Resistance bands used for pulling back and down exercises with spinal alignment can activate posterior shoulder girdle muscles.

“so you can get some resistance bands and just start playing maintain that elongate elongation through the spine ribs tucked down towards the hips you're not flaring your hips imagine there's a string in the back of your neck slowly pulling you up to the ceiling so you're creating that elongation through the whole spine you want to really open up that hose and then just start playing with creating a little bit of activation turning those muscles in the back”