Background: Individuals with knee osteoarthritis are restricted in their daily activity because of walking difficulty. The purpose of this investigation was to examine the association between self-reported walking difficulty and knee flexion excursion during gait in Japanese patients with knee osteoarthritis.
Methods: Twenty-eight patients with knee osteoarthritis participated in this study. Knee flexion excursions in loading response and swing during gait were measured through an inertial measurement unit-based motion capture system. The walking difficulty was assessed by a subitem in the Japanese Knee Osteoarthritis Measure. Pain intensity was assessed by a visual analog scale. Characteristics and gait variables were compared between groups that were determined a priori using the results of the walking difficulty assessment. The relationship between knee flexion excursion during gait and walking difficulty were analyzed using logistic regression.
Results: The participants with walking difficulty had significantly small knee flexion excursion in both loading response and swing with large pain. After controlling the effect of pain, only knee flexion excursion in the swing was significantly related to the walking difficulty.
Conclusions: This study suggested that the knee flexion excursion in swing during gait is helpful for understanding the walking difficulty experienced in Japanese patients with knee osteoarthritis.
Keywords: gait; inertial measurement unit; knee flexion excursion; knee osteoarthritis; motion capture; swing; walking difficulty.