Tai chi chuan is an internal Chinese martial art often practiced for health reasons. Tai chi is typically practiced for a variety of reasons: its soft martial techniques, demonstration competitions, health and longevity. Consequently, a multitude of training forms exist, both traditional and modern, which correspond to those aims. Some of tai chi chuan's training forms are well known to Westerners as the slow motion routines that groups of people practice together every morning in parks around the world, particularly in China.
Today, tai chi has spread worldwide. Most modern styles of tai chi trace their development to at least one of the five traditional schools: Chen, Yang, Wu/Hao, Wu and Sun. The origins and creation of tai chi are a subject of much argument and speculation. However, the oldest documented tradition is that of the Chen family from the 1820s.
The physical techniques of tai chi chuan are described in the tai chi classics (a set of writings by traditional masters) as being characterized by the use of leverage through the joints based on coordination in relaxation, rather than muscular tension, in order to neutralize or initiate attacks. The slow, repetitive work involved in the process of learning how that leverage is generated gently and measurably increases, opens the internal circulation (breath, body heat, blood, lymph, peristalsis, etc.)
Tai chi classes have become popular in hospitals, clinics, community and senior centers in the last twenty years or so, as baby boomers age and the art's reputation as a low stress training for seniors became more well-known. As a result of this popularity, there has been some divergence between those who say they practice tai chi primarily for self-defense, those who practice it for its aesthetic appeal (see wushu below), and those who are more interested in its benefits to physical and mental health. The wushu aspect is primarily for show; the forms taught for those purposes are designed to earn points in competition and are mostly unconcerned with either health maintenance or martial ability. More traditional stylists believe the two aspects of health and martial arts are equally necessary: the yin and yang of tai chi chuan. The tai chi "family" schools therefore still present their teachings in a martial art context, whatever the intention of their students in studying the art.
Along with Yoga, tai chi is one of the fastest growing fitness and health maintenance activities in the United States.