I have been involved with roller derby for about a year and half. I joined a team as a skater, switched to reffing. I left that team, joined another as a ref and wanted to become a skater. Not too long ago, I felt a tear/pop in my knee. X-rays show nothing, up next is an MRI too tell me that I shouldn't be doing derby. This pretty much sucks! My knee hurts no matter what I do or don't do.