For me, when I get to full draw and get the bones lined up, I feel an apparent reduction of bow weight (kind of like the let off on a C bow) AND I feel like my string side shoulder blade is leaning against a wall. BUT!! for me it is only on the string shoulder side, the bow shoulder side is set and static == no tension in the back on the bow shoulder side.
I get this in the draw by only using the string side shoulder and upper arm to draw.
Arne