Evaluating fatigue during rehabilitation can help prevent overexertion to improve motor learning. The purpose of this study is to quantify how walking with transcutaneous spinal cord stimulation (tSCS) impacts muscle fatigue during treadmill training with and without a resistive ankle exoskeleton (Exo) in children with cerebral palsy (CP). Nine children with CP (4−14 years old) participated in four walking conditions: (1) No Device, (2) tSCS only, (3) Exo only, and (4) tSCS+Exo. Plantarflexor maximum voluntary contraction (MVC) was performed before and after each condition. Soleus amplitude root mean square (RMS) and median frequency (MDF) from electromyography were used as biomarkers for muscle fatigue. Only in the first five minutes of the Exo only condition did participants show signs of soleus fatigue with an increase in RMS (p < 0.001) and a decrease in MDF (p < 0.001). After ten minutes of walking, there was a slight decrease in MDF in the No Device and tSCS only conditions (p ≡ 0.002) but no change in RMS. There were no significant differences in changes in the MVC force, RMS, or MDF. Walking with tSCS may reduce the impact of the Exo on muscle fatigue in children with CP.
Caskey et al. (Tue,) studied this question.