The City of Norfolk appeals an award by the Workers' Compensation Commission to Janet Vaughan for medical benefits. The issue on appeal is whether the commission erred by determining that Vaughan's injury arose out of her employment. For the following reasons we reverse the commission's decision.

The claimant was employed as a telecommunication for the Emergency Services Office of the City of Norfolk. One day after roll call the claimant and a coworker were told that they had been selected for a routine random drug screening. Troy Lapetina the office coordinator drove both employees to the police station for a portion of the test. The vehicle was a standard city-owned four-door "K" car. After performing a breath test for alcohol the claimant the coworker and the supervisor returned to the car. The claimant was bending down entering the rear driver side door when she hit her head on the back of the door frame. She immediately expressed pain. Both the coworker and the supervisor asked if she was all right.

The claimant filed a claim for temporary total disability benefits for three days of work missed due to her injury. The deputy commissioner denied her application because she did not show that the injury resulted from a risk caused by a condition of the workplace. The commission on review found that the injury arose out of the claimant's employment and entered an award for medical benefits only.

On appeal we view the evidence in the light most favorable to the party prevailing before the commission. R.G. Moore Bldg. Corp. v. Mullins 10 Va. App. 211 212 390 S.E.2d 788 788 (1990).

Whether credible evidence exists to support a factual finding is a question of law which is properly review able on appeal. . . . Causation is a factual determination to be made by the commission but the standards required to prove causation and whether the evidence is sufficient to meet those standards are legal issues which we must determine.

Hercules Inc. v. Gunther 13 Va. App. 357 361 412 S.E.2d 185 187 (1991) (citing Morris v. Morris 238 Va. 578 385 S.E.2d 858 (1989)).

In order for an injury to arise out of employment "a claimant [must] show that the conditions of the workplace or that some significant work related exertion caused the injury. The mere happening of an accident at the workplace not caused by any work related risk or significant work related exertion is not compensable." Plumb Rite Plumbing Serv. v. Barbour 8 Va. App. 482 484 382 S.E.2d 305 306 (1989); see also Richard E. Brown Inc. v. Caporaletti 12 Va. App. 242 244 402 S.E.2d 709 710 (1991).

An injury that results from a hazard or risk to which the employee is equally exposed apart from the employment does not arise out of the employment and is noncompensable. United Parcel Service v. Fetterman 230 Va. 257 258 336 S.E.2d 892 892 (1985).

No evidence in the record proves that a particular risk associated with the claimant's work caused her injury. See County of Chesterfield v. Johnson 237 Va. 180 376 S.E.2d 73 (1989). There was nothing unusual about the car or its door and the claimant was not performing any significant work-related activity when she hit her head on the door frame. Nothing about the manner in which she was doing her job or any condition of the workplace caused her injury or constituted a risk of injury to the claimant. The commission erred by concluding that the injury was compensable. We therefore reverse the decision of the commission.

Reversed and dismissed.