Not an ME question per se probably but for years now (10? 15?), if I lie flat on my back with my legs lying straight, the back of my left calf starts to hurt so much that I have to move it after a few minutes. As long as it's not in contact with the ground it's OK. It doesn't hurt in any other situation or in any other position. So far I've dealt with this by ignoring it or by trying occasional but ineffectual calf stretches (the "pushing a tree down" variety where you lean forward against a wall with your feet about 12" way with the offending leg stretched behind you and tilt your hip forward to stretch the calf muscle/hamstring). But now I'm trying to start meditating and a lying-flat posture would be a huge help. Does this actually sound like a shortened muscle/hamstring problem? If so, how much stretching and for how long is likely to necessary to shift it? Is there anything else I should be doing about it?