Effects of single bout of a novel mechano-sensory cycling training on soleus h-reflex paired depression: A preliminary study


A novel mechano-sensory bicycle (MSR) was developed to facilitate movement training for individuals with incomplete spinal cord injury (iSCI) (Moravati & Moussavi, 2012). The bicycle stimulates multisensory input including foot mechanoreceptors and hip position sensors through mechanical stimulation at the pedals and induced passive cycling movement respectively. These sensory inputs have important roles in regulating locomotion patterns (Muir & Steeves, 1995; Dietz, 2002).The purpose of this study was to investigate the immediate effects of MSR training on neurological networks in healthy individuals. We hypothesized that soleus muscle paired H-reflex depression increases immediately following 30-minutes of MSR training. In a within participant pre-post test design, ten healthy adults completed MSR training and had H-reflex measurements. Nervous system responses to movement training were measured using paired H-reflex depression at different inter-stimulus intervals (ISI) ranging from 45-200ms. A longer ISI range (>60ms) may involve supraspinal and corticospinal pathways in modifying spinal reflexes adjacent to the spinal pathways. Trends toward greater H-reflex depression after MSR training at all ISIs were found; reflex depression was highest (12%) at the longest ISI (200ms), which could indicate involvement of supraspinal structures. We found trends that 30-minutes of MSR training impacted spinal and possibly supraspinal pathways in healthy participants. Soleus H-reflex depression (inhibition) may be an appropriate outcome measure to assess spinal and supraspinal pathway plasticity following movement training in iSCI individuals. Future studies will investigate the effects of MSR training for individuals with iSCI with and without mechanical stimulation.