Ok this is how it happened. I was heading back to our camping area across the street from the Brickyard and there is a guard rail separating the parking lot from the grass field. I've done this move a million times doing road work along highways; I step on the guard rail with my left foot and propel myself up and land with both feet on the ground. This time when I pushed off my left foot it slipped on the way up and when I came back down my left foot was fully extended. When that foot landed my knee locked and the force of the impact when straight to my hip. At first I thought I'd be ok, but soon the pain got worse and the range of motion decreased. I played football for most of my life, high school and Division 1, and this if the first bone I've broken in my life. If nothing else I've learned that I'm not nearly as indestructible as I thought I was.