Li F, Harmer P, Fitzgerald K, et al. Tai chi and postural stability in patients with Parkinson’s disease. N Engl J Med. 2012;366(6):511‐519. doi:10.1056/NEJMoa1107911
At a glance
Patients with Parkinson’s disease have a substantial impairment of balance, resulting in reduced functional capacity and an increased risk of falling. Although exercise is regularly recommended by specialists, few programs have proven their effectiveness. The practice of Tai Chi appears to reduce balance disorders in patients with mild to moderate Parkinson’s disease, with additional benefits of improved functional capacity and reduced falls.
What is already known
Parkinson’s is one of the most common neurodegenerative diseases. Its evolution is slow but progressive and involves, mainly, some motor functions such as movement and balance control. With the progression of the disease, patients lose postural stability and have gait dysfunction, difficulty in managing daily life activities, and frequent falls. Although some motor manifestations, such as tremors, can be alleviated with medication, features such as postural instability are less sensitive to medication and require alternative approaches. For this reason, exercise is an integral part of the management of Parkinson’s disease because physical activity has been shown to delay deterioration of motor function and prolong functional independence. Exercise against resistance has been shown to have positive effects on balance and strength deficits. However, it depends on the availability of specific equipment that presents a certain risk in use and therefore requires careful safety monitoring. As a result, research into alternative forms of exercise that improve balance, gait, and motor function in patients with Parkinson’s disease has led to Tai Chi as a very promising form of exercise.
Tai Chi (or, more precisely, Tàijíquán), an ancient Chinese practice that combines physical and mental exercise, has been shown to improve strength, balance and physical function and prevent falls in the elderly.
Design and Method
The study examined whether an adapted Tai Chi program could improve postural stability in patients with Parkinson’s disease.
Sessions of 60 minutes, twice a week for 24 weeks were scheduled in three groups of subjects for a total of 309, who performed:
- Tai Chi classes
- exercise against resistance
- low impact stretching sessions (control)
Eligibility criteria included clinical diagnosis of Parkinson’s disease; age 40 to 85 years; presence of tremor, stiffness, postural stability or bradykinesia; stable use of medication; ability to walk with or without an assistive device. The exclusion criteria were current participation in any other behavioral or pharmacological study or an instructor-led exercise program, a Mini-Mental State examination score of less than 24, debilitating conditions or impaired vision that would prevent full participation in the study.
Tai chi: The protocol consisted of six Tai Chi movements integrated into an 8 Yang Form routine, specifically designed to balance balance balance and gait by making participants perform symmetrical and diagonal movements, such as weight shifting, controlled center of mass shifting based on support, ankle sway and anterior-posterior and lateral pitch. Natural breathing has been integrated into the training routine.
Exercise against resistance: The protocol, developed by the exercise literature, focused on strengthening muscles important for posture, balance and gait. Resistance with a weighted waistcoat was initially set at 1% of body weight and was gradually increased until it reached 5% of body weight. Ankle weights ranged from 0.45 to 1.36 kg. The routine included 8 to 10 exercises, including forward and lateral steps, squats, forward and lateral lunges and heel and toe lifts.
Low impact stretching: This control condition was designed to provide a low intensity exercise program associated with the social interaction and satisfaction inherent in the other two interventions, but without similar training benefits in terms of lift, strength or lower limb balance. The main activities included a variety of sitting and standing stretches involving the upper body and lower limbs, with the use of gentle joint extension and flexion and trunk rotation.
This study found that a bi-weekly 24-week Tai Chi program is more effective in improving postural stability and other motor functions in patients with mild to moderate Parkinson’s disease than an endurance training or stretching program. Tai Chi training has also significantly reduced the incidence of falls compared to a stretching program. Improvements in primary and secondary goals were maintained 3 months after surgery. No serious adverse events were observed during the practice of Tai Chi, confirming the safety and usefulness of this intervention for people with Parkinson’s disease.
In addition, patients in the Tai Chi group demonstrated a marked increase in gait speed associated with a significant increase in stride length. These improvements in gait characteristics support the effectiveness of Tai Chi in relieving the bradykinetic movements associated with Parkinson’s disease.
The Tai Chi protocol works primarily on weight shifting and ankle swinging to effectively move the person’s center of gravity to the limits of stability, alternating between a narrow and a wide position to continuously change the support base, increasing the support leg support time and leg swing time, involving rotational movements of the torso with upright posture and performing step-by-step heel to toe (forward) and toe to heel (backward) movements to strengthen dorsiflexion and plantar flexion. These intrinsic training characteristics may have led to improved postural control and walking ability.
Firstly, given the behavioural-based treatments, participants were aware of their intervention tasks. This awareness may have introduced distortions in the results, as people interested in participating may have had positive expectations about the benefits of the exercise. In addition, all participants were tested during “on” periods, which may have masked the underlying changes induced by the training interventions.