Background

It is commonly assumed that abnormal foot biomechanics cause plantar fasciitis; however, this assumption is not well supported. In this study, we investigated rearfoot to medial-forefoot coordination of healthy and plantar fasciitis individuals. We hypothesized that chronic plantar fasciitis individuals would exhibit greater intersegmental rearfoot to medial-forefoot anti-phase coordination and greater coordinative variability than a healthy cohort.

Methods

Twenty-two individuals with chronic plantar fasciitis (symptomatic mean 4.5 years) and 22 healthy individuals participated. Three-dimensional kinematics of the rearfoot and medial forefoot segments were captured using reflective markers for walking trials. After resolving rearfoot and medial-forefoot segment angle data, a modified vector coding method was used to compute coupling angles, anti-phase movements, and coordinative variability.

Findings

Compared to healthy individuals, individuals with plantar fasciitis exhibited fewer anti-phase movements (frontal plane: P = 0.003, effect size = 0.38). No group differences were detected in coordinative variability magnitude (sagittal, frontal, transverse, respectively: P = 0.99, 0.72, 0.86; effect sizes = 0.00, 0.12, 0.04). There were significant main effect differences in coupling variability between stance periods (P < 0.0001).

Interpretation

Contrary to our hypothesis, these data suggest that a relative reduction of rearfoot to medial-forefoot anti-phase movements with a chronic plantar fasciitis injury indicates a coordinative deficit, and that a greater frequency of anti-phase movements is associated with healthy foot function. Pain, guarding, and/or the state of chronic injury may be impairing fluid inter-segmental motion. Although no group differences were found in coordinative variability, this variability increased around transitions between loading, weight acceptance, and propulsive phases of gait.

中文翻译：

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慢性足底筋膜炎减少了后足到内侧前足反相协调

背景

通常认为异常的足部生物力学会导致足底筋膜炎；然而，这一假设并没有得到很好的支持。在这项研究中，我们调查了健康和足底筋膜炎个体的后足与内侧前足协调。我们假设慢性足底筋膜炎个体将表现出比健康人群更大的节间后足到内侧前足反相协调和更大的协调变异性。

方法

22 名患有慢性足底筋膜炎（症状平均为 4.5 年）和 22 名健康人参加。使用反射标记捕捉后足和前足内侧部分的 3D 运动学以进行步行试验。在解析后足和内侧前足段角度数据后，使用改进的矢量编码方法来计算耦合角度、反相运动和协调变异性。

发现

与健康个体相比，足底筋膜炎患者的反相运动较少（额面：P  = 0.003，效应大小 = 0.38）。在协调变异幅度中未检测到组差异（分别为矢状、正面、横向：P  = 0.99、0.72、0.86；效应大小 = 0.00、0.12、0.04）。站立期之间的耦合变异性存在显着的主效应差异（P  <0.0001）。

解释

与我们的假设相反，这些数据表明，慢性足底筋膜炎损伤后足到内侧前足反相运动的相对减少表明协调性缺陷，并且反相运动的更高频率与健康的足部功能相关。疼痛、防护和/或慢性损伤状态可能会损害流体节段间运动。虽然在协调变异性中没有发现组间差异，但这种变异性在负荷、重量接受和步态推进阶段之间的过渡期间增加。