I'd had left upper back pain for close to a year, the kind that makes it impossible to sleep on that side and really uncomfortable to sit for long periods of time. I'd tried focused myofascial release with cork balls on the area, and while that provided some temporary relief, it didn't last. At the advice of my sister-in-law, I tried this foam roller. It provided the same kind of temporary relief at first, but after using for perhaps a month, the pain has gone and stayed away. I can't be positiv...