Effects of a Biomechanical-based Tai Chi Program on Gait and Posture in People With Parkinson's Disease

Parkinson's disease (PD) is associated with changes in gait and posture that can lead to a higher frequency of falls and injuries in this population. Research has shown a positive effect of tai chi (TC) training on the movement capacity for those with PD, however the understanding of the impact of TC training on gait and postural stability in PD is lacking. This study aims to examine the impact of a biomechanical-based TC intervention on dynamic postural stability and how it relates to walking performance. It is hypothesized that the effects of the TC intervention will help to improve measures relating to postural stability, gait, and cognition.

A prospective, single-blind, randomized control trial of 40 individuals with early-stage PD (Hoehn \& Yahr stages 1 to 3). Those with PD will be randomly assigned to either a TC group or a control group. The TC group will participate in a biomechanical-based TC training program that is formed based on the movement analysis of TC and will be practiced two to three times a week for 12 weeks. The control group will be asked to engage or maintain their regular physical activity for a period of 12 weeks. The primary and secondary outcomes will be assessed at baseline, 6-week, and 12-week after commencing the study protocol. The primary outcome measures will include gait speed, cadence, step length during level surface walking (simple task) and fixed-obstacle crossing (challenging task); the dynamic postural stability will be indicated by the center of mass and center of pressure (COM-COP) separation distance and clearance distance measured during fixed-obstacle crossing. The secondary measures will be the Unified Parkinson's disease Rating scale (UPDRS-III), single leg-stance test with eyes open and closed, and three cognitive scores (Stroop Test, Trail Making Test- Part B, and the Wisconsin Card Sorting Test).

Eligibility Criteria:
Inclusion Criteria:

* Have been diagnosed with PD and demonstrate a disease severity ranging from 1 to 3 on the Hoehn and Yahr (H\&Y) scale
* Have no fluctuations in motor symptoms as reported by the motor section of the Unified Parkinson's Disease Rating Scale (UPDRS-III)
* Have stable PD (such as levodopa or carbidopa) and doctor-prescribed medication use, that is, fluctuation did not occur at the time of medication intake;
* Can stand and walk independently
* Availability: three times per week over a period of 12 weeks
* Be able to engage in PA for at least 60 min on their own, thrice per week, without prior experience practicing TC regularly.

Exclusion Criteria:

* Enrolled into any other behavioral or pharmacological studies
* Have a Montreal Cognitive Assessment (MoCA) score of \< 26/27 (that indicate some mild cognitive impairment (MCI))
* Have had a serious medical condition or uncontrolled hypertension (equal or greater than a systolic 180 or diastolic 110 reading)
* Have any debilitating conditions that could prevent them from performing any PA for a minimum of 60 minutes.
* Have practiced or have experience of practicing TC in an organized class or program within the last 5 years at the start of participation in the study.