You need to get an Aarn pack. I have spondylolisthesis, 2 pars defects and slippages in my neck. I am taking physical therapy right now for these issues. I quit backpacking because
of my constant pain when using traditional backpacks. After finding the Aarn pack, I am back on the trail. These packs are not backpacks at all, since the weight is evenly split between the front and back of the pack-they are better called
bodypacks. The load is almost ALL on your hips. Not just one area of your hips, but distributed across the whole cirumference of your hips. There is no weight on my shoulders. I can pickup the shoulder strap with my left pinky easily while carrying 40lbs. Its like its not there. The pack balances the weight between the front and back of your torso via detachable waterproof front pockets. They detach to form a daypack when at camp and going doing tasks like getting water, or simply going for a dayhike. I can carry all the gear i need immediate access to in the front 14-liter front pockets. They hang freely not touching my torso due to built in stays that load their weight onto the shoulder straps, lifting the weight off my shoulders creating that weightless shoulder feeling. I use the featherlite freedom. I would never suggesta frameless pack for someone with back problems. You need support.
I recently completed a 3.5 day 70 mile hike with it, no redness or soreness in the shoulders or anywhere else on the body. The key to these packsmare adjustments. You can get it to fit your body like a glove. The hip belt is 2 pieces that attach via velcro. This means you can alter the angle/fit ofthe belt to fit your hips perdectly. a stay runs down the middle of the back as well.
Its also important to try lots of shoes to find a pair that your doc will agree to and fits you properly. Adding ul hikin poles like ti goats or gg"s is essential as well. I cannot emphasize enough proper shoe selection and hiking poles. The way you walk should also be something you pay attention to. If you have back problems it may be affecting your gait. I suggest going to a physical therapist and getting therapy if your doctor recommends it, second, having them analyze your natural gait for problems. Third, analyze your posture all day when your sitting at work/home. Learn proper posture and do your best to remind yourself to maintain it. One of the things i did was place my desk top monitor on top of sevearl thick books. Raising it up high so im not looking down at it, instead looking straight ahead. This alleivated some neck pain.
The only downside to these packs are the fiddleness of them.
I've used them for years now and I have it down to a process though:
First before you order, watch the videos on the site to get your measurements via standing against the wall and using a book to make marks on the wall. This video is on the website. Basically you goto the website, watch the supplied videos and follow the directions. Get the shoulder straps at the appropriate width for you before heading out for a test run. Get hip where you think it should be, and head out with a heavier than normal load(35-40LBS or so, these packs can haul HEAVY loads and do better with heavier loads due to weight distribution). Plan on a few miles. After 20-30 minutes you will discover the places where the hip belt is out of angle. You will feel an uncomfortable pain on the top/bottom/side of your hip bone. Simply take off the pack, and alter the angle of the hip belt on the corresponding side to accomodate the pain at the part of the hip bone. Make small adjustments of a few degrees. If the pain is at the top of the hip bone, angle the belt down. After that, put it back on. If you got it in the right place, the pain will be gone. After making your fine adjustments via hiking, you should be set.
My base weight for summer is around 11lbs, total pack weight (full 2L h20+food)4-5 days = 21LBS.
My base weight for fall is around 13LBS, total pack weight (full 2L h20+food)4-5 days = 23lbs.
My base weight for winter is around 14LBS, total pack weight (full 2L h20+food)4-5 days = 28LBS.
Backpacking will still mildly aggravate my back issues if im on difficult terrain. This is to be expected since my issues are going to be aggravated anyway even by walking. However, I can say for sure that without the aarn pack i wouldn't be hiking. I have tried all the popular packs ULtrs use and all of them caused me problems that were untolerable due to loading the shoulders too much/not distributing weight to the hips. At the end of a trail day, im not aching to get in my hammock anymore, I actually enjoy the walking due mainly to the AARN pack but also to proper shoe selection and the use of ul hiking poles.