Medical evidence
Expert reports and delta-v: what do they actually establish?
A technical, medical or occupational report answers different questions. Understand the expert’s task before accepting the conclusion.
Identify the question the expert was asked
A collision expert may reconstruct movement or impact. A medical expert may assess symptoms, restrictions and prognosis. An occupational expert may examine how limitations affect work. These reports should not silently replace each other.
Ask whether the expert was instructed jointly, by one party or by a court. That context can affect the process and how disagreement is handled. The word independent should not prevent you from checking the information and reasoning.
Read the assumptions as carefully as the result
Vehicle weights, impact angles, available photographs and repair information can affect a reconstruction. Medical opinions may depend on the history supplied and the questions posed. If a material fact is wrong, identify it precisely rather than rejecting the whole report because its conclusion is unwelcome.
Keep comments factual and submit them through the appropriate route. Do not contact an expert in a way that conflicts with an agreed joint-instruction process.
Understand the limits of delta-v
Delta-v is not simply the speed shown on one vehicle’s speedometer. It is a technical concept used in collision analysis. An estimate may help understand the event, but it does not directly measure the symptoms experienced by a particular occupant.
For the medical side, read whiplash symptoms and normal imaging. A claim requires the relevant evidence to be considered together rather than treating one numerical threshold as a universal legal rule.
Ask what happens if disagreement remains
Clarification, supplementary questions or a different expert process may be appropriate. A court procedure is not automatically the best next step; its purpose, proportionality and costs should be discussed.
Our existing article on claim duration explains why evidence gathering can affect the timetable. Before commissioning your own expensive report, discuss what issue it would resolve and how costs will be addressed with Injury Lawyer.
Example: a report based on incomplete collision information
Illustrative example · fictional situation, not a client case
An insurer sends a short assessment based on photographs of repaired vehicles. The injured person still has photographs taken before repairs and the original repair estimate. Those materials may help the adviser understand what information the assessment used and what was missing.
Practical takeaway: Ask what data and assumptions the report relies on, which question it answers and whether relevant evidence was considered. A technical estimate is not itself a complete medical assessment.
For the accident background, see the car accident guide. Where the other vehicle was a heavy goods vehicle, truck accident legal support can help identify which collision records and expert questions are relevant to that particular event.
Questions to ask about an expert report
- What question was the expert instructed to answer?
- Which photographs, measurements and records were available?
- Are assumptions and uncertainties identified?
- Does the report address accident mechanics, medical causation or a different issue?
- Is there relevant evidence that was not supplied, and how can it be considered?
Questions you may still have
Is a report commissioned by an insurer automatically wrong?
No. Assess the expertise, scope, evidence and reasoning. Who commissioned it is relevant context but does not, by itself, prove the conclusion is correct or incorrect.
Should I immediately pay for a second opinion?
First clarify which issue is disputed and whether supplementary questions could resolve it. A new report can be costly and may not address the decisive legal or medical question.
Sources and legal context
General information about Dutch personal injury claims. Some source material is in Dutch. Your circumstances may require a different assessment.
This guide explains general principles. It is not a decision on liability or the value of an individual claim.