Split-belt treadmill walking and adaption for amputees
This study showed that control subjects use 2 strategies to adapt to walking on a split-belt treadmill. They show increased fast ankle work (with reduced irrelevant hip work) during step transition (1) and during single leg support centre of mass moves further back on the faster belt (whilst limiting this on the slow belt) (2). Persons with an amputation rely on the centre of mass method but can also adapt step length symmetry.
The nervous system uses sensory feedback to modify the walking pattern to adapt to specific conditions. This can be studied using a split-belt treadmill, on which each belt can move at a different speed. In this study, a control group of persons without a disability and a group of persons with transtibial amputation were used, in order to compare adaption to change in speed on one side. Where relevant, the increase in speed was applied to the treadmill belt on the side of the prosthetic limb.
In early adaption, there were similar step symmetry adaptions in both groups. However, active ankle control adaption can only be used by the control group as this is not available for transtibial amputees.
What situations are these adaptions vital to?
> From: Selgrade et al., J Biomech 53 (2017) 136-143. All rights reserved to Elsevier Ltd. Click here for the online summary.