I just remembered (sorry, getting old!) that on that 1941 trip, my mom and dad used tump lines to help support their packs. As I mentioned, there were no hip belts for packs back then. Tump lines have been used for thousands of years and are still used in countries where people have to carry heavy and bulky loads.

That might be a great option for your hubby! A quck google turned up this one, complete with video. If Yvon Chouinard can use one (even after a neck injury), so can your hubby! (Also nice to see something from Patagucci that's affordable!) Per the website, using a tump line does take some practice and muscle strengthening. I'd also still work on lightening his pack.

Please let us know how this works out for your hubby!