Herniated Discs, Shoulder Tears, and Knee Injuries: Can the Accident Mechanism Cause the Claimed Injury?

Herniated Discs, Shoulder Tears, and Knee Injuries: Can the Accident Mechanism Cause the Claimed Injury?

Following a motor vehicle accident, claimants may report neck pain, back pain, shoulder injuries, knee injuries, and other musculoskeletal complaints. Medical imaging may identify a herniated disc, rotator cuff tear, meniscus tear, or other diagnosed condition.

But the presence of a diagnosed injury does not, by itself, establish that the motor vehicle accident caused the condition.

 

For insurance carriers, claims professionals, and defense attorneys, an important causation question often remains:

Did the accident create a biomechanically plausible mechanism capable of causing the claimed injury?

Biomechanical experts analyze the physical mechanics of an accident and the movement of the human body during the event. By evaluating the direction and magnitude of forces, occupant position, restraint use, body movement, and the specific injury being claimed, a biomechanical expert can assess whether the accident provides a mechanism consistent with the diagnosed condition.

This analysis can be particularly important in claims involving herniated discs, shoulder tears, and knee injuries.

 

A Diagnosis Does Not Automatically Establish Accident Causation

Modern medical imaging can identify a wide range of conditions within the human body.

An MRI may demonstrate disc protrusions, disc herniations, degenerative changes, rotator cuff tears, labral abnormalities, meniscus tears, or cartilage damage.

The medical diagnosis may be accurate.

The causation question, however, is separate.

A biomechanical expert does not determine whether a claimant is experiencing pain or provide a medical diagnosis. Instead, the expert evaluates whether the physical mechanics of the reported accident are consistent with the mechanism generally associated with the claimed injury.

For example, if a claimant alleges a traumatic shoulder tear following a rear-end collision, the biomechanical analysis may examine whether the shoulder experienced direct impact, significant loading, forced rotation, or another movement capable of producing the claimed injury.

If the available evidence does not demonstrate such a mechanism, the expert may conclude that the accident mechanics are not consistent with causing the claimed condition.

 

How Biomechanical Experts Evaluate Injury Causation

Every accident and injury claim is different. A biomechanical analysis generally begins with an evaluation of the accident circumstances and the physical evidence.

The expert may review:

Vehicle damage photographs
Repair estimates
Accident photographs
Police reports
Event Data Recorder information, when available
Occupant seating position
Seat belt use
Airbag deployment
Vehicle impact direction
Vehicle movement during the collision
Medical records
Diagnostic imaging reports
Prior medical records
Claimed injury diagnoses
Timing of reported symptoms

The expert then evaluates how the occupant’s body would reasonably be expected to move during the accident.

This is sometimes referred to as occupant kinematics.

The direction of the collision, the movement of the vehicle, and the occupant’s interaction with the seat, seat belt, interior structures, and other components can help establish which areas of the body were potentially loaded during the event.

The biomechanical expert can then compare the expected occupant movement and loading with the mechanism associated with the claimed injury.

 

Herniated Disc Claims Following Motor Vehicle Accidents

Cervical and lumbar disc injuries are frequently alleged following automobile accidents.

The spine contains intervertebral discs that provide cushioning and allow movement between the vertebrae. Medical imaging may identify disc bulges, protrusions, herniations, and degenerative changes.

The presence of a disc abnormality on an MRI does not necessarily establish when or how the condition developed.

A biomechanical expert may evaluate whether the accident created sufficient loading and spinal movement consistent with a traumatic disc injury.

 

Evaluating the Direction of Spinal Loading

The direction of force applied to the body is an important consideration.

Different accident configurations can produce different occupant movements.

In a rear-end collision, for example, the occupant’s torso may initially move with the seat as the vehicle accelerates forward. The head and neck may move differently relative to the torso depending on the severity of the collision, seat geometry, head restraint position, and occupant posture.

In a frontal collision, the occupant may move forward relative to the vehicle and interact with the seat belt restraint system.

Side impacts may create lateral occupant movement.

A biomechanical expert evaluates whether the expected spinal loading and movement are consistent with the mechanism required to produce the claimed disc injury.

 

Traumatic Injury Versus Degenerative Changes

Disc abnormalities are commonly identified in individuals with no recent history of significant trauma.

Degenerative changes can develop gradually over time and may be identified during imaging performed after an accident.

When prior medical records or imaging are available, they can provide important information regarding whether a spinal condition existed before the reported accident.

A biomechanical expert may compare the accident mechanics with the claimed injury and evaluate whether the collision created a mechanism consistent with causing a new traumatic injury.

The expert may also consider whether the physical evidence supports significant loading of the cervical or lumbar spine.

The purpose of the analysis is not to dispute the existence of an imaging finding. The question is whether the accident mechanics provide a biomechanically plausible explanation for the condition being attributed to the collision.

 

Shoulder Tear Claims and Accident Mechanics

Shoulder injuries are also frequently alleged following motor vehicle accidents.

Common diagnoses may include:

Rotator cuff tears
Labral tears
Shoulder impingement
Tendon injuries
AC joint injuries
Soft tissue injuries

The shoulder is a complex joint capable of a wide range of motion. Traumatic shoulder injuries are often associated with specific loading mechanisms.

These mechanisms may include direct impact to the shoulder, forceful rotation of the arm, sudden traction, or loading of the arm while it is extended.

 

Was the Shoulder Actually Loaded During the Accident?

One of the primary questions in a biomechanical shoulder injury analysis is whether the accident created a mechanism that significantly loaded the shoulder.

For example, the expert may evaluate whether the claimant’s shoulder contacted the door, steering wheel, center console, or another portion of the vehicle interior.

Seat belt geometry may also be considered.

The expert may examine whether the occupant’s arm was positioned in a manner that could create significant shoulder loading.

If the claimant was seated normally and the available evidence does not demonstrate direct shoulder contact, forced arm movement, or significant loading of the shoulder joint, the accident mechanics may not provide a mechanism consistent with a traumatic shoulder tear.

 

Pre-Existing and Degenerative Shoulder Conditions

Rotator cuff and other shoulder abnormalities may develop gradually over time.

Age-related changes, repetitive use, occupational activities, sports, and previous injuries can contribute to shoulder conditions.

A biomechanical expert may review prior medical history and compare the accident mechanics with the claimed injury.

Again, the existence of a shoulder tear is not necessarily disputed.

The analysis focuses on whether the motor vehicle accident created the type of physical loading typically associated with producing the diagnosed injury.

 

Knee Injuries Following Motor Vehicle Accidents

Knee injuries may be alleged following frontal, side, and other vehicle collisions.

Common diagnoses include:

Meniscus tears
ACL injuries
MCL injuries
Patellar injuries
Cartilage damage
Soft tissue injuries

Traumatic knee injuries frequently involve specific loading mechanisms.

For example, ligament injuries may involve twisting, hyperextension, lateral loading, or significant forces applied to the knee joint.

Meniscus injuries may involve compression and rotation of the knee.

 

Did the Knee Contact the Vehicle Interior?

In motor vehicle accidents, direct knee contact can be an important factor.

A biomechanical expert may evaluate whether the claimant’s knee could have contacted the dashboard, steering column, center console, door panel, or another interior component.

The analysis may include the occupant’s seating position, height, vehicle interior dimensions, and the direction of occupant movement.

Photographs showing bruising, interior contact marks, or damaged vehicle components may also provide relevant information.

If the accident mechanics do not demonstrate direct knee contact or significant twisting, rotation, or loading of the knee, the mechanism may not be consistent with certain traumatic knee injuries.

 

Evaluating Twisting and Rotational Injury Claims

A claimant may report that the knee twisted during the accident.

A biomechanical expert can evaluate whether the expected occupant movement would reasonably produce significant rotation of the lower extremity.

Seat belt restraint, foot position, occupant posture, and vehicle movement may all be considered.

The expert may assess whether the leg was likely constrained or whether the accident created sufficient rotational movement to produce the claimed injury mechanism.

Why Vehicle Damage Alone Does Not Determine Injury Potential

Vehicle damage is an important part of the analysis, but repair costs alone do not determine whether an injury could occur.

Modern vehicles are designed with bumpers, energy-absorbing structures, crumple zones, and restraint systems.

A high repair estimate does not automatically indicate that an occupant experienced significant biomechanical loading.

Similarly, limited visible damage does not automatically mean that no injury is possible.

Biomechanical experts evaluate the accident as a complete physical event.

The analysis may consider vehicle movement, impact direction, occupant kinematics, restraint use, interior contact, and the specific injury mechanism being claimed.

 

The question is not simply:

“How much damage was there to the vehicle?”

The more important question is:

“How did the occupant’s body move, and were the forces and movements consistent with the claimed injury?”

 

Pre-Existing Conditions and the Causation Question

Pre-existing conditions can significantly complicate automobile injury claims.

A claimant may have a documented history of neck pain, back pain, shoulder problems, knee complaints, or degenerative changes before the accident.

Following a collision, similar symptoms may be reported.

A biomechanical analysis can help evaluate whether the accident created a physical mechanism consistent with causing a new traumatic injury.

Prior medical records, previous diagnostic imaging, and the claimant’s documented medical history may provide important context.

For example, an MRI performed after an accident may identify a disc herniation. If prior imaging demonstrates a similar condition, the causation analysis may focus on whether the accident mechanics support a new injury or significant traumatic change.

Biomechanical experts evaluate the mechanics of the event and whether those mechanics are consistent with the claimed injury mechanism.

 

The Role of the Biomechanical Expert

Biomechanical experts apply principles of physics, engineering, anatomy, and human movement to evaluate injury mechanisms.

Their role is different from that of a treating physician.

A physician may diagnose and treat a medical condition.

A biomechanical expert evaluates whether a specific physical event created a mechanism consistent with causing the claimed injury.

In automobile accident cases, this may include evaluating:

Occupant kinematics
Direction of force
Magnitude of loading
Seat belt interaction
Seat and head restraint interaction
Airbag deployment
Interior vehicle contact
Joint movement
Spinal loading
Injury mechanism

This analysis can provide insurance carriers and defense attorneys with a clearer understanding of whether the claimed injury is biomechanically consistent with the reported accident.

 

National Biomechanical Document Reviews

Not every injury claim requires a full accident reconstruction or vehicle inspection.

Garrett Forensics offers National Biomechanical Document Reviews for insurance carriers and defense attorneys evaluating disputed injury causation claims.

Our biomechanical experts can review available accident documentation, vehicle photographs, repair estimates, medical records, diagnostic findings, and other relevant evidence.

The expert evaluates the accident mechanics and claimed injury to determine whether the reported event provides a biomechanically plausible mechanism for the diagnosed condition.

These reviews can be particularly valuable in claims involving:

Herniated discs
Cervical and lumbar spine injuries
Rotator cuff tears
Shoulder injuries
Meniscus tears
Knee ligament injuries
Claims involving pre-existing conditions
Low-impact vehicle accidents
Delayed injury complaints
Multiple claimed injuries following a single accident

Does the Accident Mechanism Support the Claimed Injury?

A medical diagnosis confirms that a condition has been identified.

It does not always answer the question of how or when the condition occurred.

When an injury is attributed to a motor vehicle accident, the physical mechanics of the event should be evaluated.

The direction and magnitude of forces, occupant position, restraint use, body movement, and potential interior contact can provide important information regarding injury causation.

A biomechanical expert can help determine whether the accident provides a mechanism consistent with causing the claimed injury or whether the physical evidence does not support the alleged injury mechanism.

 

Garrett Forensics provides biomechanical injury causation analysis and National Biomechanical Document Reviews for insurance carriers, claims professionals, SIU investigators, and defense attorneys.

If you are evaluating a claim involving a herniated disc, shoulder tear, knee injury, or other disputed injury, contact Garrett Forensics to discuss whether a biomechanical review may help clarify the injury causation issues in the case.