Evidence map›Paper›PMID 42614455›Full record

ArticleFrontiers in sports and active living2026

Validation of AI-based markerless gait event detection during perturbed walking using smartphone videos from two camera perspectives.

Valerie Graf, Vanessa Haug, Daniel Seebacher, Manuel Stein, Michael Denkinger, Markus Gruber, Neltje Piro, Michael Munz, Tim Fleiner, Michael Schwenk

Abstract read
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Article in Frontiers in sports and active living, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

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2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

10 authors.

Valerie GrafDepartment of Sport Science, Human Performance Research Centre, University of Konstanz, Konstanz, Germany.
Vanessa HaugInstitute for Geriatric Research, Ulm University, Ulm, Germany.
Daniel SeebacherSubsequent GmbH, Konstanz, Germany.
Manuel SteinSubsequent GmbH, Konstanz, Germany.
Michael DenkingerInstitute for Geriatric Research, Ulm University, Ulm, Germany.
Markus GruberDepartment of Sport Science, Human Performance Research Centre, University of Konstanz, Konstanz, Germany.
Neltje PiroInstitute of Computer Science, Ulm University of Applied Sciences, Ulm, Germany.
Michael MunzInstitute of Medical Engineering and Mechatronics, Ulm University of Applied Sciences, Ulm, Germany.
Tim FleinerInstitute for Geriatric Research, Ulm University, Ulm, Germany.
Michael SchwenkDepartment of Sport Science, Human Performance Research Centre, University of Konstanz, Konstanz, Germany.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Background: Perturbation-based balance training (PBT) requires objective quantification of reactive stepping responses, yet gait event detection during perturbed walking remains methodologically challenging. Markerless smartphone-based gait analysis offers a scalable alternative to laboratory motion capture systems, but its robustness under perturbation-induced gait irregularities is insufficiently validated. This pilot study including five participants explored the validity of the SMARTGAIT markerless motion analysis system during normal and perturbed treadmill walking in older adults and investigated whether perturbation-specific model retraining could improve gait event detection. Methods: Five geriatric participants (mean age 83 ± 4.47 years; 40% female) walked on a perturbation treadmill while eight unexpected perturbations in both mediolateral and anteroposterior displacement were administered. Smartphone videos from frontal and diagonal perspectives were recorded and gait events (initial contact, final contact) were manually annotated as ground truth. Model performance was evaluated using F1 score, precision, and recall with a ± 33 ms tolerance window. Retraining was conducted using five-fold cross-validation on perturbed segments. Results: Across 2,477 annotated gait events (2,106 normal; 371 perturbed), initial detection performance was lower during perturbed walking (median F1 score: frontal 0.49; diagonal 0.88) compared to normal walking (median F1 score: frontal 0.68; diagonal 0.96), with large effect sizes despite non-significant Conclusion: This pilot study provides proof of concept for the application of smartphone-based markerless gait event detection during perturbation-induced walking. The findings further support perturbation-specific model retraining as a feasible strategy for adapting AI-based gait analysis to challenging movement conditions. Larger validation studies are required to confirm these preliminary findings before clinical implementation.

Indexed as

artificial intelligencemarkerless gait event detectionperturbation treadmillreactive balancetemporal gait analysis

Identifiers

PMID42614455
PMCPMC13481715

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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.