Changes in spine alignment begin with degenerative changes. Therefore, changes in spine alignment that do not cause symptoms can be seen as a normal aging phenomenon. However, alignment disorders that exceed the physiological range require a lot of energy in daily life movements, so the ideal alignment of the spine is an essential element in minimizing muscle energy consumption. In the sagittal plane, the curvatures of the spine (lordosis of the cervical region, kyphosis of the thoracic region, lordosis of the lumbar region), straight alignment in the coronal plane, balanced tension of the ligamentous tissue, and activation of the muscles around the spine are factors that enable an erect position without pain [1]. According to the “Cone of Economy” proposed by Jean Dubousset, if the center of the body is located at the center of the cone, an ergonomically ideal erect posture can be maintained, but as it deviates from the center of the Cone, more energy is needed to maintain an erect posture (Fig. 13.1). As a result, when the center of the body moves outside the cone, it is difficult to maintain posture, so external support such as a cane is needed [2].