I was diagnosed with a hip flexor strain today. I was running and could no longer raise my left knee. It came on really fast, but hurts really bad now. Has anyone else ever had this? What did you do for it? How long did it take to go away? I want to be as proactive as possible so I can get back to training. I did run in snowy/hilly comditions the prior two days, so i do believe that was the cause. Thanks for the advice