Comparison of the finishing shot and ending zone of points in Grand Slam matches of women's doubles tennis: A cross-sectional study.

Despite the importance of doubles tennis, there is little research on this modality of the game, especially in women's tennis. The aim of this study was to analyse the finishing shot, the ending zone and shot by ending zone of women´s doubles matches during three Grand Slams (GS), and to observe the differences among surfaces. Twenty-one women's doubles matches from three GS, each played on a different surface were analysed. 56.4 ± 2.3% of the points were finished from the baseline and mid court zone (BMZ), 36.1 ± 2.3% from the net zone (NZ) and 7.5 ± 4.2% from the service zone (SZ). The shot with which the points ended primarily was the forehand volley (FV) (18.2 ± 3.5%), followed by the forehand (F) (17.4 ± 4.2%), the backhand (B) (15.8 ± 4.8%), the backhand volley (BV) (12.8 ± 3.6%), the forehand return (FRT) (11.7 ± 2.7%), the backhand return (BRT) (11.4 ± 2.6%), the service (S) (7.5 ± 4.2%) and the overhead (O) (5.2 ± 3.0%). The results showed a higher percentage of F played from the BMZ in Roland Garros (RG) than in Wimbledon (W) (p = 0.011). In addition, the results also showed a higher percentage in overall F in RG than in W (p = 0.023). The FRT percentage was higher in the Australian Open (AUS) compared to RG (p = 0.026), and the O shots played from the BMZ were higher in W than RG (p = 0.038). These results suggest that in professional women's doubles tennis the net game is a determinant factor, as well as the volley (V) and F shots. Playing aggressive and close to the net may have a positive effect on the result.

Volcano transition in populations of phase oscillators with random nonreciprocal interactions.

Populations of heterogeneous phase oscillators with frustrated random interactions exhibit a quasiglassy state in which the distribution of local fields is volcanoshaped. In a recent work [Phys. Rev. Lett. 120, 264102 (2018)10.1103/PhysRevLett.120.264102], the volcano transition was replicated in a solvable model using a low-rank, random coupling matrix M. We extend here that model including tunable nonreciprocal interactions, i.e., M^{T}≠M. More specifically, we formulate two different solvable models. In both of them the volcano transition persists if matrix elements M_{jk} and M_{kj} are enough correlated. Our numerical simulations fully confirm the analytical results. To put our work in a wider context, we also investigate numerically the volcano transition in the analogous model with a full-rank random coupling matrix.

Effects of different maturity status on change of direction performance of youth tennis players.

The aim of this study was to examine the maturational status (i.e., peak height velocity [PHV]) differences in neuromuscular performance (i.e., vertical jump, linear sprint, change of direction (COD) using different tests, and change of direction deficit [CODD]) of young tennis players. One hundred and two tennis players (70 boys and 52 girls; age 13.9 ± 2.0 years, body mass 53.3 ± 12.7 kg, height 163.1 ± 11.9 cm) participated in the study and were divided into Pre-PHV (n = 26), Circa-PHV (n = 33) and Post-PHV (n = 43) groups. Testing included speed (5, 10, and 20 m), COD tests (i.e., modified 5-0-5, pro-agility and hexagon), and bilateral/unilateral countermovement jump (CMJ). Pre- and Circa-PHV players presented lower levels of performance in jumping ability (i.e., both bilateral and unilateral CMJs; P < 0.001; ES: 0.85 to 0.98), linear sprints (5 to 20 m; P < 0.05 to < 0.001; ES: 0.67 to 1.19) and COD ability tests (modified 5-0-5 test, pro-agility and hexagon) compared to the Post-PHV players. Moreover, Pre-PHV players presented lower CODD% (p < 0.05; ES: 0.68-0.72) than Post-PHV for both forehand and backhand sides, and Circa-PHV showed lower values in the CODD of the rolling situation to the forehand side (p < 0.05; ES: 0.58). Among the COD tests, the pro-agility test seems to be a simple, easy-to-implement and reliable test, which can provide interesting information about the COD with higher entry speeds. Moreover, specific training strategies related to the PHV and focused not only on the neuromuscular training and COD workouts, but also on maximizing motor skill proficiency, should be recommended.

Scoping review and quality of studies on the epidemiology of pickleball injuries

Pickleball is a sport that combines several elements of tennis, badminton and table tennis. It is played on a court similar to the badminton court and the objective of the game is to hit the ball over a net similar to the tennis net. During these years, its popularity has grown substantially in the United States of America and it has been a sport played by people of different ages. It is important to know the different injuries that can occur in this sport in order to prevent and treat them. The aim is to perform a scoping review following the PRISMA-SCR guidelines to identify the main health problems and injury characteristics suffered in pickleball athletes. A total of 4 articles from different databases were found based on the keywords and boolean operators: ("Pickleball") AND ("injury" OR "injuries" OR "pathology*" OR "illness*" OR " disease*"). The most common injuries that occur are sprains and strains, and they tend to belong to the old age. However, more epidemiological studies about pickleball injuries are needed. Few studies have been found where the data sources show limitations to subsequently be able to carry out epidemiological studies with more precision. Even so, the scientific evidence is limited to provide applicable and conclusive results and more studies are needed on this topic in pickleball. (AU)

Effects of Maturation on Lower-Body Neuromuscular Performance in Youth Tennis Players.

ABSTRACT: Fernandez-Fernandez, J, Canós-Portalés, J, Martinez-Gallego, R, Corbi, F, and Baiget, E. Effects of maturation on lower body neuromuscular performance in youth tennis players. J Strength Cond Res 37(1): 167-173, 2023-The aim of this study was to examine the maturational status differences in neuromuscular performance of young tennis players. One hundred fifty-five junior tennis players (91 boys and 64 girls; age 13.1 ± 2.2 years, body mass 50.0 ± 12.2 kg, height 159.7 ± 12.4 cm, and estimated age at peak height velocity [PHV] 12.7 ± 1.6 years) participated in the study and were divided into pre-PHV (n = 57), circa-PHV (n = 50), and post-PHV (n = 48) groups. Physical tests included speed (5, 10, and 20 m), modified 5-0-5 change of direction (COD) test, hexagon test, and bilateral or unilateral countermovement jump (CMJ). The main results showed that compared with the post-PHV, pre-PHV players presented lower levels of performance in CMJs (p < 0.001; effect size [ES]: 0.76-0.88), linear sprints, and COD ability tests (p < 0.001; ES: 1.4-1.5). In addition, compared with circa-PHV, pre-PHV players also demonstrated lower performance levels in both linear sprints (p < 0.001; ES: 0.93-1.12) and COD abilities (p < 0.01; ES: 0.58-0.94). On the contrary, COD deficit (CODDEF) was significantly lower in the pre-PHV group than the circa-PHV (p < 0.001; ES: 0.76-0.79) and post-PHV (p < 0.001; ES: 1.04-1.05) groups. These results highlight the need to use the maturity stage (i.e., PHV) instead of chronological age as a more appropriate parameter when designing training programs. Furthermore, based on the differences found between groups, specific training strategies, such as neuromuscular training and COD workouts, related to the different maturation stages should be recommended.

How do International Olympic Sport Federations innovate? The use of crowdfunding and the impact of COVID-19.

The purpose of this study was to contribute to the understanding of innovation and crowdfunding of International Olympic Sport Federations (IFs), which are the world governing bodies of their respective sports. Three research questions were addressed: the perceptions of the IFs on the implementation of their innovation programmes during the last four years (2016-2020), the impact of COVID-19 on the IFs capability to innovate, and the crowdfunding strategies of the IFs. A mixed method combining qualitative and quantitative approaches was used. An online semi-structured questionnaire which included an open answer section was completed by IFs executives (n = 22) and an analysis of the information provided by IFs through various content sources was conducted. Results showed that IFs with less funding had a significantly more innovative approach that their counterparts, that the perception of the impact of COVID-19 on the innovative capability was not unanimous, that they identified sport-specific programmes as the most innovative of all initiatives delivered during the pandemic, and that crowdfunding projects were implemented in their sport but mostly at individual and local levels. From a research perspective, since this is the first study that investigates the innovation and crowdfunding strategies of IFs, future directions include the need for further research with national and regional federations on these topics. Practical implications are suggested for IFs to deliver innovative programmes to satisfy their stakeholder needs and to consider new funding methods such as crowdfunding as part of their strategies.

Randomized phase II trial of FOLFIRI-panitumumab compared with FOLFIRI alone in patients with RAS wild-type circulating tumor DNA metastatic colorectal cancer beyond progression to first-line FOLFOX-panitumumab: the BEYOND study (GEMCAD 17-01).

PURPOSE: Panitumumab plus FOLFOX (P-FOLFOX) is standard first-line treatment for RAS wild-type (WT) metastatic colorectal cancer. The value of panitumumab rechallenge is currently unknown. We assessed addition of panitumumab to FOLFIRI (P-FOLFIRI) beyond progression to P-FOLFOX in patients with no RAS mutations in liquid biopsy (LB). METHODS: In this randomized phase II trial, patients were assigned (3:2 ratio) to second-line P-FOLFIRI (arm A) or FOLFIRI alone (arm B). LB for circulating tumor DNA analysis was collected at study entry and at disease progression. Primary endpoint was 6-month progression-free survival. Two-stage Simon design required 85 patients to be included (EudraCT 2017-004519-38). RESULTS: Between February 2019 and November 2020, 49 patients were screened (16 RAS mutations in LB detected) and 31 included (18 assigned to arm A and 13 to arm B). The study was prematurely closed due to inadequate recruitment. Serious adverse events were more frequent in arm A (44% vs. 23%). Overall response rate was 33% (arm A) vs. 7.7% (arm B). Six-month progression-free survival rate was 66.7% (arm A) and 38.5% (arm B). Median progression-free survival was 11.0 months (arm A) and 4.0 months (arm B) (hazard ratio, 0.58). At disease progression, RAS or BRAF mutations in LB were found in 4/11 patients (36%) in arm A and 2/10 (20%) in arm B. CONCLUSIONS: The BEYOND study suggests a meaningful benefit of P-FOLFIRI beyond progression to P-FOLFOX in metastatic colorectal cancer patients with WT RAS status selected by LB. This strategy deserves further investigation.

Impact of match-induced pressure on HRV of junior tennis players.

The present study aimed to assess the impact of a tennis competition on the HRV of nationally ranked junior girls and boys tennis players. A total of 22 nationally ranked tennis players (8 girls and 14 boys), with a mean age of 14.18 (2.15) and experience in national tournaments of 4.23 (2.27) years, participated in this cross-sectional study. Boys had a mean age of 14.36 (1.86) years-old and girls had a mean age of 13.87 (2.69) years old. Participants were assessed the day before and 20 min before the competition match. Significantly reduction in time-domain variables such as the time between intervals R-R (RR-interval) (p-value = 0.001), the percentage of intervals >50 ms different from the previous interval (pNN50) (p-value = 0.020) and the square root of the mean of the squares of the successive differences of the interval RR (RMSSD) (p-value = 0.028) were found between baseline and pre-match assessments. Furthermore, the non-linear measure based on the dispersion, standard deviation, of points perpendicular to the axis of line-of-identity in the Poincaré plot (SD1) (p-value = 0.028) was also significantly reduced before the match when compared to the baseline. However, differences between girls and boys junior tennis players were not found in the pre-competitive heart rate variability (HRV) variables (p-value >0.05). HRV is a convenient, non-invasive measurement that can be easily performed with a watch at home and on the field in order to control and manage match-induced pressure.

Heart Rate Variability in Elite International ITF Junior Davis Cup Tennis Players.

The aim of the present study was to investigate the evolution of the HRV during an international team tennis tournament in elite junior tennis players. A total of 11 tennis players, with a mean age of 15.36 (0.67) from six nationalities, participated in this cross-sectional study. Participants were measured one day before the event, before the first match, and before the second match of the ITF Junior Davis Cup event. Each of the registers lasted 5 min and the time domain, frequency domain and non-linear variables were extracted. The tournament took place in Valencia (Spain). Results showed that there was not a significant decrease in the heart rate variability (HRV) induced by precompetitive stress. However, significant differences (p-value < 0.05) were found between baseline and second match pre-competition HRV values in low frequency (LFNu) (p-value = 0.008) and high frequency (HFNu) power (p-value = 0.008), LF/HF ratio (p-value = 0.008) and Sample Entropy (SampEn) (p-value = 0.033) variables. Furthermore, cognitive anxiety (measured by CSAI-2r) (p-value = 0.017) and anxiety (measured by STAI-S) (p-value = 0.042) were higher before the first match than before the second match. Coaches and physical trainers could use HRV to control and manage the precompetitive anxiety of junior tennis players. The experience in international tournaments and the familiarization with the environment in the second match could explain these results.

COVID-19 Prevention Measures Implemented by Tennis Coaches: The Role of Continent, Experience, and Type of Facility.

The prevention strategies used by tennis coaches when delivering tennis lessons during the COVID-19 pandemic were analyzed in this study. An ad hoc questionnaire collected data from 655 Spanish and Portuguese speaking tennis coaches working in Latin America and Europe. Differences in the prevention measures were analyzed according to the continent, the coaches' experience, and the type of facility they worked in. Results showed that coaches used information provided from local and national organizations more than from international ones. Hand hygiene, communication of preventive strategies, and changes in the coaching methodology were the most used prevention measures. Latin American coaches and those working in public facilities implemented the measures more often than their European colleagues or those working in private venues. Finally, more experienced coaches showed a greater awareness of the adoption of the measures than their less experienced counterparts. The data provided by this research may assist in developing new specific guidelines, protocols, and interventions to help better understand the daily delivery of tennis coaching in this challenging context.

Fitness testing in tennis: Influence of anthropometric characteristics, physical performance, and functional test on serve velocity in professional players.

The aims of this study were to examine the relationship between anthropometric variables, physical performance, and functional test with serve velocity regarding tennis players' level and to design regression models that effectively predict serve velocity. A sample of sixteen male tennis players participated in this study (national level = 8, professional level = 7). Anthropometric measurements (body mass, height, body mass index and body segments) and physical test (hand strength, countermovement jump, jump on serve, and serve velocity) and functional test (medicine ball throw overhead and shot put) were performed. No differences in anthropometrics and physical test were found between national and professional levels. A significant positive correlation (p < 0.05, ranging for 0.603 to 0.932) was found between some anthropometrics measurements (body mass, height, arm, forearm, and leg segments), physical parameters (hand strength, countermovement jump) and functional test (medicine ball throw shot put and overhead) with serve velocity for all tennis players. Multiple regression analysis indicated that medicine ball throw shot put was the most important test to explain serve velocity (r2 = 0.869). The results showed how the combination of physical and anthropometric factors have an impact on serve velocity. In addition, a new functional fitness test (medicine ball throw shot put) is proposed as an alternative to traditional medicine ball throw overhead due to its high reproducibility (inter-trial reliability) and predictive validity values, as well as by multi-segmental coordination movement similar to tennis serve.

Comparison of service tactic formation on players' movements and point outcome between national and beginner level padel.

The aim of this study was to analyze the influence of service tactic formation on players' movements and point outcome at two different performance levels. The sample contained 2,148 points corresponding to 18 matches from two male padel indoor tournaments. Players were classified according to their game level: high-level (N = 36; age = 33.3 ± 6.9 years) and beginner (N = 36; age = 35.4 ± 6.8 years). Variables pertaining to service tactic formation (conventional or Australian), point outcome and movement patterns were analysed from the matches through systematic observation. The results showed how high-level players used a significantly higher percentage of the Australian formation than beginners. Also, high-level players won a significantly higher percentage of points than recreational players when using both service tactics. According to movement variables, servers were significantly closer to the net and the side wall using a conventional formation when the returner hit the ball. Furthermore, servers had to move quicker when they used the Australian formation. Finally, the comparison of movement patterns of servers according to game level, showed how high-level players ran faster to the offensive position, covered a greater distance and spent less time between serve and return impacts than beginners.

Key Physical Factors in the Serve Velocity of Male Professional Wheelchair Tennis Players.

The aim of this study was to identify the physical factors related to serve speed in male professional wheelchair tennis players (WT). Nine best nationally-ranked Spanish male wheelchair tennis players (38.35 ± 11.28 years, 63.77 ± 7.01 kg) completed a neuromuscular test battery consisting of: isometric handgrip strength; serve velocity; 5, 10 and 20 m sprint (with and without racket); agility (with and without racket); medicine ball throw (serve, forehand and backhand movements); and an incremental endurance test specific to WT. Significantly higher correlations were observed in serve (r = 0.921), forehand (r = 0.810) and backhand (r = 0.791) medicine ball throws showing a positive correlation with serve velocity. A regression analysis identified a single model with the medicine ball throw serve as the main predictor of serve velocity (r2 = 0.847, p < 0.001). In conclusion, it is recommended that coaches and physical trainers include medicine ball throw workouts in the training programs of WT tennis players due to the transfer benefits to the serve speed.

Comment on "The Winfree model with non-infinitesimal phase-response curve: Ott-Antonsen theory" [Chaos 30, 073139 (2020)].

In a recent paper [Chaos 30, 073139 (2020)], we analyzed an extension of the Winfree model with nonlinear interactions. The nonlinear coupling function Q was mistakenly identified with the non-infinitesimal phase-response curve (PRC). Here, we assess to what extent Q and the actual PRC differ in practice. By means of numerical simulations, we compute the PRCs corresponding to the Q functions previously considered. The results confirm a qualitative similarity between the PRC and the coupling function Q in all cases.

Ball Impact Position in Recreational Male Padel Players: Implications for Training and Injury Management.

Racket sports such as padel are characterized by the repetition of unilateral gestures, which can lead to negative adaptations like asymmetries or overuse musculoskeletal injuries. The purpose of this study was to determine the differences in ball impact positions (i.e., forward or backward of the center of gravity) in nine stroke types in a sample of forty-eight recreational male padel players. The sample included 14,478 shots corresponding to 18 matches from six tournaments. Forty-eight male padel players were classified into two groups according to their level: trained (n = 24) and novice (n = 24). Type of stroke and ball impact position were registered using a computerized motion tracking video system. The ball impact position was computed from the distance (cm) between the coordinates of the ball and the player's center of gravity. Results show that trained players hit the ball in a more backward position (from 11 to 25 cm, compared to novice) in serve and offensive strokes (volleys, trays, and smashes) but used more forward strokes (from 7 to 32 cm, compared to novice) in defensive shots (groundstrokes, wall strokes, and lobs). Because the current differential variables are trainable and demonstrated to be of relevance for performance, the findings of this study may assist padel coaches in designing proper training plans to improve effectiveness and to prevent musculoskeletal injuries regarding the type of stroke and ball impact position. Such knowledge may constitute a very important factor affecting technique, biomechanics, and injury management in padel players of different competitive levels.

Stroke Analysis in Padel According to Match Outcome and Game Side on Court.

The aim of this study was to analyze the distribution of padel strokes, their effectiveness, direction, and court zone, comparing between the winning and losing pairs in the match and the playing side of the players. The sample included 8441 strokes corresponding to 1055 points out of a total of nine padel matches in the First National Category. The variables analyzed were type of stroke, court area, effectiveness and directions of the strokes, match outcome, and game side. Matches were analyzed through systematic observation. The results showed that the winning pair made a significantly higher percentage of winners, and cross-court smashes and volleys from the offensive zone. In addition, players on the left side executed a higher percentage of cross-court and winning shots than the players on the right side. Such knowledge may constitute a useful guide in the design of appropriate game strategies and specific training sessions based on the shots that will help players to win the match according to the role of the player and depending on their game side.

The Winfree model with non-infinitesimal phase-response curve: Ott-Antonsen theory.

A novel generalization of the Winfree model of globally coupled phase oscillators, representing phase reduction under finite coupling, is studied analytically. We consider interactions through a non-infinitesimal (or finite) phase-response curve (PRC), in contrast to the infinitesimal PRC of the original model. For a family of non-infinitesimal PRCs, the global dynamics is captured by one complex-valued ordinary differential equation resorting to the Ott-Antonsen ansatz. The phase diagrams are thereupon obtained for four illustrative cases of non-infinitesimal PRC. Bistability between collective synchronization and full desynchronization is observed in all cases.