ArticleThe Journal of experimental biology2019
Connecting the legs with a spring improves human running economy.
Article in The Journal of experimental biology, 2019. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT06234124 (Characterization and Clinical Trial of a Variable Friction Shoe, a New Paradigm of Reduced-constraint Locomotor Therapy for People Exhibiting Foot Drop Due to Stroke), which is not on this map. Cited by 26 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Characterization and Clinical Trial of a Variable Friction Shoe, a New Paradigm of Reduced-constraint Locomotor Therapy for People Exhibiting Foot Drop Due to Stroke
Who cites it
26 citing papers in PubMed.
- Reducing the energy cost of walking in older adults using a passive hip flexion device.Journal of neuroengineering and rehabilitation · 2019Trial
- Simulation-guided design of exotendons to reduce the energetic cost of running.bioRxiv : the preprint server for biology · 2026Article
- Behavioural energetics in human locomotion: how energy use influences how we move.The Journal of experimental biology · 2025Review
- Biomechanical models in the lower-limb exoskeletons development: a review.Journal of neuroengineering and rehabilitation · 2025Review
- Establishing thresholds for swing transparency at the knee during gait to inform exoskeleton design.PloS one · 2025Article
- Elastic textile-based wearable modulation of musculoskeletal load: A comprehensive review of passive exosuits and resistance clothing.Wearable technologies · 2025Review
- Design of an ankle exoskeleton with twisted string actuation for running assistance.Wearable technologies · 2025Article
- Implementation of a passive bi-articular ankle-knee exoskeleton during maximal squat jumping.Royal Society open science · 2024Article
- The spring stiffness profile within a passive, full-leg exoskeleton affects lower-limb joint mechanics while hopping.Royal Society open science · 2024Article
- Simulating Muscle-Level Energetic Cost Savings When Humans Run with a Passive Assistive Device.IEEE robotics and automation letters · 2023Article
- A negative-work knee energy harvester based on homo-phase transfer for wearable monitoring devices.iScience · 2023Article
- Data-Driven Variable Impedance Control of a Powered Knee-Ankle Prosthesis for Adaptive Speed and Incline Walking.IEEE transactions on robotics : a publication of the IEEE Robotics and Automation Society · 2023Article
- Effects of Walking Speed and Added Mass on Hip Joint Quasi-Stiffness in Healthy Young and Middle-Aged Adults.Sensors (Basel, Switzerland) · 2023Article
- Modulating Multiarticular Energy during Human Walking and Running with an Unpowered Exoskeleton.Sensors (Basel, Switzerland) · 2022Article
- Characterizing the relationship between peak assistance torque and metabolic cost reduction during running with ankle exoskeletons.Journal of neuroengineering and rehabilitation · 2022Article
- Competing Models of Work in Quadrupedal Walking: Center of Mass Work is Insufficient to Explain Stereotypical Gait.Frontiers in bioengineering and biotechnology · 2022Article
- A portable exotendon assisting hip and knee joints reduces muscular burden during walking.Royal Society open science · 2021Article
- Biomechanical and Physiological Evaluation of a Multi-Joint Exoskeleton with Active-Passive Assistance for Walking.Biosensors · 2021Article
- Reducing the energy cost of running using a lightweight, low-profile elastic exosuit.Journal of neuroengineering and rehabilitation · 2021Article
- Understanding patient preference in prosthetic ankle stiffness.Journal of neuroengineering and rehabilitation · 2021Article
Corrections and comments
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Authors and funding
9 authors.
Funding
Abstract
Human running is inefficient. For every 10 calories burned, less than 1 is needed to maintain a constant forward velocity - the remaining energy is, in a sense, wasted. The majority of this wasted energy is expended to support the bodyweight and redirect the center of mass during the stance phase of gait. An order of magnitude less energy is expended to brake and accelerate the swinging leg. Accordingly, most devices designed to increase running efficiency have targeted the costlier stance phase of gait. An alternative approach is seen in nature: spring-like tissues in some animals and humans are believed to assist leg swing. While it has been assumed that such a spring simply offloads the muscles that swing the legs, thus saving energy, this mechanism has not been experimentally investigated. Here, we show that a spring, or 'exotendon', connecting the legs of a human reduces the energy required for running by 6.4±2.8%, and does so through a complex mechanism that produces savings beyond those associated with leg swing. The exotendon applies assistive forces to the swinging legs, increasing the energy optimal stride frequency. Runners then adopt this frequency, taking faster and shorter strides, and reduce the joint mechanical work to redirect their center of mass. Our study shows how a simple spring improves running economy through a complex interaction between the changing dynamics of the body and the adaptive strategies of the runner, highlighting the importance of considering each when designing systems that couple human and machine.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.