Muscle Network Analysis of a Dynamic Bilateral Task with an Upper Limb Exoskeleton.

The coordination between muscles during the execution of a bilateral task can be analyzed by recurring to functional muscle networks, which indicates how human muscles are mutually synchronized - i.e., share an oscillatory common input - during the motor task. So far, no studies have studied the impact of an assistive exoskeleton on the neural substrates of human muscles. This work addresses this question by extracting functional muscle networks of healthy individuals during the execution of a bilateral dynamic task without and with the support of a shoulder exoskeleton. The outcomes have revealed a global stationarity of these networks, together with a slight change of synergies' shape, reflecting how the employed assistive device can change physiological patterns from both temporal and frequency domains. Despite the limited sample size, the authors claim the potential of functional connectivity analysis as an additional tool for the evaluation of inter-muscular coordination for such clinical purposes as rehabilitation robotics.