Why can’t pain be measured directly?

Pain is by definition a personal experience. The IASP’s 2020 revision says so explicitly and adds that pain cannot be inferred solely from activity in sensory neurons. That is scientifically correct and, in a courtroom, it is a problem: the central fact of the case is the one thing no instrument reports.

The mistake is to respond by trying to measure pain anyway — with pain scales, with functional imaging, with any device marketed as objectifying suffering. Those approaches fail on cross because they are measuring a proxy and calling it the thing.

What can each objective test establish?

Why does a negative test result matter?

A physician whose tests always confirm the claim is a physician whose tests mean nothing. The value of a positive block comes entirely from the fact that a negative one was possible and would have been recorded.

In practice a meaningful minority of diagnostic blocks in this clinic are negative. Those results go in the chart, they change the diagnosis, and they sometimes end a theory of the case. That is the cost of having findings that hold up.

This practice is not aligned to a side. Its obligation runs to the patient’s health and safety, which is the same reason it is not beholden to any position that would keep it from seeing what is actually there. We do not offer opinions on liability, we do not accept a referral or a review conditioned on reaching a particular conclusion, and we will say plainly when the evidence does not support the claim — whichever party was hoping otherwise.

In what order are the tests done?

They are not ordered as a battery. Each one is chosen because the preceding step raised a specific question, which is also what makes the sequence defensible as clinical care rather than litigation support.

• History and examination generate a hypothesis about which structure is involved.
• Imaging is reviewed against that hypothesis, not before it.
• If the hypothesis names a block-testable structure, a diagnostic block tests it — and is repeated before anything irreversible follows.
• If the hypothesis names a nerve, electrodiagnostics test it once enough time has elapsed for the findings to develop.
• If the picture suggests amplification rather than a single generator, sensory testing and the metabolic panel address that.

Frequently asked questions

Is there any test that measures pain itself?

No. Anything marketed as one is measuring a correlate. What holds up is testing the generator and the machinery around it — that is the whole design of this approach.

Which single test is most useful in litigation?

A properly performed, repeated diagnostic block, because it attributes the symptom to a structure. See diagnostic nerve blocks.

What if every test comes back normal?

Then the record says so. Normal electrodiagnostics do not exclude injury, but a wholly negative workup is reported as a negative workup — see records that survive cross.

Can the other side repeat these tests?

Yes, and that is the point. A block response, an EMG waveform and a lab value are all independently checkable, unlike a narrative — see reading an independent examination.

What are examples of objective findings for pain?

Six kinds of test produce them: diagnostic nerve blocks, EMG and nerve conduction studies, imaging, quantitative sensory testing, inflammatory and metabolic markers, and functional capacity and validity testing. None of them read pain itself. Each measures the machinery around the symptom, such as whether a nerve conducts or whether numbing one structure stops the pain, and the other side can check every one.

What is the difference between objective and subjective findings?

A subjective finding is what the patient reports, and pain is by definition a personal experience. An objective finding is a result the other side can check and repeat, such as a block response, an EMG waveform or a lab value. Objective testing does not show how much someone hurts. It locates the source of the pain or documents the machinery that produces it.

Is a pain scale an objective finding?

No. A pain scale records the patient’s own rating, so it measures a proxy and calls it the thing. Functional imaging and devices marketed as objectifying suffering share the same flaw, and they fail on cross-examination. What holds up is proving the generator: showing that numbing one named structure reliably abolishes the pain, and that a controlled repeat does the same.

Related reading

• Diagnostic nerve blocks
• EMG and nerve conduction
• Imaging and correlation
• Records that survive cross
• Start here