Twitch and M-wave potentiation induced by intermittent maximal voluntary quadriceps contractions: differences between direct quadriceps and femoral nerve stimulation
Introduction: The aim of this study was to investi-gate differences in twitch and M-wave potentiation in the quadri-ceps femoris when electrical stimulation is applied over thequadriceps muscle belly versus the femoral nerve trunk. Meth-ods: M-waves and mechanical twitches were evoked usingdirect qu...
| Authors: | , , |
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| Format: | article |
| Status: | Versión aceptada para publicación |
| Publication Date: | 2013 |
| Country: | España |
| Institution: | Universidad Pública de Navarra |
| Repository: | Academica-e. Repositorio Institucional de la Universidad Pública de Navarra |
| OAI Identifier: | oai:academica-e.unavarra.es:2454/55591 |
| Online Access: | https://hdl.handle.net/2454/55591 |
| Access Level: | Open access |
| Keyword: | M-wave potentiation Twitch potentiation Neuromuscular electrical stimulation Over-the-muscle stimulation Femoral nerve stimulation Direct quadriceps stimulation |
| Summary: | Introduction: The aim of this study was to investi-gate differences in twitch and M-wave potentiation in the quadri-ceps femoris when electrical stimulation is applied over thequadriceps muscle belly versus the femoral nerve trunk. Meth-ods: M-waves and mechanical twitches were evoked usingdirect quadriceps muscle and femoral nerve stimulationbetween 48 successive isometric maximal voluntary contrac-tions (MVC) from 10 young, healthy subjects. Potentiation wasinvestigated by analyzing the changes in M-wave amplituderecorded from the vastus medialis (VM) and vastus lateralis(VL) muscles and in quadriceps peak twitch force. Results:Potentiation of twitch, VM M-wave, and VL M-wave weregreater for femoral nerve than for direct quadriceps stimulation(P < 0.05). Despite a 50% decrease in MVC force, the ampli-tude of the M-waves increased significantly during exercise.Conclusions: In addition to enhanced electrogenic Na1-K1pumping, other factors (such as synchronization in activation ofmuscle fibers and muscle architectural properties) may signifi-cantly influence the magnitude of M-wave enlargement. |
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