The influence of light touch on balance stability in different postural control tasks: evidence from EEG iAPF
Feng Guo1, Jiabing Hu2, Jianrui Guo3
1College of Exercise and Health, Shenyang Sport University, Shenyang, 110102, China. guofeng_first@163.com.
Objective:
To investigate the effect of light touch (LT) on balance stability in different postural control tasks among healthy subjects, and to obtain neural evidence of the LT effect on postural control through electroencephalogram (EEG).
Methods:
Sixteen healthy males performed eyes-closed bipedal stance on firm/soft surfaces under three conditions: no touch (NT), LT on an unstable surface (TUS), and LT on a stable surface (TSS) using a crossover design. Center of pressure (COP) and EEG were synchronously recorded. Sample entropy (SE) of COP and individual alpha peak frequency (iAPF) were analyzed.
Results:
The SE value of COP trajectory in bipedal stance on a soft surface was significantly higher than that on a firm surface (P<0.001). The effect of finger touch on COP was manifested as COP_TUSSE> COP_TSSSE (P<0.001) and COP_NTSE> COP_TSSSE (P<0.001) in both anterior-posterior and medio-lateral directions. The iAPF data showed that finger touch condition had a significant effect on iAPF, with iAPF_TUS> iAPF_TSS and iAPF_NT> iAPF_TSS (P<0.05) in the frontal, fronto-central, and centro-parietal regions under any support condition, while there was no significant difference between the TUS and NT groups.
Conclusion:
Increased task difficulty enhances thalamo-cortical information transfer for balance. LT on a stable surface provides spatial reference, improving postural control while reducing cortex-thalamus information transfer to boost neural efficiency.
