Mechanisms of Head and Spinal Injuries Due to Car Accidents: Research Summary

Head and spinal injuries are common in motor vehicle crashes and have a significant risk of becoming chronic conditions. Despite advancements in vehicle safety throughout automotive history, preventing MVA-related head and spinal injuries remains a considerable challenge despite the use of well-designed and properly functioning restraint systems, such as seatbelts, head restraints, and airbags. 

The Journal of Orthopaedic & Sports Physical Therapy clinical commentary expands on injury mechanisms during MVA and a host of factors that increase the injury risk, including occupant characteristics, pre-MVA factors, and MVA-related factors. 

Understanding Injury Mechanisms

Head and spinal injuries during MVAs are caused by blunt impact and/or inertial forces. It is helpful in presenting a case to understand these mechanisms, and to be able to demonstrate the dynamic loads and motions experienced by occupants, including the magnitude, direction, and timing of these forces during a crash. 

Simulated vs. Real-Life MVAs

Simulated MVAs in laboratory settings, which use cadaveric specimens, crash dummies, or computational models, allow for a controlled study of the injury mechanisms. These simulations help quantify the impact of specific crash scenarios on the body. In contrast, understanding injuries from real-life MVAs is complicated by a lack of precise data on occupant motion and the forces involved. Factors such as the occupant's characteristics (age, sex, bone density, etc.), awareness of the crash, and pre-crash positioning affect how injuries manifest. This variability means that no universal injury tolerance standard exists for all crash victims.

Rear-Impact and Frontal-Impact MVAs

Rear-impact crashes cause the torso to be thrust backward, often leading to seatback deflection and changes in the spine's natural curves. The cervical spine, in particular, may form an S-shape with distinct patterns of flexion and extension, resulting in potential disc, ligament, or facet joint injuries. In frontal-impact crashes, the sudden deceleration forces the head forward, placing the cervical spine at risk of hyperflexion injuries. Seatbelts mitigate some risks but can also contribute to certain types of injuries, such as flexion-distraction fractures, when improperly positioned (Paul C. Ivancic, PhD, 2016)

Schematic demonstrating cervical spine curvature within 175 milliseconds during simulated rear-impact motor vehicle collision involving a head-neck model. Reproduced with permission from Grauer et al.Read the full study here Copyright ©1997 Wolters Kluwer Health, Inc.

Side-Impact MVAs

In side-impact crashes, the risk of injury is higher due to less vehicle deformation to absorb the impact. Occupants are often subjected to significant lateral forces, which can lead to complex spinal injuries and brain trauma (Paul C. Ivancic, PhD, 2016). Studies using cadaver models have shown that side impacts can cause dangerous cervical spine motions and significant brain tissue injury due to blunt impact and inertial forces according to this study.

Traumatic Disc Injuries Without Fracture

Spinal disc injuries can occur without accompanying vertebral fractures in any MVA scenario. Simulated MVAs have demonstrated how disc strains can exceed physiological limits, leading to tears and herniations (Paul C. Ivancic, PhD, 2016). These injuries can explain how chronic neck pain and radicular symptoms occur when no bone fractures are present.

Clinical Implications

Understanding how MVA forces affect the spine is crucial for making treatment decisions. This knowledge helps clinicians determine the stability of spinal injuries and choose the appropriate interventions, whether surgical or conservative (Paul C. Ivancic, PhD, 2016). 

Injury Mitigation and Future Directions

Despite existing safety measures, MVAs still result in significant injuries and fatalities. Traditional systems like seatbelts and airbags are often optimized for average male crash dummies and may not fully protect all occupants (Paul C. Ivancic, PhD, 2016).  Emerging accident-avoidance technologies, combined with traditional safety systems, show promise in reducing injuries (Paul C. Ivancic, PhD, 2016). Ongoing research will continue to improve vehicle design, aiming to minimize the impact of MVAs and enhance occupant safety.

Read the full research article here: https://www.jospt.org/action/consumeSharedSessionAction?JSESSIONID=078E39504B4631CDC3E58D7D7219DFEF&MAID=4vyh72Q6EjVmFbphRCRS1Q&ORIGIN=572563383&RD=RD&exp=mzSAVOUy4V4DcaootWXkOQ%253D%253D

Brain injury Lawyer

This review of MVA injury mechanisms highlights the complexity of factors that influence injury risk, from occupant characteristics to crash dynamics. By understanding these mechanisms, we are better able to communicate to a jury the reason why a person has ongoing pain or functional restrictions, and the reason why treatment needs continue to exist and must be funded into the future. 

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We know every injury is personal. Behind every injury is a story of loss or a change that can be  a career put on hold; a family thrown into financial distress; and an uncertain future. For more than four decades, our brain injury lawyers have worked one-on-one with clients to successfully secure millions of dollars in compensation for their injuries and other losses. The surest way to settle your case fairly is to retain a lawyer with a history of taking cases to trial, and winning.