So for the past year an so months I have been dealing with an imbalance in my sacrum. The pain isn't in the sacrum so you wouldn't think that this was the cause the pain is in the meaty part of my hamstring. I have tried everything to deal with it message, chiropractic and stretching. They all seem to help but the issue always come back. It hasn't been fun and the time I have spent dealing with it takes away from everything. And it ends up not just being time its money too. So here is a little tip if you are dealing with hamstring pain and cant find a way to deal with. This issue may be coming from your back and your sacrum not the hamstring itself. To help it take a look at this website http://www.stop-stress-sos.com/yoga-gifts/sacro-wedgy.html and maybe even get this product.