Reliability and comparative evaluation of novel multi-segment kinematic foot model incorporating detailed midfoot kinematics during gait: single-examiner study

The accurate assessment of midfoot motion during gait presents a considerable methodological challenge in biomedical measurement and modelling. This study developed and evaluated the intra-session repeatability of the Oita foot model, a novel multi-segment kinematic foot model that incorporates a dedicated midfoot segment defined by three markers on the dorsal cuneiform and cuboid to minimize soft tissue artifacts. Foot kinematics were acquired from 20 young adult participants (20.75 ± 1.34 years) using a 10-camera three-dimensional motion-capture system. The joint angles of five foot segments were calculated across three planes during the stance phase. The repeatability of the measurements was assessed using the intraclass correlation coefficient (ICC) and coefficient of multiple correlation (CMC). Waveform similarity was compared with the Rizzoli and modified DuPont foot models. Under single-examiner conditions, this model exhibited excellent intra-session repeatability (ICC: 0.928-0.985; CMC: 0.852-0.981) and substantial waveform agreement with the Rizzoli foot model in the sagittal and frontal planes (CMC: 0.920-0.999). Under single-examiner conditions, these findings indicate that the Oita foot model may provide a useful framework for the detailed assessment of foot kinematics during gait. However, its repeatability across different examiners and clinical populations remains to be established.