Plaintiff James Walton appealed the district court’s ruling allowing expert testimony at trial. Walton sued defendant Sean Prunchack for damages arising out of a rear-end car accident. Walton alleged Prunchack was negligent in the operation of his motor vehicle, causing personal injuries to Walton. After the accident, Walton sought medical treatment for wrist and neck pain. Several months later, Walton complained of shoulder pain, resulting in a diagnosis of a rotator cuff tear. Walton claimed the shoulder injury was caused by the car accident. Prunchack denied causation.
At trial, a biomechanical engineer testified as an expert witness for the defense. The expert opined the collision did not cause Walton’s rotator cuff tear. Walton objected to the admissibility of expert testimony, challenging the basis of the expert’s opinion and its reliability. The district court allowed the expert testimony at trial.
Under Iowa law, expert testimony must be relevant to be admissible. The expert testimony must also be in the form of “scientific, technical, or other specialized knowledge that will assist the tier of fact to understand the evidence or determine a fact in issue. Furthermore, the expert witness must be qualified as an expert by knowledge, skill, experience, training, or education.
Although the expert witness was not a medical doctor, the Appellate Court found the witness qualified as an expert based upon his education, specialties, and experience. Furthermore, the Appellate Court found there is a reliable body of scientific, technical, or specialized knowledge concerning biomechanics, particularly concerning the interface between mechanics and biology in the evaluation of motor vehicle collisions and questions of injury mechanisms and causation. The Court held the expert witness’s ultimate opinion was sufficiently reliable to be admissible.