Department of Health and Kinesiology, Purdue University, West Lafayette, IN, United States; Center on Aging and the Life Course, Purdue University, West Lafayette, IN, United States.
Human Movement Research Laboratory (MOVI-LAB), Department of Physical Education, Graduate Program in Movement Sciences, School of Sciences, São Paulo State University (UNESP), Bauru, Brazil.
Gait Posture. 2021 Feb;84:340-345. doi: 10.1016/j.gaitpost.2021.01.002. Epub 2021 Jan 8.
Impaired movement stability is a common symptom of Parkinson's disease (PD) that leads to falls and mishandled objects. Decline in synergistic stabilization of movement in PD patients has been observed in manual and postural tasks. However, locomotor synergies have not been quantified in PD patients.
The purpose of this work was to quantify the strength of the synergy stabilizing the step length while crossing an obstacle in PD patients. We hypothesized that (1) the distances of the front and rear feet relative to the obstacle would display compensatory across-trial co-variance that stabilizes step length in PD patients and age-matched controls, and (2) the step-length stabilization would be weaker in PD patients.
Thirteen PD patients and eleven healthy age-matched controls walked up to and stepped over a 15 cm high obstacle fifteen times.We measured the distances of the rear and front foot toes from the obstacle during the crossing step. We used the uncontrolled manifold method to parse the across-trial variance in toe distances into a component that maintains the step length and a component that changes the step length. These variance components yielded the synergy index that quantified the stability of step length.
Step length was stabilized in PD patients as well as controls. However, the synergy index was 53% lower in the PD patients (p < 0.01). Thus, both our hypotheses were supported.
This is the first study reporting impaired locomotor synergies in PD patients. Most PD patients in our sample were early stage (10 out of 13 patients were Hoehn-Yahr ≤ 2). Therefore, this result motivates further studies to establish step-length synergy during adaptive locomotor tasks as a biomarker for early detection of locomotor impairments in PD patients.
运动稳定性受损是帕金森病（PD）的常见症状，可导致跌倒和物体处理不当。在 PD 患者的手动和姿势任务中观察到运动协同稳定性下降。然而，尚未在 PD 患者中量化运动协同作用。
本研究的目的是量化在 PD 患者穿过障碍物时稳定步长的协同作用强度。我们假设：（1）相对于障碍物的前脚和后脚的距离将显示出跨试验补偿协方差，从而稳定 PD 患者和年龄匹配的对照组的步长，（2）PD 患者的步长稳定性会较弱。
13 名 PD 患者和 11 名年龄匹配的健康对照组共进行了 15 次走过去并跨过 15 厘米高障碍物的试验。我们在跨越阶段测量了后脚和前脚脚趾与障碍物之间的距离。我们使用非控制流形方法将脚趾距离的跨试验方差分解为保持步长的分量和改变步长的分量。这些方差分量产生了协同指数，量化了步长的稳定性。
PD 患者和对照组都稳定了步长。然而，PD 患者的协同指数降低了 53%（p<0.01）。因此，我们的两个假设都得到了支持。
这是第一个报告 PD 患者运动协同作用受损的研究。我们样本中的大多数 PD 患者处于早期阶段（13 名患者中有 10 名 Hoehn-Yahr≤2）。因此，这一结果促使进一步的研究建立适应运动任务期间的步长协同作用，作为 PD 患者运动障碍早期检测的生物标志物。
