Evidence map›Paper›PMID 42711700›Full record

Trial reportJournal of neuroengineering and rehabilitation2026

Effects of an actuated ankle exoskeleton on walking stability in healthy adults: a controlled laboratory study.

Cagla Kettner, Melina Beyerlein, Charlotte Marquardt, Miha Dežman, Tamim Asfour, Thorsten Stein

Abstract readRandomized Controlled Trial
In one paragraph

Trial report in Journal of neuroengineering and rehabilitation, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

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.

2 · The registry

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.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

6 authors.

Cagla KettnerBioMotion Center, Institute of Sports and Sports Science, Karlsruhe Institute of Technology, 76131, Karlsruhe, Germany. cagla.kettner@kit.edu.ORCID http://orcid.org/0000-0003-4283-281X
Melina BeyerleinBioMotion Center, Institute of Sports and Sports Science, Karlsruhe Institute of Technology, 76131, Karlsruhe, Germany.ORCID https://orcid.org/0009-0000-9974-5368
Charlotte MarquardtHigh Performance Humanoid Technologies (H2T), Institute for Anthropomatics and Robotics, Karlsruhe Institute of Technology, 76131, Karlsruhe, Germany.ORCID https://orcid.org/0000-0002-5757-1512
Miha DežmanHigh Performance Humanoid Technologies (H2T), Institute for Anthropomatics and Robotics, Karlsruhe Institute of Technology, 76131, Karlsruhe, Germany.ORCID https://orcid.org/0000-0001-7160-749X
Tamim Asfour *High Performance Humanoid Technologies (H2T), Institute for Anthropomatics and Robotics, Karlsruhe Institute of Technology, 76131, Karlsruhe, Germany.ORCID https://orcid.org/0000-0003-4879-7680
Thorsten Stein *BioMotion Center, Institute of Sports and Sports Science, Karlsruhe Institute of Technology, 76131, Karlsruhe, Germany.ORCID https://orcid.org/0000-0002-7885-7085

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundAnkle exoskeletons are widely used to reduce the metabolic cost of walking, yet their effects on walking stability during unperturbed gait remain insufficiently understood. Walking stability can be characterized using complementary measures that capture stride-to-stride variability, global temporal organization, and local dynamic stability. Understanding how walking with an actuated ankle exoskeleton system influences these different aspects of gait stability is essential for the safe design and control of wearable robotic devices.

methodsEighteen healthy adults walked on a treadmill at a constant speed (1.1 m/s) with and without an actuated bilateral ankle exoskeleton in a randomized crossover design. Spatiotemporal variability was quantified using coefficients of variation (CoV) of stride length, step width, and stance ratio. Global gait stability was assessed using detrended fluctuation analysis of stride time. Local dynamic stability was evaluated using maximum Lyapunov exponent calculated for the trunk, hip, upper leg, lower leg, and foot. Paired-samples two-sided t-tests were used to compare conditions.

resultsWalking with the ankle exoskeleton resulted in increased stride-to-stride spatiotemporal variability, reflected by higher CoV values for stride length (p < 0.001) and stance ratio (p = 0.005), while mean stride length and step width remained unchanged. Mean stance ratio was reduced in the exoskeleton condition (p < 0.001). Global gait stability did not differ between conditions, indicating preserved long-range temporal gait organization. Local dynamic stability increased at the lower leg (p < 0.001) and foot (p = 0.019) when walking with the exoskeleton.

conclusionsWalking with the actuated ankle exoskeleton alters gait control across multiple levels during steady walking. While stride-to-stride variability in stride length and stance ratio increased, global gait stability remained unchanged. Local dynamic stability was increased at the lower leg and foot, suggesting segment-specific effects of ankle-level assistance close to the assisted joint. However, these findings should be interpreted as the combined effect of wearing the exoskeleton and receiving active assistance, rather than the isolated effect of plantarflexion assistance. These results provide insight for the design and control of ankle exoskeletons with respect to stability-related effects during walking.

Indexed as

AnkleExoskeleton DeviceGaitPostural BalanceWalkingAdultBiomechanical PhenomenaCross-Over StudiesFemaleHumansMaleYoung AdultDetrended fluctuation analysisGait variabilityLocal dynamic stabilityMaximum Lyapunov exponentMotor controlWearable robotics

Identifiers

PMID42711700
PMCPMC13555940

What OpenQuestion holds

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Registered trials

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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.