[pct-l] backpack solutions?

[ryan clark]

ive been doing lots of training hikes with lots of weight in my pack.  
the day after my hikes my color bones are always tender when i touch  
them. when im out on the hike the pack feels great. fits perfect and  
i barley notice the weight on my back. im just wondering if this is  
just something i have to man up with and get used to or if i might be  
wearing it wrong. any of you have tricks or tips you can share?

my pack is an Osprey Aether and i train with around 45 lbs. most of  
the time.