C. Another yet closely correlated ideal is that of economic postures and movements. The system of Ling is less orthopedic than orthogenic, although he sought primarily to correct bad attitudes and perverted growth. Starting from the respiratory and proceeding to the muscular system, he and his immediate pupils were content to refer to the ill-shapen bodies of most men about them. One of their important aims was to relax the flexor and tone up the extensor muscles and to open the human form into postures as opposite as possible to those of the embryo, which it tends so persistently to approximate in sitting, and in fatigue and collapse attitudes generally. The head must balance on the cervical vertebra and not call upon the muscles of the neck to keep it from rolling off; the weight of the shoulders must be thrown back off the thorax; the spine be erect to allow the abdomen free action; the joints of the thigh extended; the hand and arm supinated, etc. Bones must relieve muscles and nerves. Thus an erect, self-respecting carriage must be given, and the unfortunate association, so difficult to overcome, between effort and an involuted posture must be broken up. This means economy and a great saving of vital energy. Extensor action goes with expansive, flexor with depressive states of mind; hence courage, buoyancy, hope, are favored and handicaps removed. All that is done with great effort causes wide irradiation of tensions to the other half of the body and also sympathetic activities in those not involved; the law of maximal ease and minimal expenditure of energy must be always striven for, and the interests of the viscera never lost sight of. This involves educating weak and neglected muscles, and like the next ideal, often shades over by almost imperceptible gradation into the passive movements by the Zander machines. Realizing that certain activities are sufficiently or too much emphasized in ordinary life, stress is laid upon those which are complemental to them, so that there is no pretense of taking charge of the totality of motor processes, the intention being principally to supplement deficiencies, to insure men against being warped, distorted, or deformed by their work in life, to compensate specialties and perform more exactly what recreation to some extent aims at.