experiences with baby carriers?

Hi mummas, I'm looking for advice on baby carriers. I have a very weak back/core from seperated abs (which now that I know that I have, I plan on fixing) and had trouble with using carriers and getting a a sore back, my upper back gets very fatigued quickly. I'm hoping a carrier that crosses at the back might be a bit more supportive, can anyone recommend anything? Do Tula carriers have the ability to cross at the back?