If you look at the thread Matt started you'll see he put it another way that might help you understand back tension. I couldn't get the feel of trying to squeeze my shoulders together, but imagining the spot somewhere behind my elbow helped me get it. Same end point.

Here's the link to Tn Matt thread. Realize, he's shooting a different style release. I assume you're shooting a trigger fingerfor hunting. http://www.huntingnet.com/forum/tm.aspx?m=2683781