Simple tai chi exercise for improving elderly postural stability via complexity index analysis

The main purpose of this study is to investigate twice a day simple 9-step tai chi effects of the center of pressure (COP) and physiological signals of elderly people. Data are collected from the COP signals, electromyography (EMG), and pulse oximetry for 1 min for the period of 12 weeks. The COP signals are analyzed using multivariate empirical mode decomposition and multivariate multiscale entropy to work out and compare the complexity index (CI). Subjects in this experiment are over 65 years old who are divided into 11 men and 7 women; the average age is 74 ± 8.18 years. In conclusion, it is found that tai chi exercise can improve human body balance by just walking some simple steps in our experiment. However, we cannot find any effect or improvement in the pulse oximetry and EMG signals analysis.