Frontal-plane gait mechanics in people with medial knee osteoarthritis are different from those in people with lateral knee osteoarthritis.

The majority of research on gait mechanics in knee osteoarthritis has focused on people with medial compartment involvement. As a result, little is known about the gait mechanics of people with the less common, lateral compartment disease.The objective of this study was to compare walking mechanics--specifically, differences in frontal-plane lower-extremity kinematics and kinetics--in people with medial knee osteoarthritis, people with lateral knee osteoarthritis, and people who were healthy.A cross-sectional design was used.Fifteen people with medial knee osteoarthritis, 15 people with lateral knee osteoarthritis, and 15 people who were healthy (control group) were recruited for the study. All participants underwent a gait analysis at an intentional walking speed. The variables of interest for the study were peak frontal-plane moments and angles and angular excursions of the lower extremity during the stance phase of gait. Data were statistically analyzed with a one-way analysis of variance.Participants with lateral knee osteoarthritis exhibited significantly less knee adduction excursion, lower peak knee abduction moment, and lower peak rear-foot eversion compared with the control group and the medial knee osteoarthritis group.Participants in the control group were approximately 10 years younger than participants with knee osteoarthritis. Despite this difference, neither body mass index nor gait speed, each of which is a factor with a stronger influence on gait mechanics, differed among the groups.Participants with lateral knee osteoarthritis exhibited frontal-plane gait mechanics at the knee and rear foot that were different from those of participants with medial knee osteoarthritis. The results of this study may guide the development of interventions specific to treating people with lateral knee osteoarthritis.