The middle blocker in volleyball: A systematic review

p.24-46The objectives of this systematic review were to verify the existing scientific literature published in electronic databases about middle players in volleyball, and to describe a profile middle players should fulfill in order to achieve the highest possible level. The PRISMA protocol was followed. A search of the literature was carried out in electronic databases (ISI Web of Science™, Scopus and SPORTDiscus). Of the 1266 initial results, 41 articles were selected, comprised between 2003 and 2016. The main topics studied about middle blockers are: match analysis, technique, physical effort, muscle strength, injuries, body measures and mental skills. Overall, middle blockers tend to be the tallest and heaviest players with an ectomorph somatotype, and present the largest reach when jumping. Blocking and attacking (i.e. first tempo attack) are their main functions, thus they should dominate them. They present a higher risk of injury, particularly in their knees and fingers. Mentally, they seem to show less toughness and resiliency than other playing positions.S

The middle blocker in volleyball: a systematic review

P. 24-46Los objetivos de esta revisión sistemática fueron verificar la literatura científica existente publicada en bases de datos electrónicas sobre jugadores medios en el voleibol y describir un perfil que los jugadores medios deben cumplir para alcanzar el nivel más alto posible. Se siguió el protocolo PRISMA. Se realizó una búsqueda de la literatura en bases de datos electrónicas (ISI Web of Science ™, Scopus y SPORTDiscus). De los 1266 resultados iniciales, se seleccionaron 41 artículos, comprendidos entre 2003 y 2016. Los principales temas estudiados sobre los bloqueadores medios son: análisis de partidos, técnica, esfuerzo físico, fuerza muscular, lesiones, medidas corporales y habilidades mentales. En general, los bloqueadores medios tienden a ser los jugadores más altos y pesados con un somatotipo de ectomorfo, y presentan el mayor alcance al saltar. El bloqueo y el ataque (es decir, el primer ataque de tempo) son sus funciones principales, por lo que deben dominarlos. Presentan un mayor riesgo de lesiones, especialmente en las rodillas y los dedos. Mentalmente, parecen mostrar menos dureza y resistencia que otras posiciones de juegoS

Differences in the success of the attack between outside and opposite hitters in high level men’s volleyball

P. 251-256El objetivo era determinar el éxito de los tres atacantes más frecuentes en el voleibol masculino de élite, según su ubicación en la cancha cuando atacan. Se registraron 2925 ataques (acciones terminales) de 23 partidos del Campeonato Mundial Masculino 2010, que registró el rol de jugador (primer receptor, segundo receptor y opuesto), la ubicación en la cancha cuando tuvo lugar el ataque (frente y detrás de la cancha) y el Resultado del ataque (positivo (#) y negativo (=)). La prueba de Chi-cuadrado presentó resultados significativos (p <0,000) para las variables. El efecto de la asociación mostró una V de Cramer = 0.152. El análisis residual ajustado mostró valores más altos de lo esperado para lo contrario entre la ubicación del patio trasero y el ataque = y para la ubicación del patio delantero y el # ataque. El análisis del árbol de decisión realizado establece el resultado del ataque como la variable dependiente y el rol del jugador y la ubicación en la cancha como variables independientes. El modelo divide la muestra en dos grupos: opuesto y 1º y 2º receptor. Los receptores presentaron una probabilidad de éxito del 72.5% en sus ataques, mientras que por el contrario fue del 55.1%. Además, la probabilidad de éxito de lo contrario al realizar ataques definitivos fue del 48,4% desde el back court y el 62% del front court. La falta de importancia con respecto a la ubicación en la cancha para los receptores significa que no hubo diferencia estadística en la probabilidad de ataque entre la ubicación de la cancha delantera y trasera para ellos. Por lo tanto, todas las pruebas realizadas indican una relevancia cada vez mayor de los bateadores externos desde la cancha trasera, lo que contrasta con el uso del opuesto en el voleibol masculino como especialista en ataques de cancha trasera en lugar de cualquiera de los receptoresS

Efecto de la aplicación de un sistema automatizado de proyección de preíndices para la mejora de la capacidad de anticipación en jugadoras de voleibol

This study aimed to ascertain the efficiency of the system presented and verify whether the training applied improves the anticipation capacities of eight female volleyball players. A quasi-experimental factorial intra-group design was applied with a pre-test, two weeks of treatment, a post-test and a re-test. The independent variable was training based on the contribution of initial data in the form of the opponent's precues. The dependent variables consisted in logging the participants' responses when choosing to block. The results obtained showed an improvement in the participants' response times and a high percentage of success under these experimental conditions. The volleyball players better anticipated attack times placed behind the setter. The results obtained allow the automated system described to be considered a useful tool for sports research

The influence of limb role, direction of movement and limb dominance on movement strategies during block jump‑landings in volleyball

Financed by FEDER/Junta de Andalucia-Consejeria de Economia y Conocimiento/Proyecto A-TIC-388UGR18. This research has been partially funded by Proyect PID2020-118224RB-I00, funded by MCIN/AEI/10.13039/501100011033/FEDER "Una manera de hacer Europa".The identification of movement strategies in situations that are as ecologically valid as possible is essential for the understanding of lower limb interactions. This study considered the kinetic and kinematic data for the hip, knee and ankle joints from 376 block jump-landings when moving in the dominant and non-dominant directions from fourteen senior national female volleyball players. Two Machine Learning methods were used to generate the models from the dataset, Random Forest and Artificial Neural Networks. In addition, decision trees were used to detect which variables were relevant to discern the limb movement strategies and to provide a meaningful prediction. The results showed statistically significant differences when comparing the movement strategies between limb role (accuracy > 88.0% and > 89.3%, respectively), and when moving in the different directions but performing the same role (accuracy > 92.3% and > 91.2%, respectively). This highlights the importance of considering limb dominance, limb role and direction of movement during block jump-landings in the identification of which biomechanical variables are the most influential in the movement strategies. Moreover, Machine Learning allows the exploration of how the joints of both limbs interact during sporting tasks, which could provide a greater understanding and identification of risky movements and preventative strategies. All these detailed and valuable descriptions could provide relevant information about how to improve the performance of the players and how to plan trainings in order to avoid an overload that could lead to risk of injury. This highlights that, there is a necessity to consider the learning models, in which the spike approach unilaterally is taught before the block approach (bilaterally). Therefore, we support the idea of teaching bilateral approach before learning the spike, in order to improve coordination and to avoid asymmetries between limbs.FEDER/Junta de Andalucia-Consejeria de Economia y Conocimiento A-TIC-388UGR18MCIN/AEI/FEDER "Una manera de hacer Europa" PID2020-118224RB-I0

Ability to Predict Side-Out Performance by the Setter’s Action Range with First Tempo Availability in Top European Male and Female Teams

The aims of this study were to compare the Setter’s action range with availability of first tempo (SARA) between male and female volleyball; and to determine the relationship between several spatial and o ensive variables and their influence in the success of the side-out in male and female volleyball. A total of 1302 side-outs (639 male, 663 female) were registered (2019 European Championship). The ranking, reception e cacy, position and trajectory of the setter between reception and set, first tempo availability, side-out result, rotation, and attack lane were analyzed through Recursive Partitioning for classification, regression and survival tree models and classification and regression trees algorithms. Our results present female teams with more reduced SARAs than male teams, meaning female setters tend to play closer to the net. The correlation between the ranking and the distance from the average position of the setter to the ideal setting zone was not significant. A movement of the setter of 30 or less and more than 1 m in distance might improve the performance of the side-out. Depending on the spatial usage of the setter, some rotations might be more successful than others. When assessing performance, the teams should consider the ability to play quick attacks when their reception is not as precise as they would expect.German Research Foundation (DFG) FPU14/02234Spanish Ministry of Economy and Competitiveness - Spanish Ministry of Economy, Industry and Competitivity DEP2011-27503 TIN2016-81113-RFEDER-Junta de Andalucia, Consejeria de Economia y Conocimiento TIC.388.UGR1

Physiological characteristics of libero and central volleyball players

The aim of this study is to determine the intensity of effort in competition of the libero and central players by measuring heart rate and blood lactate. A sample of 30 players from 10 teams was used. Heart rate was measured by telemetry during the matches. Blood samples were obtained when there were substitutions for the players and about 300 samples were taken. Significant differences were observed in mean and maximal heart rate values between the central players and the libero (p<0.01). Mean and maximal heart rate values tended to decrease in the last sets in all the positions analysed. Higher levels have been observed in the libero when the set is lost than when it is won. (p<0.01). With regard to blood lactate, significant differences were found in mean values between the two central players and the libero (p<0.01). It was observed that 40.9% of all the blood lactate concentrations, regardless of the position, corresponded to values higher than 4 mmol•l-1, and 2.8% were above 8 mmol•l-1. These values are far higher than those found in earlier studies

Study about game continuity in children´s volleyball

El propósito del estudio fue apoyar con resultados el debate por la necesidad de adaptar el reglamento en las categorías menores. El único cambio dado actualmente en el ámbito español, con respecto a las normas internacionales, es la supresión del líbero en la categoría estudiada. Se analizaron datos del único campeonato de España en el que se permitió su participación. Los resultados no se muestran positivos desde una de las variables consideradas con más valor formativo: la continuidad. Del mismo modo, el ataque de primer tiempo, acción crítica debatida por su especialización temprana, da una relación positiva con el criterio focal estudiado. Resultados similares se encontraron en factores contextuales como el set y la fase de juego (saque o recepción).The aim of this study was to give information for debate about the needs to adaptation the game rules in children´s volleyball. Only there is one change between international and children´s rules in Spain. We analysed data from the only championship played in Spain when it was allowed to play with “libero”. Results don´t show a positive dependence with one of the most important factors in the player’s development: continuity. First tempo is other critical factor in the debate about early specialitation. There´s no a lot presence in this case, but it also show a positive dependence with continuity. Other contextual factors like set match playing or the different match phase (serve or reception), are in relationship with continuity

Correlation between ball speed of the spike and the strength condition of a professional women’s volleyball team during the season

The aim of this paper was to study the relationship between spike speed and the players’ characteristics, anthropometrics, and strength levels throughout the season for a women’s professional volleyball team. Players from a Spanish first division team performed a battery of tests evaluating anthropometric characteristics, strength performance, and spike speed at the beginning, in the middle, and at the end of one competitive season. The variables were: age; training experience; height; one-hand standing reach height; body mass; body mass index; height of the vertical jump with an approach (spike jump); muscle percentage of arms; 1 repetition maximum (1RM) bench press; 1RM pullover; overhead medicine ball throws for distance using 1, 2, 3, 4, and 5 kg; spike angles; and speed of standing and jump spikes. Results showed that players’ general strength (bench press and pullover) and power parameters (medicine ball throws) increased throughout theseason, while speed of the jump did not improve. The variable that best predicted the jump spike speed at all the three time points in the season was the standing spike speed. The players’ training increased their strength and upper-body power, but these improvements were not transferred to players’ hitting speed ability. Push-pull and throwing exercises were not specific enough to improve the hitting ability of the female senior volleyball players