A low carrying angle is measured in elite tennis players just before ball impact during the forehand, suggesting a dynamic varus instant accommodation moving towards full extension.

PURPOSE: The goal of this study was to use image analysis recordings to measure the carrying angle of elite male tennis players during the forehand stroke, with the hypothesis that elite tennis players overstress their elbow in valgus over the physiological degree in the frontal plane just before ball contact on forehand groundstrokes. METHODS: The carrying angle of male tennis players ranked in the top 25 positions in the ATP ranking was measured on selected video frames with the elbow as close as possible to full extension just before the ball-racket contact in forehands. These frames were extracted from 306 videos professionally recorded for training purposes by a high-profile video analyst. All measures were conducted by three independent observers. RESULTS: Sixteen frames were finally included. The mean carrying angle was 11.5° ± 4.7°. The intraclass correlation coefficient value was 0.703, showing good reliability of the measurement technique. The measured carrying angle was lower than what has been observed in historical cohorts using comparable measurement methodology, suggesting a possible instant varus accommodation mechanism before hitting the ball. CONCLUSIONS: The observed decrease in the carrying angle is a consequence of an increase in elbow flexion position dictated by the transition from a closed to open, semi-open stances. As the elbow flexes during the preparation phase, it is less constrained by the olecranon and its fossa, increasing the strain on the medial collateral ligament and capsule structures. Moving towards full extension before the ball-racket contact, the elbow is dynamically stabilised by a contraction of the flexor muscles. These observations could provide a new explanation for medial elbow injuries among elite tennis players and drive specific rehabilitation protocols. STUDY DESIGN: Descriptive epidemiology study. LEVEL OF EVIDENCE: Level IV.

Comparison of the activation and mechanical properties of scapulothoracic muscles in young tennis players with and without scapular dyskinesis: an observational comparative study.

BACKGROUND: In tennis athletes with scapular dyskinesis, the activation of the scapulothoracic muscles during serve is not known. Also, the mechanical properties (tone, elasticity, and stiffness) of the scapulothoracic muscles of the tennis athletes with scapular dyskinesis are likely to change. The study aimed to evaluate the activation of the scapulothoracic muscles while performing tennis serve and to determine the changes in the mechanical properties of the same muscles in young tennis athletes with scapular dyskinesis. METHODS: Seventeen tennis athletes with scapular dyskinesis aged between 11 and 18 years (the scapular dyskinesis group) and age- and gender-matched 17 asymptomatic tennis athletes (the control group) were included in the study. Activation of scapulothoracic muscles (descending-transverse-ascending trapezius and serratus anterior) in the 3 phases (preparation, acceleration, and follow-through) of the serve was evaluated using surface electromyography, and the mechanical properties of the same muscles were measured at rest by myotonometry. RESULTS: Ascending trapezius activation in the follow-through phase was lower in the scapular dyskinesis group compared with the control group (mean difference 95% confidence interval: -22.8 [-41.2 to -4.5]) (P = .017). The tone and stiffness of the transverse trapezius (P = .043 and P = .017, respectively) were higher, whereas the same parameters of the ascending trapezius were lower (P = .008 and P = .010, respectively) in the scapular dyskinesis group compared with the control group. CONCLUSIONS: Activation of the ascending trapezius and the tone and stiffness of the transverse-ascending trapezius were altered in tennis athletes with scapular dyskinesis. Implementations to improve these changes can be included in the rehabilitation or training programs of young tennis athletes with scapular dyskinesis.

Joint-specific Postactivation Potentiation Enhances Serve Velocity in Young Tennis Players.

ABSTRACT: Baiget, E, Colomar, J, and Corbi, F. Joint-specific postactivation potentiation enhances serve velocity in young tennis players. J Strength Cond Res 37(4): 840-847, 2023-This study aimed (a) to analyze the influence of sport-specific postactivation potentiation (PAP) on serve velocity (SV) and serve accuracy (SA) in young tennis players, (b) to compare the PAP effects of 2 different conditioning activities (CA) on SV and SA, and (c) to explore if changes in SV would be related to tennis player's neuromuscular performance. Sixteen competition young tennis players performed 3 testing sessions in a randomized order. In the control session, subjects performed a warm-up protocol followed by the SV and SA tests. The experimental sessions involved 1 (shoulder internal rotation [SHIR]) or 2 (SHIR + shoulder flexion [SHF]) repetitions of a 5 second maximal voluntary isometric contraction (MVIC) executed before the SV and SA tests. Results showed a moderate significant (p = 0.037) difference between SV at control session and following the SHIR + SHF CA protocol at minute 0 (3.4 ± 4.6%; 4.6 km·h-1; ES = 0.711). Serve accuracy did not differ between CA protocols and control session at any time point. No significant relations were found between force-time curve parameters and SV percent changes at different recovery times. Performing 2, short (5 seconds), upper-limb, tennis joint-specific MVIC seems to enhance SV without negatively affecting SA in young competition tennis players. On the contrary, performing one MVIC does not seem to obtain the same effects. Moreover, tennis players with improved neuromuscular performance do not seem to exhibit a better predisposition to postactivation performance enhancement.

Methods of core strength training in college tennis players / Métodos de treino de fortalecimento do core em tenistas universitários / Métodos de entrenamiento de fortalecimiento del core en tenistas universitarios

ABSTRACT Introduction Core strength training is essential for maintaining postural stability and explosive movement support, typical of tennis players. It has been proven that core strength training improves the motor coordination of the athlete's whole body. Therefore, it is essential to develop specific approaches to strengthen the core in tennis players. Objective Analyze the effect of core strength training in college tennis players. Methods Twenty college tennis players were selected and randomly divided into two groups: core strength training and general training. Comparative results of the experiment were statistically processed for analysis on the effect of core strength training versus general strength training. Results There is a big difference in the level of fitness indicators before and after 14 weeks of core strength training (P < 0.05). The average gain in training speed of the athletes in the experimental group was 8.24% versus 1.05% in the control group. Conclusion Core strength training can improve the physical fitness of tennis players. Complementary core strengthening training can favor performance in matches and competition results. Evidence level II; Therapeutic Studies - Investigating the results.

RESUMO Introdução O treino de fortalecimento do core é importante para a manutenção de estabilidade postural e suporte para movimentos de explosão típicos dos tenistas. É comprovado que o treino de fortalecimento do core aprimora a coordenação motora de todo o corpo do atleta. Portanto, é de grande importância elaborar condutas específicas para fortalecimento do core em tenistas. Objetivo Analisar o efeito da conduta de treino de fortalecimento do core em tenistas universitários. Métodos Foram selecionados 20 tenistas universitários, divididos aleatoriamente dois grupos: treino de fortalecimento do core e treino geral. Os resultados comparativos do experimento foram processados estatisticamente para análise do efeito do treino de fortalecimento do core versus o treino de fortalecimento geral. Resultados Existe grande diferença no nível de indicadores de aptidão física dos atletas antes e após de 14 semanas de treino com fortalecimento do core (P < 0,05). O ganho médio na velocidade de treino dos atletas no grupo experimental foi de 8,24%, contra 1,05% no grupo controle. Conclusão O treino de fortalecimento do core pode melhorar a aptidão física de tenistas. O treino de fortalecimento do core complementar pode favorecer o desempenho nos jogos e no resultado das competições. Nível de evidência II; Estudos terapêuticos - Investigação de resultados.

RESUMEN Introducción El entrenamiento de la fuerza del core es importante para mantener la estabilidad postural y el apoyo para los movimientos explosivos típicos de los tenistas. Está demostrado que el entrenamiento de la fuerza del core mejora la coordinación motriz de todo el cuerpo del atleta. Por lo tanto, es de gran importancia desarrollar formas específicas para fortalecer el núcleo en los tenistas. Objetivo Analizar el efecto de la realización de un entrenamiento de fortalecimiento del core en tenistas universitarios. Métodos Se seleccionaron 20 tenistas y se dividieron aleatoriamente en dos grupos: entrenamiento de la fuerza del core y entrenamiento general. Los resultados comparativos del experimento se procesaron estadísticamente para analizar el efecto del entrenamiento de fortalecimiento del core frente al entrenamiento del fortalecimiento general. Resultados Existe una gran diferencia en el nivel de los indicadores de aptitud física de los atletas antes y después de 14 semanas de entrenamiento de fuerza del core (P < 0,05). El aumento medio de la velocidad de entrenamiento de los atletas del grupo experimental fue del 8,24%, frente al 1,05% del grupo de control. Conclusión El entrenamiento de la fuerza del core puede mejorar la forma física de los tenistas. El entrenamiento complementario de fortalecimiento del core puede favorecer el rendimiento en los juegos y en el resultado de las competiciones. Nivel de evidencia II; Estudios terapéuticos - Investigación de resultados.

Planned Physical Workload in Young Tennis Players Induces Changes in Iron Indicator Levels but Does Not Cause Overreaching.

The current study aimed to examine the impact of the training load of two different training camps on the immunological response in tennis players, including their iron metabolism. Highly ranked Polish tennis players, between the ages of 12 and 14 years, participated in two training camps that were aimed at physical conditioning and at improving technical skills. At baseline and after each camp, blood samples were analyzed, and the fatigue was assessed. The levels of pro- and anti-inflammatory indicators, iron, and hepcidin were determined. The levels of the heat shock proteins, (Hsp) 27 and 70, were also measured. All the effects were evaluated using magnitude-based inference. Although the training camps had different objectives, the physiological responses of the participants were similar. The applied programs induced a significant drop in the iron and hepcidin levels (a small-to-very-large effect) and enhanced the anti-inflammatory response. The tumor necrosis factor α levels were elevated at the beginning of each camp but were decreased towards the end, despite the training intensity being medium/high. The changes were more pronounced in the female players compared to the male players. Altogether, the results suggest that low-grade inflammation in young tennis athletes may be attenuated in response to adequately designed training. To this end, the applied physical workload with a controlled diet and rest-controlled serum iron levels could be the marker of well-designed training.

Ulnar-Sided Wrist Pain in the Athlete: Sport-Specific Demands, Clinical Presentation, and Management Options.

ABSTRACT: Ulnar-sided wrist injuries are common in sports that require repeated pronosupination, wrist radial/ulnar deviation, axial loading, and gripping equipment. Common anatomic structures affected include the triangular fibrocartilage complex, extensor carpi ulnaris tendon, distal radioulnar and ulnocarpal joints, and hamate bone. Presenting symptoms include pain with activity, swelling, possible snapping or clicking, and reproduction of symptoms with provocative maneuvers. Imaging may confirm or rule out pathologies, but abnormal findings also may present in asymptomatic athletes. Initial treatment is usually nonoperative with splinting, load management, activity modification, strengthening the components of the kinetic chain of the particular sport, and pain management. Surgery is usually indicated in ulnar-wrist pain pathology such as hook of hamate fractures and required in associated instability. Future research should address specific treatment and rehabilitation protocols, emphasizing the complete kinetic chain along with the injured wrist.

College students' physical and mental health exercise based on tennis / Exercício de saúde física e mental de estudantes com base no tênis / Ejercicios de salud física y mental para estudiantes universitarios basados en el tenis

ABSTRACT College students are often under great pressure, and their physical and mental health is the focus of attention in college education. In order to cultivate high-quality talents and relieve the pressure of college students, many colleges and universities have set up a variety of sports courses, including tennis courses. Analyzing the influence of tennis on the physical and mental health of college students, this study studies the situation of college students participating in tennis by consulting literature, designing questionnaires and using an experimental measurement method, while it constructs the physical health evaluation index and mental health evaluation index of college students. On this basis, this study evaluates the influence of tennis on students' physical and mental health. The results show that tennis has a positive impact on the physical and mental health of college students. Tennis can not only enhance college students' cardiopulmonary function and muscle strength, but also cultivate students' independent personality, eliminate depression tendency, make students independent, flexible and active, which is conducive to the development of students' mental health. It is hoped that this study can provide some reference for the research of college students' physical and mental health exercise based on tennis.

RESUMO Los estudiantes universitarios a menudo se encuentran bajo una gran presión y su salud física y mental es el centro de atención en la educación universitaria. Para cultivar talentos de alta calidad y aliviar la presión de los estudiantes universitarios, muchos colegios y universidades han establecido una variedad de cursos deportivos, incluidos cursos de tenis. Al analizar la influencia del tenis en la salud física y mental de los estudiantes universitarios, este estudio considera la situación de los estudiantes universitarios que participan en el tenis. Para ello usa la consulta de literatura, el diseño de cuestionarios y un método de medición experimental para construir el índice de evaluación de la salud física y la salud mental. Sobre esta base, este estudio evalúa la influencia del tenis en la salud física y mental de los estudiantes. Los resultados muestran que el tenis tiene un impacto positivo en la salud física y mental de los estudiantes universitarios. El tenis no solo puede mejorar la función cardiopulmonar y la fuerza muscular de los estudiantes universitarios, sino también cultivar la personalidad independiente de los estudiantes, eliminar la tendencia a la depresión, hacer que los estudiantes sean independientes, flexibles y activos, lo que favorece el desarrollo de la salud mental de los estudiantes. Se espera que este estudio pueda proporcionar alguna referencia para la investigación del ejercicio de salud física y mental de estudiantes universitarios basado en el tenis.

RESUMEN Estudantes universitários estão frequentemente sob grande pressão, e sua saúde física e mental é o foco da atenção na educação universitária. A fim de cultivar talentos de alta qualidade e aliviar a pressão dos estudantes universitários, muitas faculdades e universidades criaram diversos cursos de esporte, incluindo cursos de tênis. Analisando a influência do tênis na saúde física e mental dos estudantes universitários, este estudo investiga a situação dos estudantes universitários que praticam tênis através de consultas de literatura, elaboração de questionário e do método de medição experimental, enquanto constrói o índice de avaliação da saúde física e da saúde mental de avaliação dos estudantes universitários. Nesta base, o estudo avalia a influência do tênis na saúde física e mental dos estudantes. Os resultados mostram que o tênis tem um impacto positivo na saúde física e mental dos estudantes universitários. O tênis pode não só aumentar a função cardiopulmonar e a força muscular dos estudantes universitários, mas também cultivar a personalidade independente dos estudantes, eliminar a tendência de depressão, torna-los alunos independentes, flexíveis e ativos, o que favorece o desenvolvimento da saúde mental dos estudantes. Espera-se que este estudo possa fornecer alguma referência para a pesquisa do exercício de saúde física e mental dos estudantes universitários com base no tênis.

Optimal cooling strategies for players in Australian Tennis Open conditions.

OBJECTIVES: We compared the utility of four cooling interventions for reducing heat strain during simulated tennis match-play in an environment representative of the peak conditions possible at the Australian Open (45°C, <10% RH, 475W/m2 solar radiation). DESIGN: Nine trained males undertook four trials in a climate chamber, each time completing 4 sets of simulated match-play. METHODS: During ITF-mandated breaks (90-s between odd-numbered games; 120-s between sets), either iced towels (ICE), an electric fan (FANdry), a fan with moisture applied to the skin (FANwet), or ad libitum 10°C water ingestion only (CON) was administered. Rectal temperature (Tre), mean skin temperature (Tsk), heart rate (HR), thermal sensation (TS), perceived exertion (RPE) and whole body sweating (WBSR) were measured. RESULTS: After set 3, Tre was lower in ICE (38.2±0.3°C) compared to FANdry (38.7±0.5°C; p=0.02) and CON (38.5±0.5°C; p=0.05), while Tre in FANwet (38.2±0.3°C) was lower than FANdry (p=0.05). End-exercise Tre was lower in ICE (38.1±0.3°C) and FANwet (38.2±0.4°C) than FANdry (38.9±0.7°C; p<0.04) and CON (38.8±0.5°C; p<0.04).Tsk for ICE (35.3±0.8°C) was lower than all conditions, and Tsk for FANwet (36.6±1.1°C) was lower than FANdry (38.1±1.3°C; p<0.05). TS for ICE and FANwet were lower than CON and FANdry (p<0.05). HR was suppressed in ICE and FANwet relative to CON and FANdry (p<0.05). WBSR was greater in FANdry compared to FANwet (p<0.01) and ICE (p<0.001). CONCLUSIONS: Fan use must be used with skin wetting to be effective in hot/dry conditions. This strategy and the currently recommended ICE intervention both reduced Tre by ∼0.5-0.6°C and Tsk by ∼1.0-1.5°C while mitigating rises in HR and TS.

Asymptomatic elite young tennis players show lateral and ventral growth plate alterations of proximal humerus on MRI.

PURPOSE: The specific aim of the study was to investigate and compare epiphyseal length and extension in the proximal humerus, closure in the growth plate and bone marrow signal intensity related to the proximal humeral physis in the dominant arm and the non-dominant arm of the asymptomatic adolescent elite tennis player. METHODS: The study sample included 35 asymptomatic elite young tennis players (15 males and 20 females, mean age 17.4 years ± 2.7). Each player contributed with two shoulders to the MRI measurement. The non-dominant arm was used as a control. RESULTS: Relative reliability between the radiologists was excellent (ICC 0.78-0.96). Statistically significant differences between dominant arm and non-dominant arm in epiphyseal length (mm) laterally (DA 27.3 vs NDA 26.7) were shown. Statistically significant differences were also found in epiphyseal extension (mm) laterally (DA 36.1 vs NDA 35.1) and ventrally (DA 36.2 vs NDA 34.8). No statistically significant differences were found between dominant arm and non-dominant arm in epiphyseal extension (mm) medially (DA 31.7 vs NDA 31.7) and dorsally (DA 22.6 vs NDA 22.1). CONCLUSIONS: Significant findings assessing MRI measurements of the epiphyseal plate in the asymptomatic adolescent elite tennis player might reflect a development of consecutive alterations in the epiphyseal plate in the dominant arm. LEVEL OF EVIDENCE: Diagnostic study, Level IV.

Myokines in Response to a Tournament Season among Young Tennis Players.

The study investigated changes in myokines, heat shock proteins, and growth factors in highly ranked, young, male tennis players in response to physical workload during the competitive season and their potential correlations with match scores. Blood collections were carried out at the beginning, the midpoint, and the end of the tournament season. Data analysis revealed a significant increase in interleukin 6 and its inverse correlation with the number of lost games (r = -0.45; 90% CI -0.06 to 0.77). Neither the irisin nor BDNF level changed notably, yet delta changes of irisin across the season significantly correlated with the number of games won. The concentration of HSP27 recorded a small increase (31.2%; 90% CI 10.7 to 55.5, most likely). A negative correlation was noted between IGF-1 and HSP27 concentration at baseline (-0.70 very high; 90% CI -0.89 to -0.31, very likely). At the end of the season IGF-1 correlated positively with the number of games won (r = 0.37 moderate, 90% CI -0.16 to 0.73, likely) but negatively with the number of games lost (r = -0.39, 90% CI -0.14 to -0.74, likely). In conclusion our data indicated that Il-6, irisin, and growth factor IGF-1 may modify overall performance during a long lasting season, expressed in the amount of games won or lost.

Shoulder motion during tennis serve: dynamic and radiological evaluation based on motion capture and magnetic resonance imaging.

PURPOSE: Rotator cuff and labral lesions in tennis players could be related to posterosuperior internal impingement or subacromial impingement during tennis serve. However, it is unknown which of these impingements are responsible for the lesions found in the tennis player's shoulder. Moreover, there is a lack of validated noninvasive methods and dynamic studies to ascertain impingement during motion. METHODS: Ten intermediate or ex-professional tennis players were motion captured with an optical tracking system while performing tennis serves. The resulting computed motions were applied to patient-specific shoulder joints' 3D models based on magnetic resonance imaging (MRI) data. During motion simulation, impingements were detected and located using computer-assisted techniques. An MRI examination was also performed to evaluate the prevalence of shoulder lesions and to determine their relevance with the simulation findings. RESULTS: Simulation showed that internal impingement was frequently observed compared to subacromial impingement when serving. The computed zones of internal impingement were mainly located in the posterosuperior or superior region of the glenoid. These findings were relevant with respect to radiologically diagnosed damaged zones in the rotator cuff and glenoid labrum. CONCLUSIONS: Tennis players presented frequent radiographic signs of structural lesions that seem to be mainly related to posterosuperior internal impingement due to repetitive abnormal motion contacts. The present study indicates that the practice of tennis serve could lead with time to cartilage/tendon hyper compression, which could be damageable for the glenohumeral joint.

Effects of a simulated tennis match on lymphocyte subset measurements.

UNLABELLED: Tennis is an activity requiring both endurance and anaerobic components, which could have immunosuppressive effects postexercise. PURPOSE: The purpose of this investigation was to determine the effect of a simulated tennis match on apoptotic and migratory markers on lymphocyte subsets. METHOD: Male high school (n = 5) and college (n = 3) tennis players (M(age) = 18.9 +/- 3.3 years) completed 10 sets of a tennis protocol including serves, forehand strokes, and backhand groundstrokes with 1-min rest periods between sets. Apoptosis antigen 1 receptor (CD95) and chemokine receptor fractalkine (CX3CR1) expression was analyzed on helper T lymphocytes (CD4+), cytotoxic T lymphocytes (CD8+), and B lymphocytes (CD19+) twice, at resting baseline and immediately after all 10 sets of the tennis protocol. RESULTS: An increase was observed in each lymphocyte subtype (p < .02, effect size = .41), and comparison of absolute changes revealed increases in CD4+/CD95+, CD8+/CD95+, and CD8+/CX3CR1 lymphocytes following the tennis protocol (p < .01, effect size = .43), but not in CD19+ cells. CONCLUSIONS: A simulated tennis match has adequate intensity to induce immune modulations in terms of increased cell death and cellular migration in T lymphocyte subsets. Lymphocytopenia following tennis play is influenced by both apoptotic and migratory mechanisms.

Perfil da formação inicial e permanente de treinadores de tênis de alto rendimento do Brasil / Profile of basic and permanent coaching of high performance tenis coaches in Brazil / Perfil de formación inicial y permanente del entrenador de tênis de Brazil

O objetivo deste estudo foi descrever o perfil da formação inicial e permanente de treinadores de tênis de alto rendimento no Brasil. Participaram da amostra 24 treinadores do sexo masculino, com idades de 38,58 ± 8,95 anos. Foi observado que a faixa etária dos treinadores de tênis é a adequada, apresentando muitos anos de prática de tênis e bom nível de jogo. A expertise adquirida pela prática parece dar suporte de intervenção para a grande maioria dos treinadores. Os treinadores de tênis fundamentam-se em aprendizagens informais e não formais; participam de atividades de formação permanente, mas identificam limitações para participação, além de perceberem outras falhas organizacionais.

The aim of this study was to describe the initial and permanent coaching of highperformance tennis coaches in Brazil. Had a sample of 24 male coaches, aged38.58 ± 8.95 years. It was observed that the age of tennis coaches is adequate, with many years of practice and good level of tennis play. The expertise gained by the practice seems to support intervention for the vast majority of coaches. The tennis coaches are based on informal learning and non-formal; they participate in continuing education activities, but identify constraints to participation and notice other organizational failures.

El objetivo de este estudio fue describir la formación inicial y continua de los entrenadores de tenis de alto rendimiento en Brasil. Una muestra de 24 entrenadores de los varones, con edades 38,58 ± 8,95 años. Se observó que los entrenadores de tenis grupo de edad es adecuada, con muchos años de práctica y el buen nivel de juego de tenis. La experiencia adquirida por la práctica parece apoyar la intervenci-ón para la gran mayoría de los entrenadores. Los entrenadores de tenis se basa en el aprendizaje informal y no formal, participar en actividades de formación permanente, pero identifican las limitaciones a la participación, otro aviso de fallos de organización.

Microinstability and internal impingement in overhead athletes.

A complex interplay exists between the static and dynamic stabilizers in the glenohumeral joint, especially in overheard athletes who need a shoulder hypermobile enough to perform overhead activity yet stable enough to prevent joint subluxation. Concomitant shoulder pathologies commonly occur in the setting of microinstability and internal impingement. Before any surgical intervention, a 3- to 6-month course of conservative measures should first be attempted, with exercises focused on rotator cuff and scapular stabilizer strengthening combined with posterior capsule stretching. If surgery is needed, arthroscopic suture plication with treatment of concomitant lesions has been shown to provide the best clinical outcomes.

Força de preensão manual de atletas tenistas avaliada por diferentes recomendações de teste / Handgrip strength evaluation on tennis players sing

A avaliação da força de preensão manual (FPM) em tenistas competitivos deve ser realizada devido à assimetria que o jogador pode desenvolver. Para avaliar a FPM, profissionais utilizam dois protocolos diferentes (das Sociedades Americana e Europeia). Os objetivos deste estudo foram comparar a FPM usando a técnica do European Test of Physical Fitness Handbook (Eurofit) e da American Society of Hand Therapists (ASHT), bem como verificar a FPM entre o lado dominante/contralateral e comparar a FPM entre as idades em atletas de tênis da categoria infanto-juvenil. Participaram do estudo 137 tenistas do gênero masculino e 45 do feminino, todos com idade entre oito e 18 anos. Para avaliar a FPM, segundo as recomendações da Eurofit e ASHT, foi utilizado um dinamômetro manual (Jamar). Nenhum dos sujeitos avaliados apresentava qualquer lesão que pudesse comprometer o teste. Os resultados mostram que não há diferença na FPM entre os posicionamentos recomendados pela Eurofit e ASHT para medir a FPM independente do gênero. A curva sigmoide foi a que melhor se adequou para regressão da FPM e idade em ambos os gêneros sendo que para o masculino a FPM tem maior inclinação aos 11 anos, já para o feminino a maior inclinação é aos 10 anos. Além disso, a partir dos 14 anos, o lado dominante dos atletas masculinos apresentou maior FPM que o lado não dominante; contudo, essa assimetria não ocorreu no feminino em qualquer idade até os 18 anos.

It is important to assess the handgrip strength (HS) in competitive tennis players due to asymmetry between the dominant and contra lateral hands that players might develop. In order to assess HS, clinicians can use two protocols already established that are different from each other (from European Test of Physical Fitness Handbook [Eurofit] or American Society of Hand Therapists [ASHT]. The objective of this study was threefold: Firstly to compare the HS using the Eurofit and ASHT technique; secondly to compare HS between dominant/nondominant hands, and last, to compare the handgrip between ages of juvenile tennis player athletes. 137 male and 45 female tennis players (aged between 8 and 18 years) participated in the study. In order to assess HS following the Eurofit and ASHT recommendations, a Jamar dynamometer was used. None of the athletes had any injury that could compromise tests. There was no difference in handgrip strength between Eurofit and ASHT recommendations regardless of sex. The best curve to describe the regression of HS and age for both genders was a sigmoid function. Males presented a higher slope at 11 years and females had a higher slope at 10 years. Moreover, in male athletes dominant HS presented higher values than non-dominant HS beginning at 14 years. However, for the females the asymmetry in HS did not occur for any age until 18 years.

Muscle hypertrophy and increased expression of leptin receptors in the musculus triceps brachii of the dominant arm in professional tennis players.

In rodents, endurance training increases leptin sensitivity in skeletal muscle; however, little is known about the effects of exercise on the leptin signalling system in human skeletal muscle. Thus, to determine whether chronic muscle loading increases leptin receptor (OB-R170) protein expression, body composition dual-energy X-ray absorptiometry was assessed in nine professional male tennis players (24 +/- 4 years old) and muscle biopsies were obtained from the dominant (DTB) and non-dominant (NDTB) arm triceps brachii (TB), and also from the right vastus lateralis (VL). In each biopsy, the protein content of OB-R170, perilipin A, suppressor of cytokine signalling 3 (SOCS3), protein tyrosine phosphatase 1B (PTP1B) and signal transducer and activator of transcription 3 (STAT3) phosphorylation were determined by western blot. The DTB had 15% greater lean mass (P < 0.05) and 62% greater OB-R170 protein expression (P < 0.05) than the NDTB. SOCS3 and PTP1B protein expression was similar in both arms, while STAT3 phosphorylation was reduced in the NDTB. OB-R170 protein content was also higher in DTB than in VL (P < 0.05). In summary, this study shows that the functional isoform of the leptin receptor is up-regulated in the hypertrophied TB. The latter combined with the fact that both SOCS3 and PTP1B protein expression were unaltered is compatible with increased leptin sensitivity in this muscle. Our findings are also consistent with a role of leptin signalling in muscle hypertrophy in healthy humans.

Morphology of the deltoid muscles in elite tennis players.

The aim of this study was to examine the deltoid muscle properties of the dominant and non-dominant arm of Greek professional male tennis players. Eight male tennis players (mean age 22.0 years, s = 3.2) were subjected to biopsy of the deltoid muscle of both arms. Adenosine triphosphate (ATPase) histochemistry and myosin heavy chain (MHC) composition were performed on the samples with homogenate electrophoresis. No significant differences were observed in the percentage of types I, IIa, IIab, and IIb muscle fibres between the deltoid muscles of the two arms. Types I, IIa, and IIx muscle fibres of the dominant and non-dominant deltoid muscles did not differ significantly for MHC isoform composition. Type IIab muscle fibres showed a similar cross-sectional area (CSA) percentage distribution between the two arms. The CSA percentage for types I, IIa, and IIb muscle fibers did not differ significantly between the dominant and the non-dominant arm. We conclude therefore that regular tennis training probably does not lead to any significant changes in the muscle fibre types of the dominant and non-dominant arms of elite tennis players.

Prevalence of bowlegs among child and adolescent soccer players.

OBJECTIVE: Little is known about the interactions of sports-related demands and human body, in particular on musculoskeletal features, during growth. Focusing on the relationship between soccer and lower limb alignment, we examined the hypothesis that varus knee deviation is more prevalent among high-performance pediatric and adolescent soccer players. DESIGN: Cross-sectional study with focused sampling. SETTING: First league sports clubs. PARTICIPANTS: 106 male child/adolescent soccer players aged 10 to 21 years and 68 age-matched tennis players. INTERVENTIONS: All athletes completed a demographic questionnaire and underwent physical examinations, which included height, weight, generalized laxity, knee, ankle, foot and spine axis, hip range of motion, tibial torsion, Q angle, foot navicular height, and progression angle. MAIN OUTCOME MEASUREMENT: Varus/valgus axis was determined by the intercondylar intermalleolar distance while standing. Soccer and tennis players were compared on knee axis and other outcome variables by analysis of covariance, adjusting for age and by t-tests within age groups. RESULTS: A significantly higher prevalence of knee varus was found among the soccer players compared to that among the tennis players. The difference in intracondylar distance was statistically significant after the age of 13 years (P < 0.001). In addition, compared to tennis players, soccer players had higher foot arches, decreased hip external rotation and increased external tibial torsion. CONCLUSIONS: Varus knee axis deviation was more common among children and adolescent soccer players than among tennis players. The prevalence was more pronounced among players aged 13 years or older. Further research is needed to explore the rationale of this phenomenon.

When physiology becomes pathology: the role of magnetic resonance imaging in evaluating bone marrow oedema in the humerus in elite tennis players with an upper limb pain syndrome.

Upper limb stresses are well recognised in tennis, and the normal physiological responses of the humerus to externally applied forces are well defined. Changes to both the microscopic and macroscopic bony architecture are often not apparent on plain radiographs in the early stages of a stress reaction. Bone scintigraphy is more sensitive, but not very specific to subtle changes, as is computer aided tomography. Magnetic resonance imaging (MRI) scans are now used to assess many musculoskeletal injuries, and may allow earlier recognition of changes. This study reports on eight high level tennis players (seven professionals, one highly ranked amateur), who all presented during the course of the 2002 Australian Open and its lead up events. All had an upper limb pain syndrome centred around the elbow. Each underwent an MRI scan. A group of asymptomatic players also had scans of the same area to serve as controls. All symptomatic patients had various levels of bone marrow oedema in their distal humerus, some with periosteal reactions, although most without. No scans revealed a cortical breach. The management of these reactions is problematic in players on an international circuit, as review is sporadic and not always coordinated. The timetabling of international tournaments means it is difficult for top players to obtain adequate rest to avoid injury. Awareness of this early overuse reaction needs to be raised to allow preventive and therapeutic options to be considered to reduce the incidence of this humeral stress response producing an upper limb pain syndrome.

Forced expiratory volume in one second and peak expiratory flow rate values in non-professional male tennis players.

AIM: Forced expiratory volume in 1 second (FEV1) is a reliable and easily measured lung function index, which is nowadays used for early detection of chronic obstructive pulmonary disease. It has also been established recently as an important predictor of all-cause, cardiovascular and cerebrovascular morbidity and mortality in the Western World. Similar implications have been made with regard to peak expiratory flow rate (PEFR). The present study was designed in order to compare the FEV1 and PEFR values of non-professional, smoking and non-smoking male athletes to those predicted for the general, non-athlete population. METHODS: A total of 141 non-professional tennis players aged 30-74 years were studied (99 smokers and 42 non-smokers). FEV1 and PEFR of all men were measured by means of a one flow spirometer, and compared to those predicted for their age and height, based on formulas for the non-athlete, healthy, non-smoking population. RESULTS: Non-professional tennis players had significantly higher FEV1 and PEFR values, compared to FEV1 and PEFR predicted, respectively. No statistically significant difference was observed between smokers and non-smokers. CONCLUSIONS: Our study confirms that even moderate physical activity, such as non-professional tennis, can improve FEV1 and PEFR values, maintaining a normal respiratory function, which is a strong predictor of reduced cardiovascular and overall morbidity and mortality. FEV1 and PEFR are easy to measure parameters that should be used more often for the assessment of general health status.