I very carefully adjusted him and I heard a crack. He had a great day. I adjusted him before bed and he had a great night. Long story short, I adjust him several times a day (always when he's calm; when he's crying he tenses up and I can't adjust him). It was truly a miracle for me. And I'm not a "miracle cure" believer. He loves carriers now, he still needs a quick adjustment when he gets out of the carseat and those baby bouncer or vibrating seats are just awful (anything I lay him in where his back is arched causes problems). He was in a lot of pain--I know that now. And I can tell now when his back has popped out again by his cry (bc I heard that cry for three straight months before I learned how to fix it).
It may not be your baby's problem--I only know my own story--but it can't hurt (assuming you're super gentle) and if it works, the change is not gradual, it's dramatic. Good luck!!!! I have my fingers crossed that this will work for you like it did me. If it does, pass it on to other moms!!!