The relationship of some physical variables and performance angles to the strength of the straight serve for junior tennis

The problem of the research in determining the appropriate angles in the strength of serve for tennis age (14-16) year according to the specific biomechanical conditions, and the extent of the relationship of each variable of the physical variables in the successful performance of the skill of serve, and achieving the strength of transmission for tennis age (14-16) year, and it is one of the biomechanical principles that can be used in evaluating the angles of body parts. age (14-16) year tennis players. The aim of the research is to identify the percentage of the contribution of some physical variables of the straight serve for tennis juniors, and the percentage of the contribution of some corners of the body to the strength of serve for the tennis age (14-16) year (18) players. The two researchers reached a number of results, the most important of which are: There is a statistically significant correlation between some physical abilities and body angles with the straight serve for tennis players. The lower the angles (elbow, shoulder, knee for the front leg) at the moment of hitting the tennis ball, the stronger the serve will be. Correlation relationship with some biomechanical variables, because the skill of serve requires the strength of the striking arm during the performance of the straight serve

Effect of practice hours on elite junior tennis players’ burnout: Gender differences

This study investigated the effect of training hours on elite junior tennis players’ burnout with attention to gender differences. A quantitative cross-sectional design was used in this research. A sample of 70 junior elite Tunisian tennis players (17.01 ± 0.81y) completed a demographic and the Athlete Burnout Questionnaire. Results showed that 64% ( n = 45) had a low risk, 14% ( n = 10) had a moderate risk, 13% ( n = 9) showed a high risk of burnout and 9% ( n = 6) had burnout with individual differences. Analysis of variance revealed that players who trained more than 12 h (high volume) reported significantly higher scores of the burnout dimensions: emotional and physical exhaustion ( p < 0.001; d = 2.18); sport devaluation ( p < 0.001; d = 2.36); reduced sense of accomplishment ( p < 0.001; d = 2.27); as well general burnout ( p < 0.01; d = 2.69), than players that trained less than 12 h (moderate volume and low volume). The effect of gender was observed in the variables of emotional and physical exhaustion (t = 2.17; p < 0.03), sport devaluation ( t = 2.23; p < 0.029), reduced sense of accomplishment ( t = 2.58; p < 0.012) and general burnout ( t = 2.41; p < 0.019) with female players showing higher scores in all of the burnout dimensions. It was concluded that the high volume of weekly training hours by junior players was associated with higher levels of the general burnout scores and that female players showed higher burnout scores than their male counterparts.

Within-Session Reliability and Validity of Overhand Ball Throw Test to Evaluate Power Ability in Junior Tennis Players

"ABSTRACT. Introduction: Coaches should be able to estimate successfully different physical attributes of junior tennis player’s performance such as power, in order to monitor players’ progress and to design the most appropriate training program. However, this process requires reliable and valid field tests. Objective: Aim of this study was to examine absolute and relative reliability of overhand ball throw (OBT) test within testing session and to investigate its validity. Methods: 257 Hungarian junior boy and girl tennis players (aged 11- 17) separated into four groups, performed OBT and serve speed (SS) tests of standardised protocol. Results: Dependent sample t-test revealed no significant (p= 0.31-57>0.05) difference between test and retest sample means within testing session and magnitude of effect size (dz=0.1-0.5) were trivial for all groups. Furthermore, all groups had low typical percentage error (CV= 3-4 %), and standard error of measurement values was consistently low (SEM= 0.12- 0.18). Within test-retest consistency illustrated strong relative reliability (ICC= 0.98-0.99). Moreover, significantly large to very large positive correlations were found between OBT and SS (r= 0.57-0.81; p˂0.01) tests. The coefficient of determination indicated that OBT explained 32-65% of the SS for groups. Conclusions: These findings suggest that absolute and relative reliability of OBT test is high within testing session and validity of OBT test is acceptable for measuring power ability of flat serve execution in junior tennis players."

The Relative Age Effect in Czech U14 Male and Female Tennis Players in 2007–2016

The issue of the Relative Age Effect (RAE) has been long researched, discussed and published both in the academic and coaching community and the number of studies on it in various sports has significantly grown in recent years. The aim of this study was to verify the existence of RAE among Czech male (n = 6552) and female (n = 4131) junior tennis players and to identify possible differences in birthdate effect between male and female players. The research was carried out in players registered in the years 2007–2016 in the U14 age category in Czech Tennis Association (CTA) database; the athletes were divided into three subgroups (‘Ranked’, ‘Top 100’, ‘Top 10’). Research data were analysed by the methods of descriptive and inferential statistics: relative and absolute frequency, chi-square goodness of fit test () and chi-square test of independence () with the use of effect size (ES index w). A declining tendency of frequencies from Q1 to Q4 between male and female junior players was proven in all three subgroups.In the whole period of 2007–2016, a significant and strong RAE was demonstrated only in the ‘Top 10’ male subgroup (RAE was significant and ES was small or trivial in the other two subgroups). Among the female players, RAE was significant in all three subgroups (ES was small or trivial). Gender differences in RAE in favour of male players were significant in ‘Top 100’ and ‘Ranked’ (ES was small or trivial in all three subgroups). In the short and long term, RAE can have significant implications for the sport development of athletes; both coaches and the professional public can therefore be recommended to pay attention to this issue. The impact of RAE in sport, i.e. the uneven distribution of athletes’ birthdates, is more pronounced especially among junior athletes and often significantly affects their sports development and career.

“Slippage” in the talent development environment of elite junior tennis players

“Slippage” occurs when there is a mismatch between the intended message communicated (by coach, parent, or talent development environment) and the received message by junior tennis players. The concept of slippage has received attention in educational settings, but research has yet to investigate the possible effects on junior tennis players. The purpose of this study was to examine the experiences of 8 UK, elite junior tennis players and describe what it is like to perform in the elite junior context. An Interpretative Phenomenological Analysis (IPA) of 8 elite junior tennis players (playing LTA Grade 2 and upwards) shows their insights into elite junior tennis. This study found that (a) participants seek meaning behind their tennis experiences and they infer messages from their environment that are not intended, (b) “slippage” is associated with unintentional pressure, and (c) “slippage” is associated with a reduction of junior tennis players’ confidence. The findings of this research contribute to an evolving, problematic epistemology of sports coaching and confirms that coaches can lose control of their intended message as players infer their own meanings from interactions within tennis. The findings present governing bodies opportunities to inform coach education literature and consider how the difference between the intended coaching message and the received coaching message can impact the emotional state of junior tennis players.

The Effects of Knee Flexion on Tennis Serve Performance of Intermediate Level Tennis Players

This study aimed to investigate the effects of knee flexion during the preparation phase of a serve on the tennis serve performance, using inertial sensors. Thirty-two junior tennis players were divided into two groups based on their maximum knee flexion during the preparation phase of serve: Smaller (SKF) and Greater (GKF) Knee Flexion. Their racket velocity, racket height, and knee extension velocity were compared during the tennis serve. Inertial sensors tracked participants’ shank, thigh, and racket motions while performing five first, flat, and valid serves. Knee flexion was analysed during the preparation phase of serve, knee extension velocity after this phase, racket velocity just before ball impact, and racket height at impact. Pre-impact racket velocity (mean difference [MD] = 3.33 km/h, p = 0.004) and the knee extension velocity (MD = 130.30 °/s, p = 0.012) were higher in the GKF than SKF; however, racket impact height was not different between groups (p = 0.236). This study’s findings support the importance of larger knee flexion during the preparation phase of serve-to-serve performance. This motion should be seen as a contributor to racket velocity.

Communication tips for juniors

Tennis in modern times is an industry that integrates sport, entertainment and business together. Nowadays, a junior tennis player is not limited to what they do on the tennis court. The junior player must be ready to face other responsibilities, among which are the media and commercial related activities.

Validity and reliability of a novel monitoring sensor for the quantification of the hitting load in tennis

Wearable sensor systems are a emerging tools for the evaluation of the sport’s activity and can be used to quantify the external workload of the athlete. The main goal of this paper was to evaluate the validity and reliability of the “Armbeep inertial measurement unit” (IMU) sensor both in a closed tennis exercise and in open matchplay. Twentyfour junior tennis players performed a baseline drill and played matches, during which they wore a combined accelerometer and gyroscope sensor. Video footage was concomitantly recorded using a digital video camera. The agreement between the measurements was assessed with the intraclass correlation coefficient (ICC) and the standard error of measurement (SEM). A simple linear regression was used to predict the number of shots registered from the video and from the Armbeep IMU sensor’s data. The number of total forehand and backhand shots during the drill repetitions showed an excellent test and re-test reproducibility (ICC≥0.90). There was a significant relationship between the Armbeep IMU sensor’s number of contacts and the total number of shots (R2 = 0.938) which indicated the excellent reliability of the tested Armbeep IMU sensor for those parameters. Considering the accuracy of the total tennis shots and the small magnitude of error for wrist speed and acceleration, the Armbeep IMU sensor appears to be an appropriate on-court tool that can be used to monitor the hitting load during tennis practice and matches.