Walking analysis of a dual-track treadmill using a foot-platform locomotion interface

This paper explains fundamental problems of single-track treadmill walking and analyze an alternative separate dual-track treadmill for better walking stability, using a foot-platform locomotion interface. The traditional single-track treadmill can cause high inertia force to users and possible sickness by excessive centre of body movements because it has the problem of the asymmetric walking velocity profile of the swing and stance feet. The treadmill can generate only a constant velocity for the stance foot during the gait cycle, even though the swing foot velocity is not constant during the swing phase. On the other hand, separate dual-track treadmill walking can cancel the stance foot motion by using the opposite swing foot motion as a control input and making two foot motions symmetric. Walking simulations and user evaluations with a foot-platform locomotion interface showed that the symmetric walking with a separate dual-track treadmill may be better than the traditional walking in terms of smoothness, absence of inertia force, and walking stability.