In certain movement practices, the area in your back that is behind your heart Chakra is called the " Heart Gate". This is often an area that is " stuck" on people, as that crucial intersection between the arms, head/neck and lumbar spine can become jammed from nearly any angle.
I have been experimenting with ways to release the back. We instinctively know how to " arch" in order to try to open the front body, but the back body is much less evident.
This class is one of my experiments, and is definitely one of the more advanced workouts. I would recommend that you wait until your body is open, and accustomed to the work before trying this one.
Be very careful to stay aware of your body when putting pressure on the front of your sternum. It is a sensitive area. If anything feels " sharp", use your body to control the pressure and back off when necessary. Breathing should be something easy. If this experience is "labored" in any way, you're going in too strong. No benefit ever comes of creating struggle. Please don't do that.