The diaphragm is a large, flat muscle, resembling a saucer, which forms the division between the chest cavity and the abdominal cavity. By downward expansion it causes the lungs to expand likewise and to suck in the air. The pressure of air being greater on the outside of the body than within, it rushes in and fills the vacuum created by the descending diaphragm. As the diaphragm relaxes and becomes contracted to its original size and position, the air is expelled from the body. (11) (To stimulate the action of the diaphragm) Lie flat on floor or mattress, the head unsupported. Relax the muscles all over the body, then inhale deeply with the diaphragm only, raising the wall of the abdomen just below the ribs without elevating either the chest or the lower abdomen. Take about four seconds to inhale, then exhale in twice that length of time, contracting the abdomen below the ribs. (12) (Internal massage) Lie on your back on a bed or couch, knees raised. Relax thoroughly, exhale and hold the breath after exhalation. While doing so, push the abdomen out and draw it in as far as possible each way. Repeat these movements as long as you can hold the breath without straining, then breathe deeply and regularly for several minutes, then repeat the massage movements. Next to deep breathing, I consider this practice of greater value than any other physical exercise. It imparts to the intestines an other abdominal organs a "washboard" motion which acts as a powerful stimulant to all the organs in the abdominal cavity. Internal massage is especially beneficial in chronic constipation. This exercise may be performed also while standing or walking. It should be practiced two or three times daily. Breathing Exercises to Be Taken in Bed (13) With hands at side, inhale slowly and deeply, as directed in Exercise Number (1), filling and emptying the lungs as much as possible, but without straining. Practice first lying on the back, then on each side. (14) Using one-or two-pound dumbbells, position recumbent on back, arms extended sideways, dumbbells in hands. Raise the arms with elbows rigid, cross arms over the chest as far as possible, at the same time expelling the air from the lungs. Extend the arms to the sides, inhaling deeply and raising the chest. (15) Lie flat on the back, arms at sides. Grasping the dumbbells, extend the arms backward over the head, inhaling. Leave them in this position for a few seconds, then raise them straight above the chest, and lower them slowly to the original position. Exhale during the second half of this exercise. As a variation, cross the arms in front of the body instead of bringing to sides. Rhythmical Breathing