No Cover Image

Journal article 385 views 32 downloads

Between-Day Reliability of Kinematic Variables Using Markerless Motion Capture for Single-Leg Squat and Single-Leg Landing Tasks

Matias Yoma, Lee Herrington, Chelsea Starbuck Orcid Logo, Luis Llurda-Almuzara, Richard Jones

International Journal of Sports Physical Therapy, Volume: 20, Issue: 8, Pages: 1160 - 1175

Swansea University Author: Chelsea Starbuck Orcid Logo

  • 69555.VOR.pdf

    PDF | Version of Record

    © The Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (CC BY-NC-4.0).

    Download (933.01KB)

Abstract

Background: Markerless motion capture has the potential to repeatedly collect biomechanical data during activities associated with injuries. Few studies have assessed reliability of this technology during single-leg tasks. Purpose: To examine the between-day reliability of trunk and lower limb kinem...

Full description

Published in: International Journal of Sports Physical Therapy
ISSN: 2159-2896
Published: North American Sports Medicine Institute (NASMI) 2025
Online Access: Check full text

URI: https://cronfa.swan.ac.uk/Record/cronfa69555
Abstract: Background: Markerless motion capture has the potential to repeatedly collect biomechanical data during activities associated with injuries. Few studies have assessed reliability of this technology during single-leg tasks. Purpose: To examine the between-day reliability of trunk and lower limb kinematics during single-leg squat and single-leg landing tasks using markerless motion capture. To examine the between-day reliability of the same protocol using marker-based motion capture. Design: Reliability. Methods: Nineteen recreational athletes performed all tasks in two sessions, one week apart. Joint angles of trunk, hip, knee, and ankle were processed using Theia3D. A separate study (10 different participants) evaluated the reliability of marker-based motion capture. Full curve analysis was examined using root mean square difference (RMSD) and statistical parametric mapping (SPM) and discrete point analysis (initial contact and peak knee flexion) using intraclass correlation coefficient (ICC), and standard error of measurement (SEM). Results: For full curve analysis, markerless motion capture demonstrated low mean RMSD for all joints and planes in both SLS (3.6˚±1.3˚) and landing tasks (forward=3.2˚±1.3˚; medial=3.4˚±1.7˚). SPM showed statistical difference for bilateral hip flexion (full curve) and unilateral hip adduction, rotation, and knee flexion during a percentage of landing tasks. For discrete point analysis, ICC mean indicated moderate to good reliability (SLS= 0.77; forward landing= 0.83; medial landing= 0.80) with low mean SEM values (SLS=3.1°±1.3˚; forward landing=2.3˚±0.9°; medial landing=2.3˚±0.8˚). Marker-based motion capture showed slightly higher mean RMSD (SLS=4.2˚±1.8˚; forward landing=3.5˚±1.0˚; medial landing=3.3˚±0.9) and SEM values (SLS=4.1˚±2.2˚; forward landing=2.7˚±1.2°; medial landing=2.8˚±1.2˚). ICC mean showed good relative reliability (SLS=0.90; forward landing=0.88; medial landing=0.88). Hip flexion presented values >5° across tasks and technologies (5° to 8°). Conclusions: Markerless motion capture using Theia3D can reliably measure single-leg tasks with measurement errors comparable to marker-based motion capture. The low measurement error provides confidence for the regular monitoring of athletes during single-leg tasks.
Keywords: repeatability, measurement error, pose estimation, deep learning
College: Faculty of Science and Engineering
Funders: This work was supported by the University of Salford and Machine Learning in Athletics.
Issue: 8
Start Page: 1160
End Page: 1175