I got this for my husband to use because he suffers from back pain, and this not only helps but also forces better posture. His shoulders tended to droop making his back pain worse and this definitely helped with that. It does run small so was pretty snug on him and he could really use a size larger. He has a very broad chest for comparison, and I got the extra-large. I would recommend this product to help train yourself and your muscles for better posture (which really does cause back pain)