Do you take milk?? You have to up your intake of calcium. That's what I do when my leg joints ache. I assume that it's the joints that are aching.
Have to differentiate if it's the bone/cartilage that is aching or the muscle that is aching. If it's just the muscle, a good massage should do the trick.
And for back, is it lower back or upper back? If it's the lower back, could it be that you're carrying your son alot?
(PS.. I dont't believe that it's coz you drank water or touch water during confinement. I bathed everyday during confinement, washed my baby's stuff and drank tons of water during confinement and am not experiencing any aches yet)