The effect of lateral wedge insole with and without subtalar strap on vertical component of ground reaction force in knee osteoarthritis

The effects of lateral wedge insoles with and without subtalar strap on vertical component of ground reaction force were compared. Twenty five patients aged over 40 years with grades I or II of medial compartment knee osteoarthritis based on Kellgrene and Lawrence grading system were participated in this study. They were tested in 3 conditions while walking in a 3-meter walkway: bare foot, lateral wedge insole and lateral wedge insole with subtalar strap. Three successful trials were recorded in each condition. Gait analysis was performed to compare the immediate effect of lateral wedge insole with and without subtalar strap on vertical component of ground reaction force. There was significant effect of lateral wedge insole with subtalar strap on second peak of vertical ground reaction force related to lateral wedge insole and without insole conditions. But no significant effect of lateral wedge insole with and without subtalar strap was found on first peak of vertical ground reaction force and walking speed. The results of this study suggest that lateral wedge insole can reduce second peak of vertical ground reaction force. Also it was understood lateral wedge insole with subtalar strap might be more efficacious than lateral wedge insole in mild knee osteoarthritis patients.