Biophysical characterization of the tennis serve: A systematic scoping review with evidence gap map

OBJECTIVES

We aimed to assess the available evidence on the biophysics of the tennis serve, mapping the populations, interventions, contexts and other relevant information to highlight what is already known and to identify gaps in the literature.

DESIGN

Systematic scoping review with evidence gap map.

METHODS

The protocol was designed according to PRISMA 2020, Prisma-ScR guidelines and the Cochrane Handbook. The searches were conducted on July 20, 2022 and updated on April 1, 2023, in PubMed, Scopus and Web of Science (core collection). The risk of bias assessment was performed using the Cochranes method for nonrandomized studies (RoBANS) and a narrative synthesis of the main findings was performed and supplemented with an evidence gap map.

RESULTS

Most trials were found on serve kinematics and kinetics (95 %), analyzing only flat serves (84 and 72 %, respectively). Few trials focused on physiology (20 %; e.g. biomarkers), under-19, left or both-handed, female and intermediate beginner or starter players (29, 17, 8 and 7 %, respectively). We found a preponderance of low and unclear risk of bias (63 and 31 %, respectively) and only 7 % high, particularly, on the assessment of confounding variables.

CONCLUSIONS

The current scoping review reveals a few trials on physiological rather than biomechanical variables, as well as the absence of the kick and slice serve, foot-back and foot-up serve, and left-handed, female, and young player analyses. We did not find systematic mistakes or limitations in the design, conduct, or analysis that would distort the results, since only 7 % presented a high risk of bias.

Multidimensional and Longitudinal Approaches in Talent Identification and Development in Racket Sports: A Systematic Review

BACKGROUND

Better methods to support talent identification and development processes may contribute to more effective and efficient athlete development programs in racket sports. Both researchers and practitioners recommend multidimensional and longitudinal approaches to better understand the nature of talent (development). However, the added value of these 'innovative' approaches has not yet been clarified for racket sports. This systematic review intends to gain further insight into the outcomes of multidimensional and longitudinal approaches for talent identification and development in racket sports and to provide directions for future talent research.

METHODS

Electronic searches were conducted in PubMed, Scopus, SPORTDiscus, and Web of Science (January 2000-August 2022). Search terms covered the areas of racket sports and talent in sports. Studies using multidimensional and/or longitudinal talent approaches were included and analyzed regarding the methodology, included performance characteristics (i.e., anthropometrical, physiological, technical, tactical, psychological), and study findings.

RESULTS

A total of thirty-two studies were included using multidimensional (n = 15), unidimensional longitudinal (n = 3) or multidimensional longitudinal designs (n = 14). Most research covered physiological characteristics (n = 28), while fewer articles investigated anthropometrics (n = 21) and technical characteristics (n = 16). Only limited research investigated psychological (n = 4) and tactical characteristics (n = 1). Almost all studies measured physiological characteristics in combination with other characteristics. There was moderate to strong evidence that physiological and technical characteristics have value for athlete development programs in racket sports. Positive but limited evidence was found for psychological and tactical characteristics. Anthropometrical assessments were generally used as controlling variables for maturation. Study designs varied, and many studies used unidimensional statistical models and analyses within multidimensional study designs and datasets.

CONCLUSIONS

This review provides an overview of talent research using multidimensional and/or longitudinal approaches within racket sports and gives guidance on what characteristics to include in decision-making and monitoring processes. However, it remains difficult to draw conclusions about the added values of these approaches due to their variety in methodology. Future talent research should include more consistent study designs and conduct multidimensional and longitudinal studies using multivariate statistical approaches that benefit from the data's multidimensionality.

Risk Prediction of Injury Among Recreational Badminton Players in India

BACKGROUND/PURPOSE

Since badminton has emerged as a frequently played non-contact recreational sport in India, it is essential to document the injury patterns and incidence. However, there is no existing literature on this topic among Indian players.

MATERIALS AND METHODS

A web-based questionnaire was circulated among recreational badminton players across North India, enquiring about demographic details, injury characteristics, and factors associated with an injury like BMI, warm-up practice, and physical training.

RESULTS

Data of 237 eligible participants revealed an injury incidence rate of 57.1%. The ankle and dominant-side shoulder were the most common anatomical regions affected. The most common injury types were ligament sprain and muscle/tendon strain. Factors like age, frequency, duration of play, type of footwear, BMI, prior warm-up, court surface, and physical training were significantly associated with injury incidence on univariate logistic regression analysis. On multivariate logistic regression analysis, we found male gender, a lack of prior warm-up, inadequate physical training, and age group between 26 and 30 years to be four independent risk factors for injury.

CONCLUSION

The recreational badminton player of India had a relatively higher incidence of injury compared with the limited published data from other countries. Modifiable factors like a proper warm-up before the game, regular physical fitness training, and injury awareness programs can reduce the injury rates.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s43465-022-00663-y.

Validating an algorithm from a trunk-mounted wearable sensor for detecting stroke events in tennis

This study analysed the accuracy of a prototype algorithm for tennis stroke detection from wearable technology. Strokes from junior-elite tennis players over 10 matches were analysed. Players wore a GPS unit containing an accelerometer, gyroscope and magnetometer. Manufacturer-developed algorithms determined stoke type and count (forehands, backhands, serves and other). Matches were video recorded to manually code ball contacts and shadow swing events for forehands, backhands and serves and further by stroke classifications (i.e., drive, volley, slice, end-range). Comparisons between algorithm and coding were analysed via ANOVA and Bland-Altman plots at the match-level and error rates for specific stroke-types. No significant differences existed for stroke count between the algorithm and manual coding (p > 0.05). Significant (p < 0.0001) overestimation of "Other" strokes were observed from the algorithm, with no difference in groundstrokes and serves (p > 0.05). Serves had the highest accuracy of all stroke types (≥98%). Forehand and backhand "drives" were the most accurate (>86%), with volleys mostly undetected (58-60%) and slices and end-range strokes likely misclassified (49-51%). The prototype algorithm accurately quantifies serves and forehand and backhand "drives" and serves. However, underestimations of shadow swings and overestimations of "other" strokes suggests strokes with reduced trunk rotation have poorer detection accuracy.

Developing a tool to assess technical skills in talented youth table tennis players-a multi-method approach combining professional and scientific literature and coaches' perspectives

Background

The assessment of technical skills as part of a multidimensional approach for talent identification and development in sports seems promising, especially in a technique-based sport like table tennis. However, current instruments mostly focus on a single element of technical skills, mainly use quantitative outcomes, and/or are not developed for talent purposes. Practice would benefit from a new instrument using a more ecologically valid approach. Thus, the purpose of this study was to identify the essential elements of technical skills in young table tennis players and to establish a first tool while using a multi-methods study design including an archive search for professional literature, a systematic search for scientific literature, as well as ten in-depth interviews with expert coaches.

Results

This approach taken ensured empirical findings to be combined with knowledge and experiences from the practical field and detailed explications by high-level expert coaches. Results for the literature searches yielded 23 professional and 21 scientific articles while data saturation was reached through all ten interviews. The triangulation process resulted in two general (i.e., individuality, interconnection between elements) and five specific (i.e., bat grip, ready position, footwork/body positioning, service, stroke) elements of technical skills in young table tennis players. In addition, criteria for both flawed and excellent executions were identified for each of the five specific elements. Finally, these results were used to create an observation sheet usable for an assessment during competition.

Conclusions

This study revealed the crucial elements of technical skills that should be taken into account when assessing sport-specific technical skills of youth table tennis players (8–12 years). Moreover, it provided concise descriptions of what is considered to be flawed or excellent executions of technical skills. Based on these findings, a first observation sheet, the Oldenburg observation sheet for Table Tennis Technique (O3T), was created to be used for the assessment of the current technical skill level within a competitive context at the early stage of a table tennis player’s career. Future research should focus on its measurement properties and its value within a multidimensional assessment for talent purposes.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40798-021-00327-5.

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.

Acute Beetroot Juice Supplementation Does Not Improve Match-Play Activity in Professional Tennis Players

OBJECTIVE

Beetroot juice is a source of dietary nitrate (NO₃-) recognized as a potential ergogenic aid to enhance tolerance during endurance exercise of submaximal-to-maximal intensity. However, little is known about the effects of beetroot juice on exercise performance in intermittent sports such as tennis. The present study aimed to determine the effect of acute beetroot juice supplementation on movement patterns during a competitive tennis match in professional players.

METHODS

In a double-blind and randomized experiment, nine professional tennis players performed two experimental trials 3 h after ingesting either 70 mL of a commercially-available concentrated beetroot juice (6.4 mmol NO₃-) or placebo (0.005 mmol NO₃-). In each experimental trial, players completed a 3-set tennis match and two performance tests (i.e., serve speed and isometric handgrip strength) before and after the match. Match-play running performance was recorded using wearable GPS and accelerometer units.

RESULTS

In comparison to the placebo trial, the acute beetroot juice supplementation did not modify any match-play running performance (p = 0.178 to 0.997, d = 0.01 to 0.42). Furthermore, beetroot juice supplementation did not alter the pre-to-post match change in serve speed (p = 0.663, ηp² = 0.03) or isometric handgrip strength (p = 0.219, ηp² = 0.18).

CONCLUSIONS

The current results indicated that acute ingestion of a commercialized shot of nitrate-rich beetroot juice (70 mL containing 6.4 mmol of NO₃-) did not produce any performance benefit on tennis matchplay. Thus, acute beetroot juice supplementation seems an ergogenic aid with little value to enhance physical performance in professional tennis players.

A cross-educational approach on skill-related movement technique performance: Central neuronal motor behaviour preceding the short badminton backhand serve

Training in a particular sport not only leads to a higher accuracy in movement, it also creates neuronal modulations in different areas of the brain. Electroencephalography (EEG) has been on the rise to detect these neuronal modulations to address applied research approaches in sports-specific setups with focus on movement-related cortical potentials (MRCP) especially the readiness potential (RP). While many studies considered the RP in laboratory settings using button pressing, there is little research on sport-specific movements performed in realistic setups. Therefore the aim of this study was to examine the short backhand serve of expert and novice badminton players. 16 healthy, right-handed men participated in this study, eight experts and eight novices. A surface EMG was recorded from limb muscles and simultaneous EEG was recorded. RP peak increased significantly (p < 0.05) in expert compared to novices when serving with the dominant hand. RP onsets revealed no significant changes (p = 0.70). In line with previous reports, this study pointed out that complex movements such as the short badminton backhand serve produces higher RP peaks when performed precisely, indicating for long lasting practice and level of experience.

The impact of badminton on health markers in untrained females

The purpose of the study was to examine the health effects of 8 weeks of recreational badminton in untrained women. Participants were matched for maximal oxygen uptake (V̇O_2max) and body fat percentage and assigned to either a badminton (n = 14), running (n = 14) or control group (n = 8). Assessments were conducted pre- and post-intervention with physiological, anthropometric, motivation to exercise and physical self-esteem data collected. Post-intervention, V̇O_2max increased (P < 0.05) by 16% and 14% in the badminton and running groups, respectively, and time to exhaustion increased (P < 0.05) by 19% for both interventions. Maximal power output was increased (P < 0.05) by 13% in the badminton group only. Blood pressure, resting heart rate and heart rate during submaximal running were lower (P < 0.05) in both interventions. Perceptions of physical conditioning increased (P < 0.05) in both interventions. There were increases (P < 0.05) in enjoyment and ill health motives in the running group only, whilst affiliation motives were higher (P < 0.05) for the badminton group only. Findings suggest that badminton should be considered a strategy to improving the health and well-being of untrained females who are currently not meeting physical activity guidelines.