Expert Witness Blog
Plaintiff sued defendants after being injured by a weedwacker. Plaintiff hired an Osteopathy Expert Witness and an Ergonomics Expert Witness to provide testimony. The defendants filed motions to exclude. The court denied the motion against Dr. Murphy and granted in part and denied in part the motion against Mr. Mitchell
Facts: This case (Thomas Hagan v. Sears Appliance and Hardware Store – United States District Court – Eastern District of Pennsylvania – March 2nd 2018) involves a products liability claim regarding a weedwacker. The plaintiff (Hagan) alleges that a weedwacker that he purchased at Sears was defectively designed and caused sever injuries to his cervical spine. Hagan hired two expert witnesses to provide testimony in this case: Dr. William Murphy (Osteopathy Expert Witness) and Mr. Dennis Mitchell (Ergonomics Expert Witness). The defendants have filed motions to exclude the testimony of these experts.
Discussion: The defendants argue that Dr. Murphy’s medical causation testimony should be excluded because is it not reliable. They claim that Dr. Murphy has not seen the weedwacker in question and has not performed any testing on the tool. Hagan points to Dr. Murphy’s education and experience in the field, as well as an evaluation of the plaintiff, his past medical records regarding the cervical spine and disc herniation, and his experience diagnosing and treating patients in the field of osteopathic medicine and rehabilitation. The court opined that Dr. Murphy’s medical causation testimony meets the requirements of Daubert and will be allowed.
Mr. Mitchell is an expert in ergonomics and will argue that the design defects of the weedwacker caused the plaintiff’s injuries. The defendants argue that his expert testimony is not reliable and does not fit the case. Mr. Mitchell’s opinion discusses three distinct defects: 1) The defect in the shoulder strap which caused an increase in hand-arm vibration; 2) a defect in the shoulder strap causing sheer force application to the shoulder and neck; and 3) the defect in the shoulder strap causing force to the shoulder when one pulls the pull chord.
The court first opines that Mr. Mitchell is qualified to testify in the area of ergonomics in this case. He is the owner of an ergonomics consulting firm and half of his work resides in expert consulting in legal matters. He also conducts product design and testing and reviews training programs related to the field of ergonomics. In his testimony, Mr. Mitchell stated that he tested the weedwacker in question and relied on numerous other pieces of information to come to his conclusions. The court concluded that Mr. Mitchell will be allowed to testify on the sheer force that was transmitted to the shoulder by the shoulder strap. However, he will not be allowed to testify on the two remaining defects. Thus, the court partially granted the defendant’s motion to exclude.
Conclusion: The motion to exclude the expert witness testimony of Dr. William Murphy was denied and the motion to exclude the expert witness testimony of Mr. Dennis Mitchell is granted in part and denied in part.