RESUMO

Introducción. Las distrofias musculares son trastornos genéticamente heredados que causan la degeneración progresiva de las fibras musculares. La electromiografía, especialmente la de alta densidad, se ha convertido en una herramienta valiosa para el diagnóstico y el estudio de la función muscular de trastornos neuromusculares. Objetivo. Describir y discutir el uso actual de esta técnica en las distrofias musculares. Métodos. Se realizó un Scoping Review sobre el uso de electromiografía de alta densidad en personas con distrofia muscular. Se buscó en PubMed, ScienceDirect, Scopus, Web of Science y Biblioteca Cochrane Plus, usando palabras clave en inglés y español. Se consideraron estudios desde 2015 a la fecha. Se identificaron tres artículos que cumplían con los criterios establecidos. Resultados. Los estudios se centraron en aplicaciones clínicas y de bioingeniería para personas con distrofia muscular de Duchenne y distrofia facioescapulohumeral. Los resultados sugieren que variables como la fatiga, la activación temporo-espacial y la dimensionalidad en gestos motores están determinados por la degeneración de las fibras musculares, el reemplazo por tejido fibrótico, los cambios adaptativos y la debilidad muscular progresiva característica de este grupo de condiciones. Se resalta la utilidad de la electromiografía de alta densidad en la evaluación y el manejo de la distrofia muscular. Conclusiones. El uso de esta técnica en estos trastornos neuromusculares sigue en aumento, pero se hace necesario explorar más aristas para ampliar su uso como herramienta en el estudio y en el desarrollo de intervenciones terapéuticas en esta condición por parte de profesionales de la salud.

Background. Muscular dystrophies are genetically inherited disorders that cause progressive degeneration of muscle fibers. Electromyography, especially high-density electromyography, has become a valuable tool for the diagnosis and study of muscle function in neuromuscular disorders, so the objective of this study is to describe and discuss the current use of this technique in muscular dystrophies. Methods. A Scoping Review was carried out on the use of high density electromyography in people with muscular dystrophy. PubMed, ScienceDirect, Scopus, Web of Science, and Cochrane Plus Library were searched using keywords in English and Spanish. Studies from 2015 to date were considered. Three articles were identified that met the established criteria. Results. The studies focused on clinical and bioengineering applications for people with Duchenne muscular dystrophy and facioscapulohumeral dystrophy. The results suggest that variables such as fatigue, temporal-spatial activation and dimensionality in motor gestures are determined by the degeneration of muscle fibers, replacement by fibrotic tissue, adaptive changes and progressive muscle weakness characteristic of this group of conditions. The usefulness of high-density electromyography in the evaluation and management of muscular dystrophy is highlighted. Conclusions. The use of this technique in these neuromuscular disorders continues to increase, but it is necessary to explore more aspects to expand its use as a tool in the management of this condition.

RESUMO

The instantaneous spatial representation of electrical propagation produced by muscle contraction may introduce bias in surface electromyographical (sEMG) activation maps. Here, we described the effect of instantaneous spatial representation (sEMG segmentation) on embedded fuzzy topological polyhedrons and image features extracted from sEMG activation maps. We analyzed 73,008 topographic sEMG activation maps from seven healthy participants (age 21.4 ± 1.5 years and body mass 74.5 ± 8.5 kg) who performed submaximal isometric plantar flexions with 64 surface electrodes placed over the medial gastrocnemius muscle. Window lengths of 50, 100, 150, 250, 500, and 1,000 ms and overlap of 0, 25, 50, 75, and 90% to change sEMG map generation were tested in a factorial design (grid search). The Shannon entropy and volume of global embedded tri-dimensional geometries (polyhedron projections), and the Shannon entropy, location of the center (LoC), and image moments of maps were analyzed. The polyhedron volume increased when the overlap was <25% and >75%. Entropy decreased when the overlap was <25% and >75% and when the window length was <100 ms and >500 ms. The LoC in the x-axis, entropy, and the histogram moments of maps showed effects for overlap (p < 0.001), while the LoC in the y-axis and entropy showed effects for both overlap and window length (p < 0.001). In conclusion, the instantaneous sEMG maps are first affected by outer parameters of the overlap, followed by the length of the window. Thus, choosing the window length and overlap parameters can introduce bias in sEMG activation maps, resulting in distorted regional muscle activation.