Effect of Knee Orthosis on Lateral Thrust in Patients with Knee Osteoarthritis

To examine the effects of wearing a flexible knee orthosis (FKO) on the lateral thrust in patients with knee osteoarthritis (OA) by changing the wearing pressure. This study was a cross-sectional study. Thirteen patients (mean age: 82.8 7.5years with Kellgren Lawrence Stages I and II knee OA were included and prescribed FKO. Patient with osteoarthritis of the knee was attending outpatient rehabilitation. Using a wireless 3-axis accelerometer, we analyzed the lateral thrust in the proximal lower leg during walking (10 m) with the knee orthosis under different wearing pressures (without orthosis, using "standard force" of application, and using "tight force"). The peak values in the outward direction of the gait cycle over the three experimental conditions were selected for analysis. The mean values for patients with K-L stages I and II were calculated and compared. We found that "tight force," i.e., tightening the hook-and-loop fastener of the knee orthosis to its maximum, resulted in significantly lower lateral thrust compared to the absence of an orthosis. The effect was more pronounced in K-L Stage II patients. Our findings confirm that increasing the wearing pressure of the knee orthosis reduces lateral thrust in patients with knee OA. In Stage 1, the lateral thrust could be suppressed by the "standard force," but the lateral thrust in "Stage 2" required "tight force" to be suppressed. Knee orthosis for knee osteoarthritis were found to have the potential to inhibit lateral thrust.