To examine hip, pelvis, and trunk walking biomechanics in individuals with medial compartment knee osteoarthritis (OA) of varying radiographic disease severities and others without knee pain.
Hip, pelvis, and trunk kinematics and hip kinetics were assessed in 75 individuals with radiographically confirmed OA and 20 asymptomatic individuals. Differences in peak hip adduction and abduction angles, the amount of contralateral pelvic drop, and peak lateral trunk lean measured by 3-dimensional gait analysis were examined using analyses of variance. Peak external hip abduction and adduction moments were compared using analyses of covariance, with gait speed as a covariate.
Those with severe OA disease exhibited significantly less peak hip adduction (5.0°), but more ipsilateral trunk lean toward the study extremity (5.0°) than all other groups (P < 0.001). Those in the severe (1.1°) and asymptomatic (0.9°) groups also exhibited significantly less lateral trunk lean toward the non-study extremity (P = 0.004). No significant differences in hip joint moments or contralateral pelvic drop were observed between the groups (P > 0.02).
Gait changes at the hip and trunk were evident across the groups based on radiographic disease severity and compared with those without knee pain. Although not conclusive from this cross-sectional study design, the results provide initial evidence to support increased lateral trunk lean as being a compensatory response to the disease.