Bra straps allow you to adjust the support level of your bra. Adjust straps to the correct length, which will allow your bra to run straight across your back and give your breasts the perfect lift. Bra straps that are too tight on the shoulder will cause the bra to pull up in the back. Straps should never leave marks or dig into your shoulders. If your bra straps are uncomfortable or hurting your shoulders, get fitted again and possibly try wider straps - cushion or comfort straps may be just the relief your shoulders need for long/hard days.