Ordered that the judgment is affirmed, with costs.
While we agree with the plaintiff that the defendants should have been precluded from eliciting expert testimony regarding the plaintiff's alleged nonuse of the lap seat belt in the car in which she was a passenger ( see, Siegfried v. Siegfried, 123 A.D.2d 621), admission of the testimony was harmless. Evidence pertaining to a plaintiff's nonuse of a seat belt goes to the issue of mitigation of damages ( see, DiMauro v. Metropolitan Suburban Bus Auth., 105 A.D.2d 236; Curry v. Moser, 89 A.D.2d 1). If the defendant is unable to show that the seat belt would have prevented some of the plaintiff's injuries, the trial court should not submit the issue to the jury ( see, Spier v. Barker, 35 N.Y.2d 444; Dowling v. Dowling, 138 A.D.2d 345). At bar, the issue was not submitted to the jury. Nor was evidence of the plaintiff's use or nonuse of the lap seat belt relevant to the issue determined by the jury, i.e., whether the plaintiff sustained a serious injury within the meaning of Insurance Law § 5102. Rosenblatt, J.P., Miller, O'Brien and McGinity, JJ., concur.