Evidence map›Paper›PMID 42658693›Full record

ArticleIEEE transactions on neural systems and rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society2026

Smartphone Video-Based Knee Extension Moments During Chair Rise Relate to MRI Measures of Muscle Force-Generating Capacity.

R Daniel Magruder, Mary Hall, Yael Vainberg, Jessica L Asay, Feliks Kogan, Jennifer L Hicks, Garry E Gold, Scott L Delp, Scott D Uhlrich, Valentina Mazzoli

Abstract read
In one paragraph

Article in IEEE transactions on neural systems and rehabilitation engineering : a publication of the IEEE Engineering in Medicine and Biology Society, 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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0citing papers in PubMed
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1 · What the graph read from it

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.

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.

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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

5 · Who and what money

Authors and funding

10 authors.

R Daniel Magruder
Mary Hall
Yael Vainberg
Jessica L Asay
Feliks Kogan
Jennifer L Hicks
Garry E Gold
Scott L Delp
Scott D Uhlrich
Valentina Mazzoli

Funding

Rapid MRI for Evaluation of OsteoarthritisR01EB002524 · NIBIB · STANFORD UNIVERSITY · PI Akshay Chaudhari, Garry E Gold · 2003 to 2026
$10.1M
TR&D Project 3: OpenSim for PredictionP41EB027060 · NIBIB · STANFORD UNIVERSITY · PI SCOTT L DELP · 2020 to 2026
$9.7M
Technology DevelopmentP2CHD101913 · NICHD · STANFORD UNIVERSITY · PI KU, JOY P · 2020 to 2024
$4.1M
Resource CoreP50HD118632 · NICHD · STANFORD UNIVERSITY · PI SCOTT L DELP, Jennifer Lee Hicks · 2025 to 2026
$3.9M
Quantitative assessment of early structural and functional changes in aging skeletal muscleR00AG071735 · NIA · NEW YORK UNIVERSITY SCHOOL OF MEDICINE · PI MAZZOLI, VALENTINA · 2023 to 2025
$742k
(Micro)structural Biomarkers of Skeletal Muscle Health Across the LifespanR21AG093093 · NIA · NEW YORK UNIVERSITY SCHOOL OF MEDICINE · PI Valentina Mazzoli · 2026 to 2026
$466k
Quantitative assessment of early structural and functional changes in aging skeletal muscleK99AG071735 · NIA · STANFORD UNIVERSITY · PI MAZZOLI, VALENTINA · 2021 to 2022
$206k
NIA NIH HHS K99 AG071735NIA NIH HHS R00 AG071735NIA NIH HHS R21 AG093093NIBIB NIH HHS P41 EB027060NIBIB NIH HHS R01 EB002524NICHD NIH HHS P2C HD101913NICHD NIH HHS P50 HD118632
6 · The paper itself

Abstract

Preserving muscle function is essential for maintaining independence during aging, but muscle force-generating capacity is not commonly measured clinically due to a lack of accessible, sensitive tools. Gold standard approaches include magnetic resonance imaging (MRI), which quantifies muscle volume and microstructure, and dynamometry, which measures joint moments during voluntary contraction. Both modalities are time-consuming and costly, so low-fidelity measures like five times sit-to-stand time (5xSTS) are often used instead. OpenCap, which quantifies musculoskeletal dynamics from smartphone videos, may provide an accessible assessment of muscle function. We evaluated whether OpenCap-derived moments during chair rise relate to MRI-based measures of quadriceps muscle volume and microstructure. We collected quadriceps MRI, dynamometry, and 5xSTS time with concurrent OpenCap for healthy adults of various ages (n = 19, 30-78 y). We computed quadriceps volume and radial diffusivity (a microstructural correlate of fiber size and type) from MRI. We estimated peak knee extension moment using OpenCap and dynamometry. The OpenCap-derived knee moment was related to quadriceps volume (r = 0.63, p = 0.014), radial diffusivity (r = 0.61, p = 0.016), and a composite metric combining the two (r = 0.77, p = 0.002). Isometric and concentric isokinetic dynamometry moments correlated with volume (r = 0.66-0.75, p = 0.002-0.009), but not radial diffusivity (r = 0.04-0.52, p = 0.054-0.91). 5xSTS time was not associated with any MRI-derived measures (r $= -0.16$ -0.01, p = 0.72-0.97). In summary, OpenCap smartphone-derived joint moments relate to muscle size and microstructure, unlike the current clinically-accessible measure-5xSTS time. OpenCap offers a rapid, scalable assessment of muscle force-generating capacity without specialized equipment, enabling higher-fidelity assessments in clinics and large-scale studies where imaging and dynamometry are impractical.

Indexed as

KneeKnee JointMagnetic Resonance ImagingQuadriceps MuscleSmartphoneAdultAgedBiomechanical PhenomenaFemaleHumansMaleMiddle AgedMuscle ContractionMuscle, SkeletalMuscle StrengthMuscle Strength Dynamometer

Identifiers

PMID42658693
PMCPMC13679900

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

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.