Differences in gait parameters between healthy subjects and persons with moderate and severe knee osteoarthritis: a result of altered walking speed?

Abstract

Background: While knee osteoarthritis has been shown to affect a multitude of kinematic, kinetic and temporo-spatial gait parameters, few investigations have examined the effect of increasing levels of radiographic osteoarthritis severity on these gait parameters. Fewer still have investigated the effect of walking speed on gait variables in persons with knee osteoarthritis. The objective of this study was to investigate the influence of walking speed on biomechanical variables associated with joint loading in persons with varying severities of medial compartment knee osteoarthritis.

Methods: Twenty-one persons with moderate osteoarthritis (Kellgren-Lawrence score 2-3) and 13 persons with severe osteoarthritis (Kellgren-Lawrence score of 4) participated. Twenty-two persons without knee pain or radiographic evidence of arthritis comprised a healthy control group. Sagittal plane kinetics, knee adduction moment, sagittal plane knee excursion, ground reaction forces and knee joint reaction forces were calculated from three-dimensional motion analysis at 1.0m/s, self-selected and fastest tolerable walking speeds. Differences were analyzed using multivariate analysis of variance and multivariate analysis of covariance with speed as a covariate.

Findings: Persons with knee osteoarthritis showed significantly lower knee and ankle joint moments, ground reaction forces, knee reaction force and knee excursion when walking at freely chosen speeds. When differences in walking speed were accounted for in the analysis, the only difference found at all conditions was decreased knee joint excursion.

Interpretation: Compared to a healthy control group, persons with knee OA demonstrate differences in joint kinetics and kinematics. Except for knee excursion, these differences in gait parameters appear to be a result of slower freely chosen walking speeds rather than a result of disease progression.

Figures

Figure 1

When speed was controlled and subjects walked at 1.0 m/s, there were no differences in sagittal plane hip, knee or ankle joint moments. No differences were seen for the knee adduction moment.

Figure 2

At self-selected walking speed subjects with moderate and severe OA showed a significant reduction in knee flexion moment (*) and subjects with severe OA showed a significant reduction in the ankle dorsiflexion moment (*). These differences were not significant when walking speed was included in the analysis. Although persons with OA had higher mean adduction moments, the difference was not significantly greater than the control group.

Figure 3

At the fast walking speed, subjects with severe knee OA showed a significant reduction in sagittal plane hip, knee and ankle moments. These differences were not significant when speed was included as a covariate in the analysis.

Figure 4

Knee joint excursion was significantly reduced in persons with knee OA at the self-selected and fast walking conditions (*). This difference was still significant for the severe group when speed was statistically controlled.