ECSS Paris 2023: CP-AP15
INTRODUCTION: The kinetic chain in tennis originates from the legs, and a proper stance is crucial for effective energy transfer to the ball [1,2]. Among the stances, the open stance forehand has gained popularity in the last twenty years despite the traditional square stance [3,4]. Hypotheses favoring open stance were supported by a study [5] that argued that this stance offers more power in strokes, allowing athletes to generate more spin and reach wider angles, however, the results in the literature are sometimes discordant [6,7] and many studies have linked the open stance to increased injury risk [8,9,10], but a clear understanding of the performance differences between the square and open stances remains elusive. This study aims to compare the effectiveness between forehand played in open and square stance, in terms of performance: 1) ball speed, 2) accuracy, 3) gesture economy. METHODS: Ten healthy competitive players (8 males, 2 females) were involved in the study. Eighty forehands were played by each subject with open and square stance, in lateral and diagonal-inside running structured situations, receiving the ball from a ball-throwing machine, and aiming to play in a square-shaped target with 2 m sides. The ball’s speed, accuracy of the shot and heart rate were acquired. Kruskal-Wallis’s tests and Dunn Post Hoc tests were used to compare the effect of stance and tactical situation on these performance variables. Wilcoxon signed-rank t-test was applied for a separate comparison of each between the two types of stances. Jasp (Version 0.18.3) and R software (Version 4.4.2) were used for the statistical analysis of the data. RESULTS: Square stance consistently resulted in significantly higher ball speeds in both lateral running (ΔMedian: 8 km/h) and diagonal-inside running (ΔMedian: 8.5 km/h), while differences in accuracy and metabolic demand were not significant. CONCLUSION: This preliminary study found that, in the examined group of competitive tennis players, square stance technique provided a clear advantage in terms of generating ball speed. Although the higher accuracy found was not significant, so was the difference in metabolic effort, it follows that the advantages in performance, together with and reduced risk of injury seem to make the square stance the preferable choice. A larger survey of a greater number of subjects is required.
Read CV Lucio CaprioliECSS Paris 2023: CP-AP15
INTRODUCTION: In tennis, open and square stances are both used to produce forehand drives, especially when players are not under time pressure [1], like in offensive situations. Interestingly, even though some biomechanical differences between these stances have been found [2;3], studies about their impact on performance are sparse. Indeed, a few studies showed no differences in racket speed [4;5] between square stance and open stances among high-level players, while the impact on shot accuracy has never been studied. Hence, the objective of our study was to examine the impact of using open or square stances during the execution of forehand drives in offensive tennis situations in terms of ball speed and shot accuracy. METHODS: Thirteen tennis players (two women and eleven men), at the regional to national level, performed a laboratory task that involved executing winning down-the-line forehand drives with the highest possible speed and accuracy. Subjects were required to perform 8 series of 5 strokes (4 series with open stances and 4 series with square stances) aiming at a target integrated into the projection of a tennis court image. A radar (Stalker Pro II) was used to record ball speed. Stroke accuracy was assessed through the distance between ball impact and the center of the target, using video footage processed with the Kinovea software. RESULTS: Wilcoxon paired samples T tests showed a significant effect for ball speed (W=8; p=.006) but not for accuracy (W=65; p=.191). Stroke speed was higher when players used square stance (130.46 km.h-1±13.49) than when they used open stance (123.3 km.h-1±11.46). An additional analysis examined whether players tended to hit higher or lower, more to the left or to the right depending on the stances used. It did not show any accuracy bias based on stance modality. CONCLUSION: While looking at the two key factors of performance in tennis forehand drives (ball speed and accuracy), only ball speed varied based on stances used. Previous studies showed no difference in terms of racket speed [4;5] but did not put players in specific situations (hitting an offensive shot within a target), hence probably hiding the overall differences. Moreover, these differences may be attributed to the players level of expertise, the controlled laboratory setting of our experiment, or the fact that all their drives occurred under favorable conditions, i.e., without time constraints. Hence it seems worthwhile to continue studying these strokes in favorable situations to analyze which stance is the most effective in a real-life situation on the tennis court. 1.Landlinger et al. (2010) 2.Bahamonde & Knudson (2003) 3.Pozzo et al. (2005) 4.Knudson & Bahamonde (1999) 5.Kawamoto et al. (2019)
Read CV Celine TRIOLETECSS Paris 2023: CP-AP15
INTRODUCTION: Traditional tennis vibration dampeners (VD) are small devices placed between the strings of a tennis racket to reduce vibrations [1], with the purpose of providing a more comfortable playing experience. However, some studies [2,3] found that VDs reduce some high frequencies, but do not reduce racket frame vibration transfer to the forearm. Thus, we hypothesize that VDs are relevant mainly to players acoustic preferences and, to a lesser extent, to proprioceptive comfort. The relevant question is whether VDs influence players’ perception and performance. METHODS: Thirty experienced tennis players (> 4 years of playing experience) wore during the test an earmuff (30dB attenuation) and used a racquet where the presence of the VD was masked. Unaware of the situation, they participated crosswise in 2 groups: Vibration Damper (VD) and Control Group (CG). The subjects performed 2 sets of 10 long line forehand shots for each situation on the same day, receiving the ball from a ball-launching machine, aiming to play as fast as possible into a 2mx2m area on the other side of the court. A speed radar (Pocket Radar Inc., Santa Rosa, CA, USA) measured the ball speed. A questionnaire regarding the presence or absence of VD and playing comfort was filled. Repeated measures MANOVA was used to detect changes in ball speed, accuracy of the shots and players comfort between the two groups. Statistical analysis was carried out with Jasp software (Version 0.18.3). Preliminary results are presented. RESULTS: The results of one participant are shown. The player perceived no difference in the sound of impact. However, being used to playing with the same racquet model of the experiment with VD, he recognized his usual situation as a playing feel and correctly guessed when the racquet had the VD. In terms of performance, there was no significant difference in accuracy between the two situations (VD: 56%; CG: 50%) and a difference of almost 3km/h, but still not significant occurred in ball speed with VD compared to the other condition: (VD: 127.3; CG: 124.5 km/h). CONCLUSION: The preliminary results provide initial insights into the potential effects of VDs on tennis performance. These findings suggest that the presence of VD, where the player was accustomed, might have subtly influenced his gesture, potentially leading to a slight increase in swing speed; highlighting the role of subjective perception and player familiarity in influencing performance and comfort feel. The analysis of the full sample size, as well as the use of inertial sensors, handle pressure sensors, and video cameras, may contribute in future studies to understanding the impact of VD on tennis performance.
Read CV Amani NajlaouiECSS Paris 2023: CP-AP15