Effect of Dyadic Haptic Collaboration on Ankle Motor Learning and Task
Performance
Abstract
Optimizing skill acquisition during novel motor tasks and (re)learning
lost motor functions have been the interest of many researchers over the
past few decades. One approach shown to accelerate motor learning is
haptically coupling two individuals through robotic interfaces. Studies
have shown that an individual’s solo performance of upper-limb tracking
tasks may improve after haptically coupled training with a partner. In
this study, our goal was to investigate whether these findings can be
translated to lower-limb motor tasks, more specifically, during an ankle
position tracking task. Using one-degree-of-freedom ankle movements,
pairs of participants (i.e., dyads) tracked target trajectories while
intermittently coupled through a virtual spring rendered between two
ankle rehabilitation robots. We compared changes in task performance
across trials while training with and without haptic coupling. We found
that dyadic haptic coupling did not lead to faster individual learning
of the tracking task. Dyadic task performance (i.e., tracking
performance while haptically coupled) improved during haptic coupling,
likely due to averaging of errors of the dyadic pair during tracking.
These results suggest that haptic coupling between unimpaired
individuals may not be an effective method of training ankle movements
during a simple one-degree-of-freedom task.