Background: With aging, the cognitive function of the prefrontal cortex (PFC) declined, postural control weakened, and fall risk increased. As a mind–body exercise, regular Tai Chi practice could improve postural control and effectively prevent falls; however, underlying brain mechanisms remained unclear, which were shed light on by analyzing the effect of Tai Chi on the PFC in older adults by means of functional near-infrared spectroscopy (fNIRS).Methods: 36 healthy older adults without Tai Chi experience were divided randomly into Tai Chi group and Control group. The experiment was conducted four times per week for 16 weeks; 27 participants remained and completed the experiment. Negotiating obstacle task (NOT) and negotiating obstacle with cognitive task (NOCT) were performed pre- and post-intervention, and Brodmann area 10 (BA10) was detected using fNIRS for hemodynamic response. A three-dimensional motion capture system measured walking speed.Results: After intervention in the Tai Chi group under NOCT, the HbO₂ concentration change value (ΔHbO₂) in BA10 was significantly greater (right BA10: p = 0.002, left BA10: p = 0.001), walking speed was significantly faster (p = 0.040), and dual-task cost was significantly lower than pre-intervention (p = 0.047). ΔHbO₂ in BA10 under NOCT was negatively correlated with dual-task cost (right BA10: r = −0.443, p = 0.021, left BA10: r = −0.448, p = 0.019). There were strong negative correlations between ΔHbO₂ and ΔHbR under NOCT either pre-intervention (left PFC r = −0.841, p < 0.001; right PFC r = −0.795, p < 0.001) or post-intervention (left PFC r = −0.842, p < 0.001; right PFC r = −0.744, p < 0.001).Conclusion: Tai Chi practice might increase the cognitive resources in older adults through the PFC bilateral activation to prioritize gait performance during negotiating obstacles under a dual-task condition.

This study aimed to evaluate the test–retest reliability of a new device for assessing ankle joint kinesthesia. This device could measure the passive motion threshold of four ankle joint movements, namely plantarflexion, dorsiflexion, inversion and eversion. A total of 21 healthy adults, including 13 males and 8 females, participated in the study. Each participant completed two sessions on two separate days with 1-week interval. The sessions were administered by the same experimenter in the same laboratory. At least 12 trials (three successful trials in each of the four directions) were performed in each session. The mean values in each direction were calculated and analysed. The ICC values of test–retest reliability ranged from 0.737 (dorsiflexion) to 0.935 (eversion), whereas the SEM values ranged from 0.21° (plantarflexion) to 0.52° (inversion). The Bland–Altman plots showed that the reliability of plantarflexion–dorsiflexion was better than that of inversion–eversion. The results evaluated the reliability of the new device as fair to excellent. The new device for assessing kinesthesia could be used to examine the ankle joint kinesthesia.

This study aims to investigate the effects of Tai Chi Chuan (TCC) and brisk walking (BW) on balance and training duration for the two exercises to significantly improve balance. A total of 48 elderly women were randomly divided into three groups. The TCC and BW groups completed a 60-min intervention training program with five sessions weekly for 16 weeks. Single-leg standing balance was tested every 4 weeks. Results showed that all the variables with eyes open improved on the eighth week (p < .05) in the TCC group and on the 12th week (p < .01) in the BW group. All variables with eyes closed improved on the 12th week (p < .01) in the TCC group and on the 16th week (p < .05) in the BW group. The results showed that 12 and 16 weeks of TCC and BW, respectively were essential to improve balance with eyes closed among the women aged 60–70 years.

This study aimed to investigate the training and detraining effects of Tai Chi (TC) on postural control ability in single leg stance (SLS) by conducting a single-blind randomized controlled trial. Forty-eight older women were randomly divided into the TC, brisk walking (BW), and control(C) groups by using computer-generated program. The participants completed a 16-week intervention training and 8-week detraining program. Postural control ability in SLS was tested at the baseline, 16 t h, 20 t h, and 24 t h weeks. The primary outcomes included single-leg stance time (Time) and secondary outcomes included maximal displacement of the center of pressure (COP) in the anterior-posterior (AP) direction (D-ap), maximal displacement of the COP in the medial-lateral (ML) direction (D-ml), total length of the COP trajectories (Lng), and 95% confidence ellipse area of the COP movements (area), mean AP total excursion velocities (V-ap), and mean ML total excursion velocities (V-ml). Significant within-group difference compared with the baseline and between-groups difference compared with control group were found at 16 t h, 20 t h, and 24 t h weeks in the TC group and at the 16 t h and 20 t h weeks in the BW group in all the primary and secondary outcomes. Most of secondary outcomes including Lng, D-ml, V-ml, Area increased significantly at the 24 t h week compared with that at the 16 t h week in BW group. TC was effective in improving postural control ability and maintaining intervention gains, and was recommended as an appropriate exercise to prevent falls in the older adults.