Effects of long-term Tai-Chi Chuan practice on whole-body balance control during obstacle-crossing in the elderly Author: Chien-Chung Kuo1,2, Sheng-Chang Chen3, Tsan-Yang Chen3, Tsung-Jung Ho4,5,6, Jaung-Geng Lin7, Tung-Wu Lu8 Affiliation: <sup>1</sup> Department of Orthopedics, China Medical University Hospital, Taichung, Taiwan, ROC. <sup>2</sup> Department of Orthopedics, School of Medicine, China Medical University, Taichung, Taiwan, ROC. <sup>3</sup> Department of Biomedical Engineering, National Taiwan University, Taipei, Taiwan, ROC. <sup>4</sup> Integration Center of Traditional Chinese and Modern Medicine, Buddhist Tzu Chi General Hospital, Hualien City, Taiwan, ROC. <sup>5</sup> Department of Chinese Medicine, Buddhist Tzu Chi Hospital, Hualien City, Taiwan, ROC. <sup>6</sup> School of Post-Baccalaureate Chinese Medicine, Tzu Chi University, Hualien City, Taiwan, ROC. <sup>7</sup> Institute of Chinese Medical Science, China Medical University, Taichung, Taiwan, ROC. <sup>8</sup> Department of Biomedical Engineering, National Taiwan University, Taipei, Taiwan, ROC. twlu@ntu.edu.tw. Conference/Journal: Sci Rep Date published: 2022 Feb 17 Other: Volume ID: 12 , Issue ID: 1 , Pages: 2660 , Special Notes: doi: 10.1038/s41598-022-06631-8. , Word Count: 256 Older people are subject to an increased risk of falling compared to the young, especially during obstacle negotiation. This study aimed to quantify the effects of long-term Tai-Chi Chuan (TCC) practice on the balance control during obstacle-crossing in older people in terms of the inclination angles (IA) of the body's centre of mass (COM) relative to the centre of pressure (COP), and the rate of change of IA (RCIA). Fifteen healthy older adults who had practised TCC for at least 13 years and 15 healthy controls without any experience in TCC performed obstacle-crossing in a gait laboratory. The TCC group showed significantly greater leading and trailing toe-obstacle clearances but smaller trailing stride lengths when compared to controls. In the sagittal plane, the TCC group showed significantly smaller average anterior IA when the COM was anterior to the COP but greater average posterior IA when the COM was posterior to the COP, with significantly smaller average and peak RCIA over the crossing cycle. Long-term TCC practitioners showed an obstacle-crossing technique for less risk of tripping and better balance control, as indicated respectively by significantly increased toe-obstacle clearances and more posterior COM position relative to the COP with smaller anterior IA and RCIA during leading crossing and greater posterior IA and frontal RCIA at trailing-toe crossing. These benefits appeared to be related to the main features of TCC movements that emphasized maintaining balance during single-leg support and keeping the body weight on the trailing limb during the slow weight-shifting of double-limb support. PMID: 35177707 PMCID: PMC8854736 DOI: 10.1038/s41598-022-06631-8