Abstract
Objective: We analyzed the effect of lateral wedged insoles which is one of conservative treatment of medial knee osteoarthritis by gait analysis using a 3-axis accelerometer. Furthermore, we compared the changes of acceleration by differences in constraint on ankle motion.
Methods: 40 patients with medial knee osteoarthritis were enrolled. Subjects were tested during walking with barefoot and during walking with four types of insoles. We fixed a 3-axis acceleration sensor in the proximal f ibular head and measured the 3-axial acceleration. Gait analysis was performed on a 20 m walkway for each subject under 5 different walking conditions; barefoot, wearing a conventional insole, sock type insole, banding type insole and semi-rigid type insole. The 3-axial acceleration during gait was measured and compared among the 5 conditions.
Results: When wearing insoles, the peak value of lateral acceleration that occurred after a heel strike significantly decreased compared to when wearing non-insoles. The semi-rigid type had the largest decrease rate of peak value, followed by the banding type. It was found that the peak value in the socks type and the conventional type were inferior to the former two. The peak value was largest in the non-insole wearing.
Conclusion: We concluded that instability is restrained by wearing lateral wedged insoles and, the results suggest that the stronger the constraining force of the subtalar joint is, the greater the restraining effect.
