Decrease in reaction time for volleyball athletes during saccadic eye movement task: A preliminary study with evoked potentials.

AIM: This preliminary study investigated the differences in event-related potential and reaction time under two groups (athletes vs. non-athletes). MATERIAL AND METHODS: The P300 was analyzed for Fz, Cz, and Pz electrodes in thirty-one healthy volunteers divided into two groups (volleyball athletes and non-athletes). In addition, the participants performed a saccadic eye movement task to measure reaction time. RESULTS: The EEG analysis showed that the athletes, in comparison to the no-athletes, have differences in the P300 in the frontal area (p = 0.021). In relation to reaction time, the results show lower reaction time for athletes (p = 0.001). CONCLUSIONS: The volleyball athletes may present a greater allocation of attention during the execution of the inhibition task, since they have a lower reaction time for responses when compared to non-athletes.

Motor alterations along the kinetic chain in amateur volleyball and handball athletes with shoulder pain: An observational comparative study.

Overhead sports overload the shoulder complex due to movement repetition and the great amount of force created during the athletic motion, which may cause adaptations in the shoulder and lead to shoulder pain. However, overhead movements include the kinetic chain, and alterations in some of the structures throughout the kinetic chain may increase stress on the shoulder complex and be associated with shoulder pain. PURPOSE: To compare kinetic chain components in overhead athletes with and without shoulder pain. METHODS: Forty-one volleyball and handball athletes (21 with and 20 without shoulder pain) were included and assessed for hip internal (IR) and external rotation (ER) range of motion (ROM), hip and trunk isometric strength, trunk endurance and neuromuscular control of the lower and upper limbs (Y balance test). RESULTS: Athletes with shoulder pain showed smaller IR ROM in both hips, lower endurance time for trunk extensors and flexors, decreased reach distance in the anterior and posteromedial direction, as well as a smaller composite score in the Y balance test (p < 0.05). CONCLUSION: Volleyball and handball athletes with shoulder pain showed changes in ROM throughout the kinetic chain in addition to lower core endurance, and decreased neuromuscular control of lower limbs.

Validity and reliability of My Jump 2® app to measure the vertical jump on elite women beach volleyball players.

Purpose: The aim of this study was to assess the reliability and validity of the My Jump 2® app in measuring jump height, flight time, and peak power among elite women beach volleyball players on sand surfaces. Methods: Eleven elite female beach volleyball players (aged 23.6 ± 6.2 years; weight 66.3 ± 5.8 kg; height 174.4 ± 5.8 cm; with 8.4 ± 4.8 years of professional experience) participated in this study. Each player performed six countermovement jumps in a wooden box filled with sand on a force platform while simultaneously recording a video for subsequent analysis using the My Jump 2® app. Results: We found excellent agreement for flight time, jump height and peak power between observers (ICC = 0.92, 0.91 and 0.97, respectively). No significant differences between force platform and My Jump 2® app were detected in the values obtained for the three variables (P > 0.05). For the force platform and the My Jump 2® app, we found a good agreement measuring jump height and flight time (ICC = 0.85 and 0.85, respectively). However, we only found a moderate agreement for peak power (ICC = 0.64). The difference in jump height showed a limit of agreement between -4.10 and 4.74 cm in Bland-Altman, indicating a high level of agreement between the two measurement tools. Conclusion: Based on our findings, the My Jump 2® app reveals a valid tool for measuring jump height and flight time of CMJ on sand surfaces. However, more caution is needed when measuring peak power.

Combination of narrow and wide bandwidth knowledge of performance in the acquisition of a complex sports motor skill.

OBJECTIVES: This study tested the effects of combining two bandwidth knowledge of performance (KP) on a complex sports motor skill. METHOD: Twenty-two elementary students were divided into combined wide and narrow bandwidth KP (WNG) and control group (CG). The task was the volleyball serve, whose goal was to hit the bull's eye center of a target lying on the floor on the opposite side of the court. The study was composed of a pre-test, acquisition phase and retention test, and had three measures (pre-test, intermediate test, and retention test) with 15 serves recorded each. The acquisition phase consisted of 252 trials. The WNG had a wide bandwidth KP in the first half of the acquisition phase and a narrow one in the second. The CG received KP in all trials. The effects of bandwidth KP were analyzed separately to infer parameters and skill structure learning. RESULTS: Both groups improved the skill structure from the first to the intermediate test, but only WNG also improved on the retention test. The parameters accuracy improved only on retention compared to the pre-test and intermediate test but had no difference between groups. CONCLUSION: Providing information using the bandwidth KP led to an initial engagement and prioritization of skill structure learning.

Risk and protective factors for shoulder complaints in indoor volleyball players: A comprehensive systematic review.

OBJECTIVE: This systematic review aimed to answer the question: "What are the risk and protective factors for shoulder complaints (pain, injury, or problem) in indoor volleyball players?". METHODS: Searches were conducted in electronic databases: PubMed/MEDLINE, Embase, CINAHL, and SPORTDiscus, as well as reference lists of the included studies. We included studies evaluating potential intrinsic and extrinsic factors associated with shoulder complaints in indoor volleyball players of any country, age, sex, and competitive level. The Quality in Prognosis Studies (QUIPS) tool was used to assess the risk of bias. RESULTS: The risk factors for shoulder complaints in volleyball players were identified through four prospective studies, which exhibited a moderate to low risk of bias. These factors included previous shoulder pain or injury, playing in outside and opposite positions, subacromial bursa thickening, and having an average external rotator (ER) isokinetic eccentric torque lower than the average internal rotator (IR) concentric torque. Protective factors were enhancing shoulder IR and ER isokinetic eccentric strength, being male sex, being older, and maintaining a concentric strength ratio ER/IR within the 0.60-0.75 range. CONCLUSIONS: This systematic review highlights risk factors that clinicians and researchers should consider when assessing and tracking indoor volleyball players.

Is There a Relationship Between Birth Quartile and Vertical Jump Performance Among Young Male Elite Volleyball Athletes?

Vertical jump is an important skill that influences volleyball performance. In this study, we analyzed the relationship between vertical jump performance and birth quartile of Brazilian male youth volleyball players. We calculated chi-square goodness-of-fit tests to compare the athletes' birthdate distributions in quarters of their birth years (Q1, Q2, Q3, and Q4) according to player age categories (U17, U18, U19, and U21). We calculated one-way ANOVAs to compare spike jump and block jump heights of players born in different quarters of the same year. Overall, we found a relative age effect (i.e., more players with birth dates early in the birth year) in U17 (p < .001), U18 (p < .001), U19 (p < .001), and U21 (p = .04). Regarding vertical jump performance, U18 athletes born in Q2 reached higher spike jump heights (p = .006) and block jump heights (p = .002) than athletes born in Q4, and U19 athletes born in Q1 reached higher block jump heights than athletes born in Q3 (p = .049). There were no significant differences in vertical jump performance across birth quartiles among U17 and U21 athletes. Thus, a relative age effect was present in all age categories but not always reflected in vertical jump performance. Volleyball coaches and policymakers are still advised to employ strategies to ensure fairer opportunities for players born later in the year of their eligibility dates, as we found RAE to be sometimes, but not always, related to higher spike or block jump heights even among these older adolescents and young adult athletes.

Análisis de Datos Antropométricos y Madurativos para la Selección de Talentos en Voleibol / Analysis of Anthropometric and Maturational Data for Talents Selection in Volleyball

El proceso madurativo tiene una gran influencia sobre los factores antropométricos y las capacidades físicas del atleta, y por tanto, sobre el proceso de selección de talentos deportivos. El objetivo de este trabajo fue analizar el estado madurativo y las características antropométricas junto con la comparación de estos datos por sexo en una muestra de 39 jugadores jóvenes de voleibol dentro de un proceso de selección de talentos (19 damas de 14,88±1,05 años y 13 varones de 15,1 años). Se obtuvieron datos de edad cronológica, altura, peso, altura sentado, altura de la madre y padre, la edad pico de crecimiento, el "timing" o periodo de tiempo por encima o por debajo de la edad pico, altura al final del proceso madurativo, el porcentaje actual de altura máxima, los centímetros restantes y el estado madurativo (pre-púber, púber o pos-púber). Los jugadores mostraron una mayor altura en el momento de las mediciones (179,92±6,87 vs 171,05±4,80; p<0,001), así como una mayor altura final calculada (189,46±3,73 vs 178,52±5,17; p<0,001), en comparación a las jugadoras. El pico en la velocidad de crecimiento también fue superior en los jugadores (14,56±0,44 vs 12,60±0,57; p<0,001), aunque su timing era inferior al de las jugadoras (0,531±1,19 vs 2,27±0,64; p<0,001). Esto se debió a un mayor porcentaje de jugadores masculinos en estados puberales, incluyendo un jugador en estadio pre-puberal, mientras que fue abundante la presencia de jugadoras en estado pospuberal. Estos datos reflejan la gran cantidad de jugadores que tienden a estar en periodos avanzados de maduración en procesos de selección de talentos. Por tanto, entrenadores y seleccionadores deben contemplar estas variables para evitar sesgos en el proceso de identificación del talento deportivo.

SUMMARY: The maturation process has a great influence on the anthropometric factors and physical capabilities of the athlete, and therefore, on the selection process of sporting talents. The objective of this work was to analyze the maturational state and anthropometric characteristics together with the comparison of these data by sex in a sample of 39 young volleyball players within a talent selection process (19 ladies of 14.88±1. 05 years old and 13 males aged 15.1 years). Data were obtained on chronological age, height, weight, sitting height, height of the mother and father, peak age of growth, timing or period of time above or below the peak age, height at the end of the process. maturation, the current percentage of maximum height, the remaining centimeters and the maturation status (pre-pubertal, pubertal or post-pubertal). The players showed a greater height at the time of the measurements (179.92±6.87 vs. 171.05±4.80; p<0.001), as well as a greater final calculated height (189.46±3.73 vs. 178.52±5.17; p<0.001), compared to the female players. The peak in growth speed was also higher in male players (14.56±0.44 vs 12.60±0.57; p<0.001), although their timing was lower than that of female players (0.531±1.19 vs 2.27±0.64; p<0.001). This was due to a higher percentage of male players in pubertal states, including one player in a pre-pubertal stage, while the presence of female players in a post-pubertal stage was abundant. These data reflect the large number of players who tend to be in advanced periods of maturation in talent selection processes. Therefore, coaches and selectors must consider these variables to avoid biases in the process of identifying sporting talent.

Differences between hemispheres and in saccade latency regarding volleyball athletes and non-athletes during saccadic eye movements: an analysis using EEG.

BACKGROUND: The saccadic eye movement is responsible for providing focus to a visual object of interest to the retina. In sports like volleyball, identifying relevant targets quickly is essential to a masterful performance. The training improves cortical regions underlying saccadic action, enabling more automated processing in athletes. OBJECTIVE: We investigated changes in the latency during the saccadic eye movement and the absolute theta power on the frontal and prefrontal cortices during the execution of the saccadic eye movement task in volleyball athletes and non-athletes. We hypothesized that the saccade latency and theta power would be lower due to training and perceptual-cognitive enhancement in volleyball players. METHODS: We recruited 30 healthy volunteers: 15 volleyball athletes (11 men and 4 women; mean age: 15.08 ± 1.06 years) and 15 non-athletes (5 men and 10 women; mean age: 18.00 ± 1.46 years). All tasks were performed simultaneously with electroencephalography signal recording. RESULTS: The latency of the saccadic eye movement presented a significant difference between the groups; a shorter time was observed among the athletes, associated with the players' superiority in terms of attention level. During the experiment, the athletes observed a decrease in absolute theta power compared to non-athletes on the electrodes of each frontal and prefrontal area. CONCLUSION: In the present study, we observed the behavior of reaction time and absolute theta power in athletes and non-athletes during a saccadic movement task. Our findings corroborate the premise of cognitive improvement, mainly due to the reduction of saccadic latency and lower beta power, validating the neural efficiency hypothesis.

ANTECEDENTES: O movimento ocular sacádico é responsável por dar foco a um objeto visual de interesse para a retina. Em esportes como o vôlei, identificar alvos relevantes o mais rápido possível é essencial para se ter um desempenho magistral. O treinamento melhora as regiões corticais subjacentes à ação sacádica, e permite um processamento mais automatizado em atletas. OBJETIVO: Investigamos as mudanças na latência durante o movimento ocular sacádico e a potência teta absoluta nos córtices frontal e pré-frontal durante a execução da tarefa de movimento ocular sacádico em atletas e não atletas de voleibol. Nossa hipótese é a de que a latência sacádica e a potência teta seriam menores em atletas devido ao treinamento e ao aprimoramento perceptivo-cognitivo em jogadores de voleibol. MéTODOS: Ao todo, 30 voluntários saudáveis foram recrutados para este estudo: 15 atletas de voleibol (11 homens e 4 mulheres; idade média: 15,08 ± 1,06 anos) e 15 não atletas (5 homens e 10 mulheres; idade média: 18,00 ± 1,46 anos). Todas as tarefas foram realizadas simultaneamente com o registro do sinal eletroencefalográfico. RESULTADOS: O resultado da latência do movimento ocular sacádico apresentou diferença significativa entre os grupos, sendo observado menor tempo entre os atletas, associado à superioridade dos jogadores em termos de nível de atenção. Durante o experimento, nos eletrodos de cada área frontal e pré-frontal, observou-se uma diminuição na potência teta absoluta nos atletas em comparação aos não atletas. CONCLUSãO: Neste estudo, observou-se o comportamento do tempo de reação e da potência teta absoluta em atletas e não atletas durante uma tarefa de movimento sacádico. Nossos achados corroboram a premissa de melhora cognitiva, principalmente pela redução da latência sacádica e menor potência beta, o que valida a hipótese de eficiência neural.

The Decision-Making of High-Level Volleyball Setters in the 2021-2022 Volleyball Men's Superliga: Does the Opponent Matter?

Our primary objective in this study was to investigate the offensive strategies employed in the attack phase of men's volleyball, specifically focusing on side-out as stratified by the type of confrontation that was determined by the opponent's team performance. We analyzed 5524 attacking actions during 22 games of the 12 teams that participated in the Volleyball Men's Superliga (season 2021-2022). Based on their final rankings in the championship, we classified these teams into three tiers: high-performance, intermediate-performance, and low-performance. Subsequently, we examined the dynamics of these matches using Social Network Analysis. We found that the opponent teams' performance levels did not influence the game dynamics. Notably, the eigenvector values were prominently higher for Attack Zones 2 and 4, wherein the middle-blocker jumped to attack close to the setter across all networks. Thus, setters opted for traditional and low-risk strategies to minimize errors, disregarding available information about the skill level of the opposing team, making their offensive tactics predictable.

Epidemiology of injuries in young volleyball athletes: a systematic review.

BACKGROUND: Volleyball is among the five most popular sports in the world. Regardless of level and age, volleyball athletes perform fast high-impact movements such as jumps, landings, and changes in direction, demanding motor and sensory skills to avoid injuries. The available scientific literature provides information regarding the incidence of injuries in volleyball, but the evidence of injuries in young volleyball athletes (12-18 years old) is not well defined. Therefore, a systematic review was conducted to investigate the incidence and prevalence of injuries in young volleyball players. METHODS: This systematic review was conducted according to the PRISMA recommendations and prospectively registered in PROSPERO (ID: CRD42022344623). An electronic search was conducted in the following databases: Web of Science, PubMed, and SportDiscuss via EBSCO in August 2022 and March 2023. Inclusion criteria followed the PICOS acronym: (P) youth volleyball players; (I) volleyball; (C) none; (O) incidence and/or prevalence of injury; and (S) cohort studies. The risk of bias was analysed using the adapted STROBE instrument. RESULTS: Five studies were included in the qualitative analysis. They had a mean methodological quality of 6 (range 4-8) on the modified STROBE scale. Injury incidence was presented in varying ways, ranging from 1.51 injuries/1000 player hours to 12.4 injuries/10,000 athlete exposures (AEs). The prevalence was 1.6 ± 1.7 per 100 AEs. A total sample of 3698 youth volleyball athletes predominantly females was found. The body sites with the highest rate of injuries were the ankle, the distal portion of the upper limbs (wrist/hand/fingers) and the knee, respectively. CONCLUSION: There was remarkable variability in the rate of injuries and the form of presentation between the studies. In addition, junior volleyball athletes had lower injury rates compared to other sports practised in high school, and older athletes had higher injury rates.

Morphological Characteristics of Elite Female Volleyball Players Under 19 / Características Morfológicas de Jugadoras de Voleibol de Élite Menores de 19 Años

SUMMARY: The aim of the article is to determine the differences in morphological characteristics and jumping abilities between female volleyball players who play for different national teams. The sample consists of 48 elite female volleyball players from four different national teams which participated in European championship qualifications. The variables studied were: body height, mass, body mass index, standing reach and spike reach. The results show differences in body mass index, standing reach and spike reach. These differences are related to the needs of the different positions with regard to the actions they execute. In conclusion morphological parameters are important components of performance in many sports (volleyball). Different sports disciplines require different body parameters and body structure for maximum performance.

El objetivo del artículo fue determinar las diferencias en las características morfológicas y habilidades de salto entre las jugadoras de voleibol que juegan en diferentes selecciones nacionales. La muestra consta de 48 jugadoras de voleibol de élite de cuatro equipos nacionales diferentes que participaron en las clasificaciones del campeonato europeo. Las variables estudiadas fueron: altura corporal, masa, índice de masa corporal, alcance de pie y alcance de remate. Los resultados muestran diferencias en el índice de masa corporal, el alcance de pie y el alcance de punta. Estas diferencias están relacionadas con las necesidades de los distintos cargos en cuanto a las acciones que ejecutan. En conclusión, los parámetros morfológicos son componentes importantes del rendimiento en muchos deportes (voleibol). Las diferentes disciplinas deportivas requieren diferentes parámetros corporales y estructuras corporales para un rendimiento máximo.

Condutas cinesioterapêuticas no tratamento das tendinopatias do manguito rotador em atletas de voleibol de quadra / Kinesiotherapeutic conducts in the treatment of rotator cuff tendinopathies in indoor volleyball athletes

Introdução: o ombro do jogador de voleibol é suscetível a lesões resultantes de sobrecargas biomecânicas e movimentos repetitivos. As frequentes queixas de dor nessa articulação evidenciam o elevado volume de ações motoras unilaterais em alta velocidade acima da cabeça, atingindo o manguito rotador (MR) e gerando limitação funcional na prática desportiva. As tendinopatias do MR, formado pelos músculos subescapular, redondo menor, infraespinhal e supraespinhal, atingem comumente os tendões do supraespinhal e do infraespinhal. Objetivo: descrever as condutas cinesioterapêuticas utilizadas no tratamento das tendinopatias do MR em atletas de voleibol de quadra. Metodologia: pesquisaram-se as bases de dados MEDLINE, SciELO e BVS. Descritores: lesões do ombro, manguito rotador, atletas, voleibol e Terapia por Exercício (pesquisados em inglês), associados dois a dois ou três a três, dentre os quais o termo atletas ou voleibol sempre foi mantido. Foram incluídos artigos de revisão, artigos originais, ensaios clínicos e estudos de coorte publicados em português e inglês, entre os anos de 2009 e 2019. Resultados: inicialmente a busca resultou em 480 artigos. Após o processo de seleção, seis estudos foram revisados na íntegra e incluídos na síntese qualitativa. Conclusão: as principais condutas cinesioterapêuticas descritas foram: fortalecimento dos rotadores externos, dos músculos do tronco, da coluna e periescapulares, alongamento da região posterior do ombro e mobilizações articulares.

Introduction: the volleyball player's shoulder is susceptible to injuries resulting from biomechanical overloads and repetitive movements. The frequent complaints of pain in this joint highlight the high volume of unilateral motor actions at high speed above the head, reaching the rotator cuff (RC) and generating functional limitation in sports. RC tendinopathies, formed by the subscapularis, teres minor, infraspinatus and supraspinatus muscles, commonly affect the supraspinatus and infraspinatus tendons. Objective: to describe the kinesiotherapeutic conducts used in the treatment of RC tendinopathies in indoor volleyball athletes. Methodology: MEDLINE, SciELO and VHL databases were searched. Descriptors: shoulder injuries, rotator cuff, athletes, volleyball and Exercise Therapy (searched in English), associated two by two or three by three, among which the term athletes or volleyball was always maintained. Review articles, original articles, clinical trials and cohort studies published in Portuguese and English between 2009 and 2019 were included. Results: initially the search resulted in 480 articles. After the selection process, six studies were fully reviewed and included in the qualitative synthesis. Conclusion: the main kinesiotherapeutic procedures described were strengthening of the external rotators, trunk, spine and periscapular muscles, stretching of the posterior region of the shoulder and joint mobilizations.

Inter e intra-variability of the best ranked teams: A network analysis in male high-level volleyball.

The present research objective was to analyze the offensive phase from Complex I in high-level male volleyball teams in a macro- and micro-level view, through the inter e intra-team variability analysis of eight best teams of the 2018 Men's Volleyball World Championship over the social network analysis and eigenvector centrality. The sample consisted of 22 matches and 2,743 offensive actions, resulting in 8 sub-networks with 368 nodes and 6221 edges. The results showed from macro view the variables that presented highest centrality values were Attack Zone 4 (range 0.56-0.90), Attack Tempo 2 (0.65-0.87), Power Attack (0.62-0.94), No Touch Block (0.61-1), Attack Effect Continuity (0.59-0.94), and Middle Blocker Centralized (0.60-0.95). In a micro view, Reception Effect, Play Position, Reception Zone, and Block Composition showed high variability in each sub-network. The intra- and inter-team variability presented the importance of to respect each team idiosyncrasies and to consider the different approaches to the game and success.

Pain and Psychological Readiness to Return to Sport in Elite Volleyball Players: A Cross-Sectional Study.

Pain is modulated by multiple factors. A relevant psychological process peculiar to athletes and which could be associated with pain is Psychological Readiness to Return to Sport (PRRS). The analysis of this association in competition context is particularly important. OBJECTIVE: To determine the correlation between the PRRS and pain intensity in elite volleyball players during their participation in a continental sporting event. METHODS: A cross-sectional study was conducted. Data from 107 male volleyball players (23.50 ± 4.08 years of age) participating in the South American Volleyball Championship were used. The athletes answered a self-report questionnaire on the day the championship began regarding their history of injuries in the previous six months. The athletes who declared injuries were asked about the current pain intensity using the Pain Numeric Rating Scale (NRS) and Psychological Readiness to Return to Sport using the Injury-Psychological Readiness to Return to Sport scale (I-PRRS). RESULTS: 43.93% (n = 47) of the athletes (23.70 ± 3.54 years) reported an injury in the six months prior to the championship. They presented a median on the NRS of three (interquartile range (IQR), 2-5), and 54 (IQR, 46-58) on the I-PRRS. The Spearman's Rho correlation test showed an inversely and moderate correlation (rs = -0.36; p = 0.011; CI: -0.64--0.08) between pain intensity and PRRS. CONCLUSIONS: In male elite volleyball players who participate in a Continental Championship in South America, higher levels of PRRS was correlated to lower pain intensity.

Are Previous Joint Injuries Associated with Muscle Performance in Volleyball Athletes? / Lesões articulares prévias são associadas ao desempenho muscular de jogadores de voleibol?

Abstract Objective The aim of the present study is to determine whether previous shoulder and knee injuries were associated with isokinetic fatigue index and agonist/antagonist ratio of shoulder internal/external rotators and knee flexors/extensors in male volleyball athletes. Methods The current study is a cross-sectional investigation of 49 male elite volleyball players competing at a high level in Brazil. Isokinetic fatigue index and agonist/antagonist profiles were assessed during the preseason. Additionally, in order to record previous injuries, the athletes answered a standardized questionnaire. We conducted a receiver operating characteristic (ROC) curve analysis to determine the association strength and the clinically relevant cut-off point for variables presenting statistical significance for the area under the curve (AUC) (α = 0.05). An independent t-test was used to compare isokinetic variables between athletes with and without previous injury (α = 0.05). Results The results of the ROC curve analysis indicated that hamstring fatigue index values at 300o/s were associated with the presence of previous knee injury (area under the curve [AUC] = 73%, p= 0.004), and shoulder external rotators fatigue index values at 360°/s were not associated with the presence of previous shoulder injury (AUC = 68%, p= 0.053). Conclusions Elite volleyball athletes who reported previous knee injuries were prone to a higher fatigue index than those reporting no injuries. Knee flexor resistance training might be useful for those athletes who reported knee injuries in the previous season.

Resumo Objetivo O objetivo deste estudo é determinar se lesões prévias de ombro e joelho estavam associadas ao índice de fadiga isocinética e razão agonista/antagonista dos rotadores internos/externos do ombro e flexores/extensores do joelho em jogadores de voleibol. Métodos Esta é uma investigação transversal com 49 jogadores de voleibol de elite que competem em alto nível no Brasil. O índice de fadiga isocinética e os perfis de agonistas/antagonistas foram avaliados durante a pré-temporada. Além disso, para registro de lesões anteriores, os atletas responderam a um questionário padronizado. Conduzimos uma análise da curva de característica de operação do receptor (receiver operating characteristic, ROC) para determinar a força de associação e o ponto de corte clinicamente relevante de variáveis com significância estatística na área sob a curva (AUC) (α = 0,05). Um teste t independente comparou as variáveis isocinéticas entre atletas com e sem lesão prévia (α = 0,05). Resultados Os resultados da análise da curva ROC indicam que os valores do índice de fadiga dos isquiotibiais a 300o/s foram associados à presença de lesão prévia no joelho (área soba a curva [AUC] = 73%, p= 0,004), enquanto os valores do índice de fadiga dos rotadores externos do ombro a 360°/s não foram associados à presença de lesão prévia no ombro (AUC = 68%, p= 0.053). Conclusões Atletas de voleibol de elite que relataram lesões anteriores no joelho estavam propensos a um índice de fadiga maior do que aqueles que não relataram lesões. O treinamento de resistência de flexores do joelho pode ser útil para atletas com relatos de lesões no joelho na temporada anterior.

Efeito do treinamento pliométrico de curta duração no salto vertical e velocidade de sprint em jogadores de vôlei / Effect of short duration plyometric training on vertical jump and sprint speed in volleyball players

INTRODUÇÃO: O voleibol é um esporte de ritmo acelerado que envolve projeções verticais e horizontais da bola por parte do jogador. O uso de treinamento pliométrico é um método popular para melhorar o desempenho dos jogadores. OBJETIVO: O presente estudo visa verificar o efeito de quatro semanas de treinamento pliométrico em jogadores de voleibol. MÉTODO: Estudo randomizado, controlado, de grupos paralelos. Foram triados 39 participantes para participação no estudo, dos quais 30 foram selecionados seguindo os critérios de inclusão e exclusão da pesquisa. Os critérios de inclusão foram: jogadores de voleibol na faixa etária de 18 a 24 anos, de ambos os sexos, experiência de jogo de no mínimo um ano e disponibilidade para participar. Os critérios de exclusão compreendiam jogadores com histórico de lesão nos últimos seis meses, qualquer distúrbio neurológico ou musculoesquelético e qualquer condição psicológica. Os participantes selecionados foram alocados aleatoriamente no Grupo A e Grupo B usando o método de sorteio. O Grupo A recebeu treinamento pliométrico por três dias em uma semana, e o Grupo B foi solicitado a continuar seus exercícios regulares de rotina. A duração total da intervenção foi de quatro semanas. A medida de resultado para o estudo foi a velocidade do sprint e a altura do salto vertical. A velocidade de sprint foi medida pelo teste de sprint de 20 m e a altura do salto vertical foi medida pelo teste sargent jump. A avaliação foi feita no início e no final de quatro semanas. O teste t não pareado foi usado para analisar as diferenças entre os grupos e o teste t pareado foi usado para analisar as diferenças dentro do grupo nas variáveis de resultado. RESULTADOS: O resultado do estudo mostrou uma melhora significativa na altura do salto vertical (MD= -7,133, IC 95% (-12,657,- 1,609) e nenhuma melhora significativa na velocidade do sprint quando comparações entre grupos foram feitas (MD=0,084, 95% IC (-0,177,-,345) com um tamanho de efeito de 0,75 para a altura do salto vertical. A comparação dentro do grupo foi considerada significativa apenas para a altura do salto vertical no Grupo A, e não houve melhora significativa na velocidade de sprint para ambos Grupo A e B. CONCLUSÃO: Quatro semanas de programa pliométrico é eficaz em melhorar a altura do salto vertical e não a velocidade de sprint em jogadores de voleibol.

INTRODUCTION: Volleyball is a fast-paced sport that involves vertical and horizontal projections of the ball by the player. The use of plyometric training is a popular method to enhance performance in players. OBJECTIVE: The present study aims to see the effect of short-duration plyometric training on vertical jump and sprint speed in volleyball players. METHOD: This study is a parallel group randomized controlled trial. Thirtynine participants were screened for participation in the study, of which 30 were selected following the inclusion and exclusion criteria for the study. The inclusion criteria for the study comprised of volleyball players of age group 18 to 24 years, both males and females, with playing experience of at least one year, and willing to participate. The exclusion criteria for the study included players with a history of injury in the last six months, any reported neurological or musculoskeletal disorder, and any psychological condition. The selected participants were randomly allocated to Group A and Group B using the lottery method. Group A was given plyometric training for three days a week and Group B was asked to continue their regular routine exercises and playing schedule. The total duration of the intervention was four weeks. The outcome measure for the study was sprint speed and vertical jump height. Sprint speed was measured by the 20 m sprint test, and the vertical jump height was measured by the Sargent jump test. The assessment was done at the baseline and at the end of four weeks. An unpaired t-test was used to analyze between-group differences, and paired t-test was used to analyze the within-group differences in the outcome variables. The significance level was set as p<0.05. RESULTS: The result of the study showed a significant improvement in vertical jump height (MD= -7.133, 95% CI-12.657, -1.609) and no significant improvement in sprint speed when between-group comparisons were made (MD=0.084, 95%CI -0.177,-.345) with an effect size of 0.75 for vertical jump height. The within-group comparison was found significant only for vertical jump height in Group A, and there was no significant improvement was found in sprint speed for both Group A and B. FINAL CONSIDERATIONS: The short-duration plyometric training is effective in improving the vertical jump height and not the sprint speed in volleyball players. The specificity of plyometric training is important for optimal improvement in sports performance.

Anthropometric profile and body composition of the Mexican olympic beach volleyball team / Perfil antropométrico y composición corporal de la selección olímpica mexicana de voleibol de playa

SUMMARY: The present research corresponds to a cross-sectional descriptive study in the anthropometric field, which allows coaches to develop standards to identify talent and optimize training in the discipline of beach volleyball. Its objective was to define the anthropometric profile and body composition of the Mexican Olympic beach volleyball teams in both sexes. The participants were couples one and two of Mexico in both sexes (defined by FIVB ranking), 4 women and 4 men with average age of 30.25±6.85 and 27.25±7.36 years. The technique used was Heath-Carter´s somatotype method and the anthropometric profile restricted ISAK protocol. Among the findings resulting from the research, unification can be observed in the male morphological characteristics (triceps skinfold, front thigh skinfold, calf skinfold, circumference of relaxed and contracted arm, waist, hip, femur diameter and BMI), as for the somatotype, both sexes of Mexican couples are positioned in mesomorphs-balanced. In relation to other studies consulted, balance in somatotype and muscular development is observed with high performance teams. Weight and height, as well as age, are important variables for the selection of talent and future optimal performance in world and professional volleyball.

La presente investigación corresponde a un estudio descriptivo transversal en el campo antropométrico, que permite a los entrenadores desarrollar estándares para identificar talentos y optimizar el entrenamiento en la disciplina de voleibol de playa. Su objetivo fue definir el perfil antropométrico y la composición corporal de las selecciones olímpicas mexicanas de voleibol de playa en ambos géneros. Los participantes fueron las parejas uno y dos de México en ambos géneros (definidos por ranking Fédération Internationale de Volleyball), 4 mujeres y 4 hombres con edad promedio de 30.25±6.85 y 27.25±7.36 años. La técnica utilizada fue el método del somatotipo de Heath-Carter y el protoolo ISAK del perfil antropométrico restringido. Entre los hallazgos resultantes de la investigación, se puede observar una unificación en las carácteristicas morfológicas masculinas (pliegue cuatáneotricipital, pliegue cutáneo anterior del muslo, pliegue citáneo de la pantorrila, circunferencia del brazo relajado y contraído, cintura, cadera, diámetro del fémur e IMC), en cuanto al somatotipo, ambos sexos de las parejas mexicanas se posicionan en mesomorfos-equilibrados. En relación a otros estudios consultados, se observa equilibrio en somatotipo y desarrollo muscular con equipos de alto rendimiento. El peso y la altura, así como la edad, son variables importantes para la selección del talento y en el futuro desempeño óptimo en el voleibol mundial y profesional.

Morphological characteristics and motor abilities differences: first and second Montenegrin league female volleyball players / Características morfológicas y diferencias en habilidades motoras de jugadoras de voleibol de la primera y segunda liga montenegrina

SUMMARY: The aim of this study is to determine whether there is a statistically significant difference in morphological characteristics and motor abilities of the first and second league female volleyball players. The sample comprised of 20 players of the first and 20 players of the second league. Only those female volleyball players who completed the whole measurement program were included in the sample. Subjects underwent measurement of morphological characteristics (7 variables) and motor abilities (8 variables). Statistically significant differences were determined with t-test for independent samples. The results of the research show that there are no statistically significant differences in morphological characteristics and motor abilities of the first and second league female volleyball players. The difference was found only in the variable for assessing balance in favor of first league female volleyball players.

El objetivo de este estudio fue determinar si existe una diferencia estadísticamente significativa en las características morfológicas y habilidades motoras de las jugadoras de voleibol de primera y segunda liga. La muestra estuvo conformada por 20 jugadores de primera y 20 jugadores de segunda liga. Solo se incluyeron en la muestra aquellas jugadoras de voleibol que completaron todo el programa de medición. Los sujetos se sometieron a la medición de las características morfológicas (7 variables) y habilidades motoras (8 variables). Las diferencias estadísticamente significativas se determinaron con la prueba t para muestras independientes. Los resultados de la investigación mostraron que no existían diferencias estadísticamente significativas en las características morfológicas y habilidades motrices de las jugadoras de voleibol de primera y segunda liga. La diferencia se encontró solo en la variable para evaluar el equilibrio a favor de las jugadoras de voleibol de primera división.

Validação da Escala de Autoeficácia no Voleibol para atletas de base (VSES-B) / Validación de la Escala de Autoeficacia de Voleibol para deportistas jóvenes (VSES-B) / Validation of the Volleyball Self-Efficacy Scale for youth athletes (VSES-B)

The aim of this study was to psychometrically test the Volleyball Self-Efficacy Scale for Brazilian athletes from youth categories. The study was conducted in four stages, with four different sample groups. For content-based evidence analysis, a group of 20 athletes participated, with a mean age of 14.30 ± 1.17 years and practice time of 4.60 ± 2.10 years, for semantic analysis, after a group of four students, with a mean age of 35.75 ± 12.23 years and experience time 25.0 ± 11.02 years, to verify the semantic analysis and another group of 20 athletes, with a mean age of 14.45 ± 1.30 years and practice time 5.50 ± 2.20 years for the pilot study. To test the evidence based on the internal structure and the evidence based on other variables, a group of 454 base athletes, of both sexes, with a mean age of 14.33 ± 1.18 years and practice time 3.79 ± 2.13 years was verified. The results pointed to evidence based on content, evidence based on internal structure and evidence based on other variables, through convergent validity (collective efficacy and results of Confirmatory Factor Analysis) and discriminant (Average Variance Extracted and correlation between the dimensions of the VSES-B). The validation process of the Volleyball Self-Efficacy Scale for Base Athletes allows us to conclude that the instrument has good psychometric properties to measure self-efficacy, considering technical, tactical, conditioning and psychological skills of emotional cognitive self-control that are part of the sport context of the modality. In addition, it provides relevant information for the development of future psychometric research based on contemporary validity references.

El objetivo de este estudio fue probar psicométricamente la Escala de Autoeficacia del Voleibol para deportistas brasileños de categorías juveniles. El estudio se llevó a cabo en cuatro etapas, con cuatro grupos de muestra diferentes. Para el análisis de evidencia basada en contenido, participó un grupo de 20 deportistas, con una edad media de 14.30 ± 1.17 años y tiempo de práctica de 4.60 ± 2.10 años, para el análisis semántico, después de un grupo de cuatro académicos, con una edad media de 35.75 ± 12.23 años y tiempo de experiencia 25.0 ± 11.02 años, para verificar el análisis semántico y otro grupo de 20 deportistas, con una edad media de 14.45 ± 1.30 años y tiempo de práctica 5.50 ± 2.20 años para el estudio piloto. Para probar la evidencia basada en la estructura interna y la evidencia basada en otras variables, se verificó un grupo de 454 atletas de base, de ambos sexos, con una edad media de 14.33 ± 1.18 años y tiempo de práctica 3.79 ± 2.13 años. Los resultados apuntaron a evidencia basada en contenido, evidencia basada en estructura interna y evidencia basada en otras variables, mediante validez convergente (eficacia colectiva y resultados del Análisis Factorial Confirmatorio) y discriminante (Varianza Media Extraída y correlación entre las dimensiones del VSES-B). El proceso de validación de la Escala de Autoeficacia de Voleibol para Atletas de Base nos permite concluir que el instrumento tiene buenas propiedades psicométricas para medir la autoeficacia, considerando las habilidades técnicas, tácticas, condicionantes y psicológicas de autocontrol cognitivo emocional que forman parte del contexto deportivo de la modalidad. Además, proporciona información relevante para el desarrollo de futuras investigaciones psicométricas basadas en referencias de validez contemporáneas.

O objetivo deste estudo foi testar psicometricamente a Escala de Autoeficácia no Voleibol para atletas brasileiros de categorias de base. O estudo foi conduzido em quatro etapas, com quatro diferentes grupos amostrais. Para análise das evidências baseadas no conteúdo, participaram um grupo de 20 atletas, com média de idade 14.30 ± 1.17 anos e tempo de prática 4.60 ± 2.10 anos, para análise semântica, logo após um grupo de quatro acadêmicos, com média de idade 35.75 ± 12.23 anos e tempo de experiência 25.0 ± 11.02 anos, para verificação da análise semântica e outro grupo de 20 atletas, com média de idade 14.45 ± 1.30 anos e tempo de prática 5.50 ± 2.20 anos para o estudo piloto. Para testar as evidências baseadas na estrutura interna e as evidências baseadas em outras variáveis, um grupo de 454 atletas de base, de ambos os sexos, com média de idade 14.33 ± 1.18 anos e tempo de prática 3.79 ± 2.13 anos foi verificado. Os resultados apontaram para evidências baseadas no conteúdo, evidências baseadas na estrutura interna e evidências baseadas em outras variáveis, por meio da validade convergente (eficácia coletiva e resultados da Análise Fatorial Confirmatória) e discriminante (Variância Média Extraída e correlação entre as dimensões da VSES-B). O processo de validação da Escala de Autoeficácia no Voleibol para Atletas de Base permite concluir que o instrumento possui boas propriedades psicométricas para mensurar a autoeficácia, considerando aspectos técnicos, táticos, condicionantes e habilidades psicológicas de autocontrole cognitivo emocional que fazem parte do contexto esportivo da modalidade. Além disso, fornece informações relevantes para o desenvolvimento de pesquisas psicométricas futuras baseadas em referências contemporâneas de validade.