Stable foundation gives an opportunity for the whole body to benefit, allowing us to experience more openness and relaxation.
In twists we increase the mobility of the thoracic spine, neck and shoulders. This enhances relaxation.
In a shoulder stand (salamba sarvagasana) we extend the upper back and release the tension in our shoulders and neck.
In both postures, we learn to give support to our heart gravity point. With this support heart region can stay open; this "feeling center" is our emotional connection with the body, in which we can experience feelings of lightness and space. This brings ease and rest within ourselves and in our interaction with the space around us.
You can practice and hear this theory first hand in classes with the founder of the critical alignment method and his leading teacher from Amsterdam.