Guidelines for Working Heights of the Lower-Limb Exoskeleton (CEX) Based on Ergonomic Evaluations

Yong-Ku Kong, Chae-Won Park, Min-Uk Cho, Seoung-Yeon Kim, Min-Jung Kim, Dong Jin Hyun, Kihyeon Bae, Jong Kyu Choi, Sang Min Ko and Kyeong-Hee Choi
Additional contact information
Yong-Ku Kong: Department of Industrial Engineering, Sungkyunkwan University, Suwon 16419, Korea
Chae-Won Park: Department of Industrial Engineering, Sungkyunkwan University, Suwon 16419, Korea
Min-Uk Cho: Department of Industrial Engineering, Sungkyunkwan University, Suwon 16419, Korea
Seoung-Yeon Kim: Department of Industrial Engineering, Sungkyunkwan University, Suwon 16419, Korea
Min-Jung Kim: Department of Industrial Engineering, Sungkyunkwan University, Suwon 16419, Korea
Dong Jin Hyun: Robotics Lab in the R&D Division, Hyundai Motor Company, Uiwang 16082, Korea
Kihyeon Bae: Robotics Lab in the R&D Division, Hyundai Motor Company, Uiwang 16082, Korea
Jong Kyu Choi: Robotics Lab in the R&D Division, Hyundai Motor Company, Uiwang 16082, Korea
Sang Min Ko: Robotics Lab in the R&D Division, Hyundai Motor Company, Uiwang 16082, Korea
Kyeong-Hee Choi: Department of Industrial Engineering, Sungkyunkwan University, Suwon 16419, Korea

IJERPH, 2021, vol. 18, issue 10, 1-12

Abstract: The aim of this study was to evaluate the muscle activities and subjective discomfort according to the heights of tasks and the lower-limb exoskeleton CEX (Chairless EXoskeleton), which is a chair-type passive exoskeleton. Twenty healthy subjects (thirteen males and seven females) participated in this experiment. The independent variables were wearing of the exoskeleton (w/ CEX, w/o CEX), working height (6 levels: 40, 60, 80, 100, 120, and 140 cm), and muscle type (8 levels: upper trapezius (UT), erector spinae (ES), middle deltoid (MD), triceps brachii (TB), biceps brachii (BB), biceps femoris (BF), rectus femoris (RF), and tibialis anterior (TA)). The dependent variables were EMG activity (% MVC) and subjective discomfort rating. When wearing the CEX, the UT, ES, RF, and TA showed lower muscle activities at low working heights (40–80 cm) than not wearing the CEX, whereas those muscles showed higher muscle activities at high working heights (100–140 cm). Use of the CEX had a positive effect on subjective discomfort rating at lower working heights. Generally, lower discomfort was reported at working heights below 100 cm when using the CEX. At working heights of 100–140 cm, the muscle activity when wearing the CEX tended to be greater than when not wearing it. Thus, considering the results of this study, the use of the lower-limb exoskeleton (CEX) at a working height of 40–100 cm might reduce the muscle activity and discomfort of whole body and decrease the risk of related disorders.

Keywords: lower-limb exoskeleton; CEX; working height; harvesting task; work-related musculoskeletal disorders (search for similar items in EconPapers)
JEL-codes: I I1 I3 Q Q5 (search for similar items in EconPapers)
Date: 2021
References: View complete reference list from CitEc
Citations: View citations in EconPapers (3)

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