Intramuscular Coherence of the Lower Flexor Muscles during Robotic Ankle-Assisted Gait

Abstract

A close-fitting assisted walking device (RE-Gait) designed to assist ankle movements might be a novel approach for acquiring the forefoot rocker function in the gait cycle. The purpose of the present study was to investigate the effects of using RE-Gait by evaluating the intramuscular coherence (IMC) of the two parts of the tibialis anterior muscles (TA), which could indicate whether a common synaptic drive is present. Seventeen healthy volunteers walked on a treadmill at a comfortable speed before, during, and immediately after 15-minute RE-Gait intervention. After RE-Gait intervention, IMC of the two parts of the TA muscles in the beta frequency band in the initial swing phase was significantly enhanced during RE-Gait intervention. In addition, IMCs in the beta and low-gamma frequency bands were significantly correlated with the enhancement ratio of the step length. These results suggest that robotic ankle plantar flexion and dorsiflexion assistance in the initial swing phase may be effective for improving gait function with enhancement of the functioning of the sensorimotor loop.

Keywords:

• walking assistive robot
• ankle joint
• tibialis anterior muscle
• intramuscular coherence

Acknowledgements

We thank all of the subjects for their voluntary participation in the present study.

Disclosure statement

LY is a director of Space Bio-Laboratories Co., Ltd (SBL), and TS is a staff of SBL, but they did not contribute to the measurement and analysis of the data. The potential conflicts of interest associated with this study have been approved by the Conflict of Interest Management　Committee of Hiroshima University. By regularly reporting research progress to the Conflicts of Interest Management Committee, we will maintain fairness regarding the interests of this study.