The Effect of a Medical Insole with Arch Support and Lateral Wedge on the Adductor Moment of the Knee Joint in Patients with Medial Knee Osteoarthritis

Purpose: Osteoarthritis frequently affects the knee joint and many people are dealing with its consequences every year. Treatment of the osteoarthritis includes conservative and non-conservative methods. Using orthotics such as insoles and knee braces are one of the non-conservative methods of treatment in osteoarthritis. The aim of this research was to evaluate the effect of a medical insole with arch support and lateral wedge on kinetics and kinematics variables of the knee joint during gait in patients with medial compartment knee osteoarthritis. Methods: Ten patients with medial compartment knee osteoarthritis with age range of 30 to 60 years and height of 176.10±14.20 cm and weight of 75.5±6.3 kg participated in this study. A medical insole with arch support and lateral wedge was used. A Kistler force platform and seven cameras were utilized to analyze the kinetics and kinematics variables of the knee joint during gait in each of the following conditions: (a) wearing the medical insole with arch support and lateral wedge (b) barefoot. Results: There was no significant difference regarding mean velocity of gait with or without wearing the medical insole (P=0.42). The first peak of the applied ground reaction force on the knee joint was significantly increased while wearing the medical insole (P=.031). The applied adductor moment on the knee joint during gait while wearing the medical insole was 0.45±.05 N/m which was significantly lower than that of the bare foot condition (P<0.01). Conclusion: The medical insole with arch support and lateral wedge reduces the applied adductor moment on the knee joint during gait which results in gait facilitation and reducing the applied forces on medial compartment of the knee joint. The medical insole improves the alignment of the femur.