O’Sullivan et al.10) reported that performing exercise to stabilize the center of the pressure on an unstable base of support stimulated more proprioceptors and motor organs of the cerebrum than exercise on a stable base of support, maximizing the sense of balance and the balance maintaining ability, and effectively enhancing trunk stabilization. The results of the aforementioned studies demonstrate the effectiveness and the importance of exercise on an unstable base of support, including exercise with a sling.