Laboratoire IRISSE - EA4075, UFR des Sciences de l'Homme et de l'Environnement, Université de la Réunion, 117 rue du Général Ailleret, 97430 Le Tampon, Ile de la Réunion, France.
Laboratoire IRISSE - EA4075, UFR des Sciences de l'Homme et de l'Environnement, Université de la Réunion, 117 rue du Général Ailleret, 97430 Le Tampon, Ile de la Réunion, France; Le Mans Université, Movement - Interactions - Performance, MIP, EA 4334, F-72000 Le Mans, France.
J Biomech. 2021 Jun 9;122:110436. doi: 10.1016/j.jbiomech.2021.110436. Epub 2021 Apr 18.
Recent evidence suggests that older adults may have difficulty controlling whole-body angular momentum (H) during volitional stepping, which could impose a major challenge for balance control and result in potential falls. However, it is not known if and how H is influenced by speed when stepping. This study aimed to investigate the effect on H of increasing speed during step initiation in older adults. Twenty-seven healthy individuals over 60 were enrolled in the current study and were instructed to perform a series of step initiations with their dominant leg under two speed conditions: at preferred speed and as fast as possible. Two force plates and a motion-capture system were used to record H and the components of the net external moment (moment arms and ground reaction forces) during the double support and step execution phases of stepping. Results revealed that increasing speed of stepping affected H differently in both stepping phases and in the different planes. H ranges in all three planes increased with speed during the double support phase. During the step execution phase, while H ranges in frontal and transversal planes decreased, sagittal plane H range significantly increased with speed. This increased H range in the sagittal plane, which may result from the task demands, could impose a greater challenge for balance control in the elderly.
最近的证据表明，老年人在自主迈步时可能难以控制全身角动量（H），这可能对平衡控制构成重大挑战，并导致潜在的跌倒。然而，目前尚不清楚 H 是否以及如何受到迈步速度的影响。本研究旨在探讨在老年人迈步起始阶段增加速度对 H 的影响。本研究纳入了 27 名 60 岁以上的健康个体，并指导他们在两种速度条件下用优势腿进行一系列迈步起始：以自身偏好的速度和最快速度。使用两个力板和一个运动捕捉系统来记录迈步的双支撑和迈步执行阶段的 H 和净外部力矩（力臂和地面反作用力）的分量。结果表明，增加迈步速度在双支撑阶段和不同平面上对 H 的影响不同。双支撑阶段 H 的范围在所有三个平面上都随速度增加而增加。在迈步执行阶段，虽然额状面和横状面的 H 范围减小，但矢状面的 H 范围随速度显著增加。这种矢状面 H 范围的增加，可能是由于任务要求，可能会给老年人的平衡控制带来更大的挑战。
