Varying negative work assistance at the ankle with a soft exosuit during loaded walking.
Varying negative work assistance at the ankle with a soft exosuit during loaded walking.
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DOI：
10.1186/s12984-017-0267-5
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发表时间：
2017-06-26
影响因子：
5.1
通讯作者：
Walsh CJ
中科院分区：
文献类型：
--
作者：
Malcolm P;Lee S;Crea S;Siviy C;Saucedo F;Galiana I;Panizzolo FA;Holt KG;Walsh CJ
直到最近，研究表明，使用机器人踝关节外骨骼可以降低空载和负重行走的代谢率。有些研究是通过高积极工作协助获得这一结果，而有些研究则是将消极工作协助和积极工作协助结合起来。对于消极工作援助的孤立作用，没有达成共识。因此，本研究的目的是检查在踝关节处变化的负功辅助的效果，同时用多关节软外装护具保持固定水平的正功辅助。我们测试了8名参与者在1.5 ms-1的步行过程中背着23 kg的背包。参与者穿着一种外装护具，通过系在车外驱动平台上的鲍登电缆来辅助跖屈。在四种活动条件下，我们提供了不同比率的外装服双侧踝关节负功辅助，范围从0.015到0.037 W kg−1，以及固定比率的正功辅助，为0.19 W kg−1。与参比条件相比，所有活动条件均显着降低了11%至15%的代谢率，其中参与者穿着外装但没有提供帮助。我们没有发现消极工作援助的显著影响。然而，有一种趋势（p = 0.08），随着负功辅助的增加，代谢率降低幅度更大，这可以通过观察到的生物踝关节和髋关节动力和力矩的降低来解释。随着代谢率的降低，负性工作辅助的增加呈非显著趋势，这激发了进一步研究负性和正性工作辅助的相对影响的价值。在更大范围内改变消极工作或将其与积极工作援助分开可能会有好处。本文的在线版本（doi：10.1186/s12984-017-0267-5）包含补充材料，可供授权用户使用。
Only very recently, studies have shown that it is possible to reduce the metabolic rate of unloaded and loaded walking using robotic ankle exoskeletons. Some studies obtained this result by means of high positive work assistance while others combined negative and positive work assistance. There is no consensus about the isolated contribution of negative work assistance. Therefore, the aim of the present study is to examine the effect of varying negative work assistance at the ankle joint while maintaining a fixed level of positive work assistance with a multi-articular soft exosuit. We tested eight participants during walking at 1.5 ms−1 with a 23-kg backpack. Participants wore a version of the exosuit that assisted plantarflexion via Bowden cables tethered to an off-board actuation platform. In four active conditions we provided different rates of exosuit bilateral ankle negative work assistance ranging from 0.015 to 0.037 W kg−1 and a fixed rate of positive work assistance of 0.19 W kg−1. All active conditions significantly reduced metabolic rate by 11 to 15% compared to a reference condition, where the participants wore the exosuit but no assistance was provided. We found no significant effect of negative work assistance. However, there was a trend (p = .08) toward greater reduction in metabolic rate with increasing negative work assistance, which could be explained by observed reductions in biological ankle and hip joint power and moment. The non-significant trend of increasing negative work assistance with increasing reductions in metabolic rate motivates the value in further studies on the relative effects of negative and positive work assistance. There may be benefit in varying negative work over a greater range or in isolation from positive work assistance. The online version of this article (doi:10.1186/s12984-017-0267-5) contains supplementary material, which is available to authorized users.