Comparison of the Performance of the Leap Motion Controller^TM with a Standard Marker-Based Motion Capture System

Area of Science:

• Biomedical Engineering
• Rehabilitation Technology
• Biomechanics

Background:

• The Leap Motion Controller (LMC) is a low-cost, markerless motion capture system gaining traction in clinical settings.
• It is increasingly used as an alternative to traditional, gold-standard motion capture systems for tracking hand and wrist movements.

Purpose of the Study:

• To compare the accuracy of finger kinematic data captured by the LMC against a gold-standard marker-based system (Qualisys Track Manager - QTM).
• To evaluate the LMC's suitability for clinical applications requiring precise hand and finger motion analysis.

Main Methods:

• Simultaneous data acquisition from LMC and QTM systems, time-synchronized.
• Participants performed standardized thumb abduction/adduction and finger flexion/extension movements.
• Static measurement of finger segment lengths and dynamic movement analysis were conducted.

Main Results:

• The LMC demonstrated acceptable agreement (Pearson's correlation coefficient r > 0.89) only for the proximal interphalangeal (PIP) joint of the middle and ring fingers during flexion/extension.
• Significant mean bias was observed across most measurements, indicating systematic inaccuracies.
• Overall, the LMC did not consistently match the precision of the QTM system.

Conclusions:

• The Leap Motion Controller (LMC) is currently not a suitable replacement for gold-standard motion capture systems in clinical environments due to accuracy limitations.
• Further research and technological advancements are necessary to improve the LMC's performance for clinical validation.
• The study highlights the need for rigorous evaluation of emerging motion capture technologies before widespread clinical adoption.