Parkinson's disease. A 33-person pilot study from Washington University School of Medicine in St. Louis, published in Gait and Posture (October 2008), found that people with mild to moderately severe Parkinson's disease showed improved balance, walking ability, and overall well-being after 20 tai chi sessions.
via The Health Benefits of Tai Chi – Harvard Health Publications.
Breast cancer. Tai chi has shown potential for improving quality of life and functional capacity (the physical ability to carry out normal daily activities, such as work or exercise) in women suffering from breast cancer or the side effects of breast cancer treatment. For example, a 2008 study at the University of Rochester, published in Medicine and Sport Science, found that quality of life and functional capacity (including aerobic capacity, muscular strength, and flexibility) improved in women with breast cancer who did 12 weeks of tai chi, while declining in a control group that received only supportive therapy.
via The Health Benefits of Tai Chi – Harvard Health Publications.