So the first clip in this video is what I recommend you all use to improve your thoracic extension and learn to put the bend in the correct part of your back, and it's not in your lower back!
Essentially, you want to lay on a foam roller or something similar, making sure to put it in your mid back like I show in the video. Put your hips squarely on ground, and while holding your hips there, try to touch your shoulders to the ground with arms over your head. Try different hand positions to feel out where your flexibility needs are.
Then try experimenting flowing around your bridges!
