When More Than One Explanation Is Possible: Understanding Multiple Causes in Injury Cases

By Dr. Steven B. Ross, DC, FASBE, DAAPM

Chiropractic Physician | Fellow, American Academy of Applied Spinal Biomechanical Engineering | Diplomate, American Academy of Pain Management.

Injury cases are not always medically straightforward.

A claimant may have a documented injury, a history of previous symptoms, a recent accident, degenerative findings on imaging, and several other factors that could potentially contribute to the condition.

In these situations, the question is not necessarily whether an injury exists.

The more difficult question may be:

What role did each factor play?

Understanding the multiple causes of injury can be important when evaluating medical evidence and determining whether the available evidence supports a particular causation opinion.

An Injury Can Have More Than One Contributing Factor

Medical conditions do not always result from a single event.

An individual may have a pre-existing condition that is later affected by an accident. Another person may have experienced symptoms before an incident but develop a significant change afterward.

There may also be factors such as:

• Age-related changes

• Previous injuries

• Degenerative conditions

• Repetitive physical activity

• A new traumatic event

• Changes in symptoms following an incident

• Subsequent injuries or events

The presence of these factors does not automatically establish or eliminate causation.

Instead, they need to be considered within the context of the individual case.

Pre-Existing Conditions Do Not Automatically Answer the Causation Question

One of the more complicated situations occurs when imaging or medical records reveal a condition that existed before the reported incident.

A pre-existing finding may be relevant, but its presence alone does not necessarily explain the claimant's current symptoms.

The important questions may include:

• Was the condition documented before the incident?

• Were symptoms present before the event?

• Did the symptoms change afterward?

• Were there new clinical findings?

• Is the mechanism of the incident consistent with the reported injury?

• What does the medical record show over time?

These questions help place an individual finding into the broader clinical history.

Timing Matters, But Timing Alone Does Not Establish Causation

A common assumption in injury cases is that because symptoms appeared after an event, the event must have caused them.

The timing may certainly be relevant.

However, temporal association and medical causation are not necessarily the same thing.

A careful analysis considers what happened before, during, and after the reported event.

For example, an expert may need to examine whether there were previous symptoms, whether the symptoms changed following the event, what treatment occurred afterward, and whether the clinical findings are consistent with the proposed explanation.

The timeline becomes one part of the overall analysis rather than the entire analysis.

What Does the Mechanism of Injury Tell Us?

The circumstances of an event can also matter.

In a motor vehicle collision, for example, an expert may consider the nature of the impact, the direction and forces involved, the reported movement of the body, the individual's position, and the symptoms that followed.

The purpose is not simply to determine whether an accident occurred.

The question is whether the available evidence supports a medically reasonable relationship between the event and the condition being attributed to it.

Different Causes Can Coexist

An important consideration in complex cases is that two explanations do not always have to be mutually exclusive.

A person can have a pre-existing condition and experience a new injury.

An accident can occur in someone who already has degenerative changes.

A condition can also develop through multiple contributing factors rather than one isolated event.

This is why simply asking, "Was the condition caused by the accident?" may sometimes be too broad.

A more precise analysis may require asking:

What was present before the event, what changed afterward, and what does the available evidence support about the contribution of the event?

The Role of Medical Expert Analysis

When multiple explanations are possible, the role of the medical expert is not simply to identify every abnormality in the record.

The expert must evaluate the evidence in context.

That may involve reviewing medical records, imaging, clinical findings, history, mechanism of injury, treatment progression, and other relevant information.

The goal is to distinguish between what the evidence establishes, what it supports, and what remains uncertain.

That distinction can be particularly important when the parties have different interpretations of the same medical evidence.

The Right Question May Be More Important Than the Quickest Answer

Complex injury cases rarely become clearer by focusing on a single piece of evidence.

A diagnosis, an imaging finding, a symptom, or the timing of treatment may each provide useful information.

But none should necessarily be considered in isolation.

When multiple causes are possible, a more complete analysis comes from examining how the different pieces of evidence fit together.

That is often where the most important causation questions emerge.

Conclusion

When more than one explanation is possible, the goal should not be to force the evidence into a single explanation.

The better approach is to examine the history, clinical findings, mechanism, timing, and available medical evidence and determine what the evidence actually supports.

In complex injury cases, understanding the multiple causes of injury can help distinguish the existence of a condition from the question of what caused it, contributed to it, or changed it.

What factors do you find most important when evaluating causation in a case involving both a pre-existing condition and a subsequent injury?

About the Author

Dr. Steven B. Ross, DC, FASBE, DAAPM is a chiropractic physician, spinal biomechanical injury analyst, Independent Medical Examiner, and expert witness with more than 40 years of clinical experience. His practice focuses on injury causation analysis, spinal biomechanics, chiropractic and medical malpractice, independent medical examinations, and evidence-based medical-legal consulting.