the 1988-96 NASS/CDS and the 1995-98 William Lehman Injury Research Center (WLIRC) are examined in this study. The subset of cases analyzed is those in which there is a vehicle-to-vehicle near-side collision, occupant compartment damage and no subsequent collision or rollover. The WLIRC data contains highly detailed occupant injury data not available in NASS. The WLIRC database 1995-1998 contains 92 side impact cases. Sixty-four cases involved occupants seated on the side impacted. The 64 near-side impacts are filtered according to object struck, presence of occupant compartment damage and no subsequent collision or rollover, resulting in a total of 46 cases. The NASS/CDS database injuries are described on the basis of body region and severity. The most frequent MAIS 3+ injured body regions in NASS/CDS are: chest/abdomen 49%, head/face 24%, pelvic/lower extremity 14%, and neck/spine 4%. The largest sources of AIS 6 injuries in the NASS/CDS are arterial injuries, followed by brain and heart injuries. The WLIRC data is more representative of severe crashes than NASS in terms of struck vehicle lateral delta-V and side crush and provides more detailed injury descriptions. In comparison to NASS/CDS, this database contains a higher percentage of the following chest/abdominal injuries: thoracic aorta 15%, heart 11%; and spleen 11%. MAIS 3+ head injuries occur in 17% of cases studied. The organs most frequently causing fatalities are: brain 21%, thoracic aorta 21%, and heart 18%. The WLIRC data contains 21 occupants in near-side vehicle-to-vehicle crashes with MAIS 3+ brain injury. Overall, the most frequent source of brain injury was the striking vehicle (35%). Heart injuries were present in 6 of the WLIRC cases, all fatal. These cases were severe crashes with a lateral delta-V for the struck vehicle in excess of 13.4 m/s or a vehicle side crush in excess of 0.61 meters. The lower side interior was the contact in 5 cases and the shoulder belt was the contact in one case. The existing triage criteria identified brain and heart injuries at the scene. The WLIRC data contains 12 cases of thoracic aortic injury. There were 11 fatalities; it is of note that 8 of the 12 initially survived the crash and were transported to a hospital. Development of additional crash scene triage criteria could be vital to assist in the early identification of these difficult-to-detect, time-critical aortic injuries. Several similarities were observed regarding the vehicle damage patterns among seven cases with the least severe door intrusion. These include: oblique principal direction of force (PDOF) relative to the struck vehicle, direct damage to the struck vehicle beginning at the front wheels and damage on the door at a high vertical level, often with limited sill intrusion. Other factors include: older occupants, female occupants, and an unrestrained occupant on the far side of the vehicle.