Evaluation of the criteria to identify single-fibre potentials in human muscle fibres
Thecriterionnormallyusedtoidentifyapotential generated byasinglemusclefibre(SFAP)isthatitmusthave identical shape at consecutive discharges. Technical problemsaccompanyingtherecordingofsingle-fibreelectromyographic (SFEMG) potentials introduce certain variability in the shape of these potentials, th...
| Autores: | , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión aceptada para publicación |
| Fecha de publicación: | 2012 |
| País: | España |
| Institución: | Universidad Pública de Navarra |
| Repositorio: | Academica-e. Repositorio Institucional de la Universidad Pública de Navarra |
| OAI Identifier: | oai:academica-e.unavarra.es:2454/55575 |
| Acceso en línea: | https://hdl.handle.net/2454/55575 |
| Access Level: | acceso abierto |
| Palabra clave: | Single-fibre EMG Single-fibre criteria Shape variability Rise-time variability Jitter distortion |
| Sumario: | Thecriterionnormallyusedtoidentifyapotential generated byasinglemusclefibre(SFAP)isthatitmusthave identical shape at consecutive discharges. Technical problemsaccompanyingtherecordingofsingle-fibreelectromyographic (SFEMG) potentials introduce certain variability in the shape of these potentials, thereby compromising the ability to detect pure SFAPs. This study aims to determine the conditions necessary for two fibres to generate a compound potential that fulfils the single-fibre criterion. This has been done by analysing the alterations in the waveform of compoundspikes formed bythesummationoftwoSFAPswhose relative weight in the composite potential can differ considerably. Several factors responsible for this shape variability, with a geometrical, physiological or accidental origin, have been included in our study. It has been shown that a distant interfering component will be hardly detected in the composite potential if it is smaller than approximately 15% of the main component. For this interfering component to generate a notch in the rising phase of the compound potential, it must be greater than about 30% of the main component. Acompound potential will fulfil the single-fibre criterion if the time dispersion between the individual components is less than 80–120µs. These results permit the estimation of the amplitude of interfering potentials so they could be useful in fibre density studies. The article also emphasises the inherent variability of SFEMG potentials and the impact of this variability on jitter estimation. |
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