The whole principle of yoga is based on learning to observe and be aware of muscular tension in the body, and then learning to relax unnecessary tension in the muscles. The Corpse pose is a good place to start learning this process. Some say this is the easiest posture there is and others will tell you this is the most difficult posture of all. Some say this is really the only pose there is and others still will say that all other poses are meant to prepare the person for the one great pose, Savasana.