Design Defects & Expert Evidence

When Expert Evidence is Necessary

In Massachusetts, to establish a product’s liability claim for defective design a plaintiff must show that the manufacturer of a product “failed to exercise reasonable care to eliminate avoidable or foreseeable dangers to the user of the product.” A defective design case thus requires proof that the product is not reasonably safe for its intended purposes and for reasonably foreseeable uses and misuses, considering the customer’s ordinary expectations about the product. In addition, to prove negligent design and breach of the implied warranty of merchantability based on design defect, a plaintiff must also show that a reasonable alternative design was available which would have reduced the risk without undue cost to the manufacturer or interference with the product. Because of the technical nature of product design, Massachusetts courts have routinely held that expert testimony in design defect cases is required. However, courts still recognize that where the jurors can simply apply their own common knowledge to determine liability because the design defect claimed is simple or obvious, the need for technical assistance is eliminated such that expert testimony may be unnecessary.

MA Case Study: When Expert Evidence is Necessary

In one recent case, a trial court judge addressed this sometimes obscure line between a seemingly simple design defect and the need for expert evidence. In this case, a woman brought a claim for defective design of hiking boots. The boots had a “speed lacing” design which included a rigid J-shaped hook comprised of a curved neck and fastening tail, most often seen on ice skates, and elastic laces. The woman was injured when the lace of her left boot caught on the hook of her right boot and she fell forward.

Following discovery, the defendant manufacturer filed a motion for summary judgment arguing that the plaintiff had no expert evidence that the design of the speed laces was defective and no evidence that an available appropriate design modification would have reduced the risk. The plaintiff contended that she needed no such expert evidence because the design was simple and straightforward, as were the facts of the accident.

In awarding summary judgment to the defendant manufacturer, the judge found that “while the speed laces in this case are of a simple design and the facts of the accident are straightforward, the analysis of the alleged design defect in the speed laces is neither simple nor straightforward.” The judge noted that the speed laces, which have been widely used in a variety of footwear for a century, did not present a gross or obvious trip hazard and that in assessing the claim, a jury would have to consider the biomechanics of a person walking in the boots, the design and location of the speed laces on the boots, and the appropriateness of an alternative design, all issues which are not sufficiently obvious that they are within the average juror’s common knowledge. The judge also concluded that the plaintiff had presented no evidence concerning similar incidents related to the speed lacing design or that the manufacturer was aware of any such risks associated with the speed laces.

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If you want more information about product liability claims, contact Attorney Bob Allison today by calling 978-740-9433 or by filling out our online form. You will receive a free consultation to review your case.