How Important is Position in Adaptive Treadmill Control?

To more closely mimic overground walking, researchers are developing adaptive treadmills (ATMs) that update belt speed in real-time based on user gait mechanics. Many existing ATM control schemes are solely based on position on the belt and do not respond to changes in gait mechanics, like propulsive forces, that result in increased overground walking speed. To target natural causal mechanisms to alter speed, we developed an ATM controller that adjusts speed via changes in position, step length, and propulsion.

Development and Validation of a Framework for Predictive Simulation of Treadmill Gait.

Treadmill training is a common intervention to promote healthy walking function for individuals with pathological gait. However, because of the heterogeneity of many patient populations, determining how an individual will respond to new treadmill protocols may require extensive trial and error, causing increased patient fatigue. The purpose of this study was to develop and validate a framework for predictive simulation of treadmill gait, which may be used in the design of treadmill training protocols.

Adaptive treadmill walking encourages persistent propulsion.

Background: Adaptive treadmills allow real-time changes in walking speed by responding to changes in step length, propulsion, or position on the treadmill. The stride-to-stride variability, or persistence, of stride time during overground, fixed-speed, and adaptive treadmill walking has been studied, but persistence of propulsion during adaptive treadmill walking remains unknown. Because increased propulsion is often a goal of post-stroke rehabilitation, knowledge of the stride-to-stride variability may aid rehabilitation protocol design.

Adaptive treadmill control can be manipulated to increase propulsive impulse while maintaining walking speed.

Adaptive treadmills (ATM) designed to promote increased propulsion may be an effective tool for gait training since propulsion is often impaired post-stroke. Our lab developed a novel ATM controller that adjusts belt speed via real-time changes in step length, propulsive impulse, and position. This study modified the relative importance of propulsion to step length in the controller to determine the effect of increased propulsive feedback gain on measures of propulsion and walking speed.