Physical and Virtual Assessment of a Passive Exoskeleton

Spada, Stefania; Ghibaudo, Lidia; Carnazzo, Chiara; Pardo, Massimo Di; Chander, Divyaksh Subhash; Gastaldi, Laura; Cavatorta, Maria Pia

doi:10.1007/978-3-319-96068-5_28

Cited by 18 publications

(14 citation statements)

References 19 publications

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“…The physical augmentation offered by (occupational) exoskeleton use is an innovative solution to control WMSDs, particularly during physically demanding jobs [3], [4]. Lab-based studies have indicated beneficial effects of passive exoskeleton on worker safety and performance, for example, during overhead tasks [5], [6], static trunk bending [7], [8], and repetitive lifting [9], [10]. Further, though limited in quantity and comprehensiveness, several industry pilots have addressed use, acceptance, and effectiveness of passive exoskeletons (e.g., Ford [11], Toyota [12], Boeing [13]).…”

Section: Introductionmentioning

confidence: 99%

Human Gait During Level Walking With an Occupational Whole-Body Powered Exoskeleton: Not Yet a Walk in the Park

et al. 2021

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With rapid advancements in exoskeleton technologies, a whole-body powered exoskeleton (WB-PEXO) for augmenting human physical capacity (a "super-operator") is generating increasing attention as an integral part of Industry 4.0. Our understanding of WB-PEXO use is lagging, however, largely due to the lack of detailed evaluations via human-subjects testing of a WB-PEXO. We examined (independently from the manufacturer of a WB-PEXO) the potential impacts of using a state-of-the-art WB-PEXO prototype (pre-alpha prototype version of the Sarcos Guardian ® XO ® ) on users (n=5) during a common basic activity in the workplace, level walking. With emphasis on "human", impacts of XO use (compared to a no EXO baseline) were assessed in terms of lower limb intersegmental coordination, muscle activity, and postural dynamic stability. A larger variance between participants was observed for intersegmental coordination with XO use, and participants appeared to rely on more hip motions. When using the XO, participants exhibited higher muscle activity levels in the lower limb muscle groups monitored. Further, there was a moderate to high similarity in muscle activity profiles between the XO and no EXO conditions ( !" ( ) = 0.70 − 0.92), yet muscle activity profiles when using the XO were generally time-lagged from those without the XO. We discuss the results within the context of developing a mental model for walking with the XO, and aspects of human-robot interaction such as transparency of the XO and understanding user state and intention. In concluding, we outline several future research topics for occupational WB-PEXO development.INDEX TERMS Gait performance, human-robot interaction, occupational exoskeleton, whole body system.

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Section: Introductionmentioning

confidence: 99%

Human Gait During Level Walking With an Occupational Whole-Body Powered Exoskeleton: Not Yet a Walk in the Park

et al. 2021

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“…Most previous research on lower-limb exoskeleton systems [ 13 , 25 , 33 ] was conducted at work heights of 100–140 cm, considering the reach of the arms, etc. Additionally, the typical work height, including the height of hydroponic cultivation, is reported to be 40 to 140 cm [ 9 , 10 , 11 , 12 , 13 , 14 ]; this presents a burden on the musculoskeletal system during harvesting of red pepper, lettuce, strawberry, and grape crops.…”

Section: Methodsmentioning

confidence: 99%

“…The ball was attached at six different levels, ranging from 40 to 140 cm, at intervals of 20 cm; these distances were chosen considering the height of the harvesting work that causes physical stress and the height that can be reached when wearing the lower extremity exoskeleton (Figure 2). Most previous research on lower-limb exoskeleton systems [13,25,33] was conducted at work heights of 100-140 cm, considering the reach of the arms, etc. Additionally, the typical work height, including the height of hydroponic cultivation, is reported to be 40 to 140 cm [9][10][11][12][13][14]; this presents a burden on the musculoskeletal system during harvesting of red pepper, lettuce, strawberry, and grape crops.…”

Section: Methodsmentioning

confidence: 99%

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

Kong

Park

Cho

et al. 2021

IJERPH

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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.

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“…A (quasi) passive exoskeleton was driven by any type of actuator, but rather applied elastic materials, springs or dampers to store energy harvested by human motion and to use this as required to support a posture or a motion (De Looze et al, 2016). LegX (6.2 kg) (Pillai et al, 2020) and the Chairless Chair (Spada et al, 2018) were passive exoskeletons, which were used to reduce the effort of muscles when the wearer was in a position (e.g., squatting and semisquatting) and they wished to maintain the position for a long time. But the chairless chair required wearers to fix a position by crouching down into the required position and pushing a button.…”

Section: Introductionmentioning

confidence: 99%

A Semi-active Exoskeleton Based on EMGs Reduces Muscle Fatigue When Squatting

Wang

Chen

et al. 2021

Front. Neurorobot.

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In dynamic manufacturing and warehousing environments, the work scene made it impossible for workers to sit, so workers suffer from muscle fatigue of the lower limb caused by standing or squatting for a long period of time. In this paper, a semi-active exoskeleton used to reduce the muscle fatigue of the lower limb was designed and evaluated. (i) Background: The advantages and disadvantages of assistive exoskeletons developed for industrial purposes were introduced. (ii) Simulation: The process of squatting was simulated in the AnyBody.7.1 software, the result showed that muscle activity of the gluteus maximus, rectus femoris, vastus medialis, vastus lateralis, vastus intermedius, and erector spinae increased with increasing of knee flexion angle. (iii) Design: The exoskeleton was designed with three working modes: rigid-support mode, elastic-support mode and follow mode. Rigid-support mode was suitable for scenes where the squatting posture is stable, while elastic-support mode was beneficial for working environments where the height of squatting varied frequently.The working environments were identified intelligently based on the EMGs of the gluteus maximus, and quadriceps, and the motor was controlled to switch the working mode between rigid-support mode and elastic-support mode. In follow mode, the exoskeleton moves freely with users without interfering with activities such as walking, ascending and descending stairs. (iv) Experiments: Three sets of experiments were conducted to evaluate the effect of exoskeleton. Experiment one was conducted to measure the surface electromyography signal (EMGs) in both condition of with and without exoskeleton, the root mean square of EMGs amplitude of soleus, vastus lateralis, vastus medialis, gastrocnemius, vastus intermedius, rectus femoris, gluteus maximus, and erector spinae were reduced by 98.5, 97.89, 80.09, 77.27, 96.73, 94.17, 70.71, and 36.32%, respectively, with the assistance of the exoskeleton. The purpose of experiment two was aimed to measure the plantar pressure with and without exoskeleton. With exoskeleton, the percentage of weight through subject's feet was reduced by 63.94, 64.52, and 65.61% respectively at 60°, 90°, and 120° of knee flexion angle, compared to the condition of without exoskeleton. Experiment three was purposed to measure the metabolic cost at a speed of 4 and 5 km/h with and without exoskeleton. Experiment results showed that the average additional metabolic cost introduced by exoskeleton was 2.525 and 2.85%. It indicated that the exoskeleton would not interfere with the movement of the wearer Seriously in follow mode. (v) Conclusion: The exoskeleton not only effectively reduced muscle fatigue, but also avoided interfering with the free movement of the wearer.

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Physical and Virtual Assessment of a Passive Exoskeleton

Cited by 18 publications

References 19 publications

Human Gait During Level Walking With an Occupational Whole-Body Powered Exoskeleton: Not Yet a Walk in the Park

Human Gait During Level Walking With an Occupational Whole-Body Powered Exoskeleton: Not Yet a Walk in the Park

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

A Semi-active Exoskeleton Based on EMGs Reduces Muscle Fatigue When Squatting

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