Phase-dependent reversal of the crossed conditioning effect on the soleus Hoffmann reflex from cutaneous afferents during walking in humans

Autor(es)

Suzuki, Shinya ^{[1, 2]} ; Nakajima, Tsuyoshi ^[1] ; Futatsubashi, Genki ^{[2, 3]} ; Mezzarane, Rinaldo A. ^{[4, 5, 6]} ; Ohtsuka, Hiroyuki ^[7] ; Ohki, Yukari ^[1] ; Komiyama, Tomoyoshi ^{[2, 6]}

Afiliação do(s) autor(es)

^[1] Kyorin Univ, Sch Med, Dept Integrat Physiol, 6-20-2 Shinkawa, Mitaka, Tokyo 1818611 - Japan

^[2] Tokyo Gakugei Univ, United Grad Sch Educ, Div Hlth & Sports Educ, Tokyo - Japan

^[3] Jobu Univ, Fac Business & Informat Sci, Gunma - Japan

^[4] Univ Brasilia, Coll Phys Educ, Lab Signal Proc & Motor Control, Brasilia, DF - Brazil

^[5] Univ Sao Paulo, EPUSP, PTC, Biomed Engn Lab, Sao Paulo - Brazil

^[6] Chiba Univ, Fac Educ, Div Hlth & Sports Sci, Chiba - Japan

^[7] Hlth Sci Univ Hokkaido, Dept Phys Therapy, Sch Rehabil Sci, Sapporo, Hokkaido - Japan

• Tipo de documento: Artigo Científico
• Fonte: Experimental Brain Research; v. 234, n. 2, p. 617-626, FEB 2016.
• Citações Web of Science: 2

Resumo

We previously demonstrated that non-noxious electrical stimulation of the cutaneous nerve innervating the contralateral foot modified the excitability of the Hoffmann (H-) reflex in the soleus muscle (SOL) in a task-dependent manner during standing and walking in humans. To date, however, it remains unclear how the crossed conditioning effect on the SOL H-reflex from the contralateral foot is modified during the various phases of walking. We sought to answer this question in the present study. The SOL H-reflex was evoked in healthy volunteers by an electrical test stimulation (TS) of the right (ipsilateral) posterior tibial nerve at five different phases during treadmill walking (4 km/h). A non-noxious electrical stimulation was delivered to the superficial peroneal nerve of the left (contralateral) ankle similar to 100 ms before the TS as a conditioning stimulation (CS). This CS significantly suppressed the H-reflex amplitude during the early stance phase, whereas the same CS significantly facilitated the H-reflex amplitude during the late stance phase. The CS alone did not produce detectable changes in the full-wave rectified electromyogram of the SOL. This result indicates that presynaptic mechanisms driven by the activation of low-threshold cutaneous afferents in the contralateral foot play a role in regulating the transmission between the Ia terminal and motoneurons in a phase-dependent manner. The modulation pattern of the crossed conditioning effect on the SOL H-reflex may be functionally relevant for the left-right coordination of leg movements during bipedal walking. (AU)

• Processo FAPESP: 12/05304-5 - Efeitos da ativação cutânea sobre a modulação de reflexos contralaterais durante a marcha em humanos
• Beneficiário: Rinaldo André Mezzarane
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado