Whenever you're lifting anything, I want you to focus on engaging your back muscles, lifting your chest, and setting the head of your arm bone in the shoulder socket by mindfully pulling your shoulder back and down slightly. (thebettyrocker.com)
Draw your right arm back into its shoulder socket to square your shoulders and chest to the front. (yogajournal.com)
Repeat this a few times until you can feel that your arm bones have settled into the sweet spot of the shoulder sockets. (yogajournal.com)