The Effects of Passive and Active Back Support Exoskeletons on Endurance,Perceived Exertion,and Back Discomfort During Fatigue-Induced Repetitive Lifting

Abstract

Back-support exoskeletons (BSEs) show promise for mitigating physical strain in industrial settings, yet their effectiveness during fatigue-inducing tasks remains underexplored. This study evaluated the effects of powered and unpowered BSEs on endurance, perceived exertion, and back discomfort during repetitive lifting. Sixteen participants lifted a box (15% body mass) at ~8 lifts/min until exhaustion under three conditions: no exoskeleton, unpowered, and powered. Endurance time (i.e., time-to-fatigue), number of lifting cycles, perceived exertion (RPE), and back discomfort (RPD) were recorded. The powered BSE significantly increased time-to-fatigue (p = .03) and number of lifting cycles (p = .03) compared to control. RPE increased over time across all conditions (p < .001) but was significantly lower with powered versus control (p = .015). The unpowered device showed a non-significant trend toward reduced RPE. Neither device significantly alleviated back-discomfort. These findings suggest powered exoskeletons may better regulate fatigue during repetitive lifting; however, further research should explore long-term biomechanics effects and user adaptation.

Keywords

back-support exoskeleton fatigue repetitive lifting endurance

Get full access to this article

View all access options for this article.

References

Bernardo

Martins

Guedes

(2018, March 26–27). Muscle fatigue assessment in manual handling of loads using motion analysis and accelerometers: A short review [Conference session]. Occupational Safety and Hygiene VI: Proceedings of the 6th International Symposium on Occupation Safety and Hygiene (SHO 2018), Guimaraes, Portugal.

Borg

(1998). Borg’s perceived exertion and pain scales. Human kinetics.

Bosch

van Eck

Knitel

de Looze

(2016). The effects of a passive exoskeleton on muscle activity, discomfort and endurance time in forward bending work. Applied Ergonomics, 54, 212–217.

Coenen

Kingma

Boot

C. R.

Twisk

J. W.

Bongers

P. M.

van Dieën

J. H.

(2013). Cumulative low back load at work as a risk factor of low back pain: A prospective cohort study. Journal of Occupational Rehabilitation, 23, 11–18.

de Looze

M. P.

Bosch

Krause

Stadler

K. S.

O’Sullivan

L. W

. (2016). Exoskeletons for industrial application and their potential effects on physical work load. Ergonomics, 59(5), 671–681.

Dolan

Adams

M. A.

(1998). Repetitive lifting tasks fatigue the back muscles and increase the bending moment acting on the lumbar spine. Journal of Biomechanics, 31(8), 713–721.

GermanBionic. (2024). German Bionic applies Tesla principle: E-exoskeletons obtain more power thanks to wireless software update. https://www.germanbionic.com/news/more-power-thanks-to-wireless-software-update

Kazemi

Mazloumi

Arjmand

Keihani

Karimi

Ghasemi

M. S.

Kordi

(2022). A comprehensive evaluation of spine kinematics, kinetics, and trunk muscle activities during fatigue-induced repetitive lifting. Human Factors, 64, 997–1012.

Kozinc

Ž.

Baltrusch

Houdijk

Šarabon

. (2021). Short-term effects of a passive spinal exoskeleton on functional performance, discomfort and user satisfaction in patients with low back pain. Journal of Occupational Rehabilitation, 31, 142–152.

10.

Kuijt-Evers

L. F.

Bosch

Huysmans

M. A.

de Looze

M. P.

Vink

(2007). Association between objective and subjective measurements of comfort and discomfort in hand tools. Applied Ergonomics, 38(5), 643–654.

11.

Poon

van Engelhoven

Kazerooni

Harris

(2019). Evaluation of a trunk supporting exoskeleton for reducing muscle fatigue. Proceedings of the Human Factors and Ergonomics Society Annual Meeting, 63, 980–983.

12.

Rodzak

K. M.

Slaughter

P. R.

Wolf

D. N.

Ice

C. C.

Fine

S. J.

Zelik

K. E.

(2024). Can back exosuits simultaneously increase lifting endurance and reduce musculoskeletal disorder risk? Wearable Technologies, 5, e17.

13.

B. C. L.

Hua

Chen

Gao

Man

S. S.

(2022). Biomechanical assessment of a passive back-support exoskeleton during repetitive lifting and carrying: Muscle activity, kinematics, and physical capacity. Journal of Safety Research, 83, 210–222.

14.

Srinivasan

Mathiassen

S. E.

(2012). Motor variability in occupational health and performance. Clinical Biomechanics, 27(10), 979–993.

15.

Tan

C. K.

Kadone

Miura

Abe

Koda

Yamazaki

Sankai

Suzuki

(2019). Muscle synergies during repetitive stoop lifting with a bioelectrically-controlled lumbar support exoskeleton. Frontiers in Human Neuroscience, 13, 142.

16.

Zelik

K. E.

Nurse

C. A.

Schall

M. C.

Jr Sesek

R. F.

Marino

M. C.

Gallagher

(2022). An ergonomic assessment tool for evaluating the effect of back exoskeletons on injury risk. Applied Ergonomics, 99, 103619.