An EMG pattern comparison of exoskeleton vs. end-effector robotic device for assisted walking training

Gait Trainer (GT) and the Lokomat (Loko) are two commercial robotic devices developed for assist task-oriented, intensive practice of walking in neurological patients. Despite the many studies involving these devices, there are not specific studies comparing electromyography (EMG) activity during sessions of walking training performed using these devices. This study aimed to explore the differences in the EMG patterns between these two devices and in respect overground walking. EMG of eight lower limb muscles were bilaterally recorded and analyzed in one healthy subject. Thigh muscles were more active during GTsession, whereas shank muscles during Loko-session. Furthermore, decreasing the guidance assistance of Loko (i.e. the percentage of force applied by the robot in respect to that needed for following the predetermined trajectory, training), all the muscles showed an increment of the EMG signal. These results showed clear differences in muscle activation patterns between the two systems and, as expected, quite different from the pattern observed in over-ground locomotion. These results are of importance for the correct use of robotic devices in gait rehabilitation and would represent the preliminary step to address their correct use in neurologically impaired subjects.