related to the best serve accuracy. Self-Myofascial Release The self-myofascial release was performed on the zone of the infraspinatus and pectoralis muscles 3 times per week at the end of the warm-up of tennis training with a new tennis ball. In the first exercise, the player was in a side-lying position
Julien Le Gal, Mickael Begon, Benoit Gillet and Isabelle Rogowski
Bart Van Gheluwe and Eric Deporte
Tennis movements are characterized essentially by lateral displacements, thus external load on the lower extremities is created predominantly by friction generated between shoes and playing surfaces. This study analyzed the behavior of frictional forces and torques produced during an open stance forehand using various playing surfaces and different sport shoes. The frictional data were obtained from 12 advanced players returning a tennis ball fired from a ball machine and hitting a large Kistler force plate located at the base line of the tennis court. Using statistical ANOVA techniques, friction was found to be more sensitive to the choice of playing surface than to the choice of tennis shoe. “Fluid” type surfaces displayed the lowest frictional values in most cases. Additionally, comparison of the frictional data collected during the forehand with the measurements from a standardized laboratory test demonstrated that extrapolation of friction results from laboratory to real field conditions may lead to erroneous conclusions.
Jack L. Groppel, In-Sik Shin, Jo Ann Thomas and Gregory J. Welk
This study explored the effects of string type and tension on various factors involved with tennis ball–racquet impact in midsized and oversized racquets. String and racquet material, racquet flexibility, and grip firmness were held constant for each test condition. The dependent variables included postimpact and preimpact ball velocity ratio, racquet head displacement, maximum ball compression, and ball contact duration. It was found that racquet size and string material have varying effects on impact. Although changes in string tension do affect the impact, it is not in a linear fashion. Various string tensions change a racquet's flexibility, thus affecting ball velocity and other factors associated with impact. The results of this study demonstrate the complexity of string and frame interaction.
M.A. Urbin, David Stodden, Rhonda Boros and David Shannon
The purpose of this study was to examine variability in overarm throwing velocity and spatial output error at various percentages of maximum to test the prediction of an inverted-U function as predicted by impulse-variability theory and a speed-accuracy trade-off as predicted by Fitts’ Law Thirty subjects (16 skilled, 14 unskilled) were instructed to throw a tennis ball at seven percentages of their maximum velocity (40–100%) in random order (9 trials per condition) at a target 30 feet away. Throwing velocity was measured with a radar gun and interpreted as an index of overall systemic power output. Within-subject throwing velocity variability was examined using within-subjects repeated-measures ANOVAs (7 repeated conditions) with built-in polynomial contrasts. Spatial error was analyzed using mixed model regression. Results indicated a quadratic fit with variability in throwing velocity increasing from 40% up to 60%, where it peaked, and then decreasing at each subsequent interval to maximum (p < .001, η2 = .555). There was no linear relationship between speed and accuracy. Overall, these data support the notion of an inverted-U function in overarm throwing velocity variability as both skilled and unskilled subjects approach maximum effort. However, these data do not support the notion of a speed-accuracy trade-off. The consistent demonstration of an inverted-U function associated with systemic power output variability indicates an enhanced capability to regulate aspects of force production and relative timing between segments as individuals approach maximum effort, even in a complex ballistic skill.
Matthew Rivera, Lindsey Eberman, Kenneth Games and Cameron J. Powden
interventions available that health care providers can use to treat muscle tightness in general and specifically in the upper-extremity. One intervention is self-myofascial release (SMR), a form of myofascial release that is applied by the patient using a tool such as foam roller or tennis ball. 5 SMR has
Ali Brian, Sally Taunton, Lauren J. Lieberman, Pamela Haibach-Beach, John Foley and Sara Santarossa
modifications Protocol modifications Throw, underhand throw, and roll Tennis ball Beeper box at wall or person clapping at wall Catch 10.16-cm plastic ball Medium-belled or beeping ball Timing mechanism: “Joey, ready? Catch!” Kick 20.32- to 25.40-cm kickball Beep kickball One-hand strike Tennis ball
Dennis Dreiskaemper, Till Utesch and Maike Tietjens
.81 .70 3.30 0.74 I am good at catching a small ball (e.g., a Tennis ball). 3.31 0.76 .63 3.22 0.86 I am good at catching a hard thrown ball. 2.99 0.89 .73 2.87 0.87 (I am good at catching a ball.) 3.36 0.77 .85 (I am good at ball catching.) 3.42 0.78 .83 I am good at kicking a ball. 3.38 0.76 .64 3.29 0
Camilo Sáenz-Moncaleano, Itay Basevitch and Gershon Tenenbaum
) rather than artificial or reduced responses. The second limitation in this vein is related to the dynamic QE (i.e., where the contextual information is moving such as a tennis ball, compared with static contextual information such as a putting hole or a basketball rim). Although in recent years, more QE
Khaya Morris-Binelli, Sean Müller and Peter Fadde
). Use of advance cues in predicting the flight of a lawn tennis ball . Journal of Human Movement Studies , 4 ( 4 ), 231 – 235 . Lewis , M. ( 2003 ). Moneyball: The art of winning the unfair game . New York, NY : W. W. Norton & Company . Loffing , F. , & Hagemann , N. ( 2014 ). Skill
Cassio M. Meira Jr and Jeffrey T. Fairbrother
augmented. Inherent feedback is the information available that comes from the learner’s sensory system as a result of engaging in the task; for example, to see the outcome of a volleyball serve, to hear a tennis ball hit on a racket or to feel the gas pedal on one’s feet. In turn, augmented feedback is