Forearm Posture Affects the Corticospinal Excitability of Intrinsic and Extrinsic Hand Muscles in Dominant and Nondominant Sides

Autor(es)

Garcia, Marco Antonio Cavalcanti ; de Carvalho, Thiago Santos ; Matsuda, Renan Hiroshi ; Baffa, Oswaldo ; Imbiriba, Luis Aureliano ; Souza, Victor Hugo

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF APPLIED BIOMECHANICS; v. 40, n. 4, p. 7-pg., 2024-06-26.

Resumo

Different forearm postures can modulate corticospinal excitability. However, there is no consensus on whether handedness plays a role in such a mechanism. This study investigated the effects of 3 forearm postures (pronation, neutral, and supination) on the corticospinal excitability of muscles from the dominant and nondominant upper limbs. Surface electromyography was recorded from the abductor digiti minimi, flexor pollicis brevis, and flexor carpi radialis from both sides of 12 right-handed volunteers. Transcranial magnetic stimulation pulses were applied to each muscle's hotspot in both cerebral hemispheres. Motor-evoked potential peak-topeak amplitude and latency and resting motor threshold were measured. The data were evaluated by analysis of variance. The level of significance was set at 5%. The resting motor threshold was similar for the 3 muscles and both sides. Motor-evoked potential peak-topeak amplitude from flexor pollicis brevis was lower during supination, and the dominant upper limb latency was longer. The flexor carpi radialis presented lower motor-evoked potential peak-to-peak amplitudes for neutral and shorter latencies during supination. Abductor digiti minimi seemed not to be affected by posture or side. Different muscles from dominant and nondominant sides may undergo corticospinal modulation, even distally localized from a particular joint and under rest. (AU)

• Processo FAPESP: 13/07699-0 - Centro de Pesquisa, Inovação e Difusão em Neuromatemática - NeuroMat
• Beneficiário: Oswaldo Baffa Filho
• Modalidade de apoio: Auxílio à Pesquisa - Centros de Pesquisa, Inovação e Difusão - CEPIDs
• Processo FAPESP: 22/14526-3 - Um modelo de árvore de contexto pode prever a excitabilidade do córtex motor primário? Um estudo de estimulação magnética transcraniana robotizada navegada por eletromiografia e eletroencefalografia.
• Beneficiário: Renan Hiroshi Matsuda
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado