Neuromuscular control of Lokomat guided gait: evaluation of training parameters

The Lokomat is a robot assisted gait trainer that is developed for the rehabilitation of gait. This device combines an exoskeleton, to robotically guide leg movements, with a bodyweight support system and a treadmill. Effective and efficient usage of Lokomat therapy requires knowledge on the neuromuscular control of Lokomat guided gait. In addition, knowledge is need on the extent to which the three training parameters (i.e. guidance, bodyweight support and treadmill speed) can be used to affect the neuromuscular control of gait. The present thesis studies both healthy and post-stroke hemiparetic walkers to obtain this knowledge.

The results show that Lokomat guided gait is characterized by fixed stepping patterns and low activity of leg muscles, in both healthy and post-stroke hemiparetic walkers. This could potentially reduce the effectiveness of Lokomat therapy, since active contribution and variable patterns are important components of motor learning. In addition, the exoskeleton of the Lokomat affects the walking pattern even when it does not provide guidance. This must be taken into account if the level of guidance is reduced during therapy. With regard to the training parameters, it was found that mainly the increase of treadmill speed induced increasing muscle activity. It is therefore advices to increase treadmill speed as soon as possible during Lokomat therapy.

In general, the results of this thesis offer valuable information about the implication of Lokomat therapy in gait rehabilitation. However, further research and development of robotics must be encouraged to improve implementation of robot assisted gait trainers.