A Model for the Evaluation of Lower Extremity Kinematics with Integrated Multisegmental Foot Motion

Background/Purpose Current models for assessing lower extremity motion during gait benefit from ease of use in the clinical environment. However, underlying assumptions regarding joint location and distal segment motion limit their effectiveness and accuracy. The aim of this study was to develop a model for lower extremity motion analysis, which integrates functional methods for estimating hip joint center (HJC) location and a multisegmental approach to modeling motion of the foot and ankle. The new model is capable of tracking the motion of six segments (pelvis, bilateral thigh, tibia, hindfoot, forefoot, and hallux) during stance and swing. Methods Ten healthy young adults underwent gait analysis with the new model and two existing standardized models, PlugInGait (PIG) and Milwaukee Foot Model (MFM), and results were compared between models. Results Pointwise correlation results demonstrate good agreement with existing standardized models in several measures; areas of lesser correlation are well-explained by differences in methods of locating joint centers and referencing to the underlying anatomy. Repeatability analysis with the coefficient of multiple correlation (CMC) found values greater than 0.9 for 16 of 18 segment/plane couplets. Discussion Correlation and repeatability analyses suggest the new model is well-suited for clinical and research applications. This model of lower extremity motion with integrated multisegmental foot kinematics will improve clinicians’ ability to characterize patient populations, plan treatment, and monitor progress.