# Verification of Industrial Worker Walking Efficiency with Wearable Hip Exoskeleton
## 5 Conclusions  
In this study, we verified the walking efficiency of an ultralight wearable hip exoskeleton. Treadmill walking and stairway ascension were tested in 10 healthy adult men, and the lower-limb muscle activity, fatigue, and energy expenditure were analyzed.  
The results showed that muscle fatigue of the GCM, oxygen uptake, EEM, total EEM, and net EEM were significantly reduced during treadmill walking while wearing the exoskeleton. In addition, when climbing stairs, the average muscle activities of the RF, ST, and GCM and muscle fatigue of the TA were significantly reduced, and a significant decrease in metabolic energy, including oxygen uptake, EEM, net EEM, and heart rate, was confirmed. This confirmed the efficiency of the hip exoskeleton device.  
The hip exoskeleton is expected to be effective in reducing lower-limb muscle fatigue and to lead to efficient energy metabolism in healthy male adults in an industrial setting.  
Although the average values of some results in this study differed greatly, that statistical significance could not be confirmed because of the large differences between individuals is a limitation of this study. In the future, we plan to supplement our study by expanding the number of subjects, verifying gender differences, and evaluating usability in terms of performance, portability, and convenience.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline  & **Type** & **Weight** & \
\begin{tabular}{c} **Test** \\ **Environment** \\ \end{tabular} &
\begin{tabular}{c} **Metabolic** \\ **Reduction** \\ \end{tabular} \\ \hline [PERSON] et al. (2022) [9] & Soft & 2.31 kg & Level ground & 7.2\% \\ \hline [PERSON] et al. (2017) [13] & Rigid & 2.8 kg & Level ground & 6.6\% \\ \hline [PERSON] et al. (2018) [14] & Rigid & 2.8 kg & Up stairs & 10.16\% \\ \hline WIM in this study & Soft and rigid & 1.4 kg & Level ground & 7.4\% \\ \hline WIM in this study & Soft and rigid & 1.4 kg & Up stairs & 12.9\% \\ \hline \hline \end{tabular}
\end{table}
Table 6: Comparison of energy metabolism reduction rates between products with similar performance.  
We hope that the results of this study will be used as basic data to improve the performance of hip-assistive devices, and they can also be presented as validation data to expand the use of wearable exoskeletons to industrial applications.  
Conceptualization, Y.C.; methodology, J.K.; software, B.L.; validation, Y.C., J.K. and B.J.; formal analysis, J.K.; investigation, G.K. and B.C.; resources, Y.L.; data curation, Y.C.; writing--original draft preparation, Y.C.; writing--review and editing, Y.C.; visualization, B.J.; supervision, Y.C.; project administration, G.K.; funding acquisition, Y.L. All authors have read and agreed to the published version of the manuscript.  
This research was conducted with the support of the customized service robot development and distribution project funded by the Korea Institute for Robot Industry Advancement, grant number 2022-05081-3.  
This study was conducted in accordance with the Declaration of Helsinki, and approved by the Institutional Bioethics Committee of the Rehabilitation Engineering Research Institute of the Korea Workers' Compensation and Welfare Service (31 March 2023, RERI-IRB-230331-2). The purpose and process of the experiment were explained to all the participants, and voluntary written consent was obtained from the patients to publish this paper.  
Informed Consent Statement: Informed consent was obtained from all subjects involved in the study.  
Data are contained within the article.  
Authors [PERSON], [PERSON] and [PERSON] were employed by the company Wirobotics Incorporation. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.