Yoga has been described as “one of the most beneficial complementary therapies for Parkinson's disease, helping to increase flexibility, correct posture, loosen tight, painful muscles, build confidence, and in general, enhance the quality of life.”
Source: You and Parkinson's disease: A Journey to Health and Healing. Peggy Van Hulsteyn
Much evidence for the benefits of yoga to Parkinson's sufferers is anecdotal. However, there are a few studies and theses studies suggest that there may be modest improvements in mobility, balance, strength, flexibility, mood and sleep.
Source: Yoga for Parkinson's: What the Research Says, Kaitlyn P Roland
One compelling suggestion from the Parkinson's Research Foundation is that holding your breath helps in moments of panic such as feet sticking to the floor when walking. Control of breathing is a major factor in Yoga.
Yoga does not offer a cure but there is a certain logic that the exercises can improve some of the problems brought on by Parkinson's. DVDs are readily available although we advise getting a practitioner's advice and coaching first.