As a regular visitor to the chiropracter I can say to make sure you strecth your back out as much as you physicaly can, from now until the trail head, if the ride to the trailhead is long your back will need stretching and some time standing without a pack before starting, riding in a car will really stiffen you up. I actually take small cold packs that you can get at grocery stores for longer trips, they are light and can be very helpful before you turn in at camp, reducing inflamation at night will make your mornings much better.