Effects of different aerobic exercise training on glycemia in patients with type 2 diabetes: A protocol for systematic review and meta analysis.

BACKGROUND: Type 2 diabetes is an emergent worldwide health crisis, and rates are growing globally. Aerobic exercise is an essential measure for patients with diabetes, which has the advantages of flexible time and low cost. Aerobic exercise is a popular method to reduce blood glucose. Due to the lack of randomized trials to compare the effects of various aerobic exercises, it is difficult to judge the relative efficacy. Therefore, we intend to conduct a network meta-analysis to evaluate these aerobic exercises. METHODS: According to the retrieval strategies, randomized controlled trials on different aerobic exercise training will be obtained from China National Knowledge Infrastructure, WanFang, SinoMed, PubMed, Web of Science, EMBASE, and Cochrane Library, regardless of publication date or language. Studies were screened based on inclusion and exclusion criteria, and the Cochrane risk bias assessment tool will be used to evaluate the quality of the literature. The network meta-analysis will be performed in Markov Chain Monte Carlo method and carried out with Stata14 and OpenBUGS software. Ultimately, the evidentiary grade for the results will be evaluated. RESULTS: Eighteen literatures with a total of 1134 patients were included for the meta-analysis. In glycemia assessment, Tennis (standard mean difference = 3.59, credible interval 1.52, 5.65), had significantly better effects than the named control group. Tennis (standard mean difference = 3.50, credible interval 1.05, 5.59), had significantly better effects than the named Taiji group. CONCLUSION: All together, these results suggest that tennis may be the best way to improve blood glucose in patients with type 2 diabetes. This study may provide an excellent resource for future control glycemia and may also serve as a springboard for creative undertakings as yet unknown.

Competition scheduling patterns of emerging elite players in professional men's tennis.

This study analysed the competition scheduling of future top 100 and 250 ranked tennis players from international tournament profiles at ages 13-18y. Retrospective tournament data were analysed for 165 future top 100 (T100) and top 250 (T250) males during their junior international tournament eligibility. Tournament/match volumes, days between tournaments and consecutive tournaments (<8 days between) were quantified for junior and professional events. A two-way (age x ranking) analysis of variance determined the effects of age and ranking group on tournament profiles. Significant interactions were observed for tournament volumes across junior and professional categories, with T100 players competing in professional tournaments earlier (p<0.05). No significant interactions were observed for volumes of junior or professional matches played (p>0.05). No significant interactions were observed for days between tournaments or consecutive tournaments played (p>0.05). Significant main effects were observed for age on tournament volume, with junior and professional volume increasing at age 15 and 17, respectively (p<0.05). Higher match volumes were observed for T100 players compared to T100-S players (p<0.05). Competition schedules intensify at age 15 compared with ages 13-14y through increased tournament and match volumes. Future T100 players' transition to professional tournaments earlier, alongside greater engagement in higher quality junior tournaments.

A person-centered approach to achievement goal orientations in competitive tennis players: Associations with motivation and mental toughness.

BACKGROUND: Research on achievement goal orientations in sport has typically relied on the use of variable-centered approaches that tend to overlook population heterogeneity. In this study, we used a person-centered approach to identify subgroups of competitive tennis players according to unique combinations of achievement goal orientations and tested for subgroup differences in motivation and mental toughness. METHODS: A sample of 323 competitive tennis athletes (69.35% male) between 15 and 25 years of age (17.60 ± 2.40 years, mean ± SD) completed the 3 × 2 Achievement Goal Questionnaire for Sport, Sport Motivation Scale II, and Mental Toughness Index. Latent profile analysis was used to identify unique combinations of achievement goal orientations. Comparisons between latent subgroups on autonomous motivation, controlled motivation, and mental toughness were performed using analysis of variance. RESULTS: Latent profile analysis supported 3 distinct patterns of achievement goal profiles that were primarily distinguishable based on valence of competence (i.e., approach vs. avoidance). Analyses of variance indicated that athletes who were classified into subgroups that endorsed approach types of goals (regardless of the types of avoidance goals they endorsed) reported higher levels of autonomous motivation and mental toughness. CONCLUSION: Results indicated that athletes tend to pursue a number of achievement goals collectively rather than in isolation. Although approach goals are more commonly linked to adaptive psychological functioning and positive outcomes, avoidance goals may also be associated with desirable psychological characteristics if they are pursued in conjunction with approach types of achievement goals.

Comparison of intensity and post-effort response in three interval trainings in young tennis players: running interval, specificinterval, and specific intermittent training / Comparación de la intensidad y la respuesta post-esfuerzo en tres entrenamientos interválicos en jóvenes tenistas: interválico de carrera, interválico específico e intermitente específico

INTRODUCTION: In recent years, considerable interest has been shown in adapting training to the specific characteristics of tennis. The use of intermittent exercise seems to adapt better to the sport's work/recovery structure and using specific movements allows for local adaptations and complex work. Nevertheless, we need to achieve a level of intensity that is at least similar to what is achieved when continuous running is used. The ability to recover between points is also a decisive factor in terms of performance. Our hypothesis is that recovery depends on stimulus type, which means the most suitable stimuli must be chosen to improve this capacity. MATERIAL AND METHOD: Our study's goal was to compare the intensity and post-effort behaviour triggered by three types of exercise: continuous running with 2-minute intervals (GIT ), rallies with 2-minute intervals (SIT ) and intermittent rallies (SIIT ). We measured heart rate (HR) and blood lactate levels during the three exercises, as well as the recovery to 130 beats and in the first 10 and 20 seconds post-effort. RESULTS: Heart rate intensity was significantly higher in SIT than in GIT and lactate levels were higher in both SIT and SIIT compared to GIT. Heart rate recovery is significantly slower in both specific exercises, increasing in the first 10 and 20 seconds with SIIT. DISCUSSION: We have reached the conclusion that specific training led to greater intensity in the specific exercises. Post-effort response is slower in the specific trainings and paradoxical in the initial seconds of intermittent training

INTRODUCCIÓN: En los últimos años se ha producido un gran interés por adaptar el entrenamiento a la especificidad del tenis. El uso de ejercicios intermitentes parece adaptarse más a la estructura de trabajo/recuperación de este deporte que las actividades continuas. A su vez, utilizar movimientos específicos permite adaptaciones locales y trabajar de forma compleja. Sin embargo, se necesita alcanzar un nivel de intensidad que sea al menos similar al que se logra cuando se utiliza la carrera continua. La capacidad de recuperar entre puntos es un factor decisivo en el rendimiento. Nuestra hipótesis es que la recuperación puede ser diferente según sea el tipo de estímulo y que habrá que escoger los más adecuados para mejorar esta capacidad. No obstante, es necesario que estos entrenamientos tengan una intensidad al menos similar a cuando se utiliza la carrera continua. MATERIAL Y MÉTODO: Nuestro objetivo en este estudio es comparar la intensidad y el comportamiento post-esfuerzo de tres ejercicios: carrera continua con intervalos de 2 minutos (GIT ), golpeo de bolas con intervalos de 2 minutos (SIT ), golpeo de bolas con intermitencias (SIIT ). Hemos medido la HR y el lactato durante los tres ejercicios y la recuperación a 130 pulsaciones, y en los 10 y 20 segundos post-esfuerzo. RESULTADOS: La intensidad cardiaca fue significativamente mayor en SIT que en GIT, y el lactato superior en SIT y SIIT, respecto a GIT. La recuperación cardiaca es significativamente más lenta en ambos ejercicios específicos, llegando a incrementarse en los 10 y 20 segundos iníciales en SIIT. DISCUSIÓN: Concluimos que con el entrenamiento específico se ha alcanzado una elevada intensidad en los trabajos específicos. La respuesta post-esfuerzo es más lenta en los entrenamientos específicos, y paradójica en los primeros segundos en el entrenamiento intermitente

'In search of lost time': Identifying the causative role of cumulative competition load and competition time-loss in professional tennis using a structural nested mean model.

Injury prevention is critical to the achievement of peak performance in elite sport. For professional tennis players, the topic of injury prevention has gained even greater importance in recent years as multiple of the best male players have been sidelined owing to injury. Identifying potential causative factors of injury is essential for the development of effective prevention strategies, yet such research is hampered by incomplete data, the complexity of injury etiology, and observational study biases. The present study attempts to address these challenges by focusing on competition load and time-loss to competition-a completely observable risk factor and outcome-and using a structural nested mean model (SNMM) to identify the potential causal role of cumulative competition load on the risk of time-loss. Using inverse probability of treatment weights to balance exposure histories with respect to player ability, past injury, and consecutive competition weeks at each time point; the SNMM analysis of 389 professional male players and 55,773 weeks of competition found that total load significantly increases the risk of time-loss (HR = 1.05 per 1,000 games of additional load 95% CI 1.01-1.10) and this effect becomes magnified with age. Standard regression showed a protective effect of load, highlighting the value of more robust causal methods in the study of dynamic exposures and injury in sport and the need for further applications of these methods for understanding how time-loss and injuries of elite athletes might be prevented in the future.

Burnout Syndrome Risk in Child and Adolescent Tennis Players and The Role of Adherence to the Mediterranean Diet.

This cross-sectional study examined the impact of adherence to Mediterranean diet on burnout syndrome risk in 94 athletes 8-15 years old. Diet pattern and burnout syndrome risk were assessed through the Athlete Burnout Questionnaire and the KIDMED Questionnaire. 55.3% of girls and 16.1% of boys had a high risk of burnout syndrome and the risk increased with age. Of the 78.7% with low adherence to Mediterranean diet, 31.1% showed no risk of burnout syndrome, 33.8% had a moderate risk, and 35.1% high risk. Of the 21.3% with a high adherence to Mediterranean diet, 35% had no risk of burnout syndrome, 45% had a moderate risk, and 20% had a high risk. Participants with moderate/high burnout syndrome risk were more likely to be girls and spend a higher number of hours watching television or playing video games. There is not enough statistical evidence in this study to reject the independence between the level of adherence to the Mediterranean diet and the risk of burnout syndrome in children, except in the case of daily consumption of fresh or cooked vegetables.

The Winning Probability of a Game and the Importance of Points in Tennis Matches.

Purpose: This study builds a stochastic model of a discrete-time Markov chain (DTMC) that fits well with a dataset of professional playing records. Methods: The point-by-point dataset of Men's single matches played in the Association of Tennis Professionals (ATP) tour from 2011 to 2015 is analyzed. A long-debated assumption on the iid-ness in the point winning probability of the server is statistically tested. A DTMC model is then developed to analyze the dataset further. Results: The statistical test results indicate that the identicality of point winning probabilities is not a valid assumption. For example, the server's point winning probability from scores 40:0, 30:15, 15:30, and 0:40 are significantly different. On the other hand, the independence is a generally valid assumption except for 40:15 where who won the previous point influences the point winning probability. Game winning probabilities and the importance of each point in winning a game are analyzed using the DTMC model by court surfaces and player groups of the different levels of serve effectiveness. Conclusion: Extensive empirical validation concludes unsealed debates over the stochastic models for tennis. The presented results reveal interesting properties in professional tennis matches.

Efecto del entrenamiento de imágenes motoras en el rendimiento del servicio de tenis en atletas de tenis jóvenes / Effect of motor imagery training on tennis service performance in young tennis athletes / Efeito do treinamento em imagens motoras no desempenho do serviço de tênis em jovens atletas de tênis

The objective of the study was to analyse the effect of motor imagery training on tennis service performance among tennis athletes. Participants were twenty-eight young male tennis players, randomly divided into two groups: imagery training (ITG, n = 14) and control group (CG, n = 14). It was a controlled and randomized experimental investigation, lasting eight weeks. the CG watched videos about the history of the Olympics, while ITG did motor imagery training. the tennis service performance was obtained by the product between accuracy and stroke velocity [accuracy x mean velocity of all strokes (km/h)]. the effect of group vs time interaction (p <.01) was identified for all performance indicators [accuracy, running speed and performance (precision x speed)], with improvement only in ITG (p = 01). It concluded that motor imagery training would be considered an effective strategy to enhance the tennis service performance among male tennis players

El objetivo del estudio fue analizar el efecto del entrenamiento de imágenes en el rendimiento del tenis de servicio entre los atletas de tenis. Los participantes fueron 28 tenistas jóvenes, divididos aleatoriamente en dos grupos: formación en imágenes (ITG, n = 14) y grupo de control (CG, n = 14). Es una investigación experimental controlada y aleatorizada, que dura ocho semanas. El CG miró videos sobre la historia de los Juegos Olímpicos, mientras que ITG hizo entrenamiento de imágenes. El rendimiento del tenis de servicio se obtuvo por el producto entre precisión y velocidad de carrera [precisión x velocidad media de todos los golpes (km/h)]. Se identificó el efecto de interacción grupo contra tiempo (p < .01) para todos los indicadores de rendimiento [precisión, velocidad de carrera y rendimiento (precisión x velocidad)], con mejoría solo en ITG (p = .01). Se concluyó que el entrenamiento con imágenes se puede considerar una estrategia efectiva para mejorar el rendimiento del tenis entre los tenistas

O objetivo do estudo foi analisar o efeito do treinamento imaginário sobre o desempenho do saque em atletas de tênis. Participaram vinte e oito jovens atletas de tênis, randomicamente divididos em dois grupos: treinamento imaginário (TI, n =14) e grupo controle (GC, n = 14). Trata-se de investigação experimental randomizada e controlada, com duração de oito semanas. O GC assistiu vídeos sobre a história das Olimpíadas, ao passo que o TI realizou o treinamento imaginário. O desempenho do saque foi mensurado pelo produto entre acurácea e velocidade da bola [acurácea x velocidade média da bola (km/h]. Foi revelado efeito de interação grupo vs. tempo (p < .01) para todos os indicadores de desempenho [acurácea, velocidade da bola e desempenho (precisão vs. velocidade)], com melhora somente para o TI (p = .01). Concluiu-se que o treinamento imaginário pode ser considerado uma estratégia efetiva para potencializar o desempenho do saque em atletas de tênis do sexo masculino

Validación española del cuestionario de locus de control en deporte infantil / Spanish validation of the Locus of control questionnaire in sport for children

El locus de control ha sido estudiado en el deporte, sin embargo no existía un instrumento válido para evaluarlo en deporte infantil. Este estudio lleva a cabo la validación española del Children's Sport Locus of Control Scale (CSLCS) que desarrollaron Tsai y Hsieh (2015). La adaptación presenta dos fases: una primera exploratoria con 248 niños entre 7 y 16 años para observar el comportamiento cualitativo de los ítems; y una segunda con 221 deportistas entre 8 y 22 años en la que se modificó el cuestionario para ajustarlo a los resultados obtenidos. Se obtiene una escala final de 10 ítems, con 5 ítems por dimensión (interna y externa), que presenta un ajuste adecuado. Los resultados demuestran que la versión española de la escala posee cualidades psicométricas adecuadas para ser utilizada en la investigación y la práctica aplicada en la evaluación deportiva infantil

Locus of control has been studied in the sport context, however there was no valid instrument to evaluate it in children's sport. This study adapts into Spanish and validates the Children's Locus of Control Scale for Sport (CSLCS) in the Spanish language. This CSLCS was developed by Tsai y Hsieh (2015). The adaptation has two phases: an initial screening of 248 children between the ages of 7 and 16 to observe the qualitative behavior of the items; and a second one with 221 athletes with children between the ages of 8 and 22 in which the questionnaire was modified to fit the results. A final 10-item scale was obtained, with 5 items per dimension (internal and external), which presents an adequate fit. Results show that the Spanish version of the scale possesses adequate psychometric qualities for its use in research and applied fields in child's sport evaluation

Time-use and environmental determinants of dropout from organized youth football and tennis.

BACKGROUND: Many adolescents drop out of organized sports. Lack of motivation and competing priorities are known as important reasons for dropout. However, time use factors as well as environmental determinants have been largely neglected in the current literature on dropout from youth sports. The aim of this study is to investigate how (changes in) time use and characteristics of the physical environment determine dropout from football and tennis among adolescents. METHODS: Data on time use and background characteristics were collected through online surveys in 2015 and 2016 among adolescents aged 13-21 (N = 2555), including both the dropped outs and those who still continued membership of their football or tennis clubs. Physical environmental determinants (travel distance to the sports club, and neighbourhood density) were measured objectively. Binary logistic regression analyses were carried out for football and tennis separately to examine the associations between time use (time spent on various activities and changes related to the school and job situation), and environmental factors on the probability of dropping out from sports. RESULTS: Time spent on sports outside the context of the sports club, and time spent on social or voluntary activities at the sports club was positively associated with continuing being football and tennis members. Tennis players who changed schools or participated in two sports at the same time had a higher probability of dropping out, whereas tennis players who travelled greater distances from home to the tennis club were less likely to drop out. CONCLUSIONS: Determinants of dropout differed between football and tennis. However, time use variables were important predictors of dropout from football as well as tennis, whereas environmental determinants hardly contributed to the prediction of dropout. To keep youths involved in organized sports, this study recommends that sports professionals should: 1) offer flexibility in training and competition schedules, 2) stimulate participation in social activities and voluntary work at the sports club, 3) pay special attention to their needs and preferences, and 4) encourage possibilities to practice and play sports outside of regular training hours, for instance at the sports club or at playgrounds or parks in the neighbourhood.

Tennis serve performances at break points: Approaching practice patterns for coaching.

Tennis comprises specific match situations when winning the next point is crucial. These big points can decide about a win or loss and, thus, reasonably arouse mental stress. Break points (BPs) are considered as big points and the outcome is influenced by, among a variety of other factors, the serve, which is well accepted being one of the dominant strokes in Men's tennis. In this study, we examined the serve behaviour for male players in the Wimbledon tournament 2016 to investigate the possible impacts of presumed mental stress within the situation of BPs, and further, if winning players perform better than losing players. A total of 28.843 points were analysed and divided into BP (n = 2.035) and non-break points - referred to as regular points (RP; n = 26.808).

Return to Sport After Shoulder Arthroplasty in Recreational Athletes: A Systematic Review and Meta-analysis.

BACKGROUND: One of the most frequent demands from patients after shoulder replacement surgery is to return to sport. PURPOSE: To determine the rate of return to sport after shoulder arthroplasty (total shoulder arthroplasty, reverse shoulder arthroplasty, hemiarthroplasty) in recreational athletes. STUDY DESIGN: Meta-analysis and systematic review. METHODS: The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines were followed to perform this systematic review and meta-analysis of the results in the literature as well as the presentation of results. A search of the literature was performed in the electronic databases MEDLINE, Scopus, Embase, and the Cochrane Library. The quality of the included studies was evaluated according to the MINORS (Methodological Index for Nonrandomized Studies) score. Inclusion criteria were studies in English evaluating return to sport after shoulder replacement surgery and on patients practicing a sport regularly, whatever the level, with all ages and sports included. The main criterion was the rate of patients who returned to a sport activity. RESULTS: Nine studies were selected among the 35 identified, including a total of 613 patients (39% male and 61% female) with a mean age of 71.7 years (range, 22.6-92.6 years). All the included patients practiced sports before surgery. The most common reported sports were golf (n = 140), swimming (n = 128), and tennis (n = 54). The mean rate of return to sport was 80.7% (range, 57.1%-97.3%). All patients who returned to sport were practicing in the 3 months before surgery. No radiological data were reported in the literature. The subgroup analysis for resuming golf after shoulder arthroplasty revealed a rate of return to sport of 79.2% (95% CI, 62.9%-89.5%). In the swimming subgroup, the rate was 75.6% (95% CI, 61.3%-85.8%) and in the tennis subgroup was 63.5% (95% CI, 34.1%-85.5%). The subgroup analysis for reverse shoulder arthroplasty reported a lower rate of return to sport than for all types of shoulder arthroplasty combined: 76.5% (95% CI, 60%-87%) versus 80.7% (95% CI, 70.9%-87.8%), respectively. CONCLUSION: Most patients returned to sport after surgery, and all who returned to sport were practicing their sport in the 3 months before surgery. No radiological data were reported in the literature.

Efectos del entrenamiento de fuerza en la velocidad de golpeo en tenistas jóvenes / Effects of strength training on hitting speed in young tennis players

La velocidad de golpeo es uno de los factores fundamentales para el rendimiento en tenis competitivo. El objetivo del estudio fue determinar el efecto de dos métodos de entrenamiento de fuerza sobre la velocidad de golpeo en tenis. 20 jugadores de nivel regional (promedio ± SD: edad 15.5 ± 0.9 años; peso 61.4 ± 7.6 Kg; talla 170.3 ± 9.4 cm) fueron asignados aleatoriamente en tres grupos. Durante 8 semanas a 3 días por sem-1, un grupo realizó un entrenamiento adicional con sobrecargas (SC), un segundo grupo entrenamiento adicional mediante lanzamientos con balón medicinal y banda elástica (L) y un tercer grupo (C, control) únicamente realizó el entrenamiento técnico-táctico. Todos los grupos mejoraron los niveles de fuerza, excepto el grupo control. El grupo SC obtuvo mayores incrementos en la velocidad de servicio. El grupo L mejoró la velocidad de lanzamiento de balón medicinal aunque no hubo transferencia en la velocidad de golpeo (AU)

Nowadays, hitting speed is an important component of tennis performance. The purpose of this study was to determine the effect of two different strength training methods on hitting speed. 20 tennis players were (mean ± SD: age 15.5 ± 0.9 years; weight 61.4 ± 7.6 kg; height 170.3 ± 9.4 cm) randomly divided into 3 groups. During 8 weeks with a frequency of 3 days per week, the first group (SC) performed one additional training with overloads, the second group (L) completed an additional training with medicine ball and elastic band; and the third group (C, control), only completed the technical-tactical training. Each group increased their strength, except the control group. SC group had the best improvement in serve speed. L group increased the strength levels although there was no transfer from the improved strength to the hitting speed (AU)

Incidencia de lesiones en tenistas profesionales. Análisis de las condiciones médicas ocurridas durante 6 ediciones de ATP 250 de Buenos Aires / Incidence of professional tennis injuries

Objetivo: conocer la incidencia de lesiones y analizar las condiciones médicas que sufrieron los tenistas que jugaron el ATP de Buenos Aires durante los años 2011 a 2016. Material y Método: Se realizó un análisis retrospectivo de las condiciones médicas que ocurrieron durante la disputa de 6 torneos consecutivos, y se obtuvo la incidencia de lesiones. Resultados: El ATP de Buenos Aires se realiza cada año durante el mes de febrero, siendo parte del calendario anual de la ATP. Presentamos datos estadísticos correspondientes a los años 2011 a 2016, 6 torneos consecutivos, registrados por el cuerpo médico a cargo de la atención médica del torneo. 556 jugadores disputaron 426 partidos, resultando en una exposición de 1036 jugadores/match durante 605 hs de juego. Se diagnosticaron 157 condiciones médicas, 85 fueron lesiones y 72 fueron enfermedades. La Incidencia de lesiones fue de 82 c/1000 match exposiciones; predominaron las lesiones musculares (50,5%) y tendinosas (25,8%), y el miembro inferior fue la región del cuerpo más afectada (48,5%). Además fueron tratadas 72 enfermedades, siendo las más frecuentes la enfermedad por calor (36,1%), las de la piel (34,7%) y las gastrointestinales (13,8%). El motivo más frecuente de atención médica durante los partidos fue alguna de las formas de la enfermedad por calor (62% de los court call). Hubo 26 retiros del juego, y 2 casos requirieron para su tratamiento ser trasladados a un hospital. Conclusión: Tratar tenistas profesionales requiere para el traumatólogo del deporte, un profundo conocimiento de las lesiones musculo-tendinosas y de la prevención y manejo de la enfermedad por calor. Nivel de evidencia: IV (Estudio observacional descriptivo).

Objective: to know the incidence of injuries and to analyze the medical conditions that suffered the tennis players who played the ATP of Buenos Aires during the years 2011 to 2016. Material and method: A retrospective analysis was made of the medical conditions that occurred during the 6 consecutive tournaments, and the incidence of injuries was obtained. Results: The Buenos Aires ATP is held every year during the month of February, being part of the annual calendar of the ATP. We present statistical data corresponding to the years 2011 to 2016, 6 consecutive tournaments, registered by the medical body in charge of the medical care of the tournament. 556 players disputed 426 parties, resulting in an exhibition of 1036 players / match during 605 hours of game. 157 medical conditions were diagnosed, 85 were injuries and 72 were diseases. The Incidence of injury was 82 / 1000 match exposures; Muscular (50.5%) and tendinous (25.8%) lesions predominated, and the lower limb was the region of the body most affected (48.5%). In addition, 72 diseases were treated, the most frequent being heat illness (36.1%), skin disease (34.7%) and gastrointestinal disease (13.8%). The most frequent reason for medical attention during matches was one of the forms of heat illness (62% of the court calls). There were 26 withdrawals from the game, and 2 cases required for their treatment to be transferred to a hospital. Conclusion: Treating professional tennis players requires a thorough knowledge of the musculoskeletal injuries and the prevention and management of heat illness for the sports traumatologist. Level of evidence: IV (observational descriptive study).

Motor and morphological profile of tennis players from 11 to 15 years old / Perfil motor y morfológico de jugadores de tenis de 11 a 15 años de edad

Determine the motor and morphological characteristics of amateur tennis players from 11 to 15 years old. Method. 11 male athletes from the Paranaense Tennis Federation were evaluated during the competition period. Anthropometric variables (total body mass, height, circumference and skinfolds) were assessed. Results. The following median values were obtained: 45.8kg of total body mass, 160cm of height, fat percentage of 14%, lean mass of 37kg, and fat mass of 5kg. Conclusion. The study concluded that athletes show a profile of body composition similar to the profile of tennis players of the same age (AU)

Objetivo. Determinar las características morfológicas y motoras de jugadores aficionados de tenis de edades de 11a15 años. Método. Fueron evaluados 11 atletas masculinos, afiliados a la Federación Paranaense de tenis, en periodo de competición. Se midieron las siguientes variables antropométricas: masa corporal total, altura, perímetros y pliegues cutáneos. Resultados. Se obtuvieron los siguientes valores medianas: masa corporal total 45.8kg; estatura 160cm; 14% de masa grasa, 37kg de masa magra y 5kg de masa grasa. Conclusión. Los atletas valorados en el presente estudio tienen un perfil de composición corporal similares al perfil de los jugadores de tenis de la misma edad (AU)

Objetivo. Determinar as características morfológicas e motoras de atletas amadores de ténis com idade de 11 a 15 anos. Método. Foram avaliados 11 atletas do sexo masculino, inscritos na Federação Paranaense de Tênis em um período de competição. Os atletas foram avaliados para as variáveis antropométricas: massa corporal total, altura, circunferência e dobras cutâneas. Resultados. Obtiveram os seguintes valores médios: 45.8kg para massa corporal total, 160 centímetros de altura, percentual de gordura de 14%, em massa magra de 37kg, e de massa de gordura de 5kg. Conclusão. O estudo concluiu que os atletas mostram um perfil de composição corporal semelhante ao perfil dos jogadores de tênis da mesma idade (AU)

Male professional tennis players maintain constant serve speed and accuracy over long matches on grass courts.

The potential effect of fatigue on stroke production in tennis players is still controversial. The aim of this study was to analyse the tennis serve speed and accuracy in prolonged male professional matches played on grass courts. We analysed tennis serve statistics from five-set Wimbledon matches (n = 15; 30 players). Results showed that match duration averaged 208.3 ± 28.3 min. The overall serve speed was 177.0 ± 10.2 km/h in the first set and 176.1 ± 11.7 km/h in the fifth set (p = .34). The difference of all accuracy values of first set serves was not significantly different from those of the fifth set: percentage of valid first serves, 63.1 ± 11.1% vs. 62.3 ± 11.8%, respectively (p = .78); percentage of "aces", 11.2 ± 9.1% vs. 10.0 ± 8.9%, respectively (p = .39); percentage of "winners", 2.6 ± 7.6% vs. 1.2 ± 2.2%, respectively (p = .36); percentage of "double faults", 2.8 ± 3.0% vs. 2.8 ± 3.4% (p = .97). In conclusion, tennis players were able to maintain constant serve speed and accuracy over five-set matches played on grass courts. Professional tennis players are capable of overcoming fatigue and/or make movement adjustments to effectively perform complex technical strokes like the serve throughout matches played on grass courts lasting more than 3 h in average.

Tennis is not dangerous for the spine during growth: results of a cross-sectional study.

PURPOSE: Tennis is widely practiced by adolescents in many countries. Many spinal deformity experts consider this activity, together with other asymmetrical sports, as risk factors for scoliosis development even though scientific data are missing. The aim of the present study was to verify the prevalence of spinal deformities and LBP in adolescent competitive tennis players compared to healthy controls. METHODS: We designed a cross-sectional study. A convenience sample of 102 adolescent tennis players (52 girls) was compared to 203 scholars (102 girls) of the same age (12 years). We used a questionnaire to collect data on LBP and we measured the ATR to screen for spinal deformities and the plumb line distances for kyphosis (C7 and C7 + L3) and lordosis (L3). RESULTS: We found similar spinal deformities in both groups: ATR female: 3.2° ± 1° (tennis) versus 2.8° ± 1° (school), NS; ATR males: 2.8° ± 1° (tennis) versus 2.6° ± 1° (school), p < 0.05. No differences were found for kyphosis and lordosis. Low back pain prevalence was similar for both groups, but a significant difference was found for limitation of usual activity, which was higher for tennis players than controls. CONCLUSION: The correlation between tennis, an asymmetric sport, and spinal deformities that has been postulated by many experts was not confirmed by our data. There was no correlation between tennis and LBP, even if there were some differences among groups for limitations of the daily activities. Adolescent competitive tennis showed to be a safe sport without an increased risk of spinal deformities and LBP.

Epidemiology of tennis injuries: An eight-year review of Davis Cup retirements.

Tennis practice, especially at elite levels, may place players at risk for debilitating musculoskeletal injuries. The aim of this study was to analyse the epidemiological pattern of retirements due to medical conditions sustained by tennis players during Davis Cup matches in the 2006-2013 period. All uncompleted matches due to a medical condition (injuries and illnesses) occurred in the above-mentioned competition were collected from the official source, registered and analysed according to published guidelines. The overall incidence of match retirements was 1.66% (12/719). The injury rate was 6.05/1000 playing hours; and 6.64/1000 match exposures. Musculotendinous lesions were the most common type of injury (66.66%). The incidence of lower-limb injuries was higher than upper-limb and trunk lesions. The incidence of retired matches due to medical conditions was higher in hard courts than in clay courts (2.97% and 0.90%, respectively; p = 0.04), while the median value of inactivity of injuries was 32.0 days (range 3-297). In conclusion, the incidence of retirements due to medical conditions in Davis Cup matches was low supporting the assumption that elite tennis is a low-risk sport activity. Findings provided scientific evidences of injury patterns among male professional tennis players and may contribute to conduct better injury prevention strategies.

Sport participation and injuries among undergraduate students of a Nigerian University.

Backgroud: Sports participation is a healthy behaviour but it is not without the risk of injuries. Information on the extent of sport participation and sport injuries among Nigerian Unversity students is sparse. Objeclive: To determine the prevalence and types of sport participation and injuries among university.students in Nigeria. Factors associated with sport participation among students were also examined. METHODS: A cross-sectional survey was conducted using a self-administered questionnaire to collect information on the frequcncy and types of sport participation and sport-related injuries among a representative sample of undergraduate students of the University of Lagos, Nigeria. Resuts: A sport participation prevalence of 64.2% (95%CI: 59.5 - 68.7) was recorded among students. Football (soccer) (53.2%) had the highest participation rate. Male students (78.4% vs.41.2%) participated more frequently in sports (p <0.001). Overall injury rate was 52.5 injuries/100 students/ year (95%CI: 46.5 - 58.5). The prevalence of injury was 45.7% in male and 12.7% in female students. About half (49.3%) of reported injuries resulted in time loss. The leg and ankle were the most frequently injured body parts for all injuries and most serious injuries. Football recorded the highest prevalence of injury (73.8%). CONCLUSION: Sport participation among students was fair and injury rate was considerably high, mostly affecting the lower extremity and most injuries resulting from football participation. This study suggests the need for improved sport participation support among students and the need for the initiation of injury prevention initiatives by stakeholders.

Cómo mejorar la efectividad en un jugador de tenis: Modelos de regresión log-lineales / How to improve the efectiveness in a tennis player: log-linear regression models

La efectividad en el deporte hace referencia al impacto alcanzado por una acción llevada a cabo en condiciones habituales, estando presente en la ejecución de cualquier actividad física, referida a la capacidad para producir el efecto deseado, y está relacionada con la eficacia, entendida como el efecto de una acción llevada a cabo en las mejores condiciones posibles, y que tiene como objetivo, lograr la meta, o conseguir el triunfo. El objetivo de este trabajo consistió en identificar la relación entre la zona y el tipo de golpe, desde la cual el tenista presenta mayor y menor efectividad en el juego. Para ello se observó a un tenista durante 12 entrenamientos con un rival de nivel equivalente, según la ATP, durante la temporada 2012-2013, registrando su situación en la cancha y el tipo de golpe de todas las devoluciones con éxito, entendido como obtención del punto o recuperación del saque. Se crearon tres criterios categóricos que constituyen un instrumento de observación para registrar el juego del tenista en la zona horizontal, y la zona vertical de la pista, además del tipo de golpe que realiza en términos de drive, revés, smash y dejada. Utilizando la técnica de regresión log-lineal, se obtuvieron resultados que indican que el jugador presenta una menor efectividad en los golpes realizados desde el lado izquierdo, y muestra una mayor efectividad en el drive y revés ejecutados desde media pista o fondo del lado derecho. La interpretación de los resultados aporta información sobre las localizaciones en la pista y los golpes, relacionados con su mayor y menor efectividad (AU)

The effectiveness in the sport refers to the impact achieved by an action carried out in normal conditions, being present in the execution of any physical activity, refers to the ability to produce the desired effect, and is related to efficiency, understood as the effect of an action carried out in the best conditions possible, and which aims achieve the goal, and got the win. the objective of this work consisted in identifying the relationship between the area and the type of shot, which tennis player has greater and lesser effectiveness in the game. this was observed to a tennis player during 12 workouts with a rival of equivalent level, according to the ATP, during the 2012-2013 season, registering their situation in the field and the type of shot of all returns successfully, understood as obtaining the point or recovery of the drawdown. three categorical criteria which constitute an instrument of observation to the game of tennis in the horizontal area, and the vertical area of the track, as well as the type of shot that performs in terms of drive, reverse, smash and left register were created. Using log-linear regression technique they were obtained results indicate that the player presents a lower effectiveness in hits from the left side, and sample a more effectively executed from half track or background on the right side the drive and reverse. the interpretation of the results provides information on the locations on the track and hits, related to its greater and lesser effectiveness (AU)

A eficiência no desporto faz referência ao impacto alcançado por uma ação realizada em condições habituais, estando presente na realização de qualquer actividade física, com base na capacidade para produzir o efeito desejado, e está relacionada com a eficácia, ou seja, o efeito de uma acção levada a cabo nas melhores condições possíveis, e que tem como fim, alcançar o objetivo ou obter a vitória. O objetivo deste estudo foi identificar a relação entre a zona do campo e o tipo de batimento, com o qual o tenista obtém maior e menor eficiência no jogo. Para isso observou- -se um tenista durante 12 treinos com um adversário de nível semelhante, de acordo com o ATP durante a temporada 2012-2013, registando a sua posição no campo e tipo de batimentos referentes a todas as devoluções efectuadas com sucesso, definido como a obtenção de ponto ou recuperação do serviço. Foram criados três critérios de categorias que constituem um instrumento de observação para registar o jogo do tenista na zona horizontal e na zona vertical do campo, para além do tipo de batimento que este realiza em termos de direita, esquerda, remate e o fiamortiefi. Utilizando a técnica de regressão log-linear, obtiveram-se resultados que indicam que o jogador apresenta menor eficiência nos batimentos realizados do lado esquerdo, e mostra maior eficiência no batimento de direita e do lado contrário ao que segura a raquete , executados a partir do meio do campo ou do fundo do campo do lado direito. A interpretação dos resultados fornece informação sobre as localizações no campo e os batimentos, relacionados com a sua maior e menor eficiência (AU)