Initiating movement from the lungs can increase range of motion in your shoulders and spine, which is different from initiating movement in your muscles.
When we bend forward, many of us are actually shifting our pelvis and center of weight backward, and bend backward by shifting our pelvis and center of weight forward.
The heart is usually approached as a separate organ that pumps blood through the rest of the circulatory system. In my experience, looking at the heart as a pump puts stress on the heart.
Going to the adrenal glands and their relationships to the skeletal system can free your spine and offer a deeper support for your muscles than just going to the muscles themselves.