Background: Toe-out gait modification (increased toe-out angle) has been proposed to decrease medial knee joint loading and slow disease progression in patients with knee osteoarthritis. However, the manner in which toe-out gait modification is performed is unknown. The purposes of this study were to assess the biomechanical strategies of achieving a toe-out gait, and to compare these strategies between older individuals with knee osteoarthritis and young, healthy individuals.
Methods: Lower limb biomechanics were evaluated for ten patients with knee osteoarthritis and for ten young, healthy individuals during treadmill walking. Two trials, consisting of natural gait followed by a ten degree increase in toe-out angle were performed. Transverse plane rotations of the thigh, shank and foot segments were calculated and compared between walking conditions and groups.
Findings: External rotation changes with toe-out were significantly different between the thigh and shank, and thigh and foot (P<0.001), but not between the shank and foot (P=0.48). External rotation at each segment was not significantly different (P>0.05) between groups, with the exception of thigh rotation during natural gait (P=0.04).
Interpretation: Current findings suggest that increased toe-out gait is primarily achieved through rotation of the shank and foot, with less contribution from the thigh, and those individuals with knee osteoarthritis perform a toe-out gait biomechanically similar to young, healthy individuals. Gait modification programs should address individuals' limitations, such as joint stiffness, to ensure functional performance of toe-out gait modification.
© 2013.