Comparing Lower Extremity Kinematics using TRAZER and Inertial Motion Capture Systems

Introduction: This study assessed the validity of a non-immersive body motion tracking system (TRAZER) as an alternative to using Inertial Measurement Units (IMU)-based motion capture (MyoMotion) for lower extremity kinematic analysis. Methods: Twenty healthy participants (10 females, 10 males) with a mean age of 24.03 years (range: 20-33 years) and a mean BMI of 25.15 kg/m² (range: 18.45-32.23 kg/m²) performed double and single-leg squats. Data Analysis: Kinematic data from TRAZER and MyoMotion IMUs were compared using a mixed two-way ANOVA. Results: No significant differences were observed in knee flexion data across all movements (p > 0.05) and knee abduction during the left single-leg squat (p = 0.855). However, significant differences were noted for knee abduction in the double-leg squats (p < 0.001) and in the right single leg squat (p = 0.03) and ankle dorsiflexion across all movements (p < 0.001). Discussion: These results suggest that while TRAZER is suitable for gross movement assessment, it may not yet serve as a substitute for more precise clinical measurements.