back of knee pain - hamstring?

[WannaRun]

About 6 to 7 weeks ago in a hot yoga class I felt a twinge and weakness/pain in the muscles or tendons in the back of my knee. I am a runner and occasionally do hot yoga for cross training, so I was assuming I just over did it. It was extremely painful for several days afterwards, and although it improved it still wasn't quite right. The main thing that causes pain is if I kneel down on the floor with my calves pressed against my thighs. It also hurts some when I move around twisting or lifting the leg in certain directions, but that's not too bad. Late in the day I sometimes think it feel like a very slight swelling either on the muscle above the back of the knee, or there abouts... very hard to tell, but nothing you can see.
I went to a sports doc and he first thought it was a hamstring pull, but then said maybe a meniscus issue. He took x-rays and said everything looked great. He didn't do an MRI. After the appt with that doc, it was much worse and bothered me all the time for a few days, I'm assuming this is because of the pushing/pulling he did in the exam, altho that didn't hurt at the time.
I have backed off on running, although running doesn't seem to hurt it during the run, and doesn't seem to make it worse afterwards. I have a half marathon I've been training for a long time coming up in 3 weeks. Does this just sound like a tight/inflamed tendon/hamstring issue? Should I just take Advil and stretch it? I really want to get out there and run this half strong, and would love any advice to help me do that!

[Heidi]

Do you remember what movement you where doing when you felt it.
I doubt its cartilage and suspect it may be more muscular.
Try some sports massage?

[WannaRun]

I'm not sure what yoga move I was doing when it happened, although I'm pretty sure it was a leg lift of some sort. I think I might have been laying on my stomach and doing various versions of leg lifts. Or one of the poses where you are standing and lift/extend your leg out and hold your foot.

I haven't had a sports massage, but if I rub the back of the leg there is not a sore or tender spot, which I guess is good.

[JackeryBakery]

It may be that you are feeling the pain from a trigger point in your hamstrings.
Perhaps try to find one of the trigger points in your hamstrings by 'poking around'. Then if you find one, try massaging them fairly deeply for about 12 strokes about 3-6 times per day.
http://triggerpoints.net/triggerpoints/hamstring.htm
Alternatively it may be your popiletus.
http://triggerpoints.net/triggerpoints/popliteus.htm

That gives you a bit more information on trigger points:
http://spas.about.com/od/massag1/a/triggerpoint.htm

Hope that helps!