I've had a mild pain in my middle back for just a few years now (I'm 20). I've been to a chiropractor a few times but he doesn't seem to help the problem completely. Specifically, the pain seems to be right along the right side of my spine. It kind of feels like a muscle is knotted up and at times, my spine (just that very small area) will feel hurt/weak. It usually doesn't bother me too much when I'm standing up or laying down. It usually does bother me when I'm bending over or sitting down without a backrest. I should probably mention that I am 6'5"/315 lbs. and I played football and lifted heavily in high school for 6 years. Should I try another chiropractor? Maybe ice/heat? Or should I do some back exercises? Thanks!
You might want to try using a Swiss Ball for stretching and strengthening. According to your height, it should be about 78cm. diameter. Most come with a list of exercises and pictures to show the proper methods. I think you may get a good result from this approach.