I have a ~22 inch torso. I bought the osprey poco plus child carrier which says it supports 22 inch torsos. I went a couple three hour hikes this weekend and my shoulders were done at the end of each. this isn’t normal, right? I am thinking of trying another carrier, but i am worried there are no child carriers for tall people.
If you can, you should tighten the waist straps so that your waist takes most of the load, and slack off your shoulder straps so they are only just holding it steady you may find it more comfortable. Otherwise heavy bags over long durations can make your shoulders and collar bone sore, it’s an occupational hazard.