Robotic-assisted stepping modulates monosynaptic reflexes in forearm muscles in the human

Abstract

Nakajima T, Kitamura T, Kamibayashi K, Komiyama T, Zehr EP, Hundza SR, Nakazawa K. Robotic-assisted stepping modulates monosynaptic reflexes in forearm muscles in the human.

Velocity-dependent suppression of the soleus H-reflex during robot-assisted passive stepping

“…The subjects were instructed to relax, and not to intervene with the movements imposed by the DGO during the passive stepping, and practiced the passive stepping task for a few minute before recording. To examine the effect of velocity, passive stepping was performed at five different stride frequencies (14,21,28,35, and 42 min −1 ). Stride frequency (min −1 ) was defined as the number of strides per minute.…”

“…It would be better that the effect of afferent input on the ol H-reflex during walking is studied in passive movements more similar to "natural" walking. Recently, a passive stepping paradigm with a driven-gait orthosis (DGO; Lokomat ® , Hocoma AG, Switzerland) has been used to investigate the effects of afferent input on H-reflex excitability during walking [9,14]. As DGO can support the upright posture of the subjects and impose passive stepping movements that are much similar to "walking," it is useful to elucidate the effects of afferent input during walking without any influence from descending inputs from the higher nervous centers.…”

Effect of sensory inputs on the motor evoked potentials in the wrist flexor muscle during the robotic passive stepping in humans

“…In recently, our group revealed that stepping-related afferent feedback suppressed the excitability of H-reflex pathway for forearm muscle [6]. This study *Resrach supported by KAKENHI: Grant-in-Aid for Scientific Research (B) 21300202.…”

“…Expansion of cortical excitatory area and change of representation was often reported after motor skill learning with improving motor performance [13]. Moreover in previous report which investigate leg or arm H-reflex during remote extremity movement [6][11] [14], it was revealed that excitability of H-reflex pathway is suppressed. This inhibition is thought to be due to presynaptic inhibition facilitated by lower limb movement [11] [14].…”

Neuromechanical Interlimb Interactions and Rehabilitation of Walking after Stroke

“…Also, reflex modulation in the legs during combined rhythmic arm and leg movement is sensitive to contributions from the arms [8] and there is specific tuning of this coupling at the level of the motoneuronal pool [9]. There is also a strong reciprocal organization such that rhythmic leg movement modulates cervical spinal cord excitability [10][11][12][13][14].…”