When a personal injury claim becomes disputed, the existence of an injury is often not the issue. Medical records may confirm that an injury occurred, but they do not necessarily answer a different question that frequently sits at the centre of transportation litigation: does the reported collision actually explain the injuries being claimed?
This is where biomechanics can assist.
A biomechanical assessment does not diagnose injuries or comment on treatment outcomes. Instead, it examines whether the forces, movements and mechanisms involved in a particular incident are consistent with the reported tissue damage. By considering collision evidence alongside engineering principles and medical documentation, a biomechanical expert witness can objectively assess the relationship between incident dynamics and damage to bodily tissues.
How Does Vehicle Damage Help Explain Injury Mechanisms?
Vehicle damage is a key part of a biomechanical assessment because it provides important evidence about how the collision occurred. The location, pattern and severity of the damage are evaluated using established engineering methods to help determine the direction of impact, the nature of the vehicle movement and finally the forces and accelerations that were transmitted to the occupant.
But damage is not interpreted from appearance alone, nor is it assumed that more visible damage must produce more severe injury. Vehicle damage is analysed through crush force calculations and compared to scientific databases and published literature.
Assessing Impact Severity
Where the evidence allows, biomechanical experts use vehicle deformation and collision geometry as well as comparative damage analysis to determine a change in velocity (delta-V) to characterise the impact. They then consider these findings alongside occupant posture, seat position, head restraint geometry, and restraint systems to assess how the occupant likely moved. Peer-reviewed scientific literature is also used to assess the location, direction, and magnitude of forces transferred to the body and compare them with known tissue tolerances.
Understanding Occupant Movement
Vehicle damage therefore forms an important part of the overall analysis, but it must be interpreted scientifically and in context. By combining damage evidence with collision dynamics and occupant kinematics—the study of how the body moves during an impact—a biomechanical expert can assess whether the direction and magnitude of the expected occupant loading are consistent with the reported injury mechanism.
What Happens When Injury Claims Do Not Match the Physical Evidence?
A recent case illustrates this point well. Following a moderate-speed frontal collision, a dispute arose regarding whether the driver had been wearing a seatbelt at the time of impact and whether restraint use would have altered the nature and severity of the injuries sustained. Answering that question required far more than reviewing medical records. The analysis incorporated vehicle damage, the condition of the seatbelt system, whether the pretensioner had fired, and the expected movement of the driver’s body under different scenarios based on published biomechanical studies. Collision investigation findings and event data recorders also contributed to this assessment.
Looking at the Full Evidence Picture
The purpose of this type of analysis is not to build a conclusion around a single piece of evidence. Rather, it determines whether the various strands of evidence support a consistent account of how the injuries were sustained. This same approach applies across a wide range of incidents, including other configurations of vehicle collisions, pedestrian impacts, motorcycle and bicycle collisions and helmet use, and slips, trips and falls.
Understanding the Role of Biomechanical Evidence
It is important to understand what biomechanics can and cannot do. Biomechanical evidence can assist with injury consistency assessments, evaluating mechanisms, and considering alternative explanations. It can help determine whether reported injuries align with the known circumstances of a collision.
It cannot establish a medical diagnosis, provide a prognosis, treatment or determine that a particular injury definitely occurred. Those remain matters for medical experts. Biomechanics forms one part of the wider evidential picture, alongside medical records, collision investigation findings, witness evidence and vehicle inspections. For solicitors, insurers and the courts, its value lies in providing an objective, evidence-based assessment of whether the account of a collision and the injuries being claimed are scientifically consistent.
What Is Injury Biomechanics?
Ultimately, biomechanics applies principles and methods of engineering mechanics to the study and solution of problems arising in biology and medicine. Injury biomechanics examines the relationships between events and tissue damage by studying the physics of events, tissue properties, and how loads are applied to tissues during potentially injurious events. This is a widely accepted discipline within the scientific community; injury biomechanics forms the basis for the safety aspects of vehicle interior design and the rules and regulations that govern vehicle crashworthiness.
How Can Rimkus Help?
Rimkus provides independent biomechanical assessments to help solicitors, insurers, and the courts evaluate whether reported injuries are consistent with the circumstances of an incident. Our experts combine engineering principles, collision analysis, medical evidence, and scientific research to deliver objective, evidence-based opinions in disputed claims.
This article is intended to provide general information and insights into prevailing industry practices. It is not intended to constitute, and should not be relied upon as, legal, technical, or professional advice. The content does not replace consultation with a qualified expert or professional regarding the specific facts and circumstances of any particular matter.