Related Experiment Video
Updated: Jun 26, 2026
07:51
Video Movement Analysis Using Smartphones ViMAS: A Pilot Study
Published on: March 14, 2017
16.8K
A Step Forward Understanding Directional Limitations in Markerless Smartphone-Based Gait Analysis: A Pilot Study
Pavol Martiš1, Zuzana Košutzká1, Andreas Kranzl2
12nd Department of Neurology, Faculty of Medicine, Comenius University, 833 05 Bratislava, Slovakia.
Sensors (Basel, Switzerland)
|May 25, 2024
Summary
Markerless motion capture shows promise for clinical assessments, accurately measuring spatial-temporal gait parameters. However, kinematic accuracy, particularly for walking away from cameras, requires further development for markerless systems.
Area of Science:
- Biomechanics
- Motion Capture Technology
- Clinical Assessment
Background:
- Markerless motion capture systems offer potential for rapid clinical assessments, but their accuracy compared to marker-based systems needs validation.
- Evaluating novel markerless systems like OpenCap against gold standards (e.g., Vicon) is crucial for clinical adoption.
- Understanding the trade-offs between markerless system convenience and accuracy is essential for clinicians.
Purpose of the Study:
- To compare the accuracy of the markerless OpenCap system against the marker-based Vicon system for capturing gait parameters during the Timed Up and Go (TUG) test.
- To identify discrepancies in spatial-temporal and kinematic parameters between markerless and marker-based motion capture.
- To assess the influence of walking direction (toward vs. away from cameras) on the accuracy of markerless systems.
Main Methods:
- Comparative analysis of OpenCap (markerless) and Vicon (marker-based) systems using 10 participants performing the TUG test.
- Collection of spatial-temporal and kinematic data for walking toward and away from two iPhone cameras.
- Correlation analysis to quantify accuracy differences and case examples for qualitative assessment.
Main Results:
- OpenCap demonstrated good accuracy for spatial-temporal gait parameters.
- Challenges were observed in accurately capturing kinematic parameters, especially when walking away from the cameras.
- Significant differences in pelvic obliquity, hip abduction, and ankle flexion were noted between walking directions.
Conclusions:
- Markerless systems like OpenCap show potential for clinical gait analysis, particularly for spatial-temporal measures.
- Further refinement is needed to improve kinematic accuracy in markerless systems, especially for complex movements and varying camera perspectives.
- Addressing directional discrepancies is key for advancing markerless technology in clinical settings.
