## Facts

- Jill Marsh was involved in four automobile accidents between 1995 and 1998.
- Marsh later developed symptoms diagnosed as fibromyalgia (and, in some filings, myofascial pain syndrome).
- Marsh sued multiple drivers and related entities for negligence, alleging the accidents caused her fibromyalgia.
- Marsh offered expert medical testimony that physical trauma from the accidents caused her condition, based on clinical evaluation and medical literature.
- A defendant moved to exclude the experts’ trauma-to-fibromyalgia causation opinions, arguing the theory was not generally accepted and therefore inadmissible under Frye.

## Issues

1. Whether Frye applies to expert medical testimony offering a causal opinion that trauma can cause fibromyalgia when the opinion is derived from standard clinical methods.
2. If Frye applies, whether the trauma-to-fibromyalgia causation opinion satisfies Frye’s general-acceptance requirement.

## Decision

- The Florida Supreme Court quashed the district court’s decision affirming exclusion of the causation testimony and summary judgment for defendants.
- The court held Frye did not apply because the experts used conventional clinical methods rather than a new or novel scientific technique.
- The court held, alternatively, that even if Frye applied, the proffered causation testimony met the general-acceptance threshold.
- The court approved the conflicting district court decision that had declined to apply Frye to similar medical causation testimony.
- The case was remanded for further proceedings consistent with admitting the causation testimony.

## Legal Principles

- Frye applies in Florida (as of the decision) to evidence derived from new or novel scientific techniques or methodologies, not to standard expert opinions drawn from conventional professional methods.
- “Pure opinion” medical testimony—grounded in clinical history, examination, and customary diagnostic reasoning—generally is not subject to Frye scrutiny.
- Frye addresses the acceptance of the underlying scientific method or technique, not whether a contested causal conclusion is universally accepted; disagreement among qualified experts typically affects weight, not admissibility.
- Where expert causation testimony is admissible under ordinary evidence rules, competing expert views are for the factfinder to evaluate through cross-examination and rebuttal proof.

## Conclusion

The Florida Supreme Court held that expert opinions linking accident-related trauma to fibromyalgia, when based on standard clinical practice rather than a novel scientific technique, are not governed by Frye and should be presented to the factfinder; it therefore quashed the exclusion order and resulting summary judgment and remanded for further proceedings.


Marsh v. Valyou, 977 So. 2d 543 (Fla. 2007)