Lateral wedges and the biomechanical risk for knee osteoarthritis.

摘要

Obesity is the primary risk factor for the development and progression of medial compartment knee osteoarthritis. Laterally-wedged insoles reduce many of the biomechanical risk factors for disease development and progression in osteoarthritis patients and lean individuals but it is unknown how efficacious they may be for asymptomatic, but at-risk, obese women.;14 Obese and 14 Control women participated. The purpose of the first study was to examine how an 8° laterally-wedged insole affected the kinetics and kinematics of the lower extremity. The results of a gait analysis indicated that the insole reduced the peak external knee adduction moment and the impulse of the moment in both groups while minimally affecting the kinematics of surrounding joints.;A second study examined the benefits of the wedge on the mediolateral shift in the center of pressure on the tibial plateau. A musculoskeletal modeling analysis estimated muscle forces and joint contact forces. The results showed that the wedge laterally shifted the center of pressure of the joint contact force and redistributed a portion of the mechanical load off the medial compartment of the knee joint. This partial unloading of the medial compartment has critical implications for medial knee osteoarthritis prevention.;The final study quantified the coordination patterns between articulating segments of the lower extremity. The purpose of this study was to determine if the insole detrimentally affected the coupled rotations. The results of a vector coding analysis indicated similar coupled transverse rotations of the leg and thigh segments and of the transverse rotations of the leg and frontal plane rotations of the foot. In conclusion, the insole may be used to relieve a biomechanical problem at the knee joint without detrimentally affecting the coordinated rotations of the lower extremity segments.;The results of these studies suggest that biomechanical benefits may be achieved through the use of laterally-wedged insoles in obese populations. Thus, obese individuals who are at risk for medial compartment knee osteoarthritis may be able to use the wedged insole to delay or prevent disease onset.