Association Between Foot Posture and Tibiofemoral Contact Forces During Barefoot Walking in Patients with Knee Osteoarthritis

Abstract

Background Accumulating evidence indicates that abnormal foot posture and function are risk factors for knee osteoarthritis (OA). However, the relationship between foot posture and function and tibiofemoral contact force (CF) during habitual weight-bearing activities remains unclear. This study aimed to determine the association between CF and foot posture and function while walking. Methods In total, 18 patients with knee OA and 18 healthy individuals participated in this cross-sectional study. Foot parameters were evaluated by foot Posture Index (FPI), Staheli Arch Index (SAI), hallux valgus angle, calcaneus inverted angle relative to the floor as a static rearfoot posture, navicular height, and toe grip strength. In addition, all participants underwent kinetic and kinematic measurements during a self-selected speed gait. The measurement device used was the three-dimensional motion analysis system with a sampling rate of 120 Hz. The musculoskeletal model, which has 92 Hill-type muscle-tendon units with 23 degrees of freedom, was used to calculate CF. Pearson's correlation coefficient was used to investigate the association between foot parameters and total, medial, and lateral CF of the first and second peaks. Results A significant negative correlation was observed between Walking SAI and first medial CF in control participants (r = -0.515, p = 0.029). SAI was also significantly positively correlated with first medial CF in patients with knee OA (r = 0.488, p = 0.040). Conclusions Our findings reveal a correlation between the medial first peak CF and the SAI. This study indicates that people with knee OA and flatfoot have excessive first medial CF during walking.