Another good find via Embrace the Moon Taijiquan and Qigong:
(BTW, the woman in the top photo is not exactly doing Tai Chi.)
Old news, but still.
A summary of recommendations from the elderly fall prevention Guideline can be found at the Amerian Geriatrics Society website: Summary of Recommendations.
Tai Chi is among the “A” list of recommendations — “A strong recommendation that the clinicians provide the intervention to eligible patients. Good evidence was found that the intervention improves health outcomes and the conclusion is that benefits substantially outweigh harm.”