I have the ZPacks Arc Haul pack with added lumbar pad and I seem to be experiencing a moderate degree of pain in the lumbar region, and lower, by the time I am half way through the day, every day. I don't think this is normal for this pack and it is comfortable in every other way. I don't know if it's the bottom bar of the frame in the pack but it seems to be as the pain is approximately in the region the bar sits, or if it's just that I'm too small for the pack (a very petite 110# and 5'5" so very little natural cushioning). I know I don't wear the pack as high on my hips as I should (buckle over the belly button) but I find that extremely constricting and uncomfortable, but it is also only about an inch or so lower and still sitting on my hip bones since I am female.
I also think this pain and pressure is causing an excess of fatigue in my hips, back and legs meaning I can't hike longer and further. I have a very low pack weight with a base weight under 10lbs (29oz quilt, 24oz tent plus stakes, 19oz pad, no or minimal alc. stove, small FA kit, base layer and extra socks etc) and two-three days of food (mostly snacks, freeze-dried/dehydrated etc) for a long-weekend and 2 liters of water at most (generally 1 liter) which is well within the specs of this pack.
Has anyone else had this experience or is it just that this pack probably doesn't fit my body type well and I should try something else. I really want to make this pack work for me but I would rather buy something else and be comfortable while backpacking.
Any and all advice or thoughts welcome. I am tempted to try a ULA Circuit at this point, and would have invested in the SMD Fusion 65 if they'd still had the older version in stock for the sale price.