Hernandez Luis, Manning John, Zhang Shuqi
Northern Illinois University, United States.
Northern Illinois University, United States.
Gait Posture. 2019 Feb;68:488-493. doi: 10.1016/j.gaitpost.2018.12.032. Epub 2019 Jan 2.
Background Physiological/biomechanical systems display high degrees of complexity in their corresponding physiological and/or biomechanical outputs, indicative of normal healthy physiological functioning, though little attention has been paid to potential mechanisms which may affect complexity. Center of pressure (CoP) dynamics also display high degrees of complexity and may be affected via altered respiratory-motor interactions such as during voluntary control of breathing. Purpose The purpose of this study was to investigate the differences in the complexity of CoP dynamics during autonomous vs. voluntary control of breathing and between different voluntarily controlled breathing conditions. Methods Center of pressure recordings were taken from 18 older adults during static standing under three different breathing conditions: 1) neutral breathing, 2) abdominal breathing, and 3) thoracic breathing, the first constituting the autonomous breathing condition and the latter two constituting voluntarily controlled breathing conditions. CoP dynamics were quantified using sample entropy, standard deviation, 95% sway area, and average radial velocity. Repeated measure MANOVAs were used to assess the effect of breathing on CoP dynamics, with top-down application of ANOVAs and pairwise comparison as needed. Results Voluntary control of breathing during both conditions resulted in significantly higher CoP variability and lower sample entropy than during autonomous control of breathing in the mediolateral direction, indicating less complex dynamics and loss of system control. No significant differences between voluntary breathing conditions were observed. Conclusion Voluntary control of breathing significantly affected on CoP dynamics during static standing. The complexity of the postural control system may be affected via alterations in respiratory-motor interactions.
生理/生物力学系统在其相应的生理和/或生物力学输出中表现出高度的复杂性，这表明正常健康的生理功能，尽管很少有人关注可能影响复杂性的潜在机制。压力中心（CoP）动力学也表现出高度的复杂性，并且可能通过改变呼吸-运动相互作用而受到影响，例如在自主控制呼吸期间。目的：本研究的目的是调查自主呼吸与自主控制呼吸期间以及不同自主控制呼吸条件下CoP动力学复杂性的差异。方法：在三种不同的呼吸条件下，对18名老年人进行静态站立时的压力中心记录：1）中性呼吸，2）腹式呼吸，3）胸式呼吸，第一种构成自主呼吸条件，后两种构成自主控制呼吸条件。使用样本熵、标准差、95%摆动面积和平均径向速度对CoP动力学进行量化。使用重复测量多因素方差分析来评估呼吸对CoP动力学的影响，并根据需要自上而下应用方差分析和成对比较。结果：在两种情况下，自主控制呼吸均导致CoP变异性显著高于自主呼吸期间，并且在内外侧方向上的样本熵低于自主呼吸期间，表明动力学复杂性降低和系统控制丧失。在自主呼吸条件之间未观察到显著差异。结论：自主控制呼吸在静态站立期间对CoP动力学有显著影响。姿势控制系统的复杂性可能通过呼吸-运动相互作用的改变而受到影响。
