Next-generation low-cost motion capture systems can provide comparable spatial accuracy to high-end systems

Area of Science:

• Biomechanics
• Motion Capture Technology
• Human Movement Analysis

Background:

• Objective quantification of 3D kinematics is increasingly vital for functional and occupational tasks.
• Low-cost passive motion capture systems are becoming accessible for diverse applications.
• Independent accuracy validation of these new systems is lacking.

Purpose of the Study:

• To assess the static and dynamic linear accuracy of a low-cost motion capture system.
• To compare gait kinematics between a high-end system (Vicon MX20) and a low-cost system (Natural Point OptiTrack).

Main Methods:

• Simultaneous data sampling for both systems during static and dynamic trials.
• Evaluation of static and dynamic linear accuracy with absolute error calculation.
• Comparison of sagittal, coronal, and transverse plane gait kinematics between systems.

Main Results:

• Both systems demonstrated excellent linear accuracy, with absolute errors below 1%.
• Strong agreement was observed in sagittal and coronal plane gait kinematics.
• Transverse plane kinematics showed differences up to 3° at the knee and hip, attributed to soft tissue artifacts.

Conclusions:

• Low-cost motion capture systems exhibit accuracy comparable to high-end competitors.
• These systems provide acceptable accuracy for research in budget-limited laboratories.
• Further investigation into soft tissue artifact mitigation may improve transverse plane accuracy.