Accuracy of a 3D temporal scanning system for gait analysis: Comparative with a marker-based photogrammetry system

Area of Science:

• Biomechanics
• Motion Analysis
• Medical Imaging

Background:

• Marker-based stereophotogrammetry offers high accuracy but is cumbersome.
• Markerless human movement analysis lacks the desired precision.
• 3D temporal scanners present a potential solution by providing detailed 3D mesh data.

Purpose of the Study:

• To evaluate if 3D temporal scanners can achieve markerless gait analysis accuracy comparable to marker-based stereophotogrammetry.
• To compare the precision of 3D temporal scanners against traditional motion capture systems.

Main Methods:

• A comparative study synchronized a 3D temporal scanner with a marker-based stereophotogrammetry system.
• Analyzed two gait cycles of twelve healthy adults, extracting 3D kinematics of the pelvis and lower limb joints.
• Quantified measurement differences using root mean square, t-tests, and F-tests.

Main Results:

• Differences in 3D landmark positions were 1.9–2.4 mm in the reference pose.
• Marker position errors increased significantly in medial-lateral and vertical directions during motion.
• Relative angle errors ranged from 3% to 43%, with hip axial rotation showing the largest discrepancy.

Conclusions:

• 3D temporal scanners achieve accuracy comparable to marker-based systems, with differences smaller than soft-tissue artifacts and manual marker placement errors.
• The accuracy surpasses other markerless systems, establishing 3D temporal scanners as a strong alternative for motion capture.
• This technology enhances usability and comfort in human movement analysis.