For about the last week or so I have had some really bad pain in my left hamstring. Funny thing is it only hurts when I go from sitting to standing, then I just walk it off and it's fine in a few steps. After I am standing the pain is only there if I try to stretch it. Otherwise I can ride my bike, play golf, ride the eliptical...etc. with no trouble. As soon as I sit down and get back up it hurts like hell. Anyone have any thoughts on this. It reminds me a lot of the back pain I just got rid of by getting a new bed. Could this be related to how I am sitting or sleeping? I have tried a few different computer chairs but nothing seems to be helping.

Any help would be appreciated. I'm out of work so I can't afford to see a doctor.

Thanks