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).