Graduate School of Science and Engineering, Chiba University, Chiba, Japan.
Department of Human Science, Faculty of Design, Kyushu University, Fukuoka, Japan.
PLoS One. 2021 Jan 7;16(1):e0245049. doi: 10.1371/journal.pone.0245049. eCollection 2021.
Most research on power assist suits (PASs) that concerned PAS-human interactions has used human physical reactions as criteria to evaluate the mechanical function, however, with minimal emphasis on human reactions in response to PASs. In this study, we focused on the physiological responses of the upper limbs including muscle activity of the biceps brachii and the triceps brachii, co-activation, force steadiness (CV) and rated perceived exertion (RPE) to various patterns of bilateral assistive force, such as unilateral assistance (L0% & R67% [% = percentage of workload force, L = left arm, R = right arm], L67% & R0%, L0% & R33%, L33% & R0%), symmetrical (L0% & R0%, L33% & R33%, L67% & R67%) and asymmetrical bilateral assistance (L33% & R67%, L67% & R33%), during bilateral isometric force-matching tasks. The results showed a similar muscular response of the two arms to bilateral assistive conditions, and the muscle activity of the arm that was being observed decreased only when the assistive force that applied on itself increased, indicating that both arms may have adopted similar but independent motor control mechanisms to acclimate to the bilateral assistive forces. Comparison between the two unilateral assistances (L0% & R33% and L33% & R0%) and the two asymmetrical bilateral assistances (L33% & R67%, L67% & R33%) showed no significant differences in muscular responses, CV and RPE, indicating that bilateral assistances with bilateral interchanged assistive levels may be equally effective regardless of which arm the higher assistive force is applied to. Comparison between unilateral and symmetrical assistive conditions that have similar overall workloads (L67% & R0%, L33% & R33%, L0% & R67%) showed a lower CV and RPE score at symmetrical assistance compared with unilateral assistance, suggesting that assisting both arms with the same level simultaneously improves task performances compared with applying the assistive force to only one arm.
大多数关于助力服（PAS）与人体相互作用的研究都使用人体的物理反应作为评估机械功能的标准，但很少关注人体对助力服的反应。在这项研究中，我们专注于上肢的生理反应，包括肱二头肌和肱三头肌的肌肉活动、共激活、力稳定性（CV）和主观用力感觉（RPE）对各种双侧助力模式的反应，例如单侧助力（L0%和 R67%[%=工作负荷力的百分比，L=左臂，R=右臂]、L67%和 R0%、L0%和 R33%、L33%和 R0%）、对称（L0%和 R0%、L33%和 R33%、L67%和 R67%）和不对称双侧助力（L33%和 R67%、L67%和 R33%），在双侧等长力量匹配任务中。结果表明，双臂对双侧助力条件的肌肉反应相似，当施加在自身上的辅助力增加时，被观察到的手臂的肌肉活动仅会减少，这表明双臂可能采用了相似但独立的运动控制机制来适应双侧辅助力。两种单侧助力（L0%和 R33%和 L33%和 R0%）和两种不对称双侧助力（L33%和 R67%、L67%和 R33%）之间的比较表明，肌肉反应、CV 和 RPE 没有显著差异，这表明无论哪只手臂施加更高的辅助力，双侧辅助力的双侧交互辅助水平可能同样有效。单侧和具有相似总工作量的对称辅助条件（L67%和 R0%、L33%和 R33%、L0%和 R67%）之间的比较表明，与单侧辅助相比，对称辅助的 CV 和 RPE 评分较低，这表明同时用相同水平辅助双臂可以提高与仅应用辅助力到一只手臂相比的任务表现。
