Neuromotor Rehabilitation Research Group, Department of Rehabilitation Sciences, KU Leuven, Leuven, Belgium.
Neuromotor Rehabilitation Research Group, Department of Rehabilitation Sciences, KU Leuven, Leuven, Belgium.
Exp Gerontol. 2023 Oct 1;181:112271. doi: 10.1016/j.exger.2023.112271. Epub 2023 Aug 26.
Postural control deteriorates with age, especially under dual-task conditions. It is currently unknown how a challenging virtual reality weight-shifting task affects lower back muscle activity. Hence, this study investigated erector spinae neuromuscular control during mediolateral weight-shifting as part of an exergame during single- (ST) and dual-task (DT) conditions in young and older adults.
Seventeen young and 17 older adults performed mediolateral weight-shifts while hitting virtual wasps in a virtual environment with and without a serial subtraction task (DT). Center of mass position was recorded in real-time using 3D motion capturing. Electromyography recorded bilateral activation of the lumbar longissimus and iliocostalis muscles.
Weight-shifting (p < 0.03) and targeting the wasps (p < 0.005) deteriorated with age and DT. Relative muscle activation during both quiet stance and weight-shifting increased with age, while the DT-effect did not differ consistently between age-groups. However, bilateral muscle co-contraction decreased with DT in young adults only. When switching direction and targeting the wasps, variability of muscle activation increased with age and DT and proved related to worse targeting performance. These effects were mainly visible at the non-dominant body side.
Older adults showed a higher erector spinae muscle contribution to perform weight-shifts with increased variability at the end of a shift, whereby muscle activity was modulated less well in older than in young adults in response to DT. Hence, the current findings point to the potential for developing postural training in which older adults learn to fine-tune trunk muscle activity to improve weight-shifting and reduce fall risk.
姿势控制随着年龄的增长而恶化，尤其是在双重任务条件下。目前尚不清楚具有挑战性的虚拟现实重量转移任务如何影响下背部肌肉活动。因此，本研究调查了在单任务（ST）和双重任务（DT）条件下，年轻人和老年人在进行侧向重量转移时竖脊肌的神经肌肉控制，这是一种外游戏的一部分。
17 名年轻和 17 名年长成年人在虚拟环境中进行侧向重量转移，同时击打虚拟黄蜂，环境中有无连续减法任务（DT）。使用 3D 运动捕捉实时记录质心位置。肌电图记录了腰椎最长肌和髂肋肌的双侧激活。
重量转移（p<0.03）和靶向黄蜂（p<0.005）随着年龄和 DT 的增加而恶化。在安静站立和重量转移期间，相对肌肉激活随着年龄的增长而增加，而 DT 效应在不同年龄组之间没有一致的差异。然而，只有年轻人的双侧肌肉协同收缩随着 DT 的增加而减少。当切换方向并靶向黄蜂时，肌肉激活的变异性随着年龄和 DT 的增加而增加，并且与更差的靶向性能相关。这些影响主要在非优势侧身体上可见。
老年人在进行重量转移时表现出更高的竖脊肌肌肉贡献，并且在转移结束时变异性增加，在 DT 下，老年人的肌肉活动调节不如年轻人好。因此，目前的研究结果表明，有可能开发出一种姿势训练，老年人可以通过微调躯干肌肉活动来提高重量转移并降低跌倒风险。
