Okay, from someone that last year had abdominal surgery, and the knowledge of my mom having heart surgery,
Part of the issue is when you hunch over things can tighten up and so straightening up afterwards can be an issue.
The answer, though this should have been done before the surgery unless you can get help with the adjustments. raise your table height to cut (cutting a bunch before would have been a better answer) that way you don't need to bend to cut. then also change your sewing machine height etc so you are not all curled up to see. it will be better all the way around even after you have gotten better. egronomics is the key and then not spending to long in one position. and if all else fails try some hand work.