Hello, I'm new to backpacking and only did a few 15ish mile 2 day trips last summer and loved every second of it except my shoulders/shoulder blades were killing me after about 3 or so miles each day. My questions is; is this a matter of conditioning or is this something that usually happens when a pack doesn't fit properly or is packed wrong? Thanks in advance for info! <img src="/forums/images/graemlins/grin.gif" alt="" />