When this started, I could mostly mitigate the situation by putting strips of mole skin over the problematic areas, but I'd need to use a whole roll of it every outing to cover the areas that are now raw and hurting. I'll probably be doing that until a more practical answer is found.
- I do cinch my waist belt fairly tight on my pack to try to prevent it from moving around, but not exceptionally tight.
- I have multiple backcountry partners as lean or leaner than me who don't have this issue (my BMI is right in the middle of the Normal range).
- I have packs of what I think being reasonable quality -- two Ospreys (24l, 38l) and an Acr'teryx (80l).
- I have not ever been professionally fitted for a pack (not sure that's a thing), but I think my packs are right sized for my body with shoulder straps adjusted correctly. However, if there's a detailed method to ensure the pack is sized and adjusted correctly for a particular body that someone's aware of and that I may not have discovered, I'd be happy to revisit this topic