Skip to main content
Key Specialties
Cardiology Diabetology Endocrinology Gastroenterology Geriatrics and Gerontology Gynecology and Obstetrics Hematology Infectious Disease Internal Medicine Nephrology Neurology Oncology Pediatrics Respiratory Medicine Rheumatology Surgery
Congress Coverage
2024 ACC Congress 2023 ESMO Congress 2023 EASD Congress 2023 ERS Congress 2023 ESC Congress
Clinical Collections
Advances in Alzheimer’s

At a glance: The ONWARDS insulin icodec trials

A round-up of the ONWARDS phase 3 clinical trials evaluating the novel weekly insulin icodec in people with diabetes.
ADVANCED SEARCH
Log in
Top
Journal of NeuroEngineering and Rehabilitation
Published in: Journal of NeuroEngineering and Rehabilitation 1/2018

Open Access 01-12-2018 | Research

Exoskeleton assistance symmetry matters: unilateral assistance reduces metabolic cost, but relatively less than bilateral assistance

Authors: Philippe Malcolm, Samuel Galle, Pieter Van den Berghe, Dirk De Clercq

Published in: Journal of NeuroEngineering and Rehabilitation | Issue 1/2018

Login to get access

Abstract

Background

Many gait impairments are characterized by asymmetry and result in reduced mobility. Exoskeletons could be useful for restoring gait symmetry by assisting only one leg. However, we still have limited understanding of the effects of unilateral exoskeleton assistance. Our aim was to compare the effects of unilateral and bilateral assistance using a within-subject study design.

Methods

Eleven participants walked in different exoskeleton conditions. In the Unilateral conditions, only one leg was assisted. In Bilateral Matched Total Work, half of the assistance from the Unilateral conditions was applied to both legs such that the bilateral sum was equal to that of the Unilateral conditions. In Bilateral Matched Work Per Leg, the same assistance as in the Unilateral conditions was provided to both legs such that the bilateral sum was the double of that of the Unilateral conditions. In the Powered-Off condition, no assistance was provided. We measured metabolic energy consumption, exoskeleton mechanics and kinematics.

Results

On average, the Unilateral, Bilateral Matched Total Work and Bilateral Matched Work Per Leg conditions reduced the metabolic rate by 7, 11 and 15%, respectively, compared with the Powered-Off condition. A possible explanation for why the Unilateral conditions effectively reduced the metabolic rate could be that they caused only very little asymmetry in gait biomechanics, except at the ankle and in the horizontal center-of-mass velocity. We found the highest ratio of metabolic rate reduction versus positive work assistance with bilateral assistance and low work per leg (Bilateral Matched Total Work). Statistical analysis indicated that assistance symmetry and assistance per leg are more important than the bilateral summed assistance for reducing the metabolic rate of walking.

Conclusions

These data bridge the gap between conclusions from studies with unilateral and bilateral exoskeletons and inform how unilateral assistance can be used to influence gait parameters, such as center-of-mass velocity.
Appendix
Available only for authorised users
Literature
1.
Hsiao-Wecksler ET, Polk JD, Rosengren KS, Sosnoff JJ, Hong S. A review of new analytic techniques for quantifying symmetry in locomotion. Symmetry (Basel). 2010;2:1135–55.CrossRef
2.
Sadeghi H, Allard P, Prince F, Labelle H. Symmetry and limb dominance in able-bodied gait: a review. Gait Posture. 2000;12:34–45.CrossRefPubMed
3.
4.
Adamczyk PG, Kuo AD. Mechanisms of gait asymmetry due to push-off deficiency in unilateral amputees. IEEE Trans Neural Syst Rehabil Eng. 2015;23:776–85.CrossRefPubMed
5.
Allen JL, Kautz SA, Neptune RR. Step length asymmetry is representative of compensatory mechanisms used in post-stroke hemiparetic walking. Gait Posture. 2011;33:538–43.CrossRefPubMedPubMedCentral
6.
Balasubramanian CK, Bowden MG, Neptune RR, Kautz SA. Relationship between step length asymmetry and walking performance in subjects with chronic hemiparesis. Arch Phys Med Rehabil. 2007;88:43–9.CrossRefPubMed
7.
Roerdink M, Beek PJ. Understanding inconsistent step-length asymmetries across hemiplegic stroke patients: impairments and compensatory gait. Neurorehabil Neural Repair. 2011;25:253–8.CrossRefPubMed
8.
Farris DJ, Hampton A, Lewek MD, Sawicki GS. Revisiting the mechanics and energetics of walking in individuals with chronic hemiparesis following stroke : from individual limbs to lower limb joints. J. Neuroeng. Rehabil. 2015;12:1–12.CrossRef
9.
Mahon CE, Farris DJ, Sawicki GS, Lewek MD. Individual limb mechanical analysis of gait following stroke. J Biomech. 2015;48:984–9.CrossRefPubMed
10.
Kobayashi H, Kakihana W, Kimura T. Combined effects of age and gender on gait symmetry and regularity assessed by autocorrelation of trunk acceleration. J. Neuroeng. Rehabil. 2014;11:109.CrossRefPubMedPubMedCentral
11.
Wutzke CJ, Sawicki GS, Lewek MD. The influence of a unilateral fixed ankle on metabolic and mechanical demands during walking in unimpaired young adults. J Biomech. 2012;45:2405–10.CrossRefPubMed
12.
Hesse S, Werner C, Bardeleben A, Barbeau H. Body weight-supported treadmill training after stroke. Curr Atheroscler Rep. 2001;3:287–94.CrossRefPubMed
13.
Tyson SF, Kent RM. Effects of an ankle-foot orthosis on balance and walking after stroke: a systematic review and pooled meta-analysis. Arch Phys Med Rehabil. 2013;94:1377–85.CrossRefPubMed
14.
Herr HM, Grabowski AM. Bionic ankle-foot prosthesis normalizes walking gait for persons with leg amputation. Proc Biol Sci. 2012;279:457–64.CrossRefPubMed
15.
Reisman DS, Wityk R, Silver K, Bastian AJ. Locomotor adaptation on a split-belt treadmill can improve walking symmetry post-stroke. Brain. 2007;130:1861–72.CrossRefPubMedPubMedCentral
16.
Finley JM, Long A, Bastian AJ, Torres-Oviedo G. Spatial and temporal control contribute to step length asymmetry during Split-Belt adaptation and Hemiparetic gait. Neurorehabil Neural Repair. 2015.
17.
Regnaux JP, Pradon D, Roche N, Robertson J, Bussel B, Dobkin B. Effects of loading the unaffected limb for one session of locomotor training on laboratory measures of gait in stroke. Clin Biomech. 2008;23:762–8.CrossRef
18.
Veneman JF. Emerging directions in lower limb externally wearable robots. Front Inf Technol Electron Eng. 2016;9184:1–8.
19.
Lin PY, Yang YR, Cheng SJ, Wang RY. The relation between ankle impairments and gait velocity and symmetry in people with stroke. Arch Phys Med Rehabil. 2006;87:562–8.CrossRefPubMed
20.
Awad LN, Bae J, O’Donnell K, De Rossi SMM, Hendron K, Sloot LH, et al. A soft robotic exosuit improves walking in patients after stroke. Sci Transl Med. 2017;9.
21.
Takahashi KZ, Lewek MD, Sawicki GS. A neuromechanics-based powered ankle exoskeleton to assist walking post-stroke: a feasibility study. J. Neuroeng. Rehabil. 2015;12:23.CrossRefPubMedPubMedCentral
22.
23.
Ding Y, Panizzolo FA, Siviy CJ, Malcolm P, Galiana I, Holt KG, et al. Effect of timing of hip extension assistance during loaded walking with a soft exosuit. J Neuroeng Rehabil. 2016;13:87.CrossRefPubMedPubMedCentral
24.
Galle S, Malcolm P, Collins SH, De Clercq D. Reducing the metabolic cost of walking with an ankle exoskeleton: interaction between actuation timing and power. J. Neuroeng. Rehabil. 2017;14:35.CrossRefPubMedPubMedCentral
25.
26.
Malcolm P, Derave W, Galle S, De Clercq D. A simple exoskeleton that assists plantarflexion can reduce the metabolic cost of human walking. PLoS One. 2013;8:e56137.CrossRefPubMedPubMedCentral
27.
28.
Quinlivan BT, Lee S, Malcolm P, Rossi DM, Grimmer M, Siviy C, et al. Assistance magnitude versus metabolic cost reductions for a tethered multiarticular soft exosuit. Sci Robot. 2017;2:eaah4416.CrossRef
29.
Panizzolo FA, Galiana I, Asbeck AT, Siviy C, Schmidt K, Holt KG, et al. A biologically-inspired multi-joint soft exosuit that can reduce the energy cost of loaded walking. J Neuroeng Rehabil. 2016;13:43.CrossRefPubMedPubMedCentral
30.
Hidler J, Nichols D, Pelliccio M, Brady K, Campbell DD, Kahn JH, et al. Multicenter randomized clinical trial evaluating the effectiveness of the Lokomat in subacute stroke. Neurorehabil Neural Repair. 2009;23:5–13.CrossRefPubMed
31.
Collins SH, Jackson RW. Inducing self-selected human engagement in robotic locomotion training. Seattle: ICORR; 2013.CrossRef
32.
Galle S, Malcolm P, Derave W, De Clercq D. Enhancing performance during inclined loaded walking with a powered ankle-foot exoskeleton. Eur J Appl Physiol. 2014.
33.
Jackson RW, Collins SH. An experimental comparison of the relative benefits of work and torque assistance in ankle exoskeletons. J Appl Physiol. 2015;119:541–57.CrossRefPubMed
34.
Galle S, Malcolm P, Derave W, De Clercq D. Uphill walking with a simple exoskeleton: plantarflexion assistance leads to proximal adaptations. Gait Posture. 2015;41:246–51.CrossRefPubMed
35.
Koller JR, Jacobs DA, Ferris DP, Remy CD. Learning to walk with an adaptive gain proportional myoelectric controller for a robotic ankle exoskeleton. J. Neuroeng. Rehabil. 2015;12:97.CrossRefPubMedPubMedCentral
36.
Mooney LM, Herr HM. Biomechanical walking mechanisms underlying the metabolic reduction caused by an autonomous exoskeleton. J. Neuroeng. Rehabil. J NeuroEng Rehabil. 2016;13:4.CrossRefPubMedPubMedCentral
37.
38.
39.
Gordon K, Ferris D. Learning to walk with a robotic ankle exoskeleton. J Biomech. 2007;40:2636–44.CrossRefPubMed
40.
Kao P-C, Lewis CL, Ferris DP. Invariant ankle moment patterns when walking with and without a robotic ankle exoskeleton. J Biomech. 2010;43:203–9.CrossRefPubMed
41.
42.
43.
Malcolm P, Quesada RE, Caputo JM, Collins SH. The influence of push-off timing in a robotic ankle-foot prosthesis on the energetics and mechanics of walking. J Neuroeng Rehabil. 2015;12:14.CrossRef
44.
Galle S, Malcolm P, Derave W, De Clercq D. Adaptation to walking with an exoskeleton that assists ankle extension. Gait Posture. 2013;38:495–9.CrossRefPubMed
45.
Brockway JM. Derivation of formulae used to calculate energy expenditure in man. Hum Nutr Clin Nutr. 1987;41:463–71.PubMed
46.
Gard SA, Miff SC, Kuo AD. Comparison of kinematic and kinetic methods for computing the vertical motion of the body center of mass during walking. Hum Mov Sci. 2004;22:597–610.CrossRefPubMed
47.
Stanhope SJ, Kepple TM, McGuire DA, Roman NL. Kinematic-based technique for event time determination during gait. Med Biol Eng Comput. 1990;28:355–60.CrossRefPubMed
48.
Waters RL, Perry J, Antonelli D, Hislop H. Energy cost of walking of amputees: the influence of level of amputation. J Bone Joint Surg Am. 1976;58:42–6.CrossRefPubMed
49.
Platts MM, Rafferty D, Paul L. Metabolic cost of overground gait in younger stroke patients and healthy controls. Med Sci Sports Exerc. 2006;38:1041–6.CrossRefPubMed
50.
51.
Sawicki GS, Ferris DP. Mechanics and energetics of level walking with powered ankle exoskeletons. J Exp Biol Company of Biologists. 2008;211:1402–13.CrossRef
52.
Long AW, Roemmich RT, Bastian AJ. Blocking trial-by-trial error correction does not interfere with motor learning in human walking. J Neurophysiol. 2016;115:2341–8.CrossRefPubMedPubMedCentral
53.
Hoogkamer W, Bruijn SM, Duysens J. Stride length asymmetry in split-belt locomotion. Gait Posture. 2014;39:652–4.CrossRefPubMed
54.
Bobbert MF, de GWW, Jonk JN, LJR C. Explanation of the bilateral deficit in human vertical squat jumping. J Appl Physiol. 2006;100:493–9.CrossRefPubMed
55.
Metadata
Title
Exoskeleton assistance symmetry matters: unilateral assistance reduces metabolic cost, but relatively less than bilateral assistance
Authors
Philippe Malcolm
Samuel Galle
Pieter Van den Berghe
Dirk De Clercq
Publication date
01-12-2018
Publisher
BioMed Central
Published in
Journal of NeuroEngineering and Rehabilitation / Issue 1/2018
Electronic ISSN: 1743-0003
DOI
https://doi.org/10.1186/s12984-018-0381-z

Other articles of this Issue 1/2018

Journal of NeuroEngineering and Rehabilitation 1/2018 Go to the issue

Research

Variables influencing wearable sensor outcome estimates in individuals with stroke and incomplete spinal cord injury: a pilot investigation validating two research grade sensors

Research

Vision-based assessment of parkinsonism and levodopa-induced dyskinesia with pose estimation

Research

fNIRS-based Neurorobotic Interface for gait rehabilitation

Research

Motor modules during adaptation to walking in a powered ankle exoskeleton

Short report

Effect of high-frequency alternating current transcutaneous stimulation over muscle strength: a controlled pilot study

Review

An investigation into closed-loop treatment of neurological disorders based on sensing mitochondrial dysfunction