BACKGROUND Individuals with autism spectrum disorder (ASD) show a reduced ability to maintain postural stability, though motor control mechanisms contributing to these issues and the extent to which they are associated with other gross motor activities (e.g., stepping) are not yet known. METHODS Seventeen individuals with ASD and 20 typically developing (TD) controls (ages 6-19 years) completed three tests of postural control during standing. During the neutral stance, individuals stood with their feet shoulder width apart. During the Romberg one stance, they stood with feet close together. During the circular sway, participants stood with feet shoulder width apart and swayed in a circular motion. The standard deviation (SD) of their center of pressure (COP) in the mediolateral (ML) and anteroposterior (AP) directions and the COP trajectory length were examined for each stance. We also assessed mutual information (MI), or the shared dependencies between COP in the ML and AP directions. Participants also completed a stepping task in which they stepped forward from one force platform to an adjacent platform. The amplitude and duration of anticipatory postural adjustments (APAs) were examined, as were the maximum lateral sway, duration, and velocity of COP adjustments following the initial step. We examined stepping variables using separate one-way ANCOVAs with height as a covariate. The relationships between postural control and stepping measures and ASD symptom severity were assessed using Spearman correlations with scores on the Autism Diagnostic Observation Schedule-Second Edition (ADOS-2) and the Autism Diagnostic Interview-Revised (ADI-R). RESULTS Individuals with ASD showed increased COP trajectory length across stance conditions (p = 0.05) and reduced MI during circular sway relative to TD controls (p = 0.02). During stepping, groups did not differ on APA amplitude (p = 0.97) or duration (p = 0.41), but during their initial step, individuals with ASD showed reduced ML sway (p = 0.06), reduced body transfer duration (p < 0.01), and increased body transfer velocity (p = 0.02) compared to controls. Greater neutral stance COPML variability (r = 0.55, p = 0.02) and decreased lateral sway (r = - 0.55, p = 0.02) when stepping were associated with more severe restricted and repetitive behaviors in participants with ASD. CONCLUSIONS We found that individuals with ASD showed reduced MI during circular sway suggesting a reduced ability to effectively coordinate joint movements during dynamic postural adjustments. Additionally, individuals with ASD showed reduced lateral sway when stepping indicating that motor rigidity may interfere with balance and gait. Postural control and stepping deficits were related to repetitive behaviors in individuals with ASD indicating that motor rigidity and key clinical issues in ASD may represent overlapping pathological processes.

中文翻译：

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自闭症谱系障碍站立和步态启动过程中的姿势控制过程。

背景技术尽管还不清楚导致这些问题的运动控制机制以及它们与其他总体运动活动（例如，踩踏）的关联程度，但是自闭症谱系障碍（ASD）的个体显示出降低的姿势稳定性能力。方法17名ASD患者和20名典型的发展中（TD）对照（6-19岁）在站立时完成了三种姿势控制测试。在中立姿态下，个体站立时双脚分开与肩同宽。在隆伯格会议期间，他们站在一起，双脚并拢。在打圈的过程中，参与者站立时双脚分开与肩同宽，并以打圈的方式摆动。对于每种姿势，检查了他们在中外侧（ML）和前后（AP）方向上的压力中心（COP）的标准偏差（SD）和COP轨迹长度。我们还评估了互信息（MI），或ML和AP方向上COP之间的共享依赖关系。参与者还完成了一项踩踏任务，其中他们从一个部队平台前进到了一个相邻平台。检查初始姿势调整（APA）的幅度和持续时间，以及初始步骤后COP调整的最大横向摆动，持续时间和速度。我们使用高度作为协变量的单独单向ANCOVA检查了步进变量。使用Spearman相关性与自闭症诊断观察时间表第二版（ADOS-2）和自闭症诊断访谈修订版（ADI-R）上的评分，评估姿势控制和踩踏措施与ASD症状严重程度之间的关系。结果相对于TD对照，患有ASD的个体表现出跨姿势条件的COP轨迹长度增加（p = 0.05），并且在圆周摆动过程中MI降低（p = 0.02）。在踏步过程中，各组的APA振幅（p = 0.97）或持续时间（p = 0.41）并无差异，但是在初始步骤中，患有ASD的个体表现出ML摇摆减少（p = 0.06），身体转移持续时间减少（p <0.01 ），并且与对照组相比，身体转移速度有所提高（p = 0.02）。更大的中立立场COPML变化（r = 0.55，p = 0.02）和减小的侧摆（r =-0.55，p = 0）。02）在ASD参与者中，踏步与更严重的受限和重复行为相关。结论我们发现，患有ASD的个体在圆形摇摆过程中MI降低，提示在动态姿势调整过程中有效协调关节运动的能力降低。此外，患有ASD的人在踩踏时表现出横向摇摆减小的现象，这表明运动僵硬可能会干扰平衡和步态。姿势控制和步态缺陷与ASD患者的重复行为有关，表明ASD的运动僵硬和关键临床问题可能代表重叠的病理过程。结论我们发现，患有ASD的个体在圆形摇摆过程中MI降低，提示在动态姿势调整过程中有效协调关节运动的能力降低。此外，患有ASD的人在踩踏时表现出减小的侧向摇摆，这表明运动僵硬可能会干扰平衡和步态。姿势控制和步态缺陷与ASD患者的重复行为有关，表明ASD的运动僵硬和关键临床问题可能代表重叠的病理过程。结论我们发现，患有ASD的个体在圆形摇摆过程中MI降低，提示在动态姿势调整过程中有效协调关节运动的能力降低。此外，患有ASD的人在踩踏时表现出减小的侧向摇摆，这表明运动僵硬可能会干扰平衡和步态。姿势控制和步态缺陷与ASD患者的重复行为有关，表明ASD的运动僵硬和关键临床问题可能代表重叠的病理过程。