Hoping someone can steer me in the right direction for help re left buttock pain near the coccyx that occurs with sitting. The discomfort is immediate upon sitting. My left knee also sometimes feels as if it has a tight band around it. Occasionally there is tightness in the back of my left thigh. The md at my chiropractor's office states this is all from a pinched nerve and that there is no treatment. However, the info I've read about a pinched nerve does not match my symptoms. Any suggestions? I sit all day at work and this discomfort has become quite old.