Krafft F C, Herzog M, Stein T, Sloot L H
Optimization, Robotics, and Biomechanics (ORB), Institute of Technical Engineering (ZITI), Heidelberg University, Heidelberg, Germany.
HEiKA-Heidelberg Karlsruhe Strategic Partnership, Karlsruhe Institute of Technology (KIT), Heidelberg University, Heidelberg, Germany.
Front Bioeng Biotechnol. 2022 Jul 11;10:876349. doi: 10.3389/fbioe.2022.876349. eCollection 2022.
Four-wheeled walkers or rollators are often used to assist older individuals in maintaining an independent life by compensating for muscle weakness and reduced movement stability. However, limited biomechanical studies have been performed to understand how rollator support affects posture and stability, especially when standing up and sitting down. Therefore, this study examined how stability and posture change with varying levels of rollator support and on an unstable floor. The aim was to collect comprehensive baseline data during standing up and sitting down in young participants. In this study, 20 able-bodied, young participants stood up and sat down both 1) unassisted and assisted using a custom-made robot rollator simulator under 2) full support and 3) touch support. Unassisted and assisted performances were analyzed on normal and unstable floors using balance pads with a compliant surface under each foot. Using 3D motion capturing and two ground-embedded force plates, we compared assistive support and floor conditions for movement duration, the relative timing of seat-off, movement stability (center of pressure (COP) path length and sway area), and posture after standing up (lower body sagittal joint angles) using ANOVA analysis. The relative event of seat-off was earliest under full support compared to touch and unassisted conditions under normal but not under unstable floor conditions. The duration of standing up and sitting down did not differ between support conditions on normal or unstable floors. COP path length and sway area during both standing up and sitting down were lowest under full support regardless of both floor conditions. Hip and knee joints were least flexed under full support, with no differences between touch and unassisted in both floor conditions. Hence, full rollator support led to increased movement stability, while not slowing down the movement, during both standing up and sitting down. During standing up, the full support led to an earlier seat-off and a more upright standing posture when reaching a stable stance. These results indicate that rollator support when handles are correctly aligned does not lead to the detrimental movement alterations of increased forward-leaning. Future research aims to verify these findings in older persons with stability and muscle weakness deficiencies.
四轮助行器或滚动助行器通常用于帮助老年人维持独立生活，以弥补肌肉无力和运动稳定性下降的问题。然而，为了解滚动助行器的支撑如何影响姿势和稳定性，尤其是在起身和坐下时，所进行的生物力学研究有限。因此，本研究考察了在不稳定地面上，随着滚动助行器支撑程度的变化，稳定性和姿势是如何改变的。目的是收集年轻参与者在起身和坐下过程中的全面基线数据。在本研究中，20名身体健全的年轻参与者在以下两种情况下起身和坐下：1）无辅助，以及2）使用定制的机器人滚动助行器模拟器在完全支撑和3）轻触支撑下进行辅助。在正常和不稳定地面上，使用每只脚下带有柔性表面的平衡垫，分析无辅助和辅助情况下的表现。使用3D运动捕捉和两个地面嵌入式测力板，我们通过方差分析比较了辅助支撑和地面条件对运动持续时间、离座相对时间、运动稳定性（压力中心（COP）路径长度和摆动面积）以及起身姿势（下半身矢状关节角度）的影响。与轻触和无辅助条件相比，在正常地面而非不稳定地面条件下，完全支撑下离座的相对事件最早。在正常或不稳定地面上，不同支撑条件下起身和坐下的持续时间没有差异。无论地面条件如何，在完全支撑下，起身和坐下过程中的COP路径长度和摆动面积最小。在完全支撑下，髋部和膝关节的弯曲程度最小，在两种地面条件下，轻触支撑和无辅助支撑之间没有差异。因此，在起身和坐下过程中，完全的滚动助行器支撑可提高运动稳定性，同时不会减慢运动速度。在起身过程中，完全支撑会导致更早离座，并在达到稳定姿势时站立得更直。这些结果表明当把手正确对齐时，滚动助行器支撑不会导致向前倾增加等有害的运动改变。未来的研究旨在验证这些在稳定性和肌肉无力方面存在缺陷的老年人中的发现。
