As discussed in a prior post, nearly 3 million people are injured annually as a direct result of a motor vehicle accident (U.S. Census Bureau). Financial costs are upwards of $300 billion and does not include loss of productivity and permanent disruption of many lives (NHTSA 2013b). The National Highway Traffic Safety Administration has identified 5 common causes of accidents, all of which potentially could be prevented. These include speeding, distracted driving (texting and cell phone use), alcoholic impairment, failure to wear or improper use of a seatbelt, and failure to take into account adverse weather conditions.
High energy forces and rapid acceleration or deceleration that is common to motor vehicle accidents leads to internal and external injuries, some of which are easily recognizable. Biomechanical studies and data derived from direct observation following motor vehicle accidents has helped identify specific injury patterns based on the type of impact involved.
In a frontal impact, air bags and seatbelts help save lives and reduce injury by reducing forces placed on the driver and passengers. Specific patterns of damage to the windshield can help identify severity of impact. For example, a smaller pattern of glass cracking or breaking can result from a hand hitting the windshield versus a large crack with hair and blood embedded in the glass from the impact of a head. A bent steering wheel may indicate signs of a chest or abdominal injury. Similarly, damage to the dashboard can point to injuries of the knee, femur, or hip. Fractures and internal derangement of the knee and dislocations of the hip commonly occur from striking the dashboard despite being seat belted in.
A side or “T-Bone” type impact can cause numerous injuries and is dependent on the speed, angle of impact and size of vehicles involved. As the side of the vehicle has no “crumple zone” like the front and rear, much of the energy of the impact can be felt by the driver and passengers. Pelvic injuries are common in lows impacts directly upon the occupant’s door. Impacts that occur higher up on the door can lead to injuries of the head, brain, chest and shoulders.
Rear impact crashes are one of the most common occurrences and account for many injuries, however the severity of these injuries does tend to be lower (NHSTA 2013d). Whiplash injuries in which the head and cervical spine is violently flexed and extended is common after a rear impact type impact. Correct use of a seat belt and properly adjusted head restraint can offer the occupant protection in this type of crash. A broken seat may indicate a high energy injury which may include spinal cord damage.
Lastly, a crash involving a vehicle rollover can lead to many severe, if not life threatening injuries. Seat belt use can help reduce occupants from serious injury in this case. Unrestrained occupants face the high risk of being partially or totally ejected from the vehicle.