Analysis of the Response Speed of Musculature of the Knee in Professional Male and Female Volleyball Players

[EN] The aim of this study was to evaluate the normalized response speed (Vrn) of the knee musculature (flexor and extensor) in high competitive level volleyball players using tensiomyography (TMG) and to analyze the muscular response of the vastus medialis (VM), rectus femoris (RF), vastus lateralis (VL), and biceps femoris (BF) in accordance with the specific position they play in their teams. One hundred and sixty-six players (83 women and 83 men) were evaluated. They belonged to eight teams in the Spanish women’s superleague and eight in the Spanish men’s superleague. The use of Vrn allows avoiding possible sample imbalances due to anatomical and functional differences and demands. We found differences between Vrn in each of the muscles responsible for extension (VM, RF, and VL) and flexion (BF) regardless of the sex. Normalized response speed differences seem to be larger in setters, liberos and outside players compared to middle blockers and larger in males when compared to females. These results of Vrn might respond to the differences in the physical and technical demands of each specific position, showing an improved balance response of the knee extensor and flexor musculature in male professional volleyball players.SIConsejo Superior de Deporte

Functional differences on knee musculature in profesional female volleyball players

[ES] El propósito del presente estudio, ha sido utilizar la TMG como instrumento de evaluación de las características mecánicas de la musculatura de jugadoras de voleibol de alto nivel competitivo, y detectar las diferencias en la respuesta muscular del vasto medial (VM), recto femoral (RF), vasto lateral (VL) y bíceps femoral (BF). Se evaluaron 63 mujeres, pertenecientes a 6 equipos de la superliga femenina española. Todas las jugadoras evaluadas presentan valores en la velocidad de respuesta (Vrn) más elevados en VL y VM que en RF y BF. Siendo más acuciada la diferencia respecto al BF, con independencia del puesto específico de la jugadora. Por otro lado, las Colocadoras, las Centrales y las Receptoras y en menor caso en las Líberos son las jugadoras que presentan mayores desequilibrios musculares, en lo que se refiere a la velocidad de respuesta de la musculatura encargada de la extensión (VM, RF y VM) y de la flexión (BF) de la articulación de la rodilla. En cambio, las Opuestas presentan un mayor equilibrio funcional entre esta musculatura del tren inferior. Por último, no se han encontrado diferencias estadísticamente significativas entre las distintas posiciones específicas de juego. Pero, sí se han obtenido datos que nos hacen pensar en exigencias físicas y técnicas que hacen distinguir a unas jugadoras de otras en función de su puesto y que repercuten en el riesgo de lesión y en la individualización del trabajo preventivo y compensatorio.SIConsejo Superior de Deporte

Assessment of Skeletal Muscle Contractile Properties by Radial Displacement: The Case for Tensiomyography

Skeletal muscle operates as a near-constant volume system; as such muscle shortening during contraction is transversely linked to radial deformation. Therefore, to assess contractile properties of skeletal muscle, radial displacement can be evoked and measured. Mechanomyography measures muscle radial displacement and during the last 20 years, tensiomyography has become the most commonly used and widely reported technique among the various methodologies of mechanomyography. Tensiomyography has been demonstrated to reliably measure peak radial displacement during evoked muscle twitch, as well as muscle twitch speed. A number of parameters can be extracted from the tensiomyography displacement/time curve and the most commonly used and reliable appear to be peak radial displacement and contraction time. The latter has been described as a valid non-invasive means of characterising skeletal muscle, based on fibre-type composition. Over recent years, applications of tensiomyography measurement within sport and exercise have appeared, with applications relating to injury, recovery and performance. Within the present review, we evaluate the perceived strengths and weaknesses of tensiomyography with regard to its efficacy within applied sports medicine settings. We also highlight future tensiomyography areas that require further investigation. Therefore, the purpose of this review is to critically examine the existing evidence surrounding tensiomyography as a tool within the field of sports medicine