M.E. Da Silva-Grigoletto

Effects of age and physical activity on response speed in knee flexor and extensor muscles

This study aims to determine the normalized response speed (Vrn) in vastus lateralis (VL) and biceps femoris (BF) muscles in different age groups using tensiomyography. Eighty-four male subjects were divided into four age groups: teenage subjects (T); undergraduate students (U), adult subjects (A), and the elderly group (E). Differences in Vrn were observed between E and T (p = 0.000), E and U (p = 0.000), and E and A (p = 0.018) for right VL and between E and T (p < 0.000) and U (p = 0.003) for left VL; between T and U (p = 0.010) and A (p = 0.000) for right VL, and A (p = 0.004) for left VL. Vrn in the BF displayed different behavior from that of the VL, increasing moderately or stabilizing and declining slightly in E, in right leg (p = 0.020). The data obtained highlighted a decline in Vrn for the VL in both legs with increasing age and, declines in BF response speed were observed only in E.

Evaluación de la respuesta muscular como herramienta de control en el campo de la actividad física, la salud y el deporte

Resumen La tensiomiografia es un metodo de evaluacion muscular desarrollado en la decada de los noventa en la Facultad de Ingenieria Electrica de la Universidad de Ljubliana (Eslovenia), bajo la direccion de Vojko Valencic. Mide la deformacion radial de un musculo cuando este es estimulado electricamente. La magnitud de estos cambios y el tiempo en el que se producen nos permiten obtener informacion sobre las caracteristicas mecanicas y la capacidad contractil de los musculos superficiales evaluados. El objetivo de este trabajo es hacer una revision actualizada de la produccion cientifica publicada y revisar los procedimientos metodologicos para su correcta aplicacion e interpretacion, aportando algunas reflexiones y propuestas que ayuden a sus usuarios y amplie la informacion disponible hasta el momento.

Study of extensor and flexor musculature in the knees of male and female volleyball players

Objective The aim of the present study was to analyse differences in muscle response and mechanical characteristics of the vastus medialis (VM), rectus femoris (RF), vastus lateralis (VL) and biceps femoris (BF) in elite volleyball players of both sexes using tensiomyography (TMG). Setting 47 players of nine nationalities playing in teams belonging to the mens and womens Spanish Superleagues (elite division) were assessed. Participants 22 women (age 24.59±4.27 years; weight 72.14±10.06 kg; height 178.40±8.50 cm) and 25 men (age 25.04±4.29 years; weight 88.76±9.07 kg; height 194.71±7.84 cm). Methods TMG was used to assess muscular response, muscular mechanical characteristics, and gender differences. For this purpose, the following variables were analysed: maximum radial displacement of muscle belly or maximum deformation (Dm), and normalised response speed (Vrn). Results The findings show, both in men and women, a higher normalised response speed (Vrn) score in the VL and VM compared to the RF and BF. A marked lateral symmetry of maximum radial deformation or displacement of the muscle belly (Dm) was also observed in the musculature of the lower limbs, with no statistically-significant differences being detected in either men or women. There were, however, clear differences in terms of muscle response between male and female volleyball players: women displayed a more pronounced difference in the Vrn of the musculature responsible for extension (VM, RF and VL) and flexion (BF) of the knee joint than men. Conclusions TMG proved to be a highly sensitive tool for detecting changes in lower limb muscle activity.

Comportamiento de diferentes manifestaciones de la resistencia en el voleibol a lo largo de una temporada, en un equipo profesional

Resumen es: El proposito del presente estudio fue analizar la relacion de la resistencia de base general con la resistencia de base especial en el voleibol profesion...