Increased hip internal abduction moment and reduced speed are the gait strategies used by women with knee osteoarthritis

The purpose of this study was to identify the gait strategies in women with mild and moderate knee osteoarthritis (OA). Forty women diagnosed with OA of the knee and 40 healthy women participated in the study. Toe-out progression angle, trunk lateral lean, hip internal abduction moment and gait speed were measured using Qualisys ProReflex System and two force plates. Principal component analysis was applied to extract features from the gait waveforms data that characterized the waveforms main modes of temporal variation. Discriminant analysis with a stepwise model was conducted to determine which strategies could best discriminate groups. According to the discriminant model, the PC2 of the internal abduction moment of the hip and the gait speed were the most discriminatory variables between the groups. The OA group showed decreased gait speed, decreased hip internal abduction moment during the loading response phase, and increased hip internal abduction moment during the mid and terminal stance phases. Interventions that may increase hip internal abduction moment, such as the strengthening of the hip abductors muscles, may benefit women with knee OA. Training slower than normal gait speeds must be considered in light of potential adverse implications on overall physical function, daily tasks, and safety.