This study aimed to examine the effects of age and the task difficulty on postural sway, variability and complexity. The participants were 90 able-bodied individuals from children (n = 39; age: 5.89 ± 0.94 years), young adults (n = 30; age: 23.23 ± 1.61 years) and older adults (n = 21; age: 64.59 ± 5.24 years) that took part in different balance tasks that were had different levels of cognitive and physical challenges. The main dependent variables were postural sway area, postural variability and postural complexity. The participants stood on a standard force plate for 10 seconds in each task condition, and the centre of pressure displacement was collected at 100 sampling frequency. The results of this study showed that children and older adults, in the more difficult tasks, had greater sway area and complexity and less postural variability. In addition, there was a linear trend in the stability measures as the difficulty of the task was increased. In conclusion, special populations, such as children and older adults, were more sensitive to the balance changes and used active control mechanisms to minimise the risk of losing balance in more challenging conditions.

中文翻译：

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年龄和任务难度对姿势摇摆、可变性和复杂性的影响

本研究旨在检查年龄和任务难度对姿势摇摆、可变性和复杂性的影响。参与者是来自儿童（n = 39；年龄：5.89 ± 0.94 岁）、年轻人（n = 30；年龄：23​​.23 ± 1.61 岁）和老年人（n = 21；年龄：64.59 ± 5.24）的 90 名身体健全的人年），他们参加了不同程度的认知和身体挑战的不同平衡任务。主要因变量是姿势摇摆面积、姿势变异性和姿势复杂性。参与者在每个任务条件下站在标准测力台上 10 秒，并以 100 个采样频率收集压力位移的中心。这项研究的结果表明，在更困难的任务中，儿童和老年人具有更大的摇摆区域和复杂性，并且姿势变异性更小。此外，随着任务难度的增加，稳定性指标呈线性趋势。总之，特殊人群，如儿童和老年人，对平衡变化更敏感，并使用主动控制机制将在更具挑战性的条件下失去平衡的风险降至最低。