Forensic, General & Medical
Expert Witnesses

How an Expert Witness Uses Biomechanics Knowledge in Seatbelt Defect Cases


Personal injury claims usually must have the elements of the case include proof that the defending party’s actions caused the incident. This makes the individual responsible for the damages owed. In order to refute this, the alleged person uses his or her lawyer to assist in showing that he or she could not be accountable due to a lack of evidence.
This usually requires additional help through an expert witness. This professional has the experience in the field of the claim in both how to explain why the victim is affected and what actually may have transpired.

When the issue requires knowing what occurred, a reconstruction expert may be hired to provide details about dynamics of incidents through vehicular problems such as seatbelt defects. This means that the expert professional may use standard methods to determine if the safety belt had defective materials that caused it to snap before the driver could be protected from harm. Another process may be utilized to show if the design of the belt was inferior and locked up to lead to the injury sustained. Another expert may be hired to assess the medical issues so that the jury or judge understand why so much compensation is necessary to make the victim whole after the accident.

Biomechanics Experts

When someone has been hired as an expert witness for a case regarding injuries due to a seatbelt, he or she may have training and education in engineering mechanics, soft tissue damage and similar fields. This knowledge may be from practical experience, through courses and observance or personal injuries the professional sustained in his or life. To explain the health issues, some of these experts have degrees in medical science, biomechanics and other comparable areas. With these completed course paths, a biomechanical professional is able to fully grasp both the medical and defect ramifications of the situation where the driver or passenger was harmed. Through this knowledge, it may be possible to reconstruct the incident and determine who is responsible for the event.

When the biomechanics expert is used as a witness, he or she usually has extensive training in how the parts of the body react, interact and work due to internal and external forces. This permits them to comprehend the stresses, strains and problems that may arise with tissues that are impacted by a force, tolerances of tissues to trauma and the variability in properties of mechanics. If the expert has more knowledge of a medical field, he or she understands anatomy and physiology to diagnose conditions. Injuries then may be classified as well as a determination made about what could have caused the injury. With these details, it is often possible to recreate the incident and explain to a judge or jury what occurred within the car.

Data Recorders Applied to Seatbelt Defects

With the use of a data recorder that was installed in the vehicle, it is often possible to obtain more details about the incident. These work much the same as the black boxes in airplanes to provide technical information so that the accident may be reconstructed. This provides enough for a biomechanics expert to analyze the recorded facts and understand where the defect exists. Based on the part of the body the injuries exist, an expert witness is capable of explaining the medical complications. With the recorded data from the installed device, these professionals are able to determine which part of the seatbelt caused the problem. This may reveal the type and extent of the defect that exists in the belt manufactured.

Data recorders such as these are only activated when an incident occurs. The moment of impact often causes the installed device to obtain as much detail of the problem as possible. This means that the time just before, during and slightly after are all monitored, recorded and then assessed with the assistance of a vehicle safety system. However, how much and which data are recorded is entirely depending on the model of data recorder installed.

Biomechanics Experts in Seatbelt Cases

Expert witnesses are applied to cases by hires from a lawyer for claims for their experience and knowledge of the field. They are able to apply training and degrees in the subject to both explain to the judge or jury what is needed as well as give testimony based on their opinion on what occurred through the evidence and data supplied. Once the expert has concluded his or her investigation into the matter, he or she is then used as a witness to explain how this applies to the case. In many instances, this is for compensation that should be awarded to the victim of the incident. In other cases, the expert witness only supplies one part of testimony for a comparison of the accident.


While every effort has been made to ensure the accuracy of this publication, it is not intended to provide legal advice as individual situations will differ and should be discussed with an expert and/or lawyer.

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