Changes in 6DOF knee kinematics during gait with decreasing gait speed.

Abstract Background Gait speed is recognized to correlate to knee kinematic alterations. Clinically, patients with knee diseases tend to walk slowly compared to healthy controls. Hence, gait speed may serve as a confounding factor in the kinematic characteristics of patients during gait compared to healthy controls. Research question Whether and how gait speed affects six degrees of freedom (6DOF) knee kinematics remains unclear. The current study was designed to explore whether and how decreased gait speeds affect 6DOF knee kinematics. Methods Thirty subjects (15 males and 15 females) were recruited for this study. A three-dimensional gait analysis system was used to assess the 6DOF knee kinematics of subjects at gait speeds of 4.0 km/h, 3.5 km/h, 3.0 km/h, 2.5 km/h, 2.0 km/h, 1.5 km/h, and 1.0 km/h. Kinematics of gait cycle (GC) were assessed at all gait speed levels. Results Decreased adduction angle (0.5–3.2 °, p Significance Our findings suggest that additional attention should be paid when dealing with kinematic comparisons of GC between controls and patients with significantly different gait speeds or genders than controls. Kinematic alterations induced by gait speed may raise concern for patients with knee diseases who struggle to walk faster than their normal speed. This may enhance our knowledge of the relationship between gait speed and 6DOF knee kinematics.