Impact of elastic ankle exoskeleton stiffness on neuromechanics and energetics of human walking across multiple speeds.

Journal of Neuroengineering and Rehabilitation
Richard W Nuckols, Gregory S Sawicki

Abstract

Elastic ankle exoskeletons with intermediate stiffness springs in parallel with the human plantarflexors can reduce the metabolic cost of walking by ~ 7% at 1.25 m s- 1. In a move toward 'real-world' application, we examined whether the unpowered approach has metabolic benefit across a range of walking speeds, and if so, whether the optimal exoskeleton stiffness was speed dependent. We hypothesized that, for any walking speed, there would be an optimal ankle exoskeleton stiffness - not too compliant and not too stiff - that minimizes the user's metabolic cost. In addition, we expected the optimal stiffness to increase with walking speed. Eleven participants walked on a level treadmill at 1.25, 1.50, and 1.75 m s- 1 while we used a state-of-the-art exoskeleton emulator to apply bilateral ankle exoskeleton assistance at five controlled rotational stiffnesses (kexo = 0, 50, 100, 150, 250 Nm rad- 1). We measured metabolic cost, lower-limb joint mechanics, and EMG of muscles crossing the ankle, knee, and hip. Metabolic cost was significantly reduced at the lowest exoskeleton stiffness (50 Nm rad- 1) for assisted walking at both 1.25 (4.2%; p = 0.0162) and 1.75 m s- 1 (4.7%; p = 0.0045). At these speeds, the metabolically optimal exo...Continue Reading

References

Jan 1, 1990·European Journal of Applied Physiology and Occupational Physiology·J J VisserP A Huijing
Jul 19, 1990·Nature·R Kram, C R Taylor
Dec 22, 1999·Journal of Applied Physiology·D L Morgan, D G Allen
Dec 18, 2002·Comparative Biochemistry and Physiology. Part A, Molecular & Integrative Physiology·Thomas J Roberts
Mar 14, 2003·Gait & Posture·Jennifer L LelasD Casey Kerrigan
Jul 20, 2004·Journal of Applied Physiology·Andrew A BiewenerMarco Temaner
Mar 10, 2005·The Journal of Experimental Biology·Richard R Neptune, Kotaro Sasaki
Apr 12, 2005·Exercise and Sport Sciences Reviews·Arthur D KuoAndy Ruina
Apr 23, 2005·Journal of Applied Physiology·Masaki IshikawaGert-Peter Bruggemann
Oct 8, 2005·Journal of Applied Physiology·Raymond C BrowningRodger Kram
Nov 15, 2006·Journal of Biomechanics·G A Lichtwark, A M Wilson
Feb 6, 2007·Journal of Biomechanics·Keith E Gordon, Daniel P Ferris
Apr 22, 2008·The Journal of Experimental Biology·Gregory S Sawicki, Daniel P Ferris
Dec 18, 2008·The Journal of Experimental Biology·Gregory S Sawicki, Daniel P Ferris
Nov 3, 2009·Journal of Biomechanics·Pei-Chun KaoDaniel P Ferris
May 27, 2011·Journal of the Royal Society, Interface·Dominic James Farris, Gregory S Sawicki
Jan 6, 2012·Proceedings of the National Academy of Sciences of the United States of America·Dominic James Farris, Gregory S Sawicki
Feb 19, 2013·Journal of Applied Physiology·Glen A LichtwarkSudarshan R Nelatury
Mar 8, 2013·Gait & Posture·S GalleD De Clercq
Jun 22, 2013·Journal of Applied Physiology·Dominic James FarrisGregory S Sawicki
Dec 18, 2013·Journal of Biomechanical Engineering·Joshua M Caputo, Steven H Collins
Dec 25, 2013·Journal of Theoretical Biology·Karl E ZelikArthur D Kuo
Jun 3, 2014·Journal of Neuroengineering and Rehabilitation·Luke M MooneyHugh M Herr
Jul 30, 2014·European Journal of Applied Physiology·Samuel GalleDirk De Clercq
Nov 15, 2014·The Journal of Experimental Biology·Natalie C HoltGraham N Askew
Mar 31, 2015·Journal of Applied Physiology·Adrian LaiMarcus G Pandy
Apr 2, 2015·Nature·Steven H CollinsGregory S Sawicki
Jul 15, 2015·Journal of Applied Physiology·Rachel W Jackson, Steven H Collins
Sep 15, 2015·Current Biology : CB·Jessica C SelingerJ Maxwell Donelan
Oct 21, 2015·IEEE Transactions on Bio-medical Engineering·Gregory S Sawicki, Nabil S Khan
Jan 29, 2016·Journal of Neuroengineering and Rehabilitation·Luke M Mooney, Hugh M Herr
Mar 28, 2017·The Journal of Experimental Biology·Rachel W JacksonSteven H Collins
Apr 30, 2017·Journal of Neuroengineering and Rehabilitation·Samuel GalleDirk De Clercq
Jun 18, 2017·Journal of Biomechanics·Katherine M SteeleSteven H Collins
Jun 24, 2017·Science·Juanjuan ZhangSteven H Collins
Aug 2, 2018·The Journal of Experimental Biology·Shalaya KippRodger Kram

❮ Previous
Next ❯

Citations

May 7, 2021·Frontiers in Bioengineering and Biotechnology·Benjamin A ShaferGregory S Sawicki
Jun 6, 2021·Scientific Reports·Hamidreza AftabiMajid Nili Ahmadabadi

❮ Previous
Next ❯

Software Mentioned

- Motion
Visual 3D
JMP

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.