Background Studies on short-term upright quiet standing tasks have presented contradictory findings about postural control in people with Parkinson’s disease (pwPD). Prolonged trial durations might better depict body sway and discriminate pwPD and controls. Objective The aim of this study was to investigate postural control in pwPD during a prolonged standing task. Methods A total of 26 pwPD and 25 neurologically healthy individuals performed 3 quiet standing trials (60 s) before completing a constrained prolonged standing task for 15 minutes. Motion capture was used to record body sway (Vicon, 100 Hz). To investigate the body sway behavior during the 15 minutes of standing, the analysis was divided into three 5-minute-long phases: early, middle, and late. The following body sway parameters were calculated for the anterior-posterior (AP) and medial-lateral (ML) directions: velocity, root-mean-square, and detrended fluctuations analysis (DFA). The body sway area was also calculated. Two-way ANOVAs (group and phases) and 1-way ANOVA (group) were used to compare these parameters for the prolonged standing and quiet standing, respectively. Results pwPD presented smaller sway area (P < .001), less complexity (DFA; AP: P < .009; ML: P < .01), and faster velocity (AP: P < .002; ML: P < .001) of body sway compared with the control group during the prolonged standing task. Although the groups swayed similarly (no difference for sway area) during quiet standing, they presented differences in sway area during the prolonged standing task (P < .001). Conclusions Prolonged standing task reduced adaptability of the postural control system in pwPD. In addition, the prolonged standing task may better analyze the adaptability of the postural control system in pwPD.

中文翻译：

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长时间站立任务影响帕金森病患者姿势控制的适应性

对短期直立安静站立任务的背景研究提出了关于帕金森病 (pwPD) 患者姿势控制的矛盾发现。延长试验时间可能更好地描述身体摇摆并区分 pwPD 和对照。目的 本研究的目的是调查长时间站立任务期间 pwPD 的姿势控制。方法 共有 26 名 pwPD 和 25 名神经系统健康个体在完成 15 分钟受限的长时间站立任务之前进行了 3 次安静的站立试验（60 秒）。动作捕捉用于记录身体摇摆（Vicon，100 Hz）。为了研究站立 15 分钟内的身体摇摆行为，分析分为三个 5 分钟长的阶段：早期、中期和晚期。计算了前后 (AP) 和内外侧 (ML) 方向的以下身体摇摆参数：速度、均方根和去趋势波动分析 (DFA)。还计算了身体摇摆面积。使用双向方差分析（组和阶段）和单向方差分析（组）分别比较长时间站立和安静站立的这些参数。结果 pwPD 显示出更小的摇摆区域 (P < .001)、更小的复杂性 (DFA；AP：P < .009；ML：P < .01) 和更快的速度 (AP：P < .002；ML：P < .001 ) 在长时间站立任务期间与对照组相比身体摇摆。尽管各组在安静站立时摇摆相似（摇摆面积没有差异），但在长时间站立任务期间，他们的摇摆面积存在差异（P < .001）。结论 长时间站立任务降低了 pwPD 姿势控制系统的适应性。此外，长时间站立任务可以更好地分析pwPD中姿势控制系统的适应性。