Jeyasurya Jeswin, Van der Loos H F Machiel, Hodgson Antony, Croft Elizabeth A
CARIS Laboratory, Department of Mechanical Engineering, Institute for Computing Information and Cognitive Systems, University of British Columbia, Vancouver, British Columbia, Canada.
J Rehabil Res Dev. 2013;50(6):835-44. doi: 10.1682/JRRD.2011.12.0233.
The ability to perform a sit-to-stand (STS) motion is important for ambulatory adults to function independently and maintain daily activities. Roughly 6% of community-dwelling older adults experience significant difficulties with STS, a major risk factor for institutionalization. While mechanical STS assistance can help address this problem, full dependence on STS assistance provided by devices such as lift chairs can lead to atrophy of the leg muscles. We investigated the mechanics of assisted STS motion in order to better understand how load-sharing STS mechanisms may facilitate STS motions while still requiring activation of the leg muscles. Experiments were conducted with 17 nondisabled older adults performing unassisted and assisted STS rises with grab bar, arm, seat, and waist assistance. Each mode of rise was evaluated based on a subject questionnaire and key biomechanical metrics relating to stability, knee effort reduction, and rise trajectory. Results show that the seat- and waist-assist modes provide statistically significant improvements in stability metrics and reductions in required knee torques over unassisted rises and bar assistance. The assists most preferred by the subjects were the seat and bar assists. Overall, our results favor a seat-assisted STS modality for nonclinical applications and indicate further testing of this modality with a clinical population.
对于能够独立行走的成年人来说，完成从坐姿到站姿（STS）的动作能力对于其独立生活和维持日常活动至关重要。大约6%的社区居住老年人在进行STS动作时存在显著困难，这是入住养老院的一个主要风险因素。虽然机械STS辅助可以帮助解决这个问题，但完全依赖升降椅等设备提供的STS辅助可能会导致腿部肌肉萎缩。我们研究了辅助STS动作的力学原理，以便更好地理解负载分担的STS机制如何在仍需要激活腿部肌肉的情况下促进STS动作。对17名无残疾的老年人进行了实验，他们在有扶手、手臂、座椅和腰部辅助的情况下进行无辅助和辅助的STS起身动作。根据受试者问卷以及与稳定性、膝关节用力减少和起身轨迹相关的关键生物力学指标对每种起身方式进行评估。结果表明，与无辅助起身和扶手辅助相比，座椅和腰部辅助模式在稳定性指标方面有统计学上的显著改善，并且所需膝关节扭矩降低。受试者最喜欢的辅助方式是座椅和扶手辅助。总体而言，我们的结果支持在非临床应用中采用座椅辅助的STS方式，并表明需要对该方式在临床人群中进行进一步测试。
