Immediate kinematic and muscle activity changes after a single robotic exoskeleton walking session post-stroke

Abstract

<b>Background</b>: Robotic Exoskeletons (EKSO) are novel technology for retraining common gait dysfunction in people post-stroke. EKSO's capability to influence gait characteristics post-stroke is unknown. <b>Objectives</b>: To compare temporospatial, kinematic, and muscle activity gait characteristics before and after a single EKSO session and examine kinematic symmetry between involved and uninvolved limbs. <b>Methods</b>: Participants post-stroke walked under two conditions: pre-EKSO, and immediately post-EKSO. A 10-camera motion capture system synchronized with 6 force plates was used to obtain temporospatial and kinematic gait characteristics from 5 walking trials of 9 meters at a self-selected speed. Surface EMG activity was obtained from bilateral gluteus medius, rectus femoris, medial hamstrings, tibialis anterior, and soleus muscles. Wilcoxon Signed Rank tests were used to analyze differences pre- and post-EKSO. Single EKSO session consisted of 22.3±6.8 minutes total time (walk time=7.2±1.5 minutes) with 250±40 steps. <b>Results</b>: Six ambulatory (Functional Ambulation Category, range=4-5) adults (3 female; 44.7±14.6 years) with chronic stroke (4.5±1.9 years post-stroke) participated. No significant differences were observed for temporospatial gait characteristics. Muscle activity was significantly less post-EKSO in the involved leg rectus femoris during swing phase (<i>p</i>=0.028). Ankle dorsiflexion range of motion on the involved leg post-EKSO was significantly less during stance phase (<i>p</i>=0.046). Differences between involved and uninvolved joint range of motion symmetry were found pre-EKSO but not post-EKSO in swing phase hip flexion and stance phase knee flexion and knee extension. <b>Conclusions</b>: EKSO training appears capable of altering gait in people with chronic stroke and a viable intervention to reduce gait dysfunction post-stroke.