Background: Overpronation has been suggested to affect the body's biomechanical chain andalter the position of the back and lower extremities. These alterations also affect muscles andtissues in the surrounding area, causing pain in the back and lower extremities, limitingactivity, and decreasing quality of life. A thorough understanding of the biomechanicalalterations due to overpronation is needed to present an effective treatment.

Aim: To study differences in the rotation angle during gait in the foot as a segment,calcaneus, tibia, femur, and pelvis by using sandals with and without wedges. A secondaryaim was to investigate the correlation between overpronation and an anterior tilt of the pelvic.

Method: An experimental intervention study was conducted, and nine test subjects withoverpronation were asked to participate. The test subject's calcaneus angle was aligned withwedges until a perpendicular angle against the floor was achieved. Two different settingswere used, sandals and sandals with wedges. Qualisys, a motion capture system, collecteddata on biomechanical angles during gait. Descriptive statistics, the Wilcoxon signed ranktest, and the Spearman correlation coefficient were conducted.

Result: Six test subjects were included. Wearing sandals with wedges significantly decreasedthe pronation of the feet (p=0.028) and the internal rotation of the right femur (p=0.028) andthe left femur (p=0.027). No significant decrease in the rotation was seen in the calcaneus ortibia.

Conclusion: The use of wedges in sandals can decrease the pronation of the feet. The effecton the biomechanical chain in the body is still unclear since a significant decrease in internalrotation was seen in femur but not in calcaneus and tibia. To achieve a thoroughunderstanding on the wedges effect on the biomechanical chain in the body, a larger studywith more test subjects needs to be conducted.