Evidence map›Paper›PMID 42424256›Full record

ArticlePloS one2026

Validity of multiple human pose estimation tools for measuring knee impact angles in video-captured falls of older adults.

Reese Michaels, Justin Ehrlich, Yajun Mei, Jongsang Son, Stephen N Robinovitch, Jacob J Sosnoff, Yaejin Moon

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Article in PloS one, 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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4 · The record

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5 · Who and what money

Authors and funding

7 authors.

Reese MichaelsDepartment of Exercise Science, Syracuse University, Syracuse, New York, United States of America.
Justin EhrlichDepartment of Sport Analytics, Syracuse University, Syracuse, New York, United States of America.
Yajun MeiDepartment of Biostatistics, New York University, School of Global Public Health, New York, New York, United States of America.
Jongsang SonDepartment of Biomedical Engineering, New Jersey Institute of Technology, Newark, New Jersey, United States of America.ORCID https://orcid.org/0000-0002-6132-5058
Stephen N RobinovitchDepartment of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, Canada.
Jacob J SosnoffDepartment of Physical Therapy, Rehabilitation Science, & Athletic Training, University of Kansas Medical Center, Kansas, Kansas, United States of America.
Yaejin MoonDepartment of Exercise Science, Syracuse University, Syracuse, New York, United States of America.ORCID https://orcid.org/0000-0002-1187-6847

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Falls are a major cause of injury in older adults. Although bending the knees during a fall has been shown to reduce stress on the hip, knee motion during falls is not well understood because laboratory fall studies are limited by safety concerns and marker occlusion in motion capture systems. AI-based pose estimation may help overcome these challenges, but its accuracy in measuring joint angles during falls has not yet been validated. We evaluated three pose estimation models (OpenPose, VideoPose3D, WHAM) for analyzing knee kinematics in video-captured falls. A total of 121 videos of 13 older adults (64.0 ± 5.9 years) falling sideways, utilizing diverse fall strategies (knee block, stick-like, tuck-and-roll), in a lab setting were analyzed. Each model generated time series of knee angles from the videos, from which knee flexion angles at ground impact were calculated and compared to ground truth data from a motion capture system. Agreement with the ground truth was assessed using mean absolute error (MAE), mean absolute percentage error (MAPE), and bias, analyzed across viewing planes (sagittal vs. frontal) and leg sides (impact vs. opposite). WHAM demonstrated the highest accuracy (MAPE:13.61 ± 10.55%) with minimal bias (<10%), consistently performing well across all views and leg sides. OpenPose performed similar to WHAM in the sagittal view (MAPE:14.38 ± 9.63%) but poorly in the frontal view (MAPE:71.33 ± 17.24%) due to substantial underestimation (bias:-71.33 ± 17.24%). VideoPose3D showed poor accuracy across all conditions (MAPE:39.09 ± 20.54%). WHAM also characterized differences in knee flexion kinematics between fall strategies (e.g., least vs. most knee flexion) but did not fully reproduce side-specific kinematic differences between legs, particularly for tuck-and-roll falls. This is the first study to validate pose estimation algorithms for estimating knee impact angles from video-captured falls in older adults. Future work should fine-tune WHAM using fall-specific data to further improve its performance in tracking body movements during falls.

Indexed as

Accidental FallsKneeKnee JointAgedBiomechanical PhenomenaFemaleHumansMaleMiddle AgedMotion CaptureRange of Motion, ArticularVideo Recording

Identifiers

PMID42424256
PMCPMC13349095

What OpenQuestion holds

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LicenceCC BY
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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.