Objective In normal walking, the ground reaction forces pass through the medial compartment of the knee and produce an external adduction torque around the knee joint. External adduction moment of the knee can lead to medial knee osteoarthritis. Adjustment of the knee alignment and modifying the biomechanical forces on the knee can reduce pain, increase performance, and parameters of walking and improve the quality of life. The use of knee orthoses is recommended to remove weight from the affected compartment and reduce pain in patients with knee osteoarthritis. However the effect of the knee orthosis height on external adduction moment and abduction force has not been measured in previous studies, so the purpose of this study was to assess of the new three-point pressure knee orthosis (e-life) on the mentioned parameters in the patients with mild to moderate knee osteoarthritis 
Materials & Methods The study subjects were 10 patients (9 females, 1 male) with mild to moderate knee Osteoarthritis (OA) that after receiving OA 2 or 3 degree by a specialist, were referred to the Rehabilitation Research Center of the Faculty of Rehabilitation. Each subject spent five different conditions in the study. Ordering and sequencing of the process was done through randomization for each individual. These five stages included no orthosis, orthosis with long lift length, common-loaded orthosis, medium-angle abdominal orthosis, and maxillary abdominal orthosis. In this study, a three-dimensional QTM motion analysis system (Version 7.2, made in Sweden) with seven 100-kHz camera (Produced by Qualisys, USA) and one Kistler force detection plate (500×600 mm, model AA 9260, manufactured by Kistler, Switzerland) was used to collect the kinetic and kinematic data variables of walking at the Musculoskeletal Research Center of Isfahan University of Medical Sciences. Visual 3D software (C-Motion USA Version 4) was used to musculoskeletal modelling of the lower limb. The temporal and spatial parameter, the moments applied to knee joint and knee range of motion were measured for each individual at all stages. SPSS (version 22) was used for data analysis and Shapiro-Wilk test to verify the normal distribution of data. The repeated-measures ANOVA test was used to compare the effect of orthosis on the parameters mentioned before and after the use of knee orthosis. 
Results Spatial parameters did not show significant differences (P>0.05). There was no significant difference between the range of motion in all three pages in different orthodontic states (P>0.05). The maximum extensor torque was applied to the knee joint without brace, but the results of statistical analysis did not show any significant difference (P>0.05). Adductor torque was significantly lower in orthosis with a lower lever arm than without brace (P<0.05).
Conclusion Orthosis did not cause any movement restrictions for the patients. Long-length orthosis has a greater effect on the reduction of external adduction moment. As a result, it may improve the treatment process and improve the quality of life of the users.