Effects of Tai Chi Exercise on Balance and Biomechanics of Lower Extremity during Gait among the Elderly

Aging degrades muscle strength, postural balance and walking stability. Tai Chi exercise has been demonstrated to improve muscle strength and postural stability, but the effects on gait among elderly are still unknown. Therefore, the purpose of this study was to investigate the effects of Tai Chi exercise on balance control and lower extremity biomechanics during gait of the elderly. A motion capture system and two force plates were used to collect the kinematic patterns and ground reaction forces of 15 Tai Chi elderly (TCG) and 15 leisure exercise elderly (CG) participants during walking. Joint angle, joint range of motion, displacement of center of pressure, joint moment and power were calculated by using kinematic and inverse dynamic approach. Results of this study showed that the elders in TCG walked faster and had longer step length than the elders in CG. The maximum flexion angle in the hip and knee were greater in TCG than the CG during the stance phase. The displacement and area of center of pressure were smaller among elderly in TCG than those of the CG. The TCG had greater knee extension moment and hip power during the braking phase, as well as greater knee power and range of motion during the propulsive phase compared to CG. This study concluded that Tai Chi exercise could improve stability and walking speed of the elderly due to superior energy generation in the hip and knee.