Potential application of a passive cycling training as a tool for modulating spinal H-reflex pathways in post-acute stroke pa- tients: a feasibility study

It has been demonstrated that passive cycling training can modulate the H-reflex spinal pathways in an animal model with complete spinal cord transection and in humans with complete spinal cord injury. The aim of this study was to understand if a similar modulation can be induced in hemiparetic patients. This aspect can be crucial in stroke rehabilitation because a recalibration of activity in the H-reflex pathway may be one possible strategy for the recovery of functional locomotor activity. A 5-days passive cycling training was defined, and specific functional (Motricity Index and voluntary cycling on a sensorized ergometer) and physiological tests (soleus Hreflex post-activation depression) were carried out in 2 stroke patients before and after the training in both legs. In the paretic leg, there was a significant increment in the H-reflex and in the homosynaptic depression. In the non-affected leg, there was a significant reduction in the amplitude of the H-reflex and in its post-activation depression. The latter outlasted the period of training. Thus, the application of the passive cycling training was associated with a persistent modulation of spinal pathways in the healthy leg. A functional improvement was observed in both lower limbs.