Originally Posted by
Sojodave
The pain is in my sit bone area and general soreness at the top of the back of the leg.
If you lean forward by rotating your pelvis instead of bending your back, then what happens is you roll forward onto the front tips of your sit bones, which get very achy. The fix is to rotate the saddle forward a little or use a saddle with a raised back, so the sit bones are flatter against it.
The other portion sounds like a muscle strain, but could also be the front of a flat saddle's wider portion digging into the muscle. The good news is tilting the saddle a little is likely to help, as is shifting the saddle ever so slightly back to relieve pressure. But it can also be muscle strain that is simple never given a chance to fully heal. If you ride by sitting fairly far back and pushing against the pedals at a low cadence, mainly using your quads, then what is preventing you from sliding back off the saddle is exactly that portion of your hamstring-glute overlap area jamming against the saddle - this could be another factor.