Acasio Julian C, Butowicz Courtney M, Golyski Pawel R, Nussbaum Maury A, Hendershot Brad D
Research & Development Section, Department of Rehabilitation, Walter Reed National Military Medical Center, United States.
Department of Industrial and Systems Engineering, Virginia Tech, United States.
J Biomech. 2018 Jun 25;75:181-185. doi: 10.1016/j.jbiomech.2018.05.006. Epub 2018 May 21.
Trunk postural control (TPC) has been investigated in several populations and tasks. Previous work observed targeted training of TPC via isolated trunk control tasks may improve performance in other activities (e.g., walking). However, the nature of this relationship remains unknown. We therefore investigated the relationship between TPC, at both the global (i.e., response to finite perturbations) and local (i.e., resistance to continuous perturbations) levels, during walking and unstable sitting, both at varying levels of task demand. Thirteen individuals (11 Male, 2 Female) with no recent history (past 12 months) of illness, injury, or musculoskeletal disorders walked on a dual-belt treadmill at four speeds (-20%, -10%, +10%, and + 20% of self-selected walking speed) and completed an unstable sitting task at four levels of chair instability (100, 75, 60, and 45% of an individual's "neutral" stability as defined by the gravitational gradient). Three-dimensional trunk and pelvic kinematics were collected. Tri-planar Lyapunov exponents and sample entropy characterized local TPC. Global TPC was characterized by ranges of motion and, for seated trials, metrics derived from center-of-pressure time series (i.e., path length, 95% confidence ellipse area, mean velocity, and RMS position). No strong or significant correlations (-0.057 < ρ < 0.206) were observed between local TPC during walking and unstable sitting tasks. However, global TPC declined in both walking and unstable sitting as task demand increased, with a moderate inter-task relationship (0.336 < ρ < 0.544). While the mechanisms regulating local TPC are inherently different, global TPC may be similarly regulated across both tasks, supporting future translation of improvements in TPC between tasks.
躯干姿势控制（TPC）已在多个群体和任务中得到研究。先前的研究发现，通过孤立的躯干控制任务对TPC进行有针对性的训练，可能会提高其他活动（如行走）的表现。然而，这种关系的本质仍然未知。因此，我们研究了在不同任务需求水平下，行走和不稳定坐姿期间，TPC在全局（即对有限扰动的反应）和局部（即对连续扰动的抵抗）水平之间的关系。13名近期（过去12个月）无疾病、损伤或肌肉骨骼疾病史的个体（11名男性，2名女性）在双带跑步机上以四种速度（自定步行速度的-20%、-10%、+10%和+20%）行走，并在四种椅子不稳定水平（根据重力梯度定义的个体“中性”稳定性的100%、75%、60%和45%）下完成不稳定坐姿任务。收集了三维躯干和骨盆运动学数据。通过三平面Lyapunov指数和样本熵来表征局部TPC。全局TPC通过运动范围来表征，对于坐姿试验，则通过从压力中心时间序列导出的指标（即路径长度、95%置信椭圆面积、平均速度和RMS位置）来表征。在行走和不稳定坐姿任务期间，未观察到局部TPC之间存在强相关性或显著相关性（-0.057 < ρ < 0.206）。然而，随着任务需求的增加，行走和不稳定坐姿中的全局TPC均下降，任务间存在中等程度的相关性（0.336 < ρ < 0.544）。虽然调节局部TPC的机制本质上不同，但全局TPC在两项任务中可能受到类似的调节，这为未来在不同任务间转化TPC的改善提供了支持。
