Explainable Machine Learning in Human Gait Analysis: A Study on Children With Cerebral Palsy

This work investigates the effectiveness of various machine learning (ML) methods in classifying human gait patterns associated with cerebral palsy (CP) and examines the clinical relevance of the learned features using explainability approaches. We trained different ML models, including convolutiona...

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Main Authors: Djordje Slijepcevic, Matthias Zeppelzauer, Fabian Unglaube, Andreas Kranzl, Christian Breiteneder, Brian Horsak
Format: Article
Language:English
Published: IEEE 2023-01-01
Series:IEEE Access
Subjects:
Online Access:https://ieeexplore.ieee.org/document/10164110/
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author Djordje Slijepcevic
Matthias Zeppelzauer
Fabian Unglaube
Andreas Kranzl
Christian Breiteneder
Brian Horsak
author_facet Djordje Slijepcevic
Matthias Zeppelzauer
Fabian Unglaube
Andreas Kranzl
Christian Breiteneder
Brian Horsak
author_sort Djordje Slijepcevic
collection DOAJ
description This work investigates the effectiveness of various machine learning (ML) methods in classifying human gait patterns associated with cerebral palsy (CP) and examines the clinical relevance of the learned features using explainability approaches. We trained different ML models, including convolutional neural networks, self-normalizing neural networks, random forests, and decision trees, and generated explanations for the trained models. For the deep neural networks, Grad-CAM explanations were aggregated on different levels to obtain explanations at the decision, class and model level. We investigate which subsets of 3D gait analysis data are particularly suitable for the classification of CP-related gait patterns. The results demonstrate the superiority of kinematic over ground reaction force data for this classification task and show that traditional ML approaches such as random forests and decision trees achieve better results and focus more on clinically relevant regions compared to deep neural networks. The best configuration, using sagittal knee and ankle angles with a random forest, achieved a classification accuracy of 93.4 % over all four CP classes (crouch gait, apparent equinus, jump gait, and true equinus). Deep neural networks utilized not only clinically relevant features but also additional ones for their predictions, which may provide novel insights into the data and raise new research questions. Overall, the article provides insights into the application of ML in clinical practice and highlights the importance of explainability to promote trust and understanding of ML models.
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spelling doaj.art-2dd2d7e0c90c4216909a10358ecddd3e2023-07-19T23:00:54ZengIEEEIEEE Access2169-35362023-01-0111659066592310.1109/ACCESS.2023.328998610164110Explainable Machine Learning in Human Gait Analysis: A Study on Children With Cerebral PalsyDjordje Slijepcevic0https://orcid.org/0000-0002-2295-7466Matthias Zeppelzauer1https://orcid.org/0000-0003-0413-4746Fabian Unglaube2Andreas Kranzl3Christian Breiteneder4Brian Horsak5https://orcid.org/0000-0002-9296-3212Institute of Creative Media Technologies, St. Pölten University of Applied Sciences, Sankt Pölten, AustriaInstitute of Creative Media Technologies, St. Pölten University of Applied Sciences, Sankt Pölten, AustriaLaboratory for Gait and Movement Analysis, Orthopaedic Hospital Speising, Vienna, AustriaLaboratory for Gait and Movement Analysis, Orthopaedic Hospital Speising, Vienna, AustriaInstitute of Visual Computing and Human-Centered Technology, TU Wien, Vienna, AustriaInstitute of Health Sciences, St. Pölten University of Applied Sciences, Sankt Pölten, AustriaThis work investigates the effectiveness of various machine learning (ML) methods in classifying human gait patterns associated with cerebral palsy (CP) and examines the clinical relevance of the learned features using explainability approaches. We trained different ML models, including convolutional neural networks, self-normalizing neural networks, random forests, and decision trees, and generated explanations for the trained models. For the deep neural networks, Grad-CAM explanations were aggregated on different levels to obtain explanations at the decision, class and model level. We investigate which subsets of 3D gait analysis data are particularly suitable for the classification of CP-related gait patterns. The results demonstrate the superiority of kinematic over ground reaction force data for this classification task and show that traditional ML approaches such as random forests and decision trees achieve better results and focus more on clinically relevant regions compared to deep neural networks. The best configuration, using sagittal knee and ankle angles with a random forest, achieved a classification accuracy of 93.4 % over all four CP classes (crouch gait, apparent equinus, jump gait, and true equinus). Deep neural networks utilized not only clinically relevant features but also additional ones for their predictions, which may provide novel insights into the data and raise new research questions. Overall, the article provides insights into the application of ML in clinical practice and highlights the importance of explainability to promote trust and understanding of ML models.https://ieeexplore.ieee.org/document/10164110/Explainable artificial intelligenceexplainabilityhuman gait analysisbiomechanical gait datakinematicsground reaction forces
spellingShingle Djordje Slijepcevic
Matthias Zeppelzauer
Fabian Unglaube
Andreas Kranzl
Christian Breiteneder
Brian Horsak
Explainable Machine Learning in Human Gait Analysis: A Study on Children With Cerebral Palsy
IEEE Access
Explainable artificial intelligence
explainability
human gait analysis
biomechanical gait data
kinematics
ground reaction forces
title Explainable Machine Learning in Human Gait Analysis: A Study on Children With Cerebral Palsy
title_full Explainable Machine Learning in Human Gait Analysis: A Study on Children With Cerebral Palsy
title_fullStr Explainable Machine Learning in Human Gait Analysis: A Study on Children With Cerebral Palsy
title_full_unstemmed Explainable Machine Learning in Human Gait Analysis: A Study on Children With Cerebral Palsy
title_short Explainable Machine Learning in Human Gait Analysis: A Study on Children With Cerebral Palsy
title_sort explainable machine learning in human gait analysis a study on children with cerebral palsy
topic Explainable artificial intelligence
explainability
human gait analysis
biomechanical gait data
kinematics
ground reaction forces
url https://ieeexplore.ieee.org/document/10164110/
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