J.S. Held Releases Insights on Risks & Opportunities Expected to Impact Organizations in 2025
Read MoreSince the widespread adoption of seatbelt use, these devices have been shown to dramatically decrease fatalities and serious injuries in motor vehicle crashes. Seatbelts limit occupant motion in the event of a collision or sudden stop and can prevent ejection or contact with structures within the vehicle such as the steering wheel or instrument panel.
A properly worn three-point seatbelt will also keep the front seat passengers in the optimal position in the event of air bag deployment. However, in certain circumstances the restraining force of a seatbelt may be enough to cause severe pain or serious injury.
The following information may be of particular interest to insurance or legal professionals who are in need of an expert opinion on a seatbelt injury from an auto accident, on the type/nature of injury sustained, or in verifying the use of seatbelts in a traffic accident.
The most common seatbelt injuries or symptoms are bruises, abrasions, inflammation, or pain at the locations on the body where the seatbelt makes contact. These are usually the shoulder, the chest, the abdomen, and the lower back, but if the seatbelt is ill fitting or worn improperly, there may be pain or injuries at other locations where the body contacts the shoulder belt or lap belt.
The risk of experiencing these symptoms or injuries will depend on the design and fit of the seatbelt, the severity and type of motor vehicle collision, and the occupant’s injury tolerance.
Bruising from the Seatbelt After the Accident
Bruises, abrasions, and other minor soft tissue injuries can occur after a collision along the locations where the seatbelt contacted the occupant’s body.
Chest Injuries from the Seatbelt
The loading applied to the torso by a seatbelt can cause injuries to the chest, including bruising of the lungs and fractures of the ribs and sternum.
Intra-Abdominal Injuries from the Seatbelt
The loading applied by the seatbelt to an occupant’s abdominal wall during an accident can not only cause visible injuries such as bruising, but also internal injury to abdominal organs.
Lumbar Spinal Injuries
Chance fractures are fractures of the lower back that occur due to excessive spinal flexion (bending forward) and are typically associated with seatbelt usage. Chance fractures are more common in occupants who are restrained by two-point lap belts rather than three-point belts, because three-point belts restrain the motion of the torso and prevent excessive flexion.
In biomechanical forensic engineering investigations, reconstructionists may be asked to comment on the likelihood that an occupant was wearing a seatbelt, or how wearing a seatbelt may have changed an unbelted occupant’s injury outcome.
In every case, reconstructionists need to determine the direction and magnitude of the forces acting upon an occupant’s body (from the motion of the vehicle, from the seatbelt, and from any other structures or items the occupant may have contacted).
Reconstructionists then refer to research on the types of injuries these forces are likely to produce. The presence or absence of common seatbelt injuries can help complete this analysis. However, it should be noted that many belted occupants experience collisions without sustaining any of the most common seatbelt injuries, which is why it is always important to investigate each case thoroughly and to consider all available evidence.
Karla Cassidy is a Senior Engineer in J.S. Held's Accident Reconstruction Practice. Ms. Cassidy has been an active member in the biomechanics community since 2006 and in the accident reconstruction industry since 2010. Her expertise spans both biomechanical and mechanical engineering. She has been involved in hundreds of cases involving vehicles, pedestrians, motorcycles, farm equipment, and cyclists. Her specialty areas are biomechanics, personal injury, injury probability, seatbelt usage, slip, trip and falls, and determination of occupant position. Ms. Cassidy also conducts collision reconstruction and damage consistency analyses. She is a published author and has provided litigation support.
Karla can be reached at [email protected] or +1 416 977 0009.
Car accidents involve various types of vehicles—typically two—moving at a range of speeds and angles. However, most standard government enforced crash tests do not necessarily exhibit what typically occurs in a real-world crash. Therefore one...
It’s common that rear-end collisions result in symptoms of whiplash. To determine how these symptoms develop, we must first consider the laws of physics. Newton’s first law of motion states that a body at rest...
Automotive safety systems have evolved significantly considering that the seatbelt was not mandatory in new North American vehicles until 1968, 13 years after the seatbelt was first made available as an option. Likewise, airbags began...