The Effectiveness of a Newly Designed Orthosis on Knee Contact Forces in Subjects with Knee Osteoarthritis

Abstract

BACKGROUND: This study was aimed to assess the effectiveness of a newly designed orthosis on knee contact forces in subjects with knee osteoarthritis (OA). MATERIAL AND METHODS: Five patients with OA participated in the study. All had knee OA on the medial side according to the American College of Rheumatology criteria, medial knee pain and radiographic osteophyte on the medial side of knee joint. The knee joint contact forces were determined by the use of Open Simm software under two conditions, namely, walking with and without the orthosis. RESULTS: There was no significant difference between the mean values of walking speed, stride length and cadence during walking with and without the orthosis. The mean and standard deviation (SD) values of the first and second peaks of the knee joint contact force in a vertical direction were 2.83+/-0.26 and 3.17+/-1.16 N/BW, respectively, compared to 2.54+/-0.22 and 2.54+/-0.958 N/BW in walking with and without the orthosis (p <0.05). CONCLUSION: The results of this study confirmed that the new design of orthosis decreases the joint contact forces, due to reduction in muscle performance needed to stabilize the knee joint.