Markerless motion capture: What clinician-scientists need to know right now

Area of Science:

• Biomechanics
• Motion Analysis
• Human Movement Science

Background:

• Markerless motion capture (mocap) technology is emerging as a potential advancement in motion analysis.
• Traditional marker-based mocap requires extensive setup and marker placement, which can be time-consuming.
• Investigating the feasibility and accuracy of markerless mocap systems is crucial for their adoption.

Purpose of the Study:

• To evaluate the markerless mocap system, Theia 3D, for motion analysis applications.
• To compare the accuracy and data quality of markerless mocap against marker-based mocap.
• To share collected data for further research and exploration by the scientific community.

Main Methods:

• Simultaneous motion data acquisition using both markerless (Theia 3D) and marker-based systems.
• Data collection included walking, squatting, and forward hopping tasks.
• Analysis focused on segment length variability and joint angle comparisons across different planes.

Main Results:

• Markerless mocap exhibited greater segment length variability compared to marker-based systems.
• Sagittal plane joint angles showed good comparability at the knee, followed by ankle and hip.
• Frontal and transverse plane joint angle data were not comparable between the two systems.

Conclusions:

• Markerless mocap offers a user-friendly data collection experience, being simpler and faster.
• Limitations include increased data processing time and reduced troubleshooting flexibility.
• Selective use of markerless mocap, with awareness of its limitations, holds promise for advancing motion analysis.