Initial Validation of Markerless Gait Analysis Using SPLYZA Motion: Waveform Agreement Under Practical Measurement Conditions

This study aimed to conduct an initial validation of markerless gait analysis using SPLYZA Motion by evaluating waveform agreement under practical measurement conditions. Joint angle waveforms were compared with those obtained from a marker-based motion capture system. SPLYZA Motion was found to be in good waveform agreement with the reference system for trunk and proximal lower-limb kinematics. Larger errors were observed in distal joints, particularly under occlusion and higher cadence; however, these differences were phase-dependent and did not substantially affect overall waveform patterns. These findings suggest that SPLYZA Motion may serve as a complementary tool for repeated waveform-based gait assessments under practical measurement conditions. Further validation in larger and more diverse populations is required before broader clinical application can be considered.