Abstract: On September 4, 2002, Employee #1, a parts employee, was on his work break and was standing against a side wall that was 41 in. from the back wall of the lubrication area. Employee #1 had his right knee sticking out from the wall when a coworker drove up in a customer's 1999 Ford F250 Super Duty Diesel. The coworker was intentionally accelerating hard and braking hard, engaging in horseplay by pretending he intended to hit Employee #1. The vehicle suddenly lurched forward and struck Employee #1's right knee. The truck's bumper pushed Employee #1's right knee into the back wall of the lube area, fracturing his ankle. Employee #1 was transported to the hospital, where he underwent surgery to insert pins in his ankle. Employee #1 was hospitalized.