I'm sitting on the toilet bowl at the office the other day and taking care of business. I've got my elbow on my quad and not really thinking about it but I guess I pinched something in there or put too much pressure on it. When I got up I had a cramp at the top of my knee bottom of my quad that lasted a good 15 minutes... it was funny walking around the office trying to avoid people so I wouldn't have to try and explain why I was limping.