Effects of Knee Osteoarthritis on Hip and Ankle Gait Mechanics

Knee osteoarthritis (OA) can affect the hip and ankle joints, as these three joints operate as a kinetic/kinematic chainwhile walking.Purpose.This study was performed to compare (1) hip and ankle joint gait mechanics between knee OA and controlgroups and (2) to investigate the effects of knee gait mechanics on the ipsilateral hip and ankle joint.Methods.The study groupincluded 89 patients with end-stage knee OA and 42 age- and sex-matchedcontrols without knee pain or OA. Kinetic and kinematicparameters were evaluated using a commercial optoelectric gait analysis system. Range of motion (ROM) during gait, coronalmotion arc, and peak joint moment of hip, knee, and ankle joints were investigated.Results.Ankle varus moment was 50% higherin the OA group (p=0.005) and was associated with higher knee adduction moment (p<0.001).TheROMofthehipandanklejoints were significantly smaller in the OA group and were associated with limited ROM of the knee joint (both p<0.001). Thecoronal motion arc of the hip was smaller in the OA group and was also associated with limited motion arc of the knee (p<0.001).Conclusions.Knee OA has a negative effect on the ROM, coronal motion arc, and joint moment of the ankle joint and hip joint. Asknee OA is associated with increased moment of the ankle joint, attention should be paid to the ankle joint when treating patientswith knee OA