the pelvis as the hub and the arms and feet as the spokes of a wheel. Furthermore, the respiration of breath is coordinated with the physical movements in a state of deep relaxation, rather than muscular tension, in order to guide the practitioners to a state of homeostasis. Tai Chi Quan is a complete martial art system with a full range of bare-hand movement sets and weapon forms, such as Tai Chi sword and Tai Chi spear, which are based on the dynamic relationship between Yin and Yang. While Tai Chi is typified by its slow movements, many styles (including the three most popular: Yang, Wu, and Chen) have secondary, faster-paced forms. Some traditional schools teach martial applications of the postures of different forms (taolu). Solo practices Taolu (solo "forms") is a choreography that serves as the encyclopedia of a martial art. Tai chi is often characterized by slow movements in Taolu practice, and one of the reasons is to develop body awareness. Accurate, repeated practice of the solo routine is said to retrain posture, encourage circulation throughout students' bodies, maintain flexibility, and familiarize students with the martial sequences implied by the forms. The traditional styles of tai chi have forms that differ in aesthetics, but share many similarities that reflect their common origin. Solo forms (empty-hand and weapon) are catalogues of movements that are practised individually in pushing hands and martial application scenarios to prepare students for self-defense training. In most traditional schools, variations of the solo forms can be practised: fast / slow, small-circle / large-circle, square / round (different expressions of leverage through the joints), low-sitting/high-sitting (the degree to which weight-bearing knees stay bent throughout the form). Breathing exercises; neigong (internal skill) or, more commonly, qigong (life energy cultivation) are practiced to develop qi (life energy) in coordination with physical movement and zhan zhuang (standing like a post) or combinations of the two. These were formerly taught as a separate, complementary training system. In the last 60 years they have become better known to the general public. Qigong involves coordinated movement, breath, and awareness used for health, meditation, and martial arts. While many scholars and practitioners consider tai chi to be a type of qigong, the two are commonly seen as separate but closely related practices. Qigong plays an important role in training for tai chi. Many tai chi movements are part of qigong practice. The focus