Long‑term Tai Chi practice promotes cortical synchronization in postural control among older adults

Abstract

Tai Chi has become increasingly popular for its health benefits in postural control. Evidence on cortical adaptation and regulation in postural control in long‑term Tai Chi practitioners remains limited. The aim of this study was to determine whether cortical adaptation and postural control differ between long-term Tai Chi practitioners and healthy older adults without Tai Chi experience. Thirty-six older adults with Tai Chi experience and twenty-five age-matched healthy older adults participated. Four postural tasks were performed by participants: quiet stance, narrow stance, tandem stance with left/right leg forward. Balance ability was assessed using Berg balance scale score (BBS). Cortical activation and functional connectivity during tasks were calculated to characterize cortical adaptation. Postural control was assessed by center of pressure (COP) velocity, Sample Entropy, mean power frequency, and distinct frequency bands. Linear mixed models were used for statistical analysis. Tai Chi practitioners exhibited a higher BBS score ( p < 0.01), with greater cortical activations in left primary somatosensory cortex during the tandem stance with left leg forward ( p = 0.02), right dorsolateral prefrontal cortex during narrow stance ( p = 0.02), and right primary motor cortex during narrow stance ( p < 0.01) and tandem stance ( p = 0.02), greater inter- and intra- functional connectivity between primary motor cortex, primary somatosensory cortex, and supplementary motor area compared to controls (all p < 0.05). In addition, lower anterior-posterior COP Sample Entropy and mean power frequency were observed in Tai Chi practitioners compared to non-practitioners (both p < 0.01). Frequency domain analysis revealed Tai Chi practitioners exhibited higher low-frequency energy content ( p < 0.05), but lower mid- frequency energy content ( p < 0.01) in more challenging conditions compared with control group. Tai Chi practitioners demonstrated greater cortical regulation in postural control, with stronger sensorimotor synchronization among cortical regions compared to older adults without Tai Chi experience. In addition, COP analysis further indicated that Tai Chi practitioners exhibited a more controlled postural strategy, characterized by smoother and less abrupt postural adjustments, as well as a reduced reliance on rapid corrective responses when postural stability was challenged.