The Santi Shi posture of xingyiquan is considered the most fundamental aspect of training in xingyiquan and it is said to be the source of all skills in this internal art. From a physiological perspective standing in Santi Shi can greatly increase the strength of the legs, core, shoulders and arms. It can also enhance the internal flow of qi through correct alignment of the meridians and increase stability and rooting through applying correct body structure. In addition to the physical aspects, standing in Santi Shi can also help to focus the mind and increase awareness. For beginners learning xingyiquan, Santi Shi is invaluable in the benefits it provides and traditionally students stood in this posture for extended periods of time before learning any other skills. When standing in Santi Shi there are 3 external and 3 internal relationships or harmonies which must be applied. The hands harmonize with the feet, the elbows harmonize with the knees and the shoulders harmonize with the hips in the external aspects, and the heart harmonizes with the intent, the intent harmonizes with the qi and the qi harmonizes with the power in the internal aspects.