Effects of eccentric exercise on muscle architecture in adults: a systematic review / Efectos del ejercicio excéntrico en la arquitectura muscular en adultos: una revisión sistemática

SUMMARY: The purpose of this systematic review was to determine the effects of eccentric training on muscle architecture in the adult population. Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) statements were followed using keywords associated with architecture muscular and eccentric training. Four databases were used: PubMed, Scopus, SPORTDiscus and Web of Science. Methodological quality was assessed using the PEDro scale. A total of 1260 articles were retrieved, 18 included in this review. The parameters most frequently evaluated in the studies consulted were pennation angle (PA), fascicle length (FL), and muscle thickness (MT). These were assessed mainly in lower limb muscles such as biceps femoris long head (BFlh), vastus lateralis (VL), medial gastrocnemius (MG) and lateral gastrocnemius (LG), respectively. Eccentric training for at least four weeks generates adaptations in these parameters, mainly by increasing MT with FL and decreasing PA, determining muscle function. These results provide evidence on the effects of eccentric training on muscle architecture, which could be helpful to prevent injuries and favor muscle recovery processes.

RESUMEN: El propósito de esta revisión sistemática fue determinar los efectos del entrenamiento excéntrico sobre la arquitectura muscular en la población adulta. Se siguieron las recomendaciones del Ìtems de referencia para publicar Revisiones Sistemáticas y Metaanálisis (PRISMA) utilizando palabras clave asociadas con la arquitectura muscular y el entrenamiento excéntrico en cuatro bases de datos: PubMed, Scopus, SPORTDiscus y Web of Science. La calidad metodológica se evaluó mediante la escala PEDro. Se encontró un total de 1260 artículos, del los cuales, 18 fueron incluidos en esta revisión. Los parámetros más frecuentemente evaluados en los estudios fueron el ángulo de penación (AP), la longitud del fascículo (LF) y el grosor muscular (Gm). Estos fueron evaluados principalmente en músculos de los miembros inferiores como la cabeza larga del bíceps femoral (CLBf), el vasto lateral (VL), el gastrocnemio medial (GM) y el gastrocnemio lateral (GL), respectivamente. El entrenamiento excéntrico durante al menos cuatro semanas genera adaptaciones en estos parámetros, principalmente aumentando el GM con la LF y disminuyendo el AP, determinando de esta manera la función muscular. Estos resultados aportan evidencias sobre los efectos del entrenamiento excéntrico en la arquitectura muscular, que podrían ser útiles para prevenir lesiones y favorecer los procesos de recuperación muscular.

Reliability of Morphological Measurement of Gastrocnemius Using Ultrasonography in Different Positions / 中国康复理论与实践

Objective:To investigate the reliability of the morphological measure of medial gastrocnemius by musculoskeletal ultrasound imaging on the standing and prone positions, and compare the differences in the structural parameters of the medial gastrocnemius in different positions. Methods:From December, 2017 to May, 2018, 30 healthy young subjects were measured the muscle thickness, fascicle length and pennation angle of medial gastrocnemius on the prone and standing position respectively by two testers with musculoskeletal ultrasound. One of the testers re-tested three days later. The intra-class correlation coefficient (ICC), measurement standard error (SEM) and minimum detectable change (MDC) of all muscle morphological parameters in different positions were calculated respectively, and the differences of the morphological measurement of the medial gastrocnemius between these two positions were compared. Results:In the prone position, the ICC of inter-rater was 0.932 to 0.943 and the ICC of intra-rater was 0.880 to 0.915. In the standing position, the ICC of inter-rater was 0.922 to 0.938, and the ICC of intra-rater was 0.839 to 0.925. There were significant differences in muscle thickness, fascicle length and pennation angle of medial gastrocnemius in standing position and prone position (P < 0.01). Inter-rater SEM of muscle thickness and fascicle length was less in standing position than in prone position, while intra-rater MDC of pennation angle was less in prone position. Conclusion:It is reliable to measure medial gastrocnemius in standing and prone positions with ultrasonography. Morphological measurement of gastrocnemius is more accurate in standing position, while the measurement in prone position is more sensitive.

Architectural Changes in the Medial Gastrocnemius on Sonography after Nerve Ablation in Healthy Adults

Architectural changes in healthy muscle after denervation have not yet been reported. This study aimed to investigate architectural changes in the medial head of the gastrocnemius muscle (GCM) after aesthetic tibial nerve ablation in healthy adults using ultrasonography (US). The effects of tibial nerve ablation were verified by visual observation and surface electromyography analysis. US images of medial GCMs were taken by one trained physician using B-mode and real-time US with a linear-array probe before nerve ablation, at 1 week after nerve ablation and at 3 months after nerve ablation in an anatomic standing position with the feet about shoulder-width apart in 19 healthy adults (17 females and 2 males). Muscle thickness was significantly reduced on the left side at 1 week and 3 months after the procedure and on the right side at 3 months after the procedure (p<0.050). Although fascicle length was not significantly changed, pennation angle was significantly reduced on both sides at 3 months after the procedure (p<0.050). Muscle thickness and pennation angle of the muscle fascicle were significantly reduced, although fascicle length was not significantly changed, after tibial nerve ablation in the medial GCM of healthy adults.