EE WAS WALKING IN THE TRACK ENTRY BY THE SCOOP THAT WAS PARKED IN FRONT OF THE LOAD CENTER WHEN EE SLIPPED ON A ROCK CAUSING EE TO FALL INTO A RUT AND HYPEREXTEND RIGHT KNEE AND CAUSING RIGHT SIDE OF BODY ABOVE THE HIP TO STRIKE THE SIDE OF THE SCOOP BESIDE THE TIRE. DIAGNOSED AS A STRAIN TO THE RIGHT KNEE