pain in calf and thigh when kneeling and after rest

[Ahari]

About 5 years ago, I found that kneeling caused a severe cramp-like pain in the back of my calves, also in the back of my thighs. Slowly, this has got worse and for about a year now, some pain is also there when lying down or in the morning. But as soon as I get up and walk, there is no pain at all and I can run and walk without any difficulties. Stretching exercise appear to ease it. Once I forgot myself and knelt quickly, resulting in collapsing with a severe cramp-like pain throughout my whole body. Recently, I noticed a similar slight pain in my upper left arm.

[Ahari]

After posting my original question, I have done a lot more research on the internet. I am now pretty certain that I have a so-called Baker's cyst, an accumulation of liquid behind the knee. My main problem is not so much just kneeling, but squatting back on my 'haunches', which is extremely painful, and that is indicative of this cyst.

[Ahari]

No, not really, as the pain is not spontaneous, but brought on by certain positions such as kneeling and to a lesser extent by lying down. But thanks for your comment!