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Sample records for adolescent tennis players

  1. Sagittal Spinal Morphology in Highly Trained Adolescent Tennis Players

    PubMed Central

    Muyor, José M.; Sánchez-Sánchez, Estefanía; Sanz-Rivas, David; López-Miñarro, Pedro A.

    2013-01-01

    Sports with a predominance of forward-bending and extension postures have been associated with alterations in the sagittal spinal curvatures and greater risk of spinal injury. Because, the tennis players adopt these postures, the aims of this study were: 1) to describe spinal curvatures and pelvic tilt in male and female highly trained adolescent tennis players during relaxed standing posture and with thoracic spine corrected (in prone lying on the floor); and 2) to determine the frequency of thoracic hyperkyphosis and lumbar hypo/hyper lordosis in these postures. Forty adolescent tennis players (24 male and 16 female) aged 13-18 years, participated voluntarily in this study. The Spinal Mouse system was used to measure sagittal spinal curvatures and pelvic tilt. The mean values in the relaxed standing posture were 43.83° ± 7.87° (thoracic kyphosis), - 27.58° ± 7.01° (lumbar lordosis), and 13.38° ± 5.57° (pelvic tilt) for male tennis players, respectively; and 36.13° ± 6.69° (thoracic kyphosis), - 32.69° ± 5.06° (lumbar lordosis), 20.94° ± 5.36° (pelvic tilt) for female tennis players (p < 0.05 between genders in all spinal parameters). The male and female tennis players showed a frequency of 62.5% and 93.8% (p = 0.032) for neutral thoracic kyphosis, and 83.3% and 93.8% (p = 0.062) in neutral lumbar lordosis, respectively. In conclusion, due to the high percentage of neutral spinal curvatures in both male and female tennis players, to practice tennis in these levels does not alter sagittal spinal morphology in the relaxed standing posture in adolescent highly trained tennis players. Key Points This study evaluated thoracic and lumbar spinal curvatures and pelvic tilt during several postures in young highly trained tennis players. Female tennis players showed statistically significant greater anterior pelvic tilt, lumbar lordosis and lower thoracic kyphosis than male tennis players. The high percentage of neutral thoracic kyphosis and lumbar

  2. Running activity profile of adolescent tennis players during match play.

    PubMed

    Hoppe, Matthias W; Baumgart, Christian; Bornefeld, Jutta; Sperlich, Billy; Freiwald, Jürgen; Holmberg, Hans-Christer

    2014-08-01

    The aims of this study were (1) to assess the running activities of adolescent tennis players during match play with respect to velocity, acceleration, and deceleration; (2) to characterize changes in these activities during the course of a match; and (3) to identify potential differences between winners and losers. Twenty well-trained adolescent male athletes (13 ± 1 y) played one simulated match each (giving a total of 10 matches), during which distances covered at different velocity categories (0 to < 1, 1 to < 2, 2 to < 3, 3 to < 4, and ≥ 4 m·s(-1)) and number of running activities involving high velocity (≥ 3 m·s(-1)), acceleration (≥ 2 m·s(-2)), and deceleration (≤ -2 m·s(-2)) were monitored using a global positioning system (10 Hz). Heart rate was also assessed. The total match time, total distance covered, peak velocity, and mean heart rate were 81.2 ± 14.6 min, 3362 ± 869 m, 4.4 ± 0.8 m·s(-1), and 159 ± 12 beats·min(-1), respectively. Running activities involving high acceleration (0.6 ± 0.2 n·min(-1)) or deceleration (0.6 ± 0.2 n·min(-1)) were three times as frequent as those involving high velocity (0.2 ± 0.1 n·min(-1)). No change in the pattern of running activities (P ≥ .13, d ≤ 0.39) and no differences between winners and losers (P ≥ .22, d ≤ 0.53) were evident during match play. We conclude that training of well-trained adolescent male tennis players need not focus on further development of their running abilities, since this physical component of multifactorial tennis performance does not change during the course of a match and does not differ between the winners and losers.

  3. Lumbar Mechanics in Tennis Groundstrokes: Differences in Elite Adolescent Players With and Without Low Back Pain.

    PubMed

    Campbell, Amity; Straker, Leon; Whiteside, David; O'Sullivan, Peter; Elliott, Bruce; Reid, Machar

    2016-02-01

    Adolescent tennis players are at risk for low back pain (LBP). Recent research has demonstrated a potential mechanical etiology during serves; however, groundstrokes have also been suggested to load this region. Therefore, this study compared lumbar mechanics between players with and without a history of LBP during open and square stance tennis forehands and backhands. Nineteen elite, adolescent, male tennis players participated, 7 with a history of recurrent disabling LBP and 12 without. Differences in three-dimensional lumbar kinetics and kinematics were compared between pain/no pain groups and groundstrokes using linear mixed models (P < .01). There were no significant differences between pain/no pain groups. Relative to a right-handed player, groundstroke comparisons revealed that forehands had greater racquet velocity, greater lumbar right lateral flexion force, as well as upper lumbar extension/rightward rotation and lower lumbar right rotation/lateral flexion movements that were closer to or further beyond end of range than backhands. Backhands required upper lumbar leftward rotation that was beyond end range, while forehands did not. Given that players typically rotated near to their end of range during the backswing of both forehands and backhands, independent of pain, groundstrokes may contribute to the cumulative strain linked to LBP in tennis players.

  4. Body composition and physical capacity of elite adolescent female tennis players.

    PubMed

    Ziemann, Ewa; Sledziewska, Ewelina; Grzywacz, Tomasz; Gibson, Ann L; Wierzba, Tomasz H

    2011-01-01

    The study was performed to evaluate relationships among the major anthropological parameters: (body mass - BM, height, body mass index - BMI, lean body mass - FFM, proportion of fat mass -Fat%), physical capacity, and the tennis federations ranking position as an index of the temporal sport success. Seventeen elite female tennis players, divided into three age-matched groups (15, 16, and 17 yr) participated in this study. All the players had a national singles ranking (positions between 1st-80th) and in International Tennis Federation's Junior Circuit ranking (ITFJC; 21st to 990th position of ITF). Body composition was assessed via bioelectrical impedance. Maximal aerobic capacity (VO2max) was calculated from the distance covered in 12-min run test via Cooper's formula. Wingate test with lactate assay was used as an index of anaerobic capacity. There was a significant age-related trend for an increase in BM, height, FFT, and Fat%, associated with impressive shift of the anthropological indexes of body weight and height, assessed by the percentile chart analysis. The unexpected body growth spurt evidently observed between aged 15 and 17 is supposed to reflect a delay in somatic development, related to extensive exercise load. Body composition did not correlate to the ranking positions. All tested tennis players revealed excellent aerobic capacity associated with poor indices of anaerobic fitness. The position in the tennis federations rankings correlated to VO2max but not with maximal power or maximal work output assessed by Wingate test. In the whole group the maximal power and work output were proportional to BMI and FFM, but not to Fat%. In conclusion, in light of the contradictory reports concerning a possible link between strenuous regular exercise performed by young children and adolescent elite sportsmen our data indicate a delayed growth spurt in the elite female tennis players to occur between ages 15 and 17. The other important finding in terms of

  5. Age-Related, Sport-Specific Adaptions of the Shoulder Girdle in Elite Adolescent Tennis Players

    PubMed Central

    Cools, Ann M.; Palmans, Tanneke; Johansson, Fredrik R.

    2014-01-01

    Context: Tennis requires repetitive overhead movements that can lead to upper extremity injury. The scapula and the shoulder play a vital role in injury-free playing. Scapular dysfunction and glenohumeral changes in strength and range of motion (ROM) have been associated with shoulder injury in the overhead athlete. Objective: To compare scapular position and strength and shoulder ROM and strength between Swedish elite tennis players of 3 age categories (<14, 14–16, and >16 years). Design: Cross-sectional study. Setting: Tennis training sports facilities. Patients or Other Participants: Fifty-nine adolescent Swedish elite tennis players (ages 10–20 years) selected based on their national ranking. Main Outcome Measure(s): We used a clinical screening protocol with a digital inclinometer and a handheld dynamometer to measure scapular upward rotation at several angles of arm elevation, isometric scapular muscle strength, glenohumeral ROM, and isometric rotator cuff strength. Results: Players older than 16 years showed less scapular upward rotation on the dominant side at 90° and 180° (P < .05). Although all absolute scapular muscle strength values increased with age, there was no change in the body-weight–normalized strength of the middle (P = .9) and lower (P = .81) trapezius or serratus anterior (P = .17). Glenohumeral internal-rotation ROM and total ROM tended to decrease, but this finding was not statistically significant (P = .052 and P = .06, respectively). Whereas normalized internal-rotator strength increased from 14 to 16 years to older than 16 years (P = .009), normalized external-rotator and supraspinatus strength remained unchanged. Conclusions: Age-related changes in shoulder and scapular strength and ROM were apparent in elite adolescent tennis players. Future authors should examine the association of these adaptations with performance data and injury incidence. PMID:25098662

  6. Asymptomatic Elite Adolescent Tennis Players' Signs of Tendinosis in Their Dominant Shoulder Compared With Their Nondominant Shoulder

    PubMed Central

    Johansson, Fredrik R.; Skillgate, Eva; Adolfsson, Anders; Jenner, Göran; DeBri, Edin; Swärdh, Leif; Cools, Ann M.

    2015-01-01

    Context Tennis is an asymmetric overhead sport with specific muscle-activation patterns, especially eccentrically in the rotator cuff. Magnetic resonance imaging (MRI) findings in asymptomatic adolescent elite tennis players have not previously been reported. Objective The first aim of the study was to describe MRI findings regarding adaptations or abnormalities, as well as muscle cross-sectional area (CSA), of the rotator cuff. The second aim of the study was to investigate the rotator cuff based on the interpretation of the MRI scans as normal versus abnormal, with the subdivision based on the grade of tendinosis, and its association with eccentric rotator cuff strength in the dominant arm (DA) of the asymptomatic elite adolescent tennis player. Setting Testing environment at the radiology department of Medicinsk Röntgen AB. Patients or Other Participants Thirty-five asymptomatic elite tennis players (age = 17.4 ± 2.7 years) were selected based on ranking and exposure time. Intervention(s) We assessed MRI scans and measured the CSA of the rotator cuff muscle. The non-DA (NDA) was used as a control. In addition, eccentric testing of the external rotators of the DA was performed with a handheld dynamometer. Results The DA and NDA displayed different frequencies of infraspinatus tendinosis (grade 1 changes) (P < .05). Rotator cuff measurements revealed larger infraspinatus and teres minor CSA (P < .05) in the DA than in the NDA. Mean eccentric external-rotation strength in the DA stratified by normal tendon and tendinosis was not different between groups (P = .723). Conclusions Asymptomatic adolescent elite tennis players demonstrated infraspinatus tendinosis more frequently in the DA than in the NDA. Clinicians must recognize these tendon changes in order to modify conditioning and performance programs appropriately. PMID:26651279

  7. Prediction of Tennis Performance in Junior Elite Tennis Players

    PubMed Central

    Kramer, Tamara; Huijgen, Barbara C.H.; Elferink-Gemser, Marije T.; Visscher, Chris

    2017-01-01

    Predicting current and future tennis performance can lead to improving the development of junior tennis players. The aim of this study is to investigate whether age, maturation, or physical fitness in junior elite tennis players in U13 can explain current and future tennis performance. The value of current tennis performance for future tennis performance is also investigated. A total of 86 junior elite tennis players (boys, n = 44; girls, n = 42) U13 (aged: 12.5 ± 0.3 years), and followed to U16, took part in this study. All players were top-30 ranked on the Dutch national ranking list at U13, and top-50 at U16. Age, maturation, and physical fitness, were measured at U13. A principal component analysis was used to extract four physical components from eight tests (medicine ball throwing overhead and reverse, ball throwing, SJ, CMJas, Sprint 5 and 10 meter, and the spider test). The possible relationship of age, maturation, and the physical components; “upper body power”, “lower body power”, “speed”, and “agility” with tennis performance at U13 and U16 was analyzed. Tennis performance was measured by using the ranking position on the Dutch national ranking list at U13 and U16. Regression analyses were conducted based on correlations between variables and tennis performance for boys and girls, separately. In boys U13, positive correlations were found between upper body power and tennis performance (R2 is 25%). In girls, positive correlations between maturation and lower body power with tennis performance were found at U13. Early maturing players were associated with a better tennis performance (R2 is 15%). In girls U16, only maturation correlated with tennis performance (R2 is 13%); later-maturing girls at U13 had better tennis performances at U16. Measuring junior elite tennis players at U13 is important for monitoring their development. These measurements did not predict future tennis performance of junior elite tennis players three years later

  8. Prediction of Tennis Performance in Junior Elite Tennis Players.

    PubMed

    Kramer, Tamara; Huijgen, Barbara C H; Elferink-Gemser, Marije T; Visscher, Chris

    2017-03-01

    Predicting current and future tennis performance can lead to improving the development of junior tennis players. The aim of this study is to investigate whether age, maturation, or physical fitness in junior elite tennis players in U13 can explain current and future tennis performance. The value of current tennis performance for future tennis performance is also investigated. A total of 86 junior elite tennis players (boys, n = 44; girls, n = 42) U13 (aged: 12.5 ± 0.3 years), and followed to U16, took part in this study. All players were top-30 ranked on the Dutch national ranking list at U13, and top-50 at U16. Age, maturation, and physical fitness, were measured at U13. A principal component analysis was used to extract four physical components from eight tests (medicine ball throwing overhead and reverse, ball throwing, SJ, CMJas, Sprint 5 and 10 meter, and the spider test). The possible relationship of age, maturation, and the physical components; "upper body power", "lower body power", "speed", and "agility" with tennis performance at U13 and U16 was analyzed. Tennis performance was measured by using the ranking position on the Dutch national ranking list at U13 and U16. Regression analyses were conducted based on correlations between variables and tennis performance for boys and girls, separately. In boys U13, positive correlations were found between upper body power and tennis performance (R(2) is 25%). In girls, positive correlations between maturation and lower body power with tennis performance were found at U13. Early maturing players were associated with a better tennis performance (R(2) is 15%). In girls U16, only maturation correlated with tennis performance (R(2) is 13%); later-maturing girls at U13 had better tennis performances at U16. Measuring junior elite tennis players at U13 is important for monitoring their development. These measurements did not predict future tennis performance of junior elite tennis players three years later. Future

  9. Spondylolysis in young tennis players

    PubMed Central

    Ruiz‐Cotorro, A; Balius‐Matas, R; Estruch‐Massana, A; Angulo, J Vilaró

    2006-01-01

    The general aetiology, diagnosis, and treatment of spondylolysis, a bone defect in the pars interarticularis of the vertebra, are reviewed. A retrospective study of young tennis players diagnosed between 2000 and 2004 with spondylolysis with or without spondylolisthesis, assessed by radiography and planar bone scintigraphy, is described. If the radiographic results were negative, computed tomography was performed. Sixty six cases were evaluated: 53 L5 lesions, eight L4 lesions, two L3 lesions, and one bilateral lesion at the L2 level. Two more lesions at two levels were found (bilateral L5 and unilateral L4 and L3 on the right side). Classification, treatment, and outcome of the cases are reported. A combination of radiography, planar bone scintigraphy, and SPECT is useful for evaluating spondylolysis in tennis players and recommending treatment. Use of a brace did not appear to achieve significant results. PMID:16632576

  10. Rectus abdominis muscle strains in tennis players.

    PubMed

    Maquirriain, Javier; Ghisi, Juan P; Kokalj, Antonio M

    2007-11-01

    Rectus abdominis muscle strains are common and debilitating injuries among competitive tennis players. Eccentric overload, followed by forced contraction of the non-dominant rectus abdominis during the cocking phase of the service motion is the accepted injury mechanism. A tennis-specific rehabilitation program emphasising eccentrics and plyometric strengthening of the abdominal wall muscles, contributes to the complete functional recovery in tennis players, and could help reduce recurrences.

  11. Rectus abdominis muscle strains in tennis players

    PubMed Central

    Maquirriain, Javier; Ghisi, Juan P; Kokalj, Antonio M

    2007-01-01

    Rectus abdominis muscle strains are common and debilitating injuries among competitive tennis players. Eccentric overload, followed by forced contraction of the non‐dominant rectus abdominis during the cocking phase of the service motion is the accepted injury mechanism. A tennis‐specific rehabilitation program emphasising eccentrics and plyometric strengthening of the abdominal wall muscles, contributes to the complete functional recovery in tennis players, and could help reduce recurrences. PMID:17957025

  12. A case study of virilizing adrenal tumor in an adolescent female elite tennis player--insight into the use of anabolic steroids in young athletes.

    PubMed

    Eliakim, Alon; Cale-Benzoor, Mia; Klinger-Cantor, Beatrice; Freud, Enrique; Nemet, Dan; Feigin, Elad; Weintrob, Neomi

    2011-01-01

    A 14-year-old Caucasian girl was referred to the endocrine clinic for evaluation of voice deepening, facial hirsutism, and acne starting 2 years previously. She had been a competitive tennis player since age 7 years, practicing for 4-6 hours daily. On physical examination she was noticed to have a masculine appearance with mild facial acne and moderate hirsutism. Tanner stage was 1 for breast tissue and 5 for pubic hair. Her androgen levels (testosterone, androstenedione, dehydroepiandrosterone sulfate) were extremely elevated. Adrenal ultrasonography revealed a round left 4.6 × 5.3-cm adrenal mass. Laparoscopic left adrenalectomy was performed. The histologic findings were compatible with a benign adrenocortical tumor. Postoperatively, androgen levels dropped to within the normal range. Breast development proceeded normally, menarche occurred 2 months after tumor resection, and menses has been regular since then. Muscle strength of the dominant and nondominant upper and lower extremities was measured 1 month before surgery and 1 year later, using an isokinetic dynamometer (Biodex Systems II, Biodex, Shirley, NY, USA). There was no significant decrease in overall muscle strength after removal of the virilizing tumor and the marked drop in circulating androgens. In addition, the patient maintained her age category, number 1, national tennis ranking. The results suggest that even extremely high levels of tumor-related circulating androgens had no evident effect on muscle strength and competitive performance in a female adolescent tennis player. The lack of beneficial effect on performance in adolescents, combined with the potentially hazardous side effects of anabolic steroids, suggests that teenage athletes should avoid their use.

  13. Low Back Pain in a Tennis Player.

    ERIC Educational Resources Information Center

    Bracker, Mark; And Others

    1988-01-01

    A group of physicians meet to discuss a case in which a middle-aged tennis player suffers from low back pain. The diagnosis, treatment and management of the case are discussed. The article is one in an occasional series. (JL)

  14. Acing common skin problems in tennis players.

    PubMed

    Basler, R S; Garcia, M A

    1998-12-01

    The following measures can help prevent skin disorders in tennis players: wearing properly fitted shoes to avoid tennis toe, talon noir, and calluses; applying lubricants to protect against blisters and chafing; washing skin thoroughly to reduce the risk of acne mechanica; and wearing a hat and sunscreen to guard against photoinjury. 'Stringer's fingers' can be prevented by breaking the habit of adjusting the racket strings after each point. Should these disorders become troublesome, conservative treatments are usually effective. For example, calluses may be carefully pared, and pain from a subungual hemorrhage can be relieved by piercing the toenail with a hot paper clip.

  15. Coach/player relationships in tennis.

    PubMed

    Prapavessis, H; Gordon, S

    1991-09-01

    The present study examined the variables that predict coach/athlete compatibility. Compatibility among a sample of 52 elite tennis coach/player dyads was assessed using a sport adapted version of Schutz's (1966) Fundamental Interpersonal Relations Orientation-Behaviour (FIRO-B), a sport adapted version of Fiedler's (1967) Least Preferred Co-worker scale (LPC), and Chelladurai and Saleh's (1980) Leadership Scale for Sport (LSS). Self-ratings of the quality of the interaction were obtained from both coach and athlete. Multiple-regression analyses using self-rating scores as the dependent measure were carried out to determine which variables best predicted the degree of compatibility. The sole inventory that significantly predicted compatibility was the LSS. More specifically, the discrepancy between the athlete's preferences and perceptions on the autocratic dimension was the best predictor. Implications for tennis coaches and recommendations for future research in this area are discussed.

  16. Gender Differences in Coping among Elite Table Tennis Players

    ERIC Educational Resources Information Center

    Kirimoglu, Huseyin

    2011-01-01

    The current study aims to investigate the explanatory power of social support and coping in relation to a competitive sport event between male and female table tennis players. 246 university students table tennis players (120 men and 126 women) from different region and part of Turkey were invited to participate in a survey study included the…

  17. Differences in energy capacities between tennis players and runners.

    PubMed

    Novak, Dario; Vucetić, Vlatko; Zugaj, Sanja

    2013-05-01

    The primary purpose of this study was to determine differences between elite athletes and tennis players in order to provide a clearer picture regarding the energy demands in modern tennis. Forty-eight (48) athletes and 24 tennis players from Croatian national leagues were compared in morphological and physiological parameters of an all-out incremental treadmill test with gas exchange measurements. Tennis players' HRmax (192.96+/-7.75 bpm) shows values that are most different to 400-meters sprinters (200.13+/-6.95 bpm). Maximum running speed of tennis players on the treadmill (vmax) is no different with the speed achieved by sprinters, while there are significant differences among other athletes. Values in running speed at anaerobic threshold (vAnT) show no statistically significant difference with the values for athlete sprinters and 400-m sprinters. Values of RvO2max for tennis players indicate significant similarities with athlete sprinters and 400-m sprinters while the values of RvO2AnT are nearly identical with the values for sprinters and show no statistically significant differences (p<0.05). The results indicate that values achieved by tennis players approximate most different those of the middle and long distance runners. This singles out the possible importance of the anaerobic capacity and the high level of sprint endurance in tennis players. Knowing these characteristics is the basis for planning and implementing training systems that will enable the increase and optimal usage of energy capacities of tennis players in possibly improving sports results.

  18. Performance demands of professional male tennis players

    PubMed Central

    Johnson, C D

    2006-01-01

    Objective To quantify the performance demands in professional male tennis. Methods Games from three grand slam tournaments were analysed by an elite tennis player from video recordings. Game related data were collected on 22 players (French Open, 8 (186 games); Wimbledon, 11 (206 games); US Open, 9 (224 games)). Total number of strokes per game was quantified separately for service and return games. Strokes were categorised by type and designated as forehand or backhand. Differences in the types of strokes in a game were analysed using one factor (type of stroke) repeated measures analysis of variance. Differences in total strokes and stroke distributions between playing surfaces were analysed by analysis of variance (surface type) with Tukey's post hoc pairwise comparisons. Results For service games there were more serves per game than any other type of stroke (p<0.001), with topspin forehand and topspin backhand the only other strokes averaging more than one per service game. For return games there were more forehand and backhand returns and topspin forehands and backhands than other types of stroke (p<0.01). Total number of strokes per game was greater in the French Open than Wimbledon (p<0.01), with more topspin forehands (p<0.01) and more topspin backhands (p<0.01). Total strokes per game in the US Open were not different from the other two tournaments. Conclusions The serve was the predominant stroke accounting for 45% (French Open) to 60% (Wimbledon) of strokes during service games. The greater number of strokes per game on clay v grass may contribute to earlier fatigue. PMID:16864564

  19. Enhanced Temporal but Not Attentional Processing in Expert Tennis Players

    PubMed Central

    Overney, Leila S.; Blanke, Olaf; Herzog, Michael H.

    2008-01-01

    In tennis, as in many disciplines of sport, fine spatio-temporal resolution is required to reach optimal performance. While many studies on tennis have focused on anticipatory skills or decision making, fewer have investigated the underlying visual perception abilities. In this study, we used a battery of seven visual tests that allowed us to assess which kind of visual information processing is performed better by tennis players than other athletes (triathletes) and non-athletes. We found that certain time-related skills, such as speed discrimination, are superior in tennis players compared to non-athletes and triathletes. Such tasks might be used to improve tennis performance in the future. PMID:18545661

  20. Knee alignment in professional tennis players.

    PubMed

    Maquirriain, Javier

    2002-01-01

    This study determined lower-limb alignment and knee geometry in professional tennis players and compared the data with those from nonathletic individuals. Twenty-four radiographs from 12 asymptomatic players (mean age: 23.4+/-3.8 years) were prospectively studied. The three angles most useful for describing limb alignment and knee geometry in the coronal plane were measured: hip-knee-ankle, condylar-hip, and plateau-ankle. The condylar-plateau angle, frontal foot rotation angle, and the relationship between the mechanical axis and tibial plateau also were calculated. Varus limb alignment was predominant and the mechanical axis passed medially through the knee center; there was increased valgus inclination of the distal femur, varus angulation of the tibial plateau, near parallel alignment of the joint, and exaggerated external foot rotation. Hip-knee-ankle, condylar-hip, plateau-ankle, and frontal foot rotation angles were significantly different (P<.05, two-tailed t test) from previously reported angles of nonathletic individuals. Variations, probably due to repetitive dynamic demands imposed on lower limbs from an early age, seem to involve both femoral condyles and proximal tibial metaphyses, maintaining normal parallel joint alignment.

  1. Cardiovascular, metabolic, and hormonal parameters in professional tennis players.

    PubMed

    König, D; Huonker, M; Schmid, A; Halle, M; Berg, A; Keul, J

    2001-04-01

    During the past decade, the physical and mental stress in professional tennis has been constantly increasing. The overall intensity in tennis ranges between 60 and 70% of maximum oxygen uptake and the energy requirements are mainly provided by aerobic energy metabolism. Therefore, particularly with respect to the duration of the tournaments and the length of the matches, a good aerobic capacity promotes continuous success in professional tennis. During frequent periods of high intensity, however, muscular energy is derived from anaerobic glycolysis. Therefore, sports-specific conditioning programs in tennis should improve both glycolytic and oxidative muscular metabolism. Years of training and competition induce a number of cardiovascular and metabolic adaptations: an increase in heart size in terms of an athlete's heart, higher oxygen uptake capacity, improved muscular oxidative enzyme activities, reduced baseline catecholamine levels, and a lower resting heart rate. In addition, tennis induces side-specific increments in bone density, bone diameter, and bone length of the upper extremity. Furthermore, structural and functional adaptations of the conducting arteries in the preferred arm could be demonstrated in professional tennis players. In conclusion, tennis is a very complex sport involving strength, power, speed, agility and explosiveness, as well as endurance components. Scientific data on exercise-related cardiovascular and metabolic parameters in professional tennis are important to evaluate the players individual fitness level and will help to improve sports-specific conditioning programs. This in turn will not only enhance performance but also prevent overstrain and burnout syndromes.

  2. Control of striking velocity by table tennis players.

    PubMed

    Marinovic, Welber; Iizuka, Cristina Akiko; Freudenheim, Andrea Michele

    2004-12-01

    This study investigated how 7 skilled table tennis players controlled velocity of a forehand drive stroke when the ball's trajectory, velocity, and spin were modified. They hit a target in response to balls launched under four different conditions. The relative and absolute times used in the backswing phase showed no significant differences among conditions. When subjects hit fastballs, there was a significant change in the time required for them to reach the peak of velocity in the forward swing phase. In addition, players decreased the velocity of their strokes to hit fast-approaching balls. These results indicate that highly skilled table tennis players need to adjust the striking velocity and striking time (relative and absolute) required to reach the peak of velocity in the forward swing phase for these task modifications. Since they used slower movement velocities to hit faster-approaching balls, skilled table tennis players may override this speed-coupling process.

  3. Split-Step Timing of Professional and Junior Tennis Players

    PubMed Central

    Leskosek, Bojan; Filipcic, Tjasa

    2017-01-01

    Abstract The purpose of the study was to determine the timing of a split-step in three categories of tennis players in four groups of strokes. Subjects were divided into three groups: male and female junior, and male professional tennis players. During two tournaments, all matches were recorded with two fixed video cameras. For every stroke, the timing of the split-step between the opponent’s impact point when hitting the ball and the player’s split-step was measured. A two-way analysis of variance (ANOVA) was used to determine the differences between groups of strokes, players and the interaction Player x Stroke Group. A Tukey post-hoc test was employed to determine specific differences. The results revealed differences between players in detecting the opponent’s movement, stroke and ball flight, which were reflected in different split-step timings. Each tennis player has his/her own timing mechanism which they adapt to various game situations. Response times differ significantly depending on the game situation. On average, they are the lowest in the serve, and then gradually rise from the return of the serve to baseline game, reaching the highest values in specific game situations. Players react faster in the first serve than in the second one and in the return of the serve, the response times are lower after the return of the second serve PMID:28210342

  4. LIPOSARCOMA OF THE KNEE IN A TENNIS PLAYER: CASE REPORT.

    PubMed

    Filho, Jorge Sayum; Sayum, Jorge; de Carvalho, Rogério Teixeira; Garms, Emerson; Ramos, Leonardo Addeo; Matsuda, Marcelo Mitsura; Ejnisman, Benno; Cohen, Moisés

    2012-01-01

    Liposarcoma is an uncommon malignant tumor. It originates in the mesenchymal cells, and is the most common of the soft tissue sarcomas. The authors report a case of a 40 year-old male tennis player with liposarcoma in the posterior right knee and distal thigh region.

  5. LIPOSARCOMA OF THE KNEE IN A TENNIS PLAYER: CASE REPORT

    PubMed Central

    Filho, Jorge Sayum; Sayum, Jorge; de Carvalho, Rogério Teixeira; Garms, Emerson; Ramos, Leonardo Addeo; Matsuda, Marcelo Mitsura; Ejnisman, Benno; Cohen, Moisés

    2015-01-01

    Liposarcoma is an uncommon malignant tumor. It originates in the mesenchymal cells, and is the most common of the soft tissue sarcomas. The authors report a case of a 40 year-old male tennis player with liposarcoma in the posterior right knee and distal thigh region. PMID:27047841

  6. Flexibility of internal and external glenohumeral rotation of junior female tennis players and its correlation with performance ranking

    PubMed Central

    Chiang, Ching-Cheng; Hsu, Chih-Chia; Chiang, Jinn-Yen; Chang, Weng-Cheng; Tsai, Jong-Chang

    2016-01-01

    [Purpose] The purpose of this study was to compare the internal and external rotation of the dominant and nondominant shoulders of adolescent female tennis players. The correlation between the shoulder rotation range of motion and the player’s ranking was also analyzed. [Subjects and Methods] Twenty-one female junior tennis players who were 13 to 18 years old participated in this study. A standard goniometer was used to measure the internal and external rotation of both glenohumeral joints. The difference in internal and external rotation was calculated as the glenohumeral rotation deficit. The year-end ranking of each player was obtained from the Chinese Taipei Tennis Association. [Results] The internal rotation of the dominant shoulder was significantly smaller than that of the nondominant shoulder. Moreover, player ranking was significantly and negatively correlated with the internal rotation range of motion of both shoulders. On the other hand, the correlations of the internal and external rotation ranges of motion with the age, height, and weight were not significant. [Conclusion] The flexibility of the glenohumeral internal rotation is smaller in the dominant shoulder than of the nondominant shoulder in these junior female tennis players. Flexibility of the glenohumeral internal rotation may be a factor affecting performance in junior female tennis players. PMID:28174438

  7. Ranking benchmarks of top 100 players in men's professional tennis.

    PubMed

    Reid, Machar; Morris, Craig

    2013-01-01

    In men's professional tennis, players aspire to hold the top ranking position. On the way to the top spot, reaching the top 100 can be seen as a significant career milestone. National Federations undertake extensive efforts to assist their players to reach the top 100. However, objective data considering reasonable ranking yardsticks for top 100 success in men's professional tennis are lacking. Therefore, it is difficult for National Federations and those involved in player development to give empirical programming advice to young players. By taking a closer look at the ranking history of professional male tennis players, this article tries to provide those involved in player development a more objective basis for decision-making. The 100 names, countries, birthdates and ranking histories of the top 100 players listed in the Association of Tennis Professionals (ATP) at 31 December 2009 were recorded from websites in the public domain. Descriptive statistics were reported for the ranking milestones of interest. Results confirmed the merits of the International Tennis Federation's junior tour with 91% of the top 100 professionals earning a junior ranking, the mean peak of which was 94.1, s=148.9. On average, top 100 professionals achieved their best junior rankings and earned their first ATP point at similar ages, suggesting that players compete on both the junior and professional tours during their transition. Once professionally ranked, players took an average 4.5, s=2.1 years to reach the ATP top 100 at the mean age of 21.5, s=2.6 years, which contrasts with the mean current age of the top 100 of 26.8, s=3.2. The best professional rankings of players born in 1982 or earlier were positively related to the ages at which players earned their first ATP point and then entered the top 100, suggesting that the ages associated with these ranking milestones may have some forecasting potential. Future work should focus on the change in top 100 demographics over time as well

  8. MUSCLE DAMAGE AFTER A TENNIS MATCH IN YOUNG PLAYERS

    PubMed Central

    Gomes, R.V.; Santos, R.C.O.; Nosaka, K.; Moreira, A.; Miyabara, E.H.

    2014-01-01

    The present study investigated changes in indirect markers of muscle damage following a simulated tennis match play using nationally ranked young (17.6 ± 1.4 years) male tennis players. Ten young athletes played a 3-hour simulated match play on outdoor red clay courts following the International Tennis Federation rules. Muscle soreness, plasma creatine kinase activity (CK), serum myoglobin concentration (Mb), one repetition maximum (1RM) squat strength, and squat jump (SJ) and counter movement jump (CMJ) heights were assessed before, immediately after, and 24 and 48 h after the simulated match play. All parameters were also evaluated in a non-exercised group (control group). A small increase in the indirect markers of muscle damage (muscle soreness, CK and Mb) was detected at 24-48 hours post-match (p < 0.05). A marked acute decrement in neuromuscular performance (1RM squat strength: -35.2 ± 10.4%, SJ: -7.0 ± 6.0%, CMJ: -10.0 ± 6.3%) was observed immediately post-match (p < 0.05). At 24 h post-match, the 1RM strength and jump heights were not significantly different from the baseline values. However, several players showed a decrease of these measures at 24 h after the match play. The simulated tennis match play induced mild muscle damage in young players. Coaches could monitor changes in the indirect markers of muscle damage to assess athletes’ recovery status during training and competition. PMID:24917686

  9. Active tuning of stroke-induced vibrations by tennis players.

    PubMed

    Chadefaux, Delphine; Rao, Guillaume; Androuet, Philippe; Berton, Eric; Vigouroux, Laurent

    2016-09-06

    This paper investigates how tennis players control stroke-induced vibration. Its aim is to characterise how a tennis player deals with entering vibration waves or how he/she has the ability to finely adjust them. A specific experimental procedure was designed, based on simultaneously collecting sets of kinematic, vibration and electromyographic data during forehand strokes using various commercial rackets and stroke intensities. Using 14 expert players, a wide range of excitations at spectral and temporal levels were investigated. Energetic and spectral descriptors of stroke-induced vibration occurring at the racket handle and at the player's wrist and elbow were computed. Results indicated that vibrational characteristics are strongly governed by grip force and to a lower extent by the racket properties. Grip force management drives the amount of energy, as well as its distribution, into the forearm. Furthermore, hand-grip can be assimilated to an adaptive filter which can significantly modify the spectral parameters propagating into the player's upper limb. A significant outcome is that these spectral characteristics are as much dependent on the player as on the racket. This contribution opens up new perspectives in equipment manufacture by underlining the need to account for player/racket interaction in the design process.

  10. The Ability of Elite Table Tennis Players with Intellectual Disabilities to Adapt Their Service/Return

    ERIC Educational Resources Information Center

    Van Biesen, Debbie; Verellen, Joeri; Meyer, Christophe; Mactavish, Jennifer; Van de Vliet, Peter; Vanlandewijck, Yves

    2010-01-01

    In this study the ability of elite table tennis players with intellectual disability (ID) to adapt their service/return to specific ball spin characteristics was investigated. This was done by examining the performance of 39 players with ID and a reference group of 8 players without ID on a standardized table tennis specific test battery. The…

  11. Muscle Hypertrophy in Prepubescent Tennis Players: A Segmentation MRI Study

    PubMed Central

    Sanchis-Moysi, Joaquin; Idoate, Fernando; Serrano-Sanchez, Jose A.; Dorado, Cecilia; Calbet, Jose A. L.

    2012-01-01

    Purpose To asses if tennis at prepubertal age elicits the hypertrophy of dominant arm muscles. Methods The volume of the muscles of both arms was determined using magnetic resonance imaging (MRI) in 7 male prepubertal tennis players (TP) and 7 non-active control subjects (CG) (mean age 11.0±0.8 years, Tanner 1–2). Results TP had 13% greater total muscle volume in the dominant than in the contralateral arm. The magnitude of inter-arm asymmetry was greater in TP than in CG (13 vs 3%, P<0.001). The dominant arm of TP was 16% greater than the dominant arm of CG (P<0.01), whilst non-dominant arms had similar total muscle volumes in both groups (P = 0.25), after accounting for height as covariate. In TP, dominant deltoid (11%), forearm supinator (55%) and forearm flexors (21%) and extensors (25%) were hypertrophied compared to the contralateral arm (P<0.05). In CG, the dominant supinator muscle was bigger than its contralateral homonimous (63%, P<0.05). Conclusions Tennis at prepubertal age is associated with marked hypertrophy of the dominant arm, leading to a marked level of asymmetry (+13%), much greater than observed in non-active controls (+3%). Therefore, tennis particpation at prepubertal age is associated with increased muscle volumes in dominant compared to the non-dominant arm, likely due to selectively hypertrophy of the loaded muscles. PMID:22428074

  12. Stress injury of the lunate in tennis players: a case series and related biomechanical considerations

    PubMed Central

    Maquirriain, Javier; Ghisi, Juan P

    2007-01-01

    Objective To investigate clinical and imaging differential diagnosis and tennis stroke biomechanics potentially involved in lunate stress injury pathogenesis. Methods The present report describes five competitive tennis players with overuse‐related dorsal wrist pain assessed by magnetic resonance imaging. Results Magnetic resonance imaging revealed the presence of lunate stress injury. All players were treated conservatively, with symptom resolution and complete functional recovery achieved at 14 weeks. Conclusions Lunate stress injuries should be considered in the differential diagnosis of overuse‐related dorsal wrist pain in tennis players. PMID:17957020

  13. Effect of long-term unilateral activity on bone mineral density of female junior tennis players.

    PubMed

    Haapasalo, H; Kannus, P; Sievänen, H; Pasanen, M; Uusi-Rasi, K; Heinonen, A; Oja, P; Vuori, I

    1998-02-01

    High peak bone mass in early adulthood is an important protective factor against osteoporotic fractures in later life, but little is known about the effects of exercise on growing bone. The purpose of this cross-sectional study was to determine at which state of maturity (Tanner stage), the areal bone mineral density (BMD) differences between the playing and nonplaying arms of junior tennis players become obvious, and to clarify in each developmental stage which training and background variables, if any, could explain the interindividual differences in bones' response to mechanical loading. Ninety-one 7- to 17-year-old female tennis players and 58 healthy female controls were measured. In each Tanner stage, differences in BMD in playing and nonplaying (dominant and nondominant) arms (proximal humerus, humeral shaft, and distal radius) and BMD of the lumbar spine and nondominant distal radius were compared between the controls and players. Within each Tanner stage of players, the associations between training and background variables and BMD differences were analyzed with Spearman rank correlation coefficients. In players, BMD differences between the playing and nonplaying arms were significant (P < 0.05- < 0.001) in all Tanner stages, with the mean difference ranging from 1.6 to 15.7%. In controls, these dominant-to-nondominant arm differences were clearly smaller (ranging from -0.2 to 4.6%), but significant at some measured sites. In comparison with the relative side-to-side arm differences between the players and controls (i.e., examination of the training effect), the mean difference was not obvious and significant until the adolescent growth spurt (i.e., the girls in Tanner stage III with a mean age of 12.6 years). In the lumbar spine, significant BMD differences between players and controls were not found until Tanner stage IV (mean age 13.5 years; 8.7%, P < 0.05) and V (mean age 15.5 years; 12.4%, P < 0.05). In a nonloaded site of the skeleton (nondominant

  14. Participation motivation and competition anxiety among Korean and non-Korean wheelchair tennis players.

    PubMed

    Jeong, Irully; Park, Sunghee

    2013-01-01

    The purpose of this study was to examine differences in participation motivation and competition anxiety between Korean and non-Korean wheelchair tennis players and to identify relations between participation motivation and competition anxiety in each group. Sixty-six wheel-chair tennis players who participated in the 2013 Korea Open Wheel-chair Tennis Tournament in Seoul completed the Participation Motivation Survey and the Competitive State Anxiety Inventory II. Data were analyzed by a frequency analysis, descriptive statistics, Pearson's correlation analysis, and independent samples t-test to identify participants' demographic characteristics, differences in participation motivation, competition anxiety between Korean and non-Korean players, and correlations between participation motivation and competition anxiety in each group. Korean players reported significantly higher motivation in purification compared to non-Korean players, whereas non-Korean players reported significantly higher motivation in enjoyment. In addition, non-Korean players demonstrated higher cognitive anxiety and self-confidence compared to Korean players. Moreover, the physical anxiety of Korean players was negatively correlated with learning, health-fitness, and enjoyment motivation. On the other hand, only self-confidence was significantly related to learning motivation and enjoyment motivation in non-Korean players. Thus, the results presented herein provide evidence for the development of specialized counseling programs that consider the psychological characteristics of Korean wheelchair tennis players.

  15. Participation motivation and competition anxiety among Korean and non-Korean wheelchair tennis players

    PubMed Central

    Jeong, Irully; Park, Sunghee

    2013-01-01

    The purpose of this study was to examine differences in participation motivation and competition anxiety between Korean and non-Korean wheelchair tennis players and to identify relations between participation motivation and competition anxiety in each group. Sixty-six wheel-chair tennis players who participated in the 2013 Korea Open Wheel-chair Tennis Tournament in Seoul completed the Participation Motivation Survey and the Competitive State Anxiety Inventory II. Data were analyzed by a frequency analysis, descriptive statistics, Pearson’s correlation analysis, and independent samples t-test to identify participants’ demographic characteristics, differences in participation motivation, competition anxiety between Korean and non-Korean players, and correlations between participation motivation and competition anxiety in each group. Korean players reported significantly higher motivation in purification compared to non-Korean players, whereas non-Korean players reported significantly higher motivation in enjoyment. In addition, non-Korean players demonstrated higher cognitive anxiety and self-confidence compared to Korean players. Moreover, the physical anxiety of Korean players was negatively correlated with learning, health-fitness, and enjoyment motivation. On the other hand, only self-confidence was significantly related to learning motivation and enjoyment motivation in non-Korean players. Thus, the results presented herein provide evidence for the development of specialized counseling programs that consider the psychological characteristics of Korean wheelchair tennis players. PMID:24409429

  16. Physiological responses and match characteristics in professional tennis players during a one-hour simulated tennis match

    PubMed Central

    Şenel, Ömer; Arslan, Erşan; Can, Sema

    2016-01-01

    Abstract The purpose of this study was to investigate the effects of serve and return game situations on physiological responses and match characteristics in professional male tennis players during one hour-long simulated singles tennis matches. Ten internationally ranked tennis players (age 22.2 ± 2.8 years; body height 180.7 ± 4.4 cm; body mass 75.9 ± 8.9 kg) participated in this study. Their physiological responses were measured using two portable analyzers during indoor hard court matches. Ratings of perceived exertion were also determined at the end of the game. The variables describing the characteristics of the matches determined from video recordings were: (a) duration of rallies; (b) rest time; (c) work-to-rest ratio; (d) effective playing time; and (d) strokes per rally. Significant differences (p<0.05) were found between serving and returning conditions in an hour-long simulated singles tennis match in terms of oxygen uptake, a heart rate, ratings of perceived exertion, pulmonary ventilation, respiration frequency and a respiratory gas exchange ratio. In addition, both the heart rate and ratings of perceived exertion responses were moderately correlated with the duration of rallies and strokes per rally (r = 0.60 to 0.26; p<0.05). Taken together, these results indicate that the serve game situation has a significant effect on the physiological response in an hour-long simulated tennis match between professional male tennis players. These findings might be used for the physiological adaptations required for tennis-specific aerobic endurance. PMID:28149371

  17. Physiological responses and match characteristics in professional tennis players during a one-hour simulated tennis match.

    PubMed

    Kilit, Bülent; Şenel, Ömer; Arslan, Erşan; Can, Sema

    2016-06-01

    The purpose of this study was to investigate the effects of serve and return game situations on physiological responses and match characteristics in professional male tennis players during one hour-long simulated singles tennis matches. Ten internationally ranked tennis players (age 22.2 ± 2.8 years; body height 180.7 ± 4.4 cm; body mass 75.9 ± 8.9 kg) participated in this study. Their physiological responses were measured using two portable analyzers during indoor hard court matches. Ratings of perceived exertion were also determined at the end of the game. The variables describing the characteristics of the matches determined from video recordings were: (a) duration of rallies; (b) rest time; (c) work-to-rest ratio; (d) effective playing time; and (d) strokes per rally. Significant differences (p<0.05) were found between serving and returning conditions in an hour-long simulated singles tennis match in terms of oxygen uptake, a heart rate, ratings of perceived exertion, pulmonary ventilation, respiration frequency and a respiratory gas exchange ratio. In addition, both the heart rate and ratings of perceived exertion responses were moderately correlated with the duration of rallies and strokes per rally (r = 0.60 to 0.26; p<0.05). Taken together, these results indicate that the serve game situation has a significant effect on the physiological response in an hour-long simulated tennis match between professional male tennis players. These findings might be used for the physiological adaptations required for tennis-specific aerobic endurance.

  18. Tournament Structure and Success of Players Based on Location in Men's Professional Tennis.

    PubMed

    Filipcic, Ales; Panjan, Andrej; Reid, Machar; Crespo, Miguel; Sarabon, Nejc

    2013-01-01

    This article discusses the relationship between success of professional male tennis players according to the country and world region from which they originate and the professional tournament structure in men's tennis in that world region and country. The success of a country or world region was defined by the number of players in the top 300 ATP rankings and was calculated for seven time periods between 1975 and 2008. The results showed the correlations between the total number of top 300 ranked players, the total number of tournaments, and the annual tournament prize money of the specific country. The correlations were nearly perfect in the 1975-1990 period (r = 0.93-0.95; p < 0.01) but only high in the 2005-2008 period (r = 0.60-0.64; p < 0.01), suggesting that the association between the number of top 300 ranked tennis players and professional tournaments, while still significant, is in decline. These data should inform the policy and investment decisions of regional and national federations, particularly as they relate to domestic professional tennis tournament structures and to explore opportunities to include professional tournaments of neighbour countries in their player's development programs. Key PointsThis paper observes relation changes between the total number of players, total number of ATP tournaments and total annual prize money in particular continents from 1975 to 2008.The correlation between the tennis success, total number of tournaments and total annual prize money in tournaments was highest from 1975 to 1989 and was gradually decreasing from 1990 to 2008.The leading tennis countries organise over 20 ATP tournaments and entry professional tournaments per year. Tennis less developed countries very often is using the competition systems of the most successful tennis countries.Indications are that tennis will continue to become increasingly global and that this trend may be unlikely to reverse.

  19. A comparison of two conative characteristics of top basketball and recreational table tennis players.

    PubMed

    Sindik, Josko; Missoni, Sasa

    2013-05-01

    The purpose of this study is to adapt imported instruments for measuring multidimensional perfectionism in sport situations and perceived group cohesion, in terms of construct validity and reliability, as well as from the aspect of interpretability, addressed on Croatian samples of athletes. Group Environment Questionnaire (GEQ) and Sport Multidimensional Perfectionism Scale (MSSP) are applied. The sample of 223 male Croatian athletes comprises of N1 = 107 top basketball players from nine teams in A-1 Croatian Basketball League and N2 = 116 recreational table tennis players who play in Table Tennis Organization of Clubs and Actives in Zagreb. Principal Components Analyses at both instruments showed two-component structures: combined social-task cohesion and friendship were latent dimensions of perceived group cohesion, while the internalized standards and externalized standards revealed two aspects of multidimensional perfectionism in sport situations. In perceived group cohesion, basketball players achieved higher average results than table tennis players in the friendship, while the table tennis players showed higher combined social and task orientation than basketball players. In multidimensional sport perfectionism, basketball players have higher average result than table tennis players in the dimension of internalized perfectionism, but in externalized perfectionism there is no statistical significant difference. Younger players showed higher average results than older players in the dimension of friendship, while older players showed higher combined social and task orientation than younger players. Younger players have higher average scores in internalized perfectionism. The main importance of the research is adjustment of multidimensional perfectionism in sport situations and perceived group cohesion to Croatian athletes, providing additional possibility of cross-cultural adjustment of both concepts, psychometrically and theoretically.

  20. Electromyographic assessment of forearm muscle function in tennis players with and without Lateral Epicondylitis.

    PubMed

    Alizadehkhaiyat, Omid; Frostick, Simon P

    2015-12-01

    There is no consensus about the main aetiology of Lateral Epicondylitis (LE) or Tennis Elbow. While electromyographic assessment of alterations in neuromuscular control and activation patterns of forearm muscles has received increasing interest as potential intrinsic factors in non-tennis players, there has been insufficient attention in tennis players. The purpose of present review was to search the literature for the electromyographic studies of forearm muscles in tennis players in order to (1) identify related implications for LE, (2) highlight key technical and methodological shortcomings, and (3) suggest potential pathways for future research. An electronic search of PubMed, Scopus, Web of Science, and Google Scholars (1980 to October 2014) was conducted. Titles, abstracts, and full-text articles were screened to identify "peer-reviewed" studies specifically looking into "electromyographic assessment of forearm muscles" in "tennis players". After screening 104 articles, 13 original articles were considered in the main review involving a total of 216 participants (78% male, 22% female). There were indications of increased wrist extensor activity in all tennis strokes and less experienced single-handed players, however with insufficient evidence to support their relationship with the development of LE. Studies varied widely in study population, sample size, gender, level of tennis skills, electrode type, forearm muscles studied, EMG recording protocol, EMG normalisation method, and reported parameters. As a result, it was not possible to present combined results of existing studies and draw concrete conclusions in terms of clinical implications of findings. There is a need for establishment of specific guidelines and recommendations for EMG assessment of forearm musculature particularly in terms of electrode and muscle selection. Further studies of both healthy controls and tennis players suffering from LE with adequate sample sizes and well-defined demographics

  1. Anaerobic capacity may not be determined by critical power model in elite table tennis players.

    PubMed

    Zagatto, Alessandro M; Papoti, Marcelo; Gobatto, Claudio A

    2008-01-01

    The aim of the present study was to verify the applicability of anaerobic work capacity (AWC) determined from the critical power model in elite table tennis players. Eight male international level table tennis players participated in the study. The tests undertaken were: 1) A critical frequency test used to determinate the anaerobic work capacity; 2) Wingate tests were performed using leg and arm ergometers. AWC corresponded to 99.5 ± 29.1 table tennis balls. AWC was not related to peak (r = -0.25), mean (r = -0.02), relative peak (r = -0.49) or relative mean power (r = 0.01), nor fatigue index (r = -0.52) (Wingate leg ergometer). Similar correlations for peak (r = -0.34), mean (r = -0.04), relative peak (r = -0.49), relative mean power (r = -0.14) and peak blood lactate concentration (r = -0.08) were determined in the Wingate arm ergometer test. Based on these results the AWC determined by a modified critical power test was not a good index for measurement of anaerobic capacity in table tennis players. Key pointsAnaerobic work capacity (AWC) was not good index of anaerobic capacity in table tennis.AWC determined using the table tennis ergometer showed low correlations with the Wingate test measures for cycle and arm ergometry.A sport-specific protocol is required for measuring anaerobic capacity in table tennis.

  2. Injury profile in junior tennis players: a prospective two year study.

    PubMed

    Hjelm, Nina; Werner, Suzanne; Renstrom, Per

    2010-06-01

    The aim of this study was to prospectively make a survey of injuries in junior players from a Swedish local tennis club during a 2-year period in relation to gender, anatomic location, month of the year when injured, injury type and injury severity. All 12-18 years old members in a tennis club playing more than twice weekly were asked to participate. Fifty-five junior tennis players, 35 boys and 20 girls accepted to participate. All tennis-related injuries were prospectively registered and evaluated. Time of exposure for playing tennis was recorded. Thirty-nine players sustained 100 injuries, 73 in boys and 27 in girls. Injury incidence for boys was 1.7 injuries/1000 h of tennis playing time and for girls 0.6 injuries/1000 h. Ankle sprains, low back pain and knee injuries were the most common ones. Sixty-five percent were new injuries, and the majority of these injuries were located at the knee joint followed by the ankle joint, while most of the recurrent injuries were found in the lumbar spine. Boys suffered mainly from low back pain and ankle injuries and girls from low back pain and knee injuries. Forty-three percent of the injuries caused absence from tennis for more than 4 weeks and 31% more than 1 week.

  3. [ANTHROPOMETRIC CHILEAN TABLE TENNIS PLAYERS OF COMPETITIVE FEATURES].

    PubMed

    Yáñez Sepúlveda, Rodrigo; Barraza, Fernando; Rosales Soto, Giovanni; Báez, Eduardo; Tuesta, Marcelo

    2015-10-01

    The aim of the study was to characterize the anthropometric profile and somatotype of a sample of 50 players table tennis competitive with an average age 21.6 (± 3.1) years belonging to the Chilean team and institutions of higher education in the region of Valparaiso. The evaluation was conducted under the protocol marking the International Society for the Advancement of Kinanthropometry (ISAK) for the measurement procedure 25 restricted profile variables described by Drinkwater, Norton and Olds. Order to determine the body composition, fat, muscle, bone, skin and tissue residual was considered, using the equations proposed by Kerr. The body shape is characterized through somatotype method proposed by Carter. The sample was divided into 4 groups; Chilean Selection, Traditional Private Universities, State Universities and Private Universities Traditional Nontraditional. Regarding body composition; the Chilean team has the highest values of muscle tissue (45.6 ± 1.7%) and the lowest values of adipose tissue (25.2 ± 1.8%), also presenting lesser value in the Σ 6 skinfolds (mm) . The results showed no significant differences between groups in the aforementioned variables. In general somatotype compared by analyzing SANOVA no significant differences between groups (p = 0.409) was observed. The results show a biotype with such a characterization of endo-mesomorph with average values (4,1-4,9-1,8). This study provides updated data biotypological reference for this sport that can be used for decision-making.

  4. Implementation of Motor Imagery during Specific Aerobic Training Session in Young Tennis Players

    PubMed Central

    Guillot, Aymeric; Di Rienzo, Franck; Pialoux, Vincent; Simon, Germain; Skinner, Sarah; Rogowski, Isabelle

    2015-01-01

    The aim of this study was to investigate the effects of implementing motor imagery (MI) during specific tennis high intensity intermittent training (HIIT) sessions on groundstroke performance in young elite tennis players. Stroke accuracy and ball velocity of forehand and backhand drives were evaluated in ten young tennis players, immediately before and after having randomly performed two HIIT sessions. One session included MI exercises during the recovery phases, while the other included verbal encouragements for physical efforts and served as control condition. Results revealed that similar cardiac demand was observed during both sessions, while implementing MI maintained groundstroke accuracy. Embedding MI during HIIT enabled the development of physical fitness and the preservation of stroke performance. These findings bring new insight to tennis and conditioning coaches in order to fulfil the benefits of specific playing HIIT sessions, and therefore to optimise the training time. PMID:26580804

  5. Injury risk factors in junior tennis players: a prospective 2-year study.

    PubMed

    Hjelm, N; Werner, S; Renstrom, P

    2012-02-01

    The aim was to investigate injury risk factors in junior tennis players. Fifty-five players, 35 boys and 20 girls, answered a questionnaire about training habits, time of exposure, previous injuries and equipment factors. A battery of clinical tests and functional performance tests were also carried out. All tennis-related injuries that occurred during a 2-year period were identified and recorded. An injury was defined as an injury if it was impossible to participate in regular tennis training or playing matches during at least one occasion, a time loss injury. Potential injury risk factors were tested in a forward stepwise logistic regression model for injury. Thirty-nine players sustained totally 100 new and recurrent injuries. Injuries to the lower extremity were the most common ones (51%) followed by the upper extremity (24%) and the trunk (24%). Injured players performed more singles per week (P<0.0001) and played more tennis hours per year (P=0.016) than the uninjured players. Playing tennis more than 6 h/week was found to be a risk factor for back pain. A previous injury regardless of location was identified as an injury risk factor, and a previous injury to the back was a risk factor for back pain.

  6. ACUTE CHANGES IN PASSIVE GLENOHUMERAL ROTATION FOLLOWING TENNIS PLAY EXPOSURE IN ELITE FEMALE PLAYERS

    PubMed Central

    Kibler, W. Ben; Myers, Natalie L.; Smith, Belinda J.

    2016-01-01

    Background Alterations in glenohumeral (GH) rotation especially internal rotation and total range of motion have been associated with altered GH kinematics and susceptibility to injury. Researchers have evaluated long-term change in baseball and tennis players, and short-term changes in baseball players. However, acute (short-term) changes in GH rotation have not been evaluated in tennis players. Hypotheses/Purpose The purpose of this study was to quantify short-term glenohumeral rotational changes within a group of professional women's tennis players following competitive play. It was hypothesized that there would be acute alterations in passive glenohumeral internal rotation and total range of motion following episodes of tennis play. Study Design Cohort Study Methods Passive glenohumeral external rotation (GER), glenohumeral internal rotation (GIR), and total range of motion (TROM) were evaluated in a cohort of 79 professional adult female tennis players. Measurements were taken at three different time points (TP): baseline before match play (TP1), immediately after match play (TP2), and 24-hours after baseline (TP3). Results There was a statistically significant decrease in the mean GIR from TP1 (43 ± 11 °) to TP2 (39 ± 9 °) (p=0.002) and from TP1 to TP3 (38 ± 10 °) (p=0.001). All measures were at the level of minimal detectable change (MDC) (4 °) indicating clinical significance. There was a decrease in mean TROM from TP1 (146 ± 11 °) to TP2 (142 ± 12 °) (p=0.04), which was not above MDC (7 °). Subgroup analysis showed that 47% of the players demonstrated a decrease in GIR beyond MDC, and 37% demonstrated a decrease in TROM beyond MDC. GER remained unchanged across all time points (p>0.05). Conclusion Both GIR and TROM were reduced after acute exposure to tennis play. In a large subgroup of the cohort, the changes were clinically significant and approached values previously demonstrated to be associated with

  7. Iliopsoas and Gluteal Muscles Are Asymmetric in Tennis Players but Not in Soccer Players

    PubMed Central

    Sanchis-Moysi, Joaquin; Idoate, Fernando; Izquierdo, Mikel; Calbet, Jose A. L.; Dorado, Cecilia

    2011-01-01

    Purpose To determine the volume and degree of asymmetry of iliopsoas (IL) and gluteal muscles (GL) in tennis and soccer players. Methods IL and GL volumes were determined using magnetic resonance imaging (MRI) in male professional tennis (TP) and soccer players (SP), and in non-active control subjects (CG) (n = 8, 15 and 6, respectively). Results The dominant and non-dominant IL were hypertrophied in TP (24 and 36%, respectively, P<0.05) and SP (32 and 35%, respectively, P<0.05). In TP the asymmetric hypertrophy of IL (13% greater volume in the non-dominant than in the dominant IL, P<0.01) reversed the side-to-side relationship observed in CG (4% greater volume in the dominant than in the contralateral IL, P<0.01), whilst soccer players had similar volumes in both sides (P = 0.87). The degree of side-to-side asymmetry decreased linearly from the first lumbar disc to the pubic symphysis in TP (r = −0.97, P<0.001), SP (r = −0.85, P<0.01) and CG (r = −0.76, P<0.05). The slope of the relationship was lower in SP due to a greater hypertrophy of the proximal segments of the dominant IL. Soccer and CG had similar GL volumes in both sides (P = 0.11 and P = 0.19, for the dominant and contralateral GL, respectively). GL was asymmetrically hypertrophied in TP. The non-dominant GL volume was 20% greater in TP than in CG (P<0.05), whilst TP and CG had similar dominant GL volumes (P = 0.14). Conclusions Tennis elicits an asymmetric hypertrophy of IL and reverses the normal dominant-to-non-dominant balance observed in non-active controls, while soccer is associated to a symmetric hypertrophy of IL. Gluteal muscles are asymmetrically hypertrophied in TP, while SP display a similar size to that observed in controls. It remains to be determined whether the different patterns of IL and GL hypertrophy may influence the risk of injury. PMID:21829539

  8. The core musculature in male prepubescent tennis players and untrained counterparts: a volumetric MRI study.

    PubMed

    Sanchis-Moysi, Joaquin; Idoate, Fernando; Álamo-Arce, David; Calbet, José A L; Dorado, Cecilia

    2017-04-01

    The effects of exercise on the core musculature have not been investigated in prepubescents. The main purpose of the present study was to determine the volume and degree of asymmetry of rectus abdominis, obliques and transversus abdominis, quadratus lumborum, iliopsoas, gluteus and paravertebralis muscles in prepubescent tennis players and in untrained boys. The muscle volume was determined using magnetic resonance imaging (MRI) in 7 male prepubescent tennis players and 10 untrained controls (mean age 11.0 ± 0.8 years, Tanner 1-2). After accounting for height and body weight as covariates, the tennis players had 14-34% greater volume than the controls in all the muscles analysed (P < 0.05) except in paravertebralis, dominant quadratus lumborum and non-dominant gluteus, which had similar volumes in both groups (P = NS). Compared to controls, the tennis players displayed a greater degree of asymmetry in quadratus lumborum and rectus abdominis (3% vs. 15%, P < 0.01 and 8% vs. 17%, P = 0.06, respectively). The level of asymmetry of obliques and transversus abdominis, iliopsoas, gluteus and paravertebralis muscles was similar in both groups (P = NS). In conclusion, tennis playing at prepubertal ages induces a selective hypertrophy of the core musculature and exaggerates the degree of asymmetry of quadratus lumborum and rectus abdominis compared to untrained boys.

  9. Neuromuscular, metabolic and hormonal profiles of young tennis players and untrained boys.

    PubMed

    Mero, A; Jaakkola, L; Komi, P V

    1989-01-01

    This study compared the neuromuscular, metabolic and hormonal profiles of trained prepubescent tennis players and an untrained group. The boys in the experimental group (n = 9; mean age +/- S.D. = 11.4 +/- 0.5 years) had participated in tennis training for 2.3 +/- 1.0 years and the boys in the control group (n = 9; mean age +/- S.D. = 10.9 +/- 0.4 years) were normal active volunteers. The tennis players were found to be physically more active than the controls when the comparison was made for either 1 year (4.9 +/- 1.8 vs 2.6 +/- 2.5 times per week; P less than 0.05) or for 1 week (3.4 +/- 1.2 vs 0.4 +/- 0.5 times; P less than 0.001) preceding the tests. Choice reaction time was significantly (P less than 0.01) shorter in the experimental group (258 +/- 16 ms) than in the control group (344 +/- 81 ms). Dropping height in the best drop jump was significantly (P less than 0.05) higher in the tennis players (0.46 +/- 0.19 m) than in the control boys (0.27 +/- 0.10 m). The tennis players had significantly lower oxygen consumption at the 'anaerobic threshold' than the controls (P less than 0.05). There were no significant differences between the groups in serum hormone levels. The small differences that existed may have been caused by active participation in sport by the tennis players.

  10. Fitness testing of tennis players: How valuable is it?

    PubMed Central

    Fernandez-Fernandez, Jaime; Ulbricht, Alexander; Ferrauti, Alexander

    2014-01-01

    In tennis, sport-specific technical skills are predominant factors, although a complex profile of physical performance factors is also required. The fitness test batteries assist in examining tennis players’ capabilities for performance at different levels in the laboratory as well as in the field, in the junior or elite level. While laboratory tests can be, and are, used to evaluate basic performance characteristics of athletes in most individual sports, in a more specific approach, field-based methods are better suited to the demands of complex intermittent sports like tennis. A regular test battery performed at different periods of the year allows to obtain an individual's performance profile, as well as the ability to prescribe individual training interventions. Thus, the aim of the present review was to describe and evaluate the different physical tests recommended and used by practitioners, sports scientists and institutions (national tennis federations). PMID:24668375

  11. Pyomyositis in a 69-year-old tennis player.

    PubMed

    Burkhart, Bradd G; Hamson, Karl R

    2003-11-01

    Pyomyositis is an acute bacterial infection of skeletal muscle usually caused by Staphylococcus aureus. Outside of tropical areas, pyomyositis is rare, especially in an otherwise healthy individual. We present a case of a 69-year-old tennis professional who developed pyomyositis of the piriformis muscle following a tennis tournament. We discuss the literature on pyomyositis and the need for high clinical suspicion in the diagnosis of this disorder, as well as the need for early aggressive antibiotic treatment.

  12. Characteristics of upper limb muscular strength in male wheelchair tennis players

    PubMed Central

    Moon, Hyo-Bin; Park, Seung-Jae; Kim, Al-Chan; Jang, Jee-Hun

    2013-01-01

    The purpose of this study was to identify the characteristics of muscular strength in upper limb and to present the preliminary information for development of sports injury prevention program and exercise rehabilitation program in wheelchair tennis players. Participants were 12 male wheelchair tennis players. Muscular strength was measured in shoulder and elbow joints with isokinetic dynamometer. Ipsilateral (IR) and bilateral (BR) balance ratio were calculated with isokinetic strength at 60°/sec. As a result, extension strength (ES) was significantly higher than flexion strength (FS) (P< 0.001), and IR in both sides and BR in ES were maintained within normal range whereas BR in FS was lower than normal range in shoulder joint. In elbow joint FS was significantly higher than ES (P< 0.05), and IR and BR were lower than normal range. Consequently, the different tendency in IR between shoulder and elbow joints and lower IR and BR in elbow joints could be the characteristics in male wheelchair tennis players. It is suggested that flexor strengthening program in nondominant shoulder joint, extensor strengthening program in both elbow joint, and flexor strengthening program in non-dominant elbow joint should be introduced for male wheelchair tennis players. PMID:24278887

  13. The incidence and distribution of stress fractures in elite tennis players

    PubMed Central

    Maquirriain, J; Ghisi, J P

    2006-01-01

    Background Modern professional tennis involves powerful movements repeatedly subjecting the musculoskeletal system to heavy mechanical load. Thus tennis players are exposed to high risk of overuse injuries including stress fractures. Objective To determine the incidence and distribution of stress fractures in elite tennis players. Study design Retrospective cohort study. Methods The cohort study population consisted of 139 elite players (mean (SD) age, 20.0 (5.0) years; 48 female, 91 male). Stress fractures were identified and confirmed radiologically from medical records during a two year period. Injuries were analysed according to age, sex, site, severity, delay in diagnosis, and time needed to return to sports. Results 15 players sustained 18 stress fractures, corresponding to an overall case incidence of 12.9% (95% confidence interval (CI), 8.1 to 20.0). The tarsal navicular was most affected (n = 5; 27%), followed by the pars interarticularis (n = 3; 16%), the metatarsals (n = 3; 16%), the tibia (n = 2; 11%) and the lunate (n = 2; 11%). Magnetic resonance imaging showed a greater incidence of “high grade” lesions (94.4%). Stress fracture incidence was significantly higher in juniors (20.3% (95% CI, 11.4 to 33.2)) than in professional players (7.5% (2.8 to 15.6)) (p = 0.045). Conclusions There was a high absolute risk (12.9%) of stress fractures in elite tennis players over a two year period. Junior players were at highest risk. The lesions are a major cause of disruption both of training and of competition. Risk factors should therefore be identified and prevention emphasised. PMID:16632579

  14. Winning the game: brain processes in expert, young elite and amateur table tennis players

    PubMed Central

    Wolf, Sebastian; Brölz, Ellen; Scholz, David; Ramos-Murguialday, Ander; Keune, Philipp M.; Hautzinger, Martin; Birbaumer, Niels; Strehl, Ute

    2014-01-01

    This study tested two hypotheses: (1) compared with amateurs and young elite, expert table tennis players are characterized by enhanced cortical activation in the motor and fronto-parietal cortex during motor imagery in response to table tennis videos; (2) in elite athletes, world rank points are associated with stronger cortical activation. To this aim, electroencephalographic data were recorded in 14 expert, 15 amateur and 15 young elite right-handed table tennis players. All subjects watched videos of a serve and imagined themselves responding with a specific table tennis stroke. With reference to a baseline period, power decrease/increase of the sensorimotor rhythm (SMR) during the pretask- and task period indexed the cortical activation/deactivation (event-related desynchronization/synchronization, ERD/ERS). Regarding hypothesis (1), 8–10 Hz SMR ERD was stronger in elite athletes than in amateurs with an intermediate ERD in young elite athletes in the motor cortex. Regarding hypothesis (2), there was no correlation between ERD/ERS in the motor cortex and world rank points in elite experts, but a weaker ERD in the fronto-parietal cortex was associated with higher world rank points. These results suggest that motor skill in table tennis is associated with focused excitability of the motor cortex during reaction, movement planning and execution with high attentional demands. Among elite experts, less activation of the fronto-parietal attention network may be necessary to become a world champion. PMID:25386126

  15. Who Is the Best Player Ever? A Complex Network Analysis of the History of Professional Tennis

    PubMed Central

    Radicchi, Filippo

    2011-01-01

    We considered all matches played by professional tennis players between 1968 and2010, and, on the basis of this data set, constructed a directed and weighted network of contacts. The resulting graph showed complex features, typical of many real networked systems studied in literature. We developed a diffusion algorithm and applied it to the tennis contact network in order to rank professional players. Jimmy Connors was identified as the best player in the history of tennis according to our ranking procedure. We performed a complete analysis by determining the best players on specific playing surfaces as well as the best ones in each of the years covered by the data set. The results of our technique were compared to those of two other well established methods. In general, we observed that our ranking method performed better: it had a higher predictive power and did not require the arbitrary introduction of external criteria for the correct assessment of the quality of players. The present work provides novel evidence of the utility of tools and methods of network theory in real applications. PMID:21339809

  16. Has player development in men's tennis really changed? An historical rankings perspective.

    PubMed

    Bane, Michael Kenneth; Reid, Machar; Morgan, Stuart

    2014-01-01

    Tennis federations are regularly faced with decisions regarding which athletes should be supported in financial terms, and for how long. The financial investments can be considerable, given the cost of competing on tour has been estimated at a minimum $121,000 per year and only the top 130 professionally ranked athletes earned enough prize money to cover this cost in 2012. This study investigates key points of progression in tennis players' careers, to determine how these have changed over time and how that evolution may inform talent development. Approximately 400,000 weekly rankings for 273 male professional tennis players between 1985 and 2010 were compiled, and historical trends in the time taken to reach career milestones were investigated by least-squares regression. The time between earning a first professional ranking point and entry into the Top 100 significantly increased over time for all considered athletes. This was at the detriment of time spent within the Top 100 for some athletes. Career peak Top 50-100 athletes have shown an increase in longevity. These results assist tennis federations in assessing the progress of developing athletes and highlight the evolving nature of the competition for top players.

  17. Large Asymmetric Hypertrophy of Rectus Abdominis Muscle in Professional Tennis Players

    PubMed Central

    Sanchis-Moysi, Joaquin; Idoate, Fernando; Dorado, Cecilia; Alayón, Santiago; Calbet, Jose A. L.

    2010-01-01

    Purpose To determine the volume and degree of asymmetry of the musculus rectus abdominis (RA) in professional tennis players. Methods The volume of the RA was determined using magnetic resonance imaging (MRI) in 8 professional male tennis players and 6 non-active male control subjects. Results Tennis players had 58% greater RA volume than controls (P = 0.01), due to hypertrophy of both the dominant (34% greater volume, P = 0.02) and non-dominant (82% greater volume, P = 0.01) sides, after accounting for age, the length of the RA muscle and body mass index (BMI) as covariates. In tennis players, there was a marked asymmetry in the development of the RA, which volume was 35% greater in the non-dominant compared to the dominant side (P<0.001). In contrast, no side-to-side difference in RA volume was observed in the controls (P = 0.75). The degree of side-to-side asymmetry increased linearly from the first lumbar disc to the pubic symphysis (r = 0.97, P<0.001). Conclusions Professional tennis is associated with marked hypertrophy of the musculus rectus abdominis, which achieves a volume that is 58% greater than in non-active controls. Rectus abdominis hypertrophy is more marked in the non-dominant than in the dominant side, particularly in the more distal regions. Our study supports the concept that humans can differentially recruit both rectus abdominis but also the upper and lower regions of each muscle. It remains to be determined if this disequilibrium raises the risk of injury. PMID:21209832

  18. Feasibility and efficacy of progressive electrostimulation strength training for competitive tennis players.

    PubMed

    Maffiuletti, Nicola A; Bramanti, Jacopo; Jubeau, Marc; Bizzini, Mario; Deley, Gaëlle; Cometti, Gilles

    2009-03-01

    The purpose of this preliminary study was to show the feasibility of electrostimulation (ES) strength exercise incorporated into tennis sessions during the preparatory season of competitive players, and its impact on anaerobic performance. Twelve tennis players (5 men, 7 women) completed 9 sessions of quadriceps ES (duration: 16 minutes; frequency: 85 Hz; on-off ratio: 5.25-25 seconds) during 3 weeks. The ES sessions were integrated into tennis training sessions. Subjects were baseline tested and retested 1 (week 4), 2 (week 5), 3 (week 6), and 4 weeks (week 7) after the ES training program for maximal quadriceps strength, vertical jump height, and shuttle sprint time. Participants were able to progressively increase ES current amplitude and evoked force throughout the 9 training sessions, with an optimal treatment compliance of 100%. Maximal quadriceps strength significantly increased during the entire duration of the experiment (p < 0.001). Countermovement jump height at week 5 (+5.3%) and week 6 (+6.4%) was significantly higher than at baseline (p < 0.05). In addition, 2 x 10-m sprint time at week 6 was significantly shorter (-3.3%; p = 0.004) compared with pretraining. The 3-week ES strength training program was successfully incorporated into preseason tennis training with a linear progression in all training parameters. Throughout the study period, a delayed enhancement of anaerobic power and stretch-shortening cycle performance was observed. Progressive ES strength training may be safely included in the early tennis season and can lead to improvements in the anaerobic performance of men and women players.

  19. Improving the 'how' and 'what' decisions of elite table tennis players.

    PubMed

    Raab, Markus; Masters, Rich S W; Maxwell, Jonathan P

    2005-06-01

    Training methods in sport usually focus on improving either technical or tactical aspects of performance, ignoring the fact that successful performance requires the athlete to simultaneously decide what movement to perform and how it should be executed. Young elite table tennis players were trained, in a first phase, to improve their forehand and backhand movements and, in a second phase, to make a tactical switch between forehand and backhand movements. Half of the players took part in behavioral training focusing on how to perform the required movements, whereas half received additional video feedback about their technical and tactical performance (decision training). The results indicate that improvements of how decisions (techniques) and what decisions (tactics) can occur as a consequence of combining technical and tactical training. These results were stable in delayed Post-test analyses of competitive matches. It was concluded that a combination of both technical and tactical training is beneficial to elite table tennis performers, particularly during early seasonal training programs.

  20. Comparison of Visual Acuity in Reduced Lumination and Facility of Ocular Accommodation in Table Tennis Champions and Non- Players

    PubMed Central

    Jafarzadehpur, Ebrahim; Yarigholi, Mohammad R.

    2004-01-01

    A table tennis player should fixate at different distances; track the objects with different speed, and in different visual environment. Their visual skills must be well developed for these capabilities. Therefore, visual acuity in reduced lumination and facility of ocular accommodation those are two criteria for visual skills have been compared in table tennis players and normal non-players. Twenty-nine young table tennis champions and 29 normal matched non-players (did not take part in any racket sports game) were evaluated. Basic visual and eye examinations were done for both of them. Normal results in basic examination were fundamental requirement for all the subjects. +/-2.00 sphere lenses for accommodation facility are used. An electrical current regulator changed the output light intensity of a conventional chart projector (Topcon). Light intensity decreased to 10 cd·m-2 and visual acuity tested. In comparison of visual acuity in reduced lumination and facility of ocular accommodation in table tennis champions and non-players there are significant differences (p < 0.001). In the preliminary visual tests there was not any significant different in the two groups but the results in the top level table tennis player was very uniform and in every test and the standard deviation was lesser in tennis player group than non-players. These results show that motor and sensorial functions of expert players are well developed. That is consistent with other researchers. This result was interpreted as reflecting a better perceptual system of experts to the constraints encountered during table tennis and its use in practical settings for evaluating athletes or detecting sport talents. However some visual and perceptual training that usually used in orthoptics can be used for novice table tennis player to improve their abilities. Key Points That the ability of a champion depends on many sensory, motor and perceptual factors. Visual factors such as facility of accommodation

  1. A heuristic biomarker selection approach based on professional tennis player ranking strategy.

    PubMed

    Han, Bin; Xie, Ruifei; Li, Lihua; Zhu, Lei; Wang, Shen

    2014-01-01

    Extracting significant features from high-dimension and small sample size biological data is a challenging problem. Recently, Michał Draminski proposed the Monte Carlo feature selection (MC) algorithm, which was able to search over large feature spaces and achieved better classification accuracies. However in MC the information of feature rank variations is not utilized and the ranks of features are not dynamically updated. Here, we propose a novel feature selection algorithm which integrates the ideas of the professional tennis players ranking, such as seed players and dynamic ranking, into Monte Carlo simulation. Seed players make the feature selection game more competitive and selective. The strategy of dynamic ranking ensures that it is always the current best players to take part in each competition. The proposed algorithm is tested on 8 biological datasets. Results demonstrate that the proposed method is computationally efficient, stable and has favorable performance in classification.

  2. Tennis Play Intensity Distribution and Relation with Aerobic Fitness in Competitive Players

    PubMed Central

    Baiget, Ernest; Fernández-Fernández, Jaime; Iglesias, Xavier; Rodríguez, Ferran A.

    2015-01-01

    The aims of this study were (i) to describe the relative intensity of simulated tennis play based on the cumulative time spent in three metabolic intensity zones, and (ii) to determine the relationships between this play intensity distribution and the aerobic fitness of a group of competitive players. 20 male players of advanced to elite level (ITN) performed an incremental on-court specific endurance tennis test to exhaustion to determine maximal oxygen uptake (VO2max) and the first and second ventilatory thresholds (VT1, VT2). Ventilatory and gas exchange parameters were monitored using a telemetric portable gas analyser (K4 b2, Cosmed, Rome, Italy). Two weeks later the participants played a simulated tennis set against an opponent of similar level. Intensity zones (1: low, 2: moderate, and 3: high) were delimited by the individual VO2 values corresponding to VT1 and VT2, and expressed as percentage of maximum VO2 and heart rate. When expressed relative to VO2max, percentage of playing time in zone 1 (77 ± 25%) was significantly higher (p < 0.001) than in zone 2 (20 ± 21%) and zone 3 (3 ± 5%). Moderate to high positive correlations were found between VT1, VT2 and VO2max, and the percentage of playing time spent in zone 1 (r = 0.68–0.75), as well as low to high inverse correlations between the metabolic variables and the percentage of time spent in zone 2 and 3 (r = -0.49–0.75). Players with better aerobic fitness play at relatively lower intensities. We conclude that players spent more than 75% of the time in their low-intensity zone, with less than 25% of the time spent at moderate to high intensities. Aerobic fitness appears to determine the metabolic intensity that players can sustain throughout the game. PMID:26098638

  3. [Metabolic and cardiovascular adaptation and the performance of professional tennis players].

    PubMed

    Keul, J; Stockhausen, W; Pokan, R; Huonker, M; Berg, A

    1991-05-17

    14 professional tennis players of world rank were examined (7 men, mean age 23 +/- 3 years; 7 women, mean age 18 +/- 2 years). Heart volume (HV) was 11.9 +/- 0.9 ml/kg in women, 12.7 +/- 1.3 ml/kg in men, 20-30% higher than in untrained persons. Correspondingly, end-diastolic (EDV) and end-systolic volume, left-ventricular muscle mass (LVM) and stroke volume (SV) were elevated, while contractility parameters as well as the ratios of SV and of LVM to EDV and HV were within normal limits. The changes are to be taken as adaptations in the sense of athlete's heart. Maximal treadmill speed was 18 km/h in women and 19.3 km/h in men, with maximal lactate levels of 9.3 mmol/l (women) and 11.4 mmol/l (men). Anaerobic threshold was reached at a treadmill speed of 13.3 km/h (women) and 14.8 km/h (men). These data indicate a good performance range and were clearly better than in earlier groups of tennis players. This adaptation requires additional interval and endurance training. In 11 tennis players the serum concentration of magnesium and in 5 that of iron was below the recommended lower limit (magnesium: 0.8 mmol/l; iron: 14 mumols/l). Serum concentrations of creatine kinase and of lactate dehydrogenase were always two to three times higher than normal, if tennis training had taken place the day before, but all other biochemical values were within normal limits.

  4. Positive and negative stimuli in relation to tennis players' reaction time.

    PubMed

    Mead, T P; Drowatzky, J N; Hardin-Crosby, L

    2000-02-01

    Research has indicated that negative and positive thoughts may affect sport performance. The purpose of this analogue study was to assess whether negative and positive stimuli influenced tennis performance similar to positive and negative thought. The reaction time (RT) of 40 competitive tennis players was measured during a timed response to a tennis ball rotating in a topspin, sidespin, or backspin direction on the computer screen. Immediately prior to the ball presentation, a phrase (accessory stimulus) was presented visually or aurally. The accessory stimulus provided either positive (e.g., 'nice shot') or negative information (e.g., 'bad shot') followed by the subject's name. Analysis showed a main effect only for the type of spin. The slowest RT occurred when responding to a tennis ball rotating in a backspin direction. A significant interaction was found for the sensory modality (audition vs vision) and polarity (positive vs negative) of the accessory stimulus. RT to negative stimuli was slowest when the accessory stimulus was presented aurally. The quickest RT to positive stimuli occurred when the accessory stimulus was presented aurally. These results indicated that negative and positive stimuli, when presented aurally, affected performance as positive and negative thoughts measured in other studies. Not measured was whether negative and positive stimuli actually produce the negative and positive thoughts, respectively, that have been reported to affect performance.

  5. Differences in Movement Speed Before and After a Split-Step Between Professional and Junior Tennis Players

    PubMed Central

    Leskošek, Bojan; Munivrana, Goran; Ochiana, Gabriela; Filipčič, Tjaša

    2017-01-01

    Abstract This study investigated tennis players’ speed before, during and after the split-step, deceleration before and acceleration after the split-step in four different stroke groups in three age categories. Seven male professional, eleven male and ten female junior tennis players were recorded with video cameras at official tournaments. Using the SAGIT system, we gathered data on 8,545 split-steps. Tennis players performed a split-step in 82.9% of cases. A tennis player’s speed, deceleration and acceleration were measured 0.2 s before and after the split-step. Differences between categories and stroke groups for each of the five variables were analyzed with a two-way ANOVA. The differences between the groups of players were generally much higher in the speed before, during and after the split-step than in the deceleration before and acceleration after the split-step. Most of these differences were observed between the various stroke groups. These results suggest that players use three types of movement while performing a split-step. In the first type, which is typical of serving and returning, the speed before, during and after the split-step is lower (0.55 to 1.2 m/s). The second type of movement is characteristic of baseline strokes where tennis players achieve higher speed than in the first type (0.7 to 1.66 m/s). The third type occurs in strokes where a tennis player is moving or already at the net (0.78 to 1.9 m/s). Movement in tennis is an area that requires constant development in terms of designing and upgrading movement patterns, increasing speed and practice in specific game situations. PMID:28210344

  6. The effect of moderate and high-intensity fatigue on groundstroke accuracy in expert and non-expert tennis players.

    PubMed

    Lyons, Mark; Al-Nakeeb, Yahya; Hankey, Joanne; Nevill, Alan

    2013-01-01

    Exploring the effects of fatigue on skilled performance in tennis presents a significant challenge to the researcher with respect to ecological validity. This study examined the effects of moderate and high-intensity fatigue on groundstroke accuracy in expert and non-expert tennis players. The research also explored whether the effects of fatigue are the same regardless of gender and player's achievement motivation characteristics. 13 expert (7 male, 6 female) and 17 non-expert (13 male, 4 female) tennis players participated in the study. Groundstroke accuracy was assessed using the modified Loughborough Tennis Skills Test. Fatigue was induced using the Loughborough Intermittent Tennis Test with moderate (70%) and high-intensities (90%) set as a percentage of peak heart rate (attained during a tennis-specific maximal hitting sprint test). Ratings of perceived exertion were used as an adjunct to the monitoring of heart rate. Achievement goal indicators for each player were assessed using the 2 x 2 Achievement Goals Questionnaire for Sport in an effort to examine if this personality characteristic provides insight into how players perform under moderate and high-intensity fatigue conditions. A series of mixed ANOVA's revealed significant fatigue effects on groundstroke accuracy regardless of expertise. The expert players however, maintained better groundstroke accuracy across all conditions compared to the novice players. Nevertheless, in both groups, performance following high-intensity fatigue deteriorated compared to performance at rest and performance while moderately fatigued. Groundstroke accuracy under moderate levels of fatigue was equivalent to that at rest. Fatigue effects were also similar regardless of gender. No fatigue by expertise, or fatigue by gender interactions were found. Fatigue effects were also equivalent regardless of player's achievement goal indicators. Future research is required to explore the effects of fatigue on performance in tennis

  7. Anger Management - Evaluation of a Cognitive-Behavioral Training Program for Table Tennis Players

    PubMed Central

    2017-01-01

    Abstract Based on a systematic review of the literature on anger and anger management in sport, there is evidence that anger might be dysfunctional, especially in sports requiring selective attention and fine-tuned motor skills. The research literature suggests that cognitive-behavioral intervention programs can be fruitful in helping athletes to understand and control dysfunctional anger. Therefore, the main goal of the present study was to evaluate the effectiveness of a brief training program for table tennis players in cognitive-behavioral anger management that aimed at changing their noneffective anger reactions. The sample comprised 18 young competitive table tennis players (age range from 16 to 22 years) divided randomly into a treatment (n = 10) and a control group (n = 8). A trained group leader instructed the treatment group. Six sessions were held over a period of two months. Cognitive-relaxation coping skills associated with social skills of subjects from the treatment group were compared to no-treatment controls. Psychological measurements (i.e., self-reports on anger) were applied before, during and after treatment as well as in a follow-up session. The one-year follow-up session revealed that, in contrast to the control group, the treatment group showed a significant reduction in outwardly negative anger expression as well as anger reactions specific to table tennis. Despite limitations inherent in the research design, the training program was deemed effective. PMID:28210339

  8. Sleep restriction and serving accuracy in performance tennis players, and effects of caffeine.

    PubMed

    Reyner, L A; Horne, J A

    2013-08-15

    Athletes often lose sleep on the night before a competition. Whilst it is unlikely that sleep loss will impair sports mostly relying on strength and endurance, little is known about potential effects on sports involving psychomotor performance necessitating judgement and accuracy, rather than speed, as in tennis for example, and where caffeine is 'permitted'. Two studies were undertaken, on 5h sleep (33%) restriction versus normal sleep, on serving accuracy in semi-professional tennis players. Testing (14:00 h-16:00 h) comprised 40 serves into a (1.8 m×1.1 m) 'service box' diagonally, over the net. Study 1 (8 m; 8 f) was within-Ss, counterbalanced (normal versus sleep restriction). Study 2 (6m;6f -different Ss) comprised three conditions (Latin square), identical to Study 1, except for an extra sleep restriction condition with 80 mg caffeine vs placebo in a sugar-free drink, given (double blind), 30 min before testing. Both studies showed significant impairments to serving accuracy after sleep restriction. Caffeine at this dose had no beneficial effect. Study 1 also assessed gender differences, with women significantly poorer under all conditions, and non-significant indications that women were more impaired by sleep restriction (also seen in Study 2). We conclude that adequate sleep is essential for best performance of this type of skill in tennis players and that caffeine is no substitute for 'lost sleep'. 210.

  9. Balance Training Exercises Decrease Lower-Limb Strength Asymmetry in Young Tennis Players

    PubMed Central

    Sannicandro, Italo; Cofano, Giacomo; Rosa, Rosa A.; Piccinno, Andrea

    2014-01-01

    The issue of functional asymmetries in the lower-limbs has been the subject of numerous recent investigations concerning many different contact, limited-contact and non-contact sports. The presence of strength asymmetries in the lower-limbs of young athletes practicing various sporting disciplines is considered an intrinsic risk factor for injury; in such cases, compensation strategies should thus be implemented aimed at eliminating, or at least limiting, the degree of asymmetry in order to avoid the negative consequences asymmetries can have upon the health of young sportsmen and women on the long-term. The aim of the present study was to examine the presence of functional asymmetries in the lower-limbs of young tennis players in strength and speed drill performance and to test a specific balance-training programme in its capacity to effectively reduce such asymmetries. Twenty-three young tennis players were randomly assigned to the Experimental Group (EG) (n = 11: 4 females, 7 males; 13.2 ± 0.9 years; 50.8 ± 8.9 Kg; 1.63 ± 0.08 m) or Comparison Group (CG) (n = 12: 4 females, 8 males; 13.0 ± 0.9 years; 51.1 ± 9.2 Kg; 1.61 ± 0.09 m). To quantify percent asymmetries in lower-limb strength before (T0) and following (T1) training, performances were assessed in the one-leg hop test (OLH), side-hop test (SH) and side steps and forward 4.115-m test (4m-SSF). Performances in the 10 and 20m sprint tests and the Foran test were also assessed. The EG completed a total of 12 training sessions directed at balance training: two 30-minute sessions/week over a 6-week period. The CG followed an identical training schedule, but training sessions consisted of tennis-specific drills only. The results reveal significant differences between pre- and post-training tests in the EG only: the degree of lower-limb asymmetry was decreased in the EG following completion of the training programme, as assessed using the OLH test (p < 0.001), SH test (p < 0.001) and 4m-SSF test (p < 0

  10. The hypertrophy of the lateral abdominal wall and quadratus lumborum is sport-specific: an MRI segmental study in professional tennis and soccer players.

    PubMed

    Sanchis-Moysi, Joaquin; Idoate, Fernando; Izquierdo, Mikel; Calbet, Jose A; Dorado, Cecilia

    2013-03-01

    The aim was to determine the volume and degree of asymmetry of quadratus lumborum (QL), obliques, and transversus abdominis; the last two considered conjointly (OT), in tennis and soccer players. The volume of QL and OT was determined using magnetic resonance imaging in professional tennis and soccer players, and in non-active controls (n = 8, 14, and 6, respectively). In tennis players the hypertrophy of OT was limited to proximal segments (cephalic segments), while in soccer players it was similar along longitudinal axis. In tennis players the hypertrophy was asymmetric (18% greater volume in the non-dominant than in the dominant OT, p = 0.001), while in soccer players and controls both sides had similar volumes (p > 0.05). In controls, the non-dominant QL was 15% greater than that of the dominant (p = 0.049). Tennis and soccer players had similar volumes in both sides of QL. Tennis alters the dominant-to-non-dominant balance in the muscle volume of the lateral abdominal wall. In tennis the hypertrophy is limited to proximal segments and is greater in the non-dominant side. Soccer, however, is associated to a symmetric hypertrophy of the lateral abdominal wall. Tennis and soccer elicit an asymmetric hypertrophy of QL.

  11. Enhancing physical performance in elite junior tennis players with a caffeinated energy drink.

    PubMed

    Gallo-Salazar, César; Areces, Francisco; Abián-Vicén, Javier; Lara, Beatriz; Salinero, Juan José; Gonzalez-Millán, Cristina; Portillo, Javier; Muñoz, Victor; Juarez, Daniel; Del Coso, Juan

    2015-04-01

    The aim of this study was to investigate the effectiveness of a caffeinated energy drink to enhance physical performance in elite junior tennis players. In 2 different sessions separated by 1 wk, 14 young (16 ± 1 y) elite-level tennis players ingested 3 mg caffeine per kg body mass in the form of an energy drink or the same drink without caffeine (placebo). After 60 min, participants performed a handgrip-strength test, a maximal-velocity serving test, and an 8 × 15-m sprint test and then played a simulated singles match (best of 3 sets). Instantaneous running speed during the matches was assessed using global positioning (GPS) devices. Furthermore, the matches were videotaped and notated afterward. In comparison with the placebo drink, the ingestion of the caffeinated energy drink increased handgrip force by ~4.2% ± 7.2% (P = .03) in both hands, the running pace at high intensity (46.7 ± 28.5 vs 63.3 ± 27.7 m/h, P = .02), and the number of sprints (12.1 ± 1.7 vs 13.2 ± 1.7, P = .05) during the simulated match. There was a tendency for increased maximal running velocity during the sprint test (22.3 ± 2.0 vs 22.9 ± 2.1 km/h, P = .07) and higher percentage of points won on service with the caffeinated energy drink (49.7% ± 9.8% vs 56.4% ± 10.0%, P = .07) in comparison with the placebo drink. The energy drink did not improve ball velocity during the serving test (42.6 ± 4.8 vs 42.7 ± 5.0 m/s, P = .49). The preexercise ingestion of caffeinated energy drinks was effective to enhance some aspects of physical performance of elite junior tennis players.

  12. The Effect of Moderate and High-Intensity Fatigue on Groundstroke Accuracy in Expert and Non-Expert Tennis Players

    PubMed Central

    Lyons, Mark; Al-Nakeeb, Yahya; Hankey, Joanne; Nevill, Alan

    2013-01-01

    Exploring the effects of fatigue on skilled performance in tennis presents a significant challenge to the researcher with respect to ecological validity. This study examined the effects of moderate and high-intensity fatigue on groundstroke accuracy in expert and non-expert tennis players. The research also explored whether the effects of fatigue are the same regardless of gender and player’s achievement motivation characteristics. 13 expert (7 male, 6 female) and 17 non-expert (13 male, 4 female) tennis players participated in the study. Groundstroke accuracy was assessed using the modified Loughborough Tennis Skills Test. Fatigue was induced using the Loughborough Intermittent Tennis Test with moderate (70%) and high-intensities (90%) set as a percentage of peak heart rate (attained during a tennis-specific maximal hitting sprint test). Ratings of perceived exertion were used as an adjunct to the monitoring of heart rate. Achievement goal indicators for each player were assessed using the 2 x 2 Achievement Goals Questionnaire for Sport in an effort to examine if this personality characteristic provides insight into how players perform under moderate and high-intensity fatigue conditions. A series of mixed ANOVA’s revealed significant fatigue effects on groundstroke accuracy regardless of expertise. The expert players however, maintained better groundstroke accuracy across all conditions compared to the novice players. Nevertheless, in both groups, performance following high-intensity fatigue deteriorated compared to performance at rest and performance while moderately fatigued. Groundstroke accuracy under moderate levels of fatigue was equivalent to that at rest. Fatigue effects were also similar regardless of gender. No fatigue by expertise, or fatigue by gender interactions were found. Fatigue effects were also equivalent regardless of player’s achievement goal indicators. Future research is required to explore the effects of fatigue on performance in

  13. Prelongitudinal screening of hypothesized developmental sequences for the overhead tennis serve in experienced tennis players 9-19 years of age.

    PubMed

    Messick, J A

    1991-09-01

    A cross-sectional study was conducted to investigate developmental characteristics within six body component actions for the overhead serve in tennis and to determine if such actions should be validated through longitudinal study. Developmental sequences, hypothesized for two components during the preparatory phase and four components during the force production phase of the overhead tennis serve, were used to classify the videotaped serving actions of 30 male and 30 female tennis players. Sequences hypothesized for the Preparatory Trunk, Elbow, and Forearm/Racket actions met the prelongitudinal screening criteria proposed by Roberton (1978); Roberton, Williams, and Langendorfer (1980); and Langendorfer (1982). Sequences for these component actions should be validated through longitudinal study. Steps within sequences for the Preparatory Backswing, Trunk for Force, and Feet/Legs are apparently misordered or not characteristic of a developmental process. Further cross-sectional study of these component actions prior to longitudinal study is recommended.

  14. A Physiological Case Study of a Paralympic Wheelchair Tennis Player: Reflective Practise

    PubMed Central

    Diaper, Nicholas J.; Goosey-Tolfrey, Victoria L.

    2009-01-01

    This study was designed to examine the physiological changes caused by long-term training in a world class female tennis player in preparation for a major championship. Additionally, we aim to describe the training interventions and determine a suitable cooling strategy that was to be used at the 2004 Paralympic Games. The athlete underwent regular physiological assessment during 2003-2004. Physiological measures involved body composition, submaximal and peak oxygen uptake and key variables associated with maximal sprinting. In addition, a suitable match-play cooling intervention and hydration strategy was also explored. Body composition improved over the course of the study. Aerobic capacity fell by 21%, yet the submaximal physiological variables such as lactate profile and pushing economy improved. The trade off of aerobic capacity was perhaps noticeably counter-balanced with the maintenance of the peak sprinting speed and improvement found in the fatigue profile across ten repeated sprints. The extensive training programme was responsible for these changes and these adaptations resulted in a more confident athlete, in peak physical condition leading into the Paralympic Games. It is difficult to appreciate the extent to which this work had an impact on tennis performance given the skill requirements of wheelchair tennis and this warrants future attention. Key points Physiological adaptations were apparent over the two-year training period. The training emphasis resulted in a reduction in aerobic capacity, yet an improvement in repetitive sprint performance was seen leading into the Major competition. An effective cooling technique was identified that could be used during wheelchair tennis performance. The athlete and coaches were complimentary to the physiological support provided, which resulted in a more confident athlete at the Paralympic Games. PMID:24149542

  15. A notational analysis of shot characteristics in top-level table tennis players.

    PubMed

    Malagoli Lanzoni, Ivan; Di Michele, Rocco; Merni, Franco

    2014-01-01

    This study aimed to analyse selected shot characteristics in top-level table tennis matches, with a special focus on comparing the playing style of Asian and European players. Ten men's matches played by 20 top-ranked players (14 Asians and 6 Europeans) were analysed. The indicators examined were the area of ball bouncing for serves (n =918), and the stroke type, footwork type and shot outcome for other shots (n=3692). The interrelationships between variables were analysed using chi-squared tests, log-linear modelling and multiple correspondence analysis. A strong association was found between strokes and footwork types, with most stroke types executed each after specific footwork types. Furthermore, a clear tendency to have a positive, negative or neutral outcome was observed for each stroke type. When compared to Europeans, Asians used more frequently the most aggressive strokes and footwork types, confirming anecdotal claims on their particularly offensive playing style. Asians showed also a better serving effectiveness, often sending the ball in those areas of the table from which a counterattack is difficult to make. In summary, this study gives a systematic description of highly relevant technical and tactical characteristics in top-level table tennis, thus providing valuable information for coaches and performance analysts.

  16. MONITORING TRAINING LOADS, STRESS, IMMUNE-ENDOCRINE RESPONSES AND PERFORMANCE IN TENNIS PLAYERS

    PubMed Central

    Moreira, A.; Lodo, L.; Nosaka, K.; Coutts, A.J.; Aoki, M.S.

    2013-01-01

    The study aim was to investigate the effect of a periodised pre-season training plan on internal training load and subsequent stress tolerance, immune-endocrine responses and physical performance in tennis players. Well-trained young tennis players (n = 10) were monitored across the pre-season period, which was divided into 4 weeks of progressive overloading training and a 1-week tapering period. Weekly measures of internal training load, training monotony and stress tolerance (sources and symptoms of stress) were taken, along with salivary testosterone, cortisol and immunoglobulin A. One repetition maximum strength, running endurance, jump height and agility were assessed before and after training. The periodised training plan led to significant weekly changes in training loads (i.e. increasing in weeks 3 and 4, decreasing in week 5) and post-training improvements in strength, endurance and agility (P < 0.05). Cortisol concentration and the symptoms of stress also increased in weeks 3 and/or 4, before returning to baseline in week 5 (P < 0.05). Conversely, the testosterone to cortisol ratio decreased in weeks 3 and 4, before returning to baseline in week 5 (P < 0.05). In conclusion, the training plan evoked adaptive changes in stress tolerance and hormonal responses, which may have mediated the improvements in physical performance. PMID:24744485

  17. Mental Toughness in Talented Youth Tennis Players: A Comparison Between on-Court Observations and a Self-Reported Measure

    PubMed Central

    Houwer, Ruben; Kramer, Tamara; den Hartigh, Ruud; Kolman, Nikki; Elferink-Gemser, Marije

    2017-01-01

    Abstract In tennis, mental toughness is often considered highly important in achieving the elite level. The current study is the first to examine behavioural expressions of mental toughness on the court and their relationships with self-reported measures. Based on the input of five experienced tennis coaches of junior tennis players and behaviours used in previous studies, we developed a taxonomy consisting of six positive behaviours and ten negative ones. To investigate the relationship between these on-court behaviours of mental toughness and how the players rated their own mental toughness, emotional control in particular, six talented tennis players (aged 10-13) were recorded during tennis matches and filled out the self-reported measure of mental toughness (MTQ48). The intra- and inter-rater reliability of the taxonomy was high. With regard to the relationships between on-court behaviours and self-reported mental toughness (total score and subscale emotional control), results revealed no significant correlations between the ratios of positive and negative behaviours (range r = -0.49 - 0.11, p > 0.05) or between the variability of negative behaviours (r = 0.54 & r = 0.10, p > 0.05) and the self-reported measure. However, interestingly, we found negative correlations between the variability of positive behaviours and self-reported mental toughness (r = -0.93 & r = -0.84, ρ < 0.05). These results indicate that variability in on-court behaviours provides interesting information about tennis players’ mental toughness, more specifically on the (in)stability of their psychological state during a match. PMID:28210346

  18. Impact of a competition with two consecutive matches in a day on physical performance in young tennis players.

    PubMed

    Gallo-Salazar, Cesar; Del Coso, Juan; Barbado, David; Lopez-Valenciano, Alejandro; Santos-Rosa, Francisco Javier; Sanz-Rivas, David; Moya, Manuel; Fernandez-Fernandez, Jaime

    2017-02-23

    The purpose of this study was to analyze the effects of playing two tennis matches on the same day on physical performance in young tennis players. Twelve well-trained young tennis players took part in a simulated tennis competition consisting of two tennis matches on the same day (morning and afternoon sessions). Before and the day after the competition, physical performance was measured using a battery of countermovement jumps (CMJ), a 10-m sprint, the 5-0-5 agility test, hip, grip and shoulder maximal isometric strength, shoulder range of motion (ROM) and a serve velocity test. Post-competition results showed reduced performance in 10-m (-3.3%, effect size (ES)= small), dominant-and-non-dominant 5-0-5 agility test (-4.6%, ES=moderate; -4.2%, ES=moderate, respectively), bilateral (-5.2%, ES=small) and unilateral CMJ (dominant leg: -7.2%, ES=small; non-dominant leg: -9.1%, ES=small). Both dominant and non-dominant shoulder external rotation (ER) ROM increased (12.2%, ES=moderate; 5.6%, ES=small) while internal rotation (IR) decreased (-4.2%, ES=small; -3.3%, ES=small) in the post-competition tests, together with the dominant-shoulder ER (-10.7%, ES=moderate) and IR (-9.3%, ES=small) strength. Physical impairments occurred in neuromuscular performance variables involving lower (e.g. jumping, sprinting and change of direction) and upper (e.g. isometric strength and range of motion) limbs the day after playing a competition with two consecutive matches on the same day. These alterations in neuromuscular and sport-specific performance need to be taken into consideration when planning tournament schedules for young tennis players, as well as preparing match and recovery strategies.

  19. Preseason Training: The Effects of a 17-Day High-Intensity Shock Microcycle in Elite Tennis Players

    PubMed Central

    Fernandez-Fernandez, Jaime; Sanz-Rivas, David; Sarabia, Jose Manuel; Moya, Manuel

    2015-01-01

    Preseasons in tennis are normally reduced to 5 to 7 weeks duration, and coaches should use an integrated approach to conditioning and skill-based work. The aim of the present study was to investigate the effects of adding a high-intensity training (HIT) shock microcycle to the normal training content in several physical performance indicators in the preseason training of high-level male tennis players. Over 17 days, 12 male tennis players performed 13 HIT sessions in addition to their usual training. Physical performance tests (30:15 intermittent fitness test [VIFT], 20 m sprint, countermovement jump [CMJ], repeated sprint ability [RSA]) were conducted before (pre-test) and 5 days after the intervention (post-test). After the shock microcycle, results showed a significant increase in the VIFT (p < 0.001; Large ES) and a significant decrease in the mean RSA time (RSAm) (p = 0.002; Small ES), while there were no significant changes in the other parameters analysed (e.g., 20 m, CMJ, best RSA time [RSAb]; percentage of decrement in the RSA [%Dec]). Moreover, the training load (TL) during tennis sessions was significantly higher (p < 0.01; Large ES) than the TL during the integrated sessions, except during the first training session. A 17-day shock microcycle (i.e., 13 HIT sessions) in addition to the regular tennis training significantly improved parameters that can impact physical performance in tennis. Moreover, additional sessions, including running exercises based on the 30:15ITF and on-court specific exercises, were characterised by significantly lower TL than tennis-training sessions. Key points HIT shock microcycle increases performance in professional tennis players in a short period of time. The inclusion of additional sessions, with running exercises based on the 30:15ITF and on-court specific exercises, was characterised by a significantly lower TL than tennis-training sessions alone. Coaches should be aware of TL (e.g., RPE) and fatigue-related parameters

  20. A comparison of visual search strategies of elite and non-elite tennis players through cluster analysis.

    PubMed

    Murray, Nicholas P; Hunfalvay, Melissa

    2017-02-01

    Considerable research has documented that successful performance in interceptive tasks (such as return of serve in tennis) is based on the performers' capability to capture appropriate anticipatory information prior to the flight path of the approaching object. Athletes of higher skill tend to fixate on different locations in the playing environment prior to initiation of a skill than their lesser skilled counterparts. The purpose of this study was to examine visual search behaviour strategies of elite (world ranked) tennis players and non-ranked competitive tennis players (n = 43) utilising cluster analysis. The results of hierarchical (Ward's method) and nonhierarchical (k means) cluster analyses revealed three different clusters. The clustering method distinguished visual behaviour of high, middle-and low-ranked players. Specifically, high-ranked players demonstrated longer mean fixation duration and lower variation of visual search than middle-and low-ranked players. In conclusion, the results demonstrated that cluster analysis is a useful tool for detecting and analysing the areas of interest for use in experimental analysis of expertise and to distinguish visual search variables among participants'.

  1. The effect of equipment scaling on the skill acquisition of beginning tennis players.

    PubMed

    Farrow, Damian; Reid, Machar

    2010-05-01

    In this study, we examined the effectiveness of equipment scaling (tennis ball modification and court size) on beginner tennis player skill acquisition and associated psychological responses within a structured competitive development/participation programme. The participants' ability to rally and their stroke proficiency were recorded before and after a 5-week acquisition phase. Coupled to these dependent measures were within-practice session recording of hitting opportunities, resultant success, and the affective measure of session happiness. The participants who practised using a standard ball and standard court (adult constraints) were afforded a significantly poorer learning experience relative to the other ball/court scaling combinations. In particular, the adult standardized intervention group recorded significantly less hitting opportunities on the forehand and backhand side than the scaled-court intervention conditions. The decreased hitting opportunities experienced within the standardized adult condition then flowed into significantly poorer hitting success relative to the scaled court groups. The modified ball/scaled court intervention group rated their experience significantly happier than the standardized adult group. Discussion centres on the stronger learning effect generated by court scaling relative to the influence of ball type and the broader application of these findings to skill acquisition theory and practice.

  2. Cognitive Predictors of Performance in Well-Trained Table Tennis Players With Intellectual Disability.

    PubMed

    Van Biesen, Debbie; Mactavish, Jennifer; Kerremans, Janne; Vanlandewijck, Yves C

    2016-10-01

    Evidence-based classification systems in Paralympic sport require knowledge of the underlying effect of impairment in a specific sport. This study investigated the relationship between cognition and tactical proficiency in 88 well-trained table tennis players with intellectual disability (ID; 29 women, 59 men, M ± SD IQ 59.9 ± 9.6). Data were collected at 3 competitions sanctioned by the International Federation for Para-Athletes with Intellectual Disabilities (INAS). A generic cognitive test consisting of 8 neuropsychological subtests was used to assess cognitive abilities relevant to sport (reaction time, processing speed, and decision speed; spatial visualization; fluid reasoning; memory; executive functioning; and visual processing). The backward stepwise-regression analysis model revealed that 18% of the variance in tactical proficiency was attributed to spatial visualization and simple reaction time. Applications of these findings resulted in an evidence-based classification system that led to the reinclusion of athletes with ID in Paralympic table tennis and provide the basis for future research in this important area.

  3. A 2-year follow-up study on muscle size and dynamic strength in teenage tennis players.

    PubMed

    Kanehisa, H; Kuno, S; Katsuta, S; Fukunaga, T

    2006-04-01

    Growth trends in the cross-sectional area of the quadriceps femoris (CSA(QF)) and its dynamic strength in 12 teenage tennis players (six boys and six girls), aged from 10.7 to 13.2 years at the onset of the study, were investigated through a 2-year follow-up survey. CSA(QF) values at the three levels (proximal, mid, and distal to the knee joint) and dynamic torques during knee extensions at three pre-set velocities (1.05, 3.14, and 5.24 rad/s) were determined year by year, i.e., three times (T1, T2, and T3), using magnetic resonance imaging and an isokinetic dynamometer, respectively. In both genders, the CSA(QF) values at the three levels tended to increase across the measurement times, with greater gains in the boys than in the girls at the levels mid and distal to the knee joint. Among these changes, only the CSA(QF) at the level proximal to the knee joint significantly increased regardless of changes in both skeletal age and body height. The ratios of torque to the sum of CSA(QF) at the three levels (T/CSA) at 3.14 and 5.24 rad/s for the boys and at 5.24 rad/s for the girls were significantly higher in T2 and T3 than T1. Further, the relative increases in torque and T/CSA values at 3.14 and 5.24 rad/s were greater in the boys than the girls. The findings presented here indicate that young tennis players who are in the earlier stage of adolescence increase the CSA of the QF muscle beyond normally expected growth change at the level proximal to the knee joint and show a predominant development in torque generation capability during high-velocity knee extensions, with a greater gain in boys compared with girls.

  4. A Comparison of Serve Speed and Motor Coordination between Elite and Club Level Tennis Players

    PubMed Central

    2017-01-01

    Abstract The purpose of this study was to compare the serve speed and motor coordination of elite and club level junior tennis players aged 11-14 years. Participants (n=35) were assigned to one of the two groups according to their experience, weekly training volume and competition level. Serve speed was assessed with a sports radar gun. Motor coordination was evaluated by means of the Körperkoordinationstest für Kinder. The main results revealed that serve speed and motor coordination performance levels of the elite group were significantly higher than those of the club group. This study emphasized the importance of early participation and training intensity, which can play an important role in enhancement of serve speed and motor coordination. PMID:28210349

  5. Motor skill failure or flow-experience? Functional brain asymmetry and brain connectivity in elite and amateur table tennis players.

    PubMed

    Wolf, Sebastian; Brölz, Ellen; Keune, Philipp M; Wesa, Benjamin; Hautzinger, Martin; Birbaumer, Niels; Strehl, Ute

    2015-02-01

    Functional hemispheric asymmetry is assumed to constitute one underlying neurophysiological mechanism of flow-experience and skilled psycho-motor performance in table tennis athletes. We hypothesized that when initiating motor execution during motor imagery, elite table tennis players show higher right- than left-hemispheric temporal activity and stronger right temporal-premotor than left temporal-premotor theta coherence compared to amateurs. We additionally investigated, whether less pronounced left temporal cortical activity is associated with more world rank points and more flow-experience. To this aim, electroencephalographic data were recorded in 14 experts and 15 amateur table tennis players. Subjects watched videos of an opponent serving a ball and were instructed to imagine themselves responding with a specific table tennis stroke. Alpha asymmetry scores were calculated by subtracting left from right hemispheric 8-13 Hz alpha power. 4-7 Hz theta coherence was calculated between temporal (T3/T4) and premotor (Fz) cortex. Experts showed a significantly stronger shift towards lower relative left-temporal brain activity compared to amateurs and a significantly stronger right temporal-premotor coherence than amateurs. The shift towards lower relative left-temporal brain activity in experts was associated with more flow-experience and lower relative left temporal activity was correlated with more world rank points. The present findings suggest that skilled psycho-motor performance in elite table tennis players reflect less desynchronized brain activity at the left hemisphere and more coherent brain activity between fronto-temporal and premotor oscillations at the right hemisphere. This pattern probably reflect less interference of irrelevant communication of verbal-analytical with motor-control mechanisms which implies flow-experience and predict world rank in experts.

  6. Professional tennis players' serve: correlation between segmental angular momentums and ball velocity.

    PubMed

    Martin, Caroline; Kulpa, Richard; Delamarche, Paul; Bideau, Benoit

    2013-03-01

    The purpose of the study was to identify the relationships between segmental angular momentum and ball velocity between the following events: ball toss, maximal elbow flexion (MEF), racket lowest point (RLP), maximal shoulder external rotation (MER), and ball impact (BI). Ten tennis players performed serves recorded with a real-time motion capture. Mean angular momentums of the trunk, upper arm, forearm, and the hand-racket were calculated. The anteroposterior axis angular momentum of the trunk was significantly related with ball velocity during the MEF-RLP, RLP-MER, and MER-BI phases. The strongest relationships between the transverse-axis angular momentums and ball velocity followed a proximal-to-distal timing sequence that allows the transfer of angular momentum from the trunk (MEF-RLP and RLP-MER phases) to the upper arm (RLP-MER phase), forearm (RLP-MER and MER-BI phases), and the hand-racket (MER-BI phase). Since sequence is crucial for ball velocity, players should increase angular momentums of the trunk during MEF-MER, upper arm during RLP-MER, forearm during RLP-BI, and the hand-racket during MER-BI.

  7. Acute and Time-Course Effects of Traditional and Dynamic Warm-Up Routines in Young Elite Junior Tennis Players

    PubMed Central

    Moreno-Pérez, Víctor; Vera-Garcia, Francisco J.; Moya, Manuel; Sanz-Rivas, David

    2016-01-01

    Despite the large number of studies that have examined the acute effects of different warm up modalities (WU) on physical performance, none of them have documented the time course of potential performance recovery in tennis players. The aim of this study was twofold: (a) to analyze and compare the acute effects of two different WU modalities (traditional WU [TWU] and dynamic WU [DWU]) on physical performance (i.e., CMJ, sprint, serve speed and accuracy) in elite junior players, as well as (b) to monitor the time course of any WU-induced changes after 30 and 60 min of simulated match-play. Twelve junior elite players completed both WUs modalities (TWU and DWU) in a counterbalanced order on separate days. In each experimental session, counter movement jump (CMJ), 20-m sprint, tennis serve speed and accuracy tests were performed before (immediately after TWU or DWU) during (30 min) and after 60 min of a simulated match play. Measures were compared via four factorial (WU intervention and time) repeated measures ANOVAs. There were main effects of WU (TWU and DWU) throughout the time for all the variables analysed. The results indicate that DWU routine led to significantly faster 20 m sprint times and higher CMJs as well as faster and more accurate tennis serves at both post warm-up and 30 min match-play testing moments in comparison with the scores reported by the TWU routine (p < 0.05; positive effects with a probability of >75–99%). No significant intergroup differences were found at 60-min match-play testing moment in any variable (except for the 20 m sprint). Therefore, the findings of this study recommend for optimal performance in these elite tennis players, DWU routines should be performed prior to formal training and competition rather than TWU routines. PMID:27071014

  8. Do High Blood Hepcidin Concentrations Contribute to Low Ferritin Levels in Young Tennis Players at the End of Tournament Season?

    PubMed Central

    Ziemann, Ewa; Kasprowicz, Katarzyna; Kasperska, Anna; Zembroń-Lacny, Agnieszka; Antosiewicz, Jedrzej; Laskowski, Radoslaw

    2013-01-01

    The purpose of the present study was to verify whether impaired iron metabolism in young athletes is a consequence of an excessive workload during the tournament season. Low levels of ferritin (under 25 µg·L-1) have been frequently observed in young tennis players. We considered this finding to be related to the high-intensity workload or to insufficient rest, which both trigger a strong immune response. Groups of male, well-trained young tennis players (16 ± 0.9 years old, average of 10-year training experience) and a control peer group participated in this study. The research consisted of two examination sessions (March and September 2010). Blood samples were collected to determine haematological and immunological parameters. Additionally, body composition and physical capacity were assessed. In both periods of the study, the trained groups were characterised by low levels of ferritin, but also elevated levels of pro- inflammatory cytokine IL-1β. Moreover, an inverse correlation between IL-1β and blood ferritin was observed. Additionally, an increased concentration of the iron homeostasis regulator hepcidin was found in blood samples (mean 71 ng·ml-1; range from 48 to 100 ng·ml-1). We concluded that the pro- inflammatory cytokine IL-1β, most likely induced by an extensive workload during the tournament season, was responsible for the low level of ferritin in young, professional athletes. Key Points The first research demonstrating low grade inflammation-induced iron deficiency to be associated with elevated blood hepcidin levels in young tennis athletes. Evaluation of immunological response after the complete tournament season in young male tennis players. Conclusion to introduce the assessment of hepcidin to monitor trainings as well as symptoms of overreaching more effectively. Research providing practical information for coaches that changes in diet and modifications in workloads applied in physical training could be more effective than iron

  9. Reliability and criterion-related validity of the 20-yard shuttle test in competitive junior tennis players

    PubMed Central

    Eriksson, Anna; Johansson, Fredrik R; Bäck, Maria

    2015-01-01

    Purpose This study adds to the previous work in the field of sport-specific fitness testing by evaluating a tennis-specific agility test called “the 20-yard shuttle test”. The aim of the study was to evaluate the test–retest reliability, the inter-rater reliability, and the criterion-related validity of the 20-yard shuttle test on competitive junior tennis players. Participants and methods Totally, 34 Swedish tennis players (13 girls), mean age 14±1.6 years, participated in the study. To examine test–retest reliability, the subjects performed the 20-yard shuttle test three times on the same day and then the same procedure was repeated after 3 days. To test the inter-rater reliability, the time was measured with a stopwatch simultaneously by two different raters. The time recorded manually was compared to the gold standard of digital timing to evaluate the criterion-related validity. Results Excellent test–retest reliability was found both within the same day (intraclass correlation coefficient [ICC] 0.95) and between days (ICC 0.91). Furthermore, the results showed excellent inter-rater reliability (ICC 0.99) and criterion-related validity on both test occasions (ICC 0.99). Conclusion We have provided introductory support for the 20-yard shuttle test as a reliable and valid test for use in competitive junior tennis players. The ease of administration makes this test a practical alternative to evaluate physical fitness in order to optimally train the athletes. PMID:26316829

  10. On the Use of a Test to Exhaustion Specific to Tennis (TEST) with Ball Hitting by Elite Players

    PubMed Central

    2016-01-01

    Purpose We aimed to a) introduce a new Test to Exhaustion Specific to Tennis (TEST) and compare performance (test duration) and physiological responses to those obtained during the 20-m multistage shuttle test (MSST), and b) determine to which extent those variables correlate with performance level (tennis competitive ranking) for both test procedures. Methods Twenty-seven junior players (8 males, 19 females) members of the national teams of the French Tennis Federation completed MSST and TEST, including elements of the game (ball hitting, intermittent activity, lateral displacement), in a randomized order. Cardiorespiratory responses were compared at submaximal (respiratory compensation point) and maximal loads between the two tests. Results At the respiratory compensation point oxygen uptake (50.1 ± 4.7 vs. 47.5 ± 4.3 mL.min-1.kg-1, p = 0.02), but not minute ventilation and heart rate, was higher for TEST compared to MSST. However, load increment and physiological responses at exhaustion did not differ between the two tests. Players’ ranking correlated negatively with oxygen uptake measured at submaximal and maximal loads for both TEST (r = -0.41; p = 0.01 and -0.55; p = 0.004) and MSST (r = -0.38; P = 0.05 and -0.51; p = 0.1). Conclusion Using TEST provides a tennis-specific assessment of aerobic fitness and may be used to prescribe aerobic exercise in a context more appropriate to the game than MSST. Results also indicate that VO2 values both at submaximal and maximal load reached during TEST and MSST are moderate predictors of players competitive ranking. PMID:27035342

  11. The effects of daily-wear contact lenses on contrast sensitivity in selected professional and collegiate female tennis players.

    PubMed

    Kluka, D A; Love, P A

    1993-03-01

    Contrast sensitivity (CS) has recently emerged as an important predictor of visual performance. Few studies, however, have been published involving CS and its role in vision for sport. The purpose of this investigation was to determine if significant differences occurred in CS between female professional and collegiate tennis players who wore daily-wear soft contact lenses (N = 10) and those players who wore no corrective lenses (N = 10) in competition as measured by the Stereo Optical Optec 2000 Vision Tester. Subjects were between the ages of 18 and 37 years. Mean ages were 21.76 (+/- 4.018) and 25.40 (+/- 5.379) years for those wearing lenses and those not, respectively. Each subject was preliminarily screened for SVA-distance, lateral/vertical phorias, stereopsis, and color perception. All subjects were within accepted limits. CS was assessed at 1.5, 3, 6, 12, and 18 cycles per degree (cpd). Each subject was assessed monocularly; eye initially assessed was determined randomly. A 2 x 2 factorial analysis of variance (alpha = .05) was used to analyze data. No significant differences were found between eyes. Significant differences were found at 3, 6, 12, and 18 cpd. It may be concluded that those female professional and collegiate tennis players wearing no corrective lenses were significantly higher in CS at intermittent and high spatial frequencies than those who wore daily-wear soft contact lenses in competition.

  12. Can Perceptuo-Motor Skills Assessment Outcomes in Young Table Tennis Players (7-11 years) Predict Future Competition Participation and Performance? An Observational Prospective Study.

    PubMed

    Faber, Irene R; Elferink-Gemser, Marije T; Faber, Niels R; Oosterveld, Frits G J; Nijhuis-Van der Sanden, Maria W G

    2016-01-01

    Forecasting future performance in youth table tennis players based on current performance is complex due to, among other things, differences between youth players in growth, development, maturity, context and table tennis experience. Talent development programmes might benefit from an assessment of underlying perceptuo-motor skills for table tennis, which is hypothesized to determine the players' potential concerning the perceptuo-motor domain. The Dutch perceptuo-motor skills assessment intends to measure the perceptuo-motor potential for table tennis in youth players by assessing the underlying skills crucial for developing technical and tactical qualities. Untrained perceptuo-motor tasks are used as these are suggested to represent a player's future potential better than specific sport skills themselves as the latter depend on exposure to the sport itself. This study evaluated the value of the perceptuo-motor skills assessment for a talent developmental programme by evaluating its predictive validity for competition participation and performance in 48 young table tennis players (7-11 years). Players were tested on their perceptuo-motor skills once during a regional talent day, and the subsequent competition results were recorded half-yearly over a period of 2.5 years. Logistic regression analysis showed that test scores did not predict future competition participation (p >0.05). Yet, the Generalized Estimating Equations analysis, including the test items 'aiming at target', 'throwing a ball', and 'eye-hand coordination' in the best fitting model, revealed that the outcomes of the perceptuo-motor skills assessment were significant predictors for future competition results (R2 = 51%). Since the test age influences the perceptuo-motor skills assessment's outcome, another multivariable model was proposed including test age as a covariate (R2 = 53%). This evaluation demonstrates promising prospects for the perceptuo-motor skills assessment to be included in a talent

  13. Effects of Tennis Training on Personality Development in Children and Early Adolescents

    ERIC Educational Resources Information Center

    Demir, Erdal; Sahin, Gülsah; Sentürk, Ugur; Aydin, Halide; Altinkök, Mustafa

    2016-01-01

    The objective of this study was to investigate the effects of a 12-week basic tennis training program on the personality development of early adolescents aged between 9 and 11 years. The research methodology consisted of a single group pre-test/post-test design implemented with a total of eight volunteer children (three boys and five girls). The…

  14. Myokines in Response to a Tournament Season among Young Tennis Players

    PubMed Central

    Witek, K.; Żurek, P.; Jaworska, J.; Lipińska, P.; Dzedzej-Gmiat, A.; Antosiewicz, J.

    2016-01-01

    The study investigated changes in myokines, heat shock proteins, and growth factors in highly ranked, young, male tennis players in response to physical workload during the competitive season and their potential correlations with match scores. Blood collections were carried out at the beginning, the midpoint, and the end of the tournament season. Data analysis revealed a significant increase in interleukin 6 and its inverse correlation with the number of lost games (r = −0.45; 90% CI −0.06 to 0.77). Neither the irisin nor BDNF level changed notably, yet delta changes of irisin across the season significantly correlated with the number of games won. The concentration of HSP27 recorded a small increase (31.2%; 90% CI 10.7 to 55.5, most likely). A negative correlation was noted between IGF-1 and HSP27 concentration at baseline (−0.70 very high; 90% CI −0.89 to −0.31, very likely). At the end of the season IGF-1 correlated positively with the number of games won (r = 0.37 moderate, 90% CI −0.16 to 0.73, likely) but negatively with the number of games lost (r = −0.39, 90% CI −0.14 to −0.74, likely). In conclusion our data indicated that Il-6, irisin, and growth factor IGF-1 may modify overall performance during a long lasting season, expressed in the amount of games won or lost. PMID:27652258

  15. Physical performance changes after unsupervised training during the autumn/spring semester break in competitive tennis players

    PubMed Central

    Kovacs, Mark S; Pritchett, Robert; Wickwire, P Jason; Green, J Matthew; Bishop, Phillip

    2007-01-01

    Background All competitive tennis players take time away from coaches throughout the year; however, little information is available as to the short‐term physiological effect of these breaks. Objective The purpose of this investigation was to evaluate the impact of a 5 week off‐campus structured, yet unsupervised, break from regular training in top collegiate tennis players. Methods A nationally ranked collegiate NCAA Division I male tennis team (n = 8) performed a test battery in December and again in January after a 5 week period of recommended, yet unsupervised, training. The tests performed were 5, 10 and 20 m sprints, spider agility test, medicine ball power throws, standing long jump, Wingate anaerobic power test, VO2max, push‐up and sit‐up test, grip strength and range of motion (ROM) measures (goniometer) of the shoulder, hip, hamstring and quadriceps. Results Paired t tests (p<0.05) showed significant decreases in mean (SEM) Wingate power measurements in Watts/kg (pre: 8.35 (0.19) w/kg ; post: 7.80 (0.24) w/kg ), minimum Wingate power (pre: 5.89 (0.27) w/kg; post: 5.10 (0.38) w/kg) and VO2max values (pre: 53.90 (1.11) ml/kg/min; post: 47.86 (1.54) ml/kg/min). A significant increase was seen in the athlete's fatigue index (pre: 44.26 (2.85)%; post: 51.41 (3.53)%), fastest 5 m (pre: 1.07 (0.03) s; post: 1.12 (0.02) s), 10 m (pre: 1.79 (0.03) s; post: 1.84 (0.04) s) and 20 m (pre: 3.07 (0.05) s; post: 3.13 (0.05) s) sprint times. No significant differences were seen for the other variables tested. Conclusions These results suggest that a 5 week interruption of normal training can result in significant reductions in speed, power and aerobic capacity in competitive tennis players, likely owing to poor compliance with the prescribed training regimen. Therefore, coaches and trainers might benefit from techniques (eg, pre‐ and post‐testing) requiring athletes' to have accountability for unsupervised workouts

  16. Metabolic and cardiorespiratory reactions in tennis-players in laboratory testing and under sport-specific conditions.

    PubMed

    Smekal, G; Baron, R; Pokan, R; Dirninger, K; Bachl, N

    1995-01-01

    Metabolic and cardiorespiratory reactions were investigated during a sport-specific incremental field test (FT) for tennis and compared with a treadmill step test (TT) in a group of 13 trained male tennis players. In both the FT and the TT lactate acid (La), heart rate and oxygen uptake (VO2) were measured. VO2 was determined using a portable telemetric system (K2, Cosmed, Italy). Aerobic- (AT) and anaerobic threshold (ANT) at a blood lactate concentration of 2 mmol/l and at 4 mmol/l respectively was indicated to characterize the endurance capacity of the athletes. In both FT and TT, minimum value of lactate equivalent (LE(min)), measured in every exercise test, was also registered. At AT and ANT values for HR (AT: p < 0.001; ANT: p < 0.001) and VO2 (AT: p < 0.001; ANT: p < 0.001) were significantly higher in FT than in TT at submaximal loads. At LE(min) only higher values for HR (p < 0.05) were registered in FT. In contrast to maximum range significantly higher values for VO2 (p < 0.001) could be seen in TT (there were no significant differences for HR). Comparing maximum lactate (La(max)) subjects reached a higher lactate (p < 0.05) in TT. A particular aim of our investigation was to characterize the individual cardiopulmonal and metabolic adaptation of tennis players, considering sport-specific criteria. As a result, differences in cardiorespiratory and metabolic adaptations could be determined between laboratory TT and FT. This finding seems to point to the fact that, using field testing in addition to laboratory exercise testing, makes a better judgement of aerobic and anaerobic endurance under sport-specific conditions possible. Furthermore, it was important for us to put data, determined in the field test into practice, using the given pattern of the field test as an element of training. This kind of training has the advantage of combining an individually intensity-controlled specific endurance training for tennis with a training of technical skills.

  17. Recognition of Tennis Serve Performed by a Digital Player: Comparison among Polygon, Shadow, and Stick-Figure Models

    PubMed Central

    Ida, Hirofumi; Fukuhara, Kazunobu; Ishii, Motonobu

    2012-01-01

    The objective of this study was to assess the cognitive effect of human character models on the observer's ability to extract relevant information from computer graphics animation of tennis serve motions. Three digital human models (polygon, shadow, and stick-figure) were used to display the computationally simulated serve motions, which were perturbed at the racket-arm by modulating the speed (slower or faster) of one of the joint rotations (wrist, elbow, or shoulder). Twenty-one experienced tennis players and 21 novices made discrimination responses about the modulated joint and also specified the perceived swing speeds on a visual analogue scale. The result showed that the discrimination accuracies of the experienced players were both above and below chance level depending on the modulated joint whereas those of the novices mostly remained at chance or guessing levels. As far as the experienced players were concerned, the polygon model decreased the discrimination accuracy as compared with the stick-figure model. This suggests that the complicated pictorial information may have a distracting effect on the recognition of the observed action. On the other hand, the perceived swing speed of the perturbed motion relative to the control was lower for the stick-figure model than for the polygon model regardless of the skill level. This result suggests that the simplified visual information can bias the perception of the motion speed toward slower. It was also shown that the increasing the joint rotation speed increased the perceived swing speed, although the resulting racket velocity had little correlation with this speed sensation. Collectively, observer's recognition of the motion pattern and perception of the motion speed can be affected by the pictorial information of the human model as well as by the perturbation processing applied to the observed motion. PMID:22439009

  18. Recognition of tennis serve performed by a digital player: comparison among polygon, shadow, and stick-figure models.

    PubMed

    Ida, Hirofumi; Fukuhara, Kazunobu; Ishii, Motonobu

    2012-01-01

    The objective of this study was to assess the cognitive effect of human character models on the observer's ability to extract relevant information from computer graphics animation of tennis serve motions. Three digital human models (polygon, shadow, and stick-figure) were used to display the computationally simulated serve motions, which were perturbed at the racket-arm by modulating the speed (slower or faster) of one of the joint rotations (wrist, elbow, or shoulder). Twenty-one experienced tennis players and 21 novices made discrimination responses about the modulated joint and also specified the perceived swing speeds on a visual analogue scale. The result showed that the discrimination accuracies of the experienced players were both above and below chance level depending on the modulated joint whereas those of the novices mostly remained at chance or guessing levels. As far as the experienced players were concerned, the polygon model decreased the discrimination accuracy as compared with the stick-figure model. This suggests that the complicated pictorial information may have a distracting effect on the recognition of the observed action. On the other hand, the perceived swing speed of the perturbed motion relative to the control was lower for the stick-figure model than for the polygon model regardless of the skill level. This result suggests that the simplified visual information can bias the perception of the motion speed toward slower. It was also shown that the increasing the joint rotation speed increased the perceived swing speed, although the resulting racket velocity had little correlation with this speed sensation. Collectively, observer's recognition of the motion pattern and perception of the motion speed can be affected by the pictorial information of the human model as well as by the perturbation processing applied to the observed motion.

  19. Examination of Anxiety Levels and Anger Expression Manners of Undergraduate Table Tennis Players

    ERIC Educational Resources Information Center

    Karademir, Tamer; Türkçapar, Ünal

    2016-01-01

    This research was done for the determination of how their anxiety levels' and anger expressions' get shaped according to some variances. For this reason there were 76 female 125 male totally 201 sportsmen, who participated to the table tennis championship between universities in 2016 and ages differ from 18 to 28, were included the research group.…

  20. Investigating Aerobic, Anaerobic Combine Technical Trainings' Effects on Performance in Tennis Players

    ERIC Educational Resources Information Center

    Suna, Gürhan; Kumartasli, Mehmet

    2017-01-01

    The aim of this study is to investigate eight-week aerobic, anaerobic combine technical trainings' effects on developments of performance. 21 athletes of tennis proficiency students from Sports Sciences Department were joined to the study voluntarily. Participated in the research athletes' ages' mean was 22,2 ± 0,3 year, lengths' mean was 177,3 ±…

  1. Changes of standard physiological-perceptual markers and circulating MicroRNAs in response to tennis match-play: A case report of two elite players

    PubMed Central

    Baumgart, Christian; Hilberg, Thomas; Freiwald, Jürgen; Wehmeier, Udo Frank

    2016-01-01

    Abstract This study aimed to describe the acute changes of both standard physiological-perceptual markers and circulating microRNAs in response to tennis match-play in a detailed case report. Two elite male baseliners with comparable tennis experience were tested for anthropometric and fitness related variables and played 2 h of match-play on a red-clay court. The changes of standard physiological-perceptual markers including the heart rate, lactate concertation, creatine kinase activity, urea concentration and rating of perceived exertion as well as circulating microRNA-133a, -486 and -126 expression rates were examined at 10 different time-points (i.e., pre, during and up to 24 h post match-play). Player 2 had lower fitness related variables, but a higher heart rate, lactate concentration, creatine kinase activity and rating of perceived exertion during play than player 1. Player 2 showed an increase in all microRNAs (≤3.83-fold), most evident post match-play, whereas player 1 demonstrated a decrease (≤0.41-fold). The time-course in the changes of all standard physiological-perceptual markers was similar in both players, whereas this of the microRNAs was different. It was concluded that the relative changes of the circulating microRNA-133a, -486 and 126 expression rates of both players differed in response to tennis match-play with respect to the experienced physiological-perceptual stress and the underlying fitness level. Therefore, circulating microRNAs can serve as additional biomarkers for tennis exercise physiology and may be assessed together with standard markers to conclude whether key cellular regulatory processes were induced in response to match-play. PMID:28149370

  2. Changes of standard physiological-perceptual markers and circulating MicroRNAs in response to tennis match-play: A case report of two elite players.

    PubMed

    Hoppe, Matthias Wilhelm; Baumgart, Christian; Hilberg, Thomas; Freiwald, Jürgen; Wehmeier, Udo Frank

    2016-06-01

    This study aimed to describe the acute changes of both standard physiological-perceptual markers and circulating microRNAs in response to tennis match-play in a detailed case report. Two elite male baseliners with comparable tennis experience were tested for anthropometric and fitness related variables and played 2 h of match-play on a red-clay court. The changes of standard physiological-perceptual markers including the heart rate, lactate concertation, creatine kinase activity, urea concentration and rating of perceived exertion as well as circulating microRNA-133a, -486 and -126 expression rates were examined at 10 different time-points (i.e., pre, during and up to 24 h post match-play). Player 2 had lower fitness related variables, but a higher heart rate, lactate concentration, creatine kinase activity and rating of perceived exertion during play than player 1. Player 2 showed an increase in all microRNAs (≤3.83-fold), most evident post match-play, whereas player 1 demonstrated a decrease (≤0.41-fold). The time-course in the changes of all standard physiological-perceptual markers was similar in both players, whereas this of the microRNAs was different. It was concluded that the relative changes of the circulating microRNA-133a, -486 and 126 expression rates of both players differed in response to tennis match-play with respect to the experienced physiological-perceptual stress and the underlying fitness level. Therefore, circulating microRNAs can serve as additional biomarkers for tennis exercise physiology and may be assessed together with standard markers to conclude whether key cellular regulatory processes were induced in response to match-play.

  3. Tennis, Anyone?

    ERIC Educational Resources Information Center

    Hodgson, Ted R.; Burke, Maurice J.

    2005-01-01

    This article describes the variety of strategies that can be used to determine the probability that a player wins a tennis game, given a probability of 60 percent that he or she wins each point. The article suggests strategies for using the problem in 9-12 classrooms.

  4. Comparison of Ball-And-Racket Impact Force in Two-Handed Backhand Stroke Stances for Different-Skill-Level Tennis Players

    PubMed Central

    Lo, Kuo-Cheng; Hsieh, Yung-Chun

    2016-01-01

    This study compared the kinetic roles of the upper extremities in racket impact force generation between the open stance (OS) and square stance (SS) for tennis players with different skill levels in two-handed backhand strokes. Twelve male tennis players were divided into an advanced group (AG) (L3-L2 skill level) and intermediate group (IG) (L7-L6 skill level), and their data were used in a three-dimensional kinetic analysis. Their motions were captured using 21 reflective markers attached to anatomic landmarks for two-handed backhand stroke motion data collection. During the acceleration phase, significant differences were not observed between both stances, but they were observed between the groups with different skill levels for the force of the upper extremities (p = 0.027). The joint forces were significantly lower in the AG than in the IG. Players performing the SS had significantly larger pronation and supination of the wrist joint moment than those in the OS (p = 0.032) during the acceleration phase, irrespective of the playing level. Higher internal rotation moment after impact was observed at each joint, particularly among young intermediate tennis players, regardless of their stance. The AG demonstrated a higher joint force and moment at every joint compared with the IG at impact. Moreover, the AG demonstrated superior stroke efficiency and effectively reduced joint moment after impact and sports injury. Key points Advanced players, regardless of open stance or square stance, have larger joint force and moment at each joint before ball impact resulting in better stroke efficiency and reduced chance of injury. Intermediate players, regardless of stance, have higher internal rotation moment at each joint instead of larger joint force as compared to advanced players before ball impact. The higher internal rotation moment will induce higher joint impact force which makes the player injury-prone. Young intermediate tennis players may want to avoid excessive

  5. Can Perceptuo-Motor Skills Assessment Outcomes in Young Table Tennis Players (7–11 years) Predict Future Competition Participation and Performance? An Observational Prospective Study

    PubMed Central

    2016-01-01

    Forecasting future performance in youth table tennis players based on current performance is complex due to, among other things, differences between youth players in growth, development, maturity, context and table tennis experience. Talent development programmes might benefit from an assessment of underlying perceptuo-motor skills for table tennis, which is hypothesized to determine the players’ potential concerning the perceptuo-motor domain. The Dutch perceptuo-motor skills assessment intends to measure the perceptuo-motor potential for table tennis in youth players by assessing the underlying skills crucial for developing technical and tactical qualities. Untrained perceptuo-motor tasks are used as these are suggested to represent a player’s future potential better than specific sport skills themselves as the latter depend on exposure to the sport itself. This study evaluated the value of the perceptuo-motor skills assessment for a talent developmental programme by evaluating its predictive validity for competition participation and performance in 48 young table tennis players (7–11 years). Players were tested on their perceptuo-motor skills once during a regional talent day, and the subsequent competition results were recorded half-yearly over a period of 2.5 years. Logistic regression analysis showed that test scores did not predict future competition participation (p >0.05). Yet, the Generalized Estimating Equations analysis, including the test items ‘aiming at target’, ‘throwing a ball’, and ‘eye-hand coordination’ in the best fitting model, revealed that the outcomes of the perceptuo-motor skills assessment were significant predictors for future competition results (R2 = 51%). Since the test age influences the perceptuo-motor skills assessment’s outcome, another multivariable model was proposed including test age as a covariate (R2 = 53%). This evaluation demonstrates promising prospects for the perceptuo-motor skills assessment to be

  6. Adolescents Risky MP3-Player Listening and Its Psychosocial Correlates

    ERIC Educational Resources Information Center

    Vogel, Ineke; Brug, Johannes; Van Der Ploeg, Catharina P. B.; Raat, Hein

    2011-01-01

    Analogue to occupational noise-induced hearing loss, MP3-induced hearing loss may be evolving into a significant social and public health problem. To inform prevention strategies and interventions, this study investigated correlates of adolescents' risky MP3-player listening behavior primarily informed by protection motivation theory. We invited…

  7. Adolescents risky MP3-player listening and its psychosocial correlates.

    PubMed

    Vogel, Ineke; Brug, Johannes; Van der Ploeg, Catharina P B; Raat, Hein

    2011-04-01

    Analogue to occupational noise-induced hearing loss, MP3-induced hearing loss may be evolving into a significant social and public health problem. To inform prevention strategies and interventions, this study investigated correlates of adolescents' risky MP3-player listening behavior primarily informed by protection motivation theory. We invited 1687 adolescents (12- to 19-year old) of Dutch secondary schools to complete questionnaires about their MP3-player listening, sociodemographic characteristics and presumed psychosocial determinants of MP3-player listening. Of all participants, 90% reported listening to music through earphones on MP3 players; 28.6% were categorized as listeners at risk for hearing loss due to estimated exposure of 89 dBA for ≥1 hour per day. Compared with listeners not at risk for hearing loss, listeners at risk were more likely not to live with both parents, to experience rewards of listening to high-volume levels, to report a high habit strength related to risky MP3 listening, and were less likely to be motivated to protect their hearing. Habit strength was the strongest correlate of risky listening behavior, suggesting that voluntary behavior change among adolescents might be difficult to achieve and that a multiple strategy approach may be needed to prevent MP3-induced hearing loss.

  8. Applied physiology of tennis.

    PubMed

    Groppel, J L; Roetert, E P

    1992-10-01

    Studies in anthropometry showed that more research is needed in the area of physical development and its relationship to playing tennis. Muscle activity patterns have been studied for the different strokes, although more data are available relative to the service. During the service, skilled tennis players were found to display more consistent muscular activity with shorter periods of activation, implying a higher level of coordination than less skilled players. In profiling players, positive correlations were found between tournament play and a number of fitness parameters. More research is needed to develop assessment measures that are tennis specific. Also, longitudinal studies will provide greater insight into player profiles. The general consensus on fitness development was that tennis players should incorporate flexibility, strength and endurance training in their programmes to minimise asymmetry and injuries, while simultaneously enhancing performance. Tennis was found to have both aerobic and anaerobic components, with the predominant energy supply coming from phosphagen energy system. These findings suggest training programmes should be designed specific to the actual energy and muscular demands of the game. The need for further research in all areas certainly still exists in order to gain a better understanding of the game.

  9. Tennis Elbow

    PubMed Central

    Bullard, J. A. A.

    1982-01-01

    Certain types of activity, particularly the wielding of a tennis racquet, put undue stress on the muscles of the forearm. The result can be extremely incapacitating as well as resistant to treatment. The earlier specific measures are introduced, the greater the success of conservative treatment. To provide this approach the physician must be aware of the multiple factors involved in the game. The backhand stroke appears to cause more problems than the forehand. Inexperienced players use the power of their elbows far more than the power of their whole bodies. Changes of technique or equipment may therefore be necessary. PMID:21286104

  10. Iliopsoas haematoma in an adolescent Taekwondo player.

    PubMed

    Maffulli, N; So, W S; Ahuja, A; Chan, K M

    1996-01-01

    A 16-year-old male Taekwondo player was admitted with a 1-day history of right groin pain and a palpable mass in the right lower abdominal quadrant following a Taekwondo training session. No history of direct trauma was given, but the pain followed a high inward-to-outward kick. The patient was not on any medication, and tumour and infection were excluded. A high-resolution real-time ultrasound scan identified a well-defined, hyperechoic, heterogeneous mass in the substance of the right iliopsoas muscle, compatible with a collection of partially clotted blood, confirming the clinical diagnosis of iliopsoas haematoma. After conservative treatment the patient resumed training and is now fully asymptomatic.

  11. Qualitative Biomechanics and the Tennis Ground Strokes. Revised

    ERIC Educational Resources Information Center

    Errington, Joseph

    This tennis stroke analysis, based on the application of biomechanic principles, is designed to help those who play tennis only once or twice a week. It is noted that, because the tennis player has a limited power potential, the only way to increase his racket head speed is to rotate his body. The mechanics of tennis are discussed by dividing it…

  12. Biomechanics and tennis

    PubMed Central

    Elliott, B

    2006-01-01

    Success in tennis requires a mix of player talent, good coaching, appropriate equipment, and an understanding of those aspects of sport science pertinent to the game. This paper outlines the role that biomechanics plays in player development from sport science and sport medicine perspectives. Biomechanics is a key area in player development because all strokes have a fundamental mechanical structure and sports injuries primarily have a mechanical cause. PMID:16632567

  13. The transfer of skill from short tennis to lawn tennis.

    PubMed

    Coldwells, A; Hare, M E

    1994-01-01

    The purpose of this study was to establish if short tennis skills transferred to lawn tennis. The experiment was conducted in two parts. In the first experiment 16 children (average age 8.9 years) were coached for 20 h (2 h/day for 2 weeks). The experimental group (n = 8) received 10 h of short tennis coaching followed by 10h of tennis coaching. The control group (n = 8) received tennis coaching only. In the second experiment 14 children (average age 8.5 years) were coached for 8h in group strokes alone (only ground strokes were tested and analysed). The experimental group (n = 7) received 4h of short tennis coaching and 4h of tennis coaching; the control group (n = 7) received tennis coaching only. Prior to coaching, all children were tested on the Dyer Backboard Test. The tests were video-taped for later analysis of technique. The video was analysed by three coaches in terms of backswing, positioning (position where player stood in reference to the bounce of the ball), follow-through, and placement (accuracy with which the ball was hit). The experimental group improved more than the control group on the Dyer Backboard Test (p < 0.05) in Experiment 1. In Experiment 2 both groups improved (p < 0.05) with coaching; there was no difference (p > 0.05) between the two groups following coaching. This implied that the short tennis skills positively transferred to tennis.(ABSTRACT TRUNCATED AT 250 WORDS)

  14. [Injuries in male and female adolescent soccer players].

    PubMed

    Schneider, A S; Mayer, H M; Geißler, U; Rumpf, M C; Schneider, C

    2013-03-01

    This study addresses the epidemiology of injuries in adolescent male and female soccer players in Germany. Therefore, the purpose of the study was to analyse the injuries in male and female youth soccer players in Germany. This study was designed as a cross-sectional web-based survey. From March until December 2011 we investigated 1110 soccer players (male n = 841; female n = 269) aged 12 - 19 years (15.0 ± 2.0 years) from 60 clubs in Southern Germany. A total of 664 (79 %) of the 841 boys and 67 (25 %) of the 269 girls reported being injured due to soccer. The total number of injuries was 2373. Respectively the frequency of injury was 2.85 in boys and 7.10 in girls. The lower extremities were affected in 70 % of all reported cases. Strains were the most common injuries in the lower and upper extremities (35 %). The boys reported in 51.5 % of all injuries that the injury was non-contact in nature. In contrast, 52.1 % of the injuries in girls were reported as contact injuries. Similar amounts of injuries were observed in training versus games for both genders. Prevention procedures, such as a thorough warm-up, should be implemented before every game and training to reduce the risk of injury.

  15. Intensity of tennis match play

    PubMed Central

    Fernandez, J; Mendez‐Villanueva, A; Pluim, B M

    2006-01-01

    This review focuses on the characteristics of tennis players during match play and provides a greater insight into the energy demands of tennis. A tennis match often lasts longer than an hour and in some cases more than five hours. During a match there is a combination of periods of maximal or near maximal work and longer periods of moderate and low intensity activity. Match intensity varies considerably depending on the players' level, style, and sex. It is also influenced by factors such as court surface and ball type. This has important implications for the training of tennis players, which should resemble match intensity and include interval training with appropriate work to rest ratios. PMID:16632566

  16. Left atrial remodelling in competitive adolescent soccer players.

    PubMed

    D'Ascenzi, F; Cameli, M; Lisi, M; Zacà, V; Natali, B; Malandrino, A; Benincasa, S; Catanese, S; Causarano, A; Mondillo, S

    2012-10-01

    Left atrial (LA) enlargement and improved myocardial diastolic properties are a component of athlete's heart. We performed a longitudinal study involving adolescent athletes to investigate the impact of training on LA remodelling and diastolic function. 21 competitive adolescent soccer players were enrolled and engaged in an 8-month training program. Echocardiographic analysis was performed at baseline, after 4 and 8 months. We assessed diastolic function by Doppler tissue imaging and we analyzed LA adaptations by 2D speckle-tracking echocardiography. After 4 months, LA mean volume index significantly increased (Δ=5.47 ± 4.38 mL/m2, p ≤ 0.0001). After 8 months, a further increase occurred (Δ=8.95 ± 4.47 mL/m2, p ≤ 0.0001). A higher E velocity (p=0.001; p=0.001), a greater E/A ratio (p=0.002; p=0.0009), a higher e' peak (p= 0.005; p=0.001), and a greater e'/a' ratio (p=0.01; p=0.0006) were observed at 4 and at 8 months, respectively. E/e' ratio significantly decreased after 8 months (p ≤ 0.005). Global peak atrial longitudinal strain and global peak atrial contraction strain values significantly decreased after 8 months (p=0.0004, p=0.01, respectively). An 8-month training program is associated with LA dimensional and functional training-specific adaptations in competitive adolescent soccer players. Myocardial diastolic properties can improve after training also in subjects already presenting with features of athlete's heart.

  17. Signs and symptoms of temporomandibular disorders in adolescent violin players.

    PubMed

    Kovero, O; Könönen, M

    1996-08-01

    Signs and symptoms of temporomandibular disorders (TMDs) and the frequency of radiologically observed abnormalities in the condyles of temporomandibular joints (TMJs) of adolescent violin players (VP group) were investigated in a group of 31 music students and in their age- and sex-matched controls (C group). All subjects underwent a routine clinical stomatognathic examination, a standardized interview, and radiography of the condyles. The VP group reported a higher frequency of the subjective symptoms: pain in the TMJ when chewing, a feeling of stiffness in the TMJ, and clenching of the teeth. Clinically, the VP group showed a greater range of maximal protrusion and of maximal laterotrusion to the right, and a greater frequency of deviation to the right on opening. They also showed more palpatory tenderness in the masticatory muscles and pain in the TMJ on maximal opening. The number of playing years and the number of weekly playing hours correlated with several signs and symptoms of TMDs. In terms of radiologic findings in the condyles of the TMJs there was no difference between the groups. It is concluded that intense violin playing may have a predisposing role in the etiology of TMDs in adolescence.

  18. Tennis Elbow

    MedlinePlus

    Tennis elbow Overview By Mayo Clinic Staff Tennis elbow (lateral epicondylitis) is a painful condition that occurs when tendons in your elbow are overloaded, usually by repetitive motions of the wrist and ...

  19. A reciprocal effects model of the temporal ordering of motivation and burnout among youth table tennis players in intensive training settings.

    PubMed

    Martinent, Guillaume; Decret, Jean-Claude; Guillet-Descas, Emma; Isoard-Gautheur, Sandrine

    2014-01-01

    Using self-determination theory (SDT) (Deci, E.L., & Ryan, R.M. (1985). Intrinsic motivation and self-determination in human behavior. New York, NY: Plenum) as the theoretical framework, we conducted a longitudinal investigation of the temporal ordering between motivation and burnout among youth athletes in intensive training setting. Data were collected from 145 table tennis players in intensive training centres at three time points during a 2-month period characterised by a simultaneous increase in social, physical and psychological demands for these athletes. Structural equation modelling of cross-lagged panel models was used to test the hypotheses. Results showed significant paths leading from athlete burnout - especially sport devaluation and reduced sense of accomplishment - at time 1 to amotivation, intrinsic and extrinsic motivations at times 2 and 3. Only two significant paths leading from motivation (introjected regulation at time 1) to burnout (emotional/physical exhaustion at time 2 and reduced sense of accomplishment at time 3) were identified. Overall, our results suggest that athlete burnout predicts motivation over time but motivation did not predict athlete burnout over time. Results are discussed in terms of current research findings on SDT.

  20. Effects of repetitive loading on the growth-induced changes in bone mass and cortical bone geometry: a 12-month study in pre/peri- and postmenarcheal tennis players.

    PubMed

    Ducher, Gaele; Bass, Shona L; Saxon, Leanne; Daly, Robin M

    2011-06-01

    Pre- and early puberty may be the most opportune time to strengthen the female skeleton, but there are few longitudinal data to support this claim. Competitive female premenarcheal (pre/peri, n = 13) and postmenarcheal (post, n = 32) tennis players aged 10 to 17 years were followed over 12 months. The osteogenic response to loading was studied by comparing the playing and nonplaying humeri for dual-energy X-ray absorptiometry (DXA) bone mineral content (BMC) and magnetic resonance imaging (MRI) total bone area (ToA), medullary area (MedA), cortical area (CoA), and muscle area (MCSA) at the humerus. Over 12 months, growth-induced gains (nonplaying arm) in BMC, ToA, and CoA were greater in pre/peri (10% to 19%, p < .001) than in post (3% to 5%, p < .05 to .001) players. At baseline, BMC, ToA, CoA, and MCSA were 8% to 18% greater in the playing versus nonplaying arms in pre/peri and post players (all p < .001); MedA was smaller in the playing versus nonplaying arms in post only players (p < .05). When comparing the annual gains in the playing arm relative to changes in the nonplaying arm, the increases in ToA and CoA were greater in pre/peri than post players (all p < .05). The smaller the side-to-side differences in BMC and CoA at baseline, the larger the exercise benefits at 12 months (r = -0.39 to -0.48, p < .01). The exercise-induced change in MCSA was predictive of the exercise benefits in BMC in pre/peri players only (p < .05). In conclusion, both pre/peri- and postmenarcheal tennis players showed significant exercise-induced skeletal benefits within a year, with greater benefits in cortical bone geometry in pre/perimenarcheal girls.

  1. Intrateam Communication and Performance in Doubles Tennis

    ERIC Educational Resources Information Center

    Lausic, Domagoj; Tennebaum, Gershon; Eccles, David; Jeong, Allan; Johnson, Tristan

    2009-01-01

    Verbal and nonverbal communication is a critical mediator of performance in team sports and yet there is little extant research in sports that involves direct measures of communication. Our study explored communication within NCAA Division I female tennis doubles teams. Video and audio recordings of players during doubles tennis matches captured…

  2. Kinematic differences of elite and high-performance tennis players in the cross court and down the line forehand.

    PubMed

    Landlinger, Johannes; Lindinger, Stefan Josef; Stöggl, Thomas; Wagner, Herbert; Müller, Erich

    2010-11-01

    This study identified and compared the full body kinematics of different skill levels in the forehand groundstroke when balls were hit cross court and down the line. Forty-three three-dimensional retroreflective marker trajectories of six elite and seven high-performance players were recorded using an eight-camera 400 Hz, Vicon motion analysis system. The six highest horizontal velocity forehands with reliable kinematics of all participants were analysed for each specific situation (a total of 156 analysed shots). Significant differences (p < 0.01) and large effect sizes were observed between elite and high-performance players in linear velocity of the shoulder (2.0 vs. 1.2 m/s), angular velocity of the pelvis (295 vs. 168 degrees/s), and angular velocity of the upper trunk (453 vs. 292 degrees/s) at impact. The elite group showed a tendency towards higher racquet velocities at impact (p < 0.05). No significant differences were found in angular displacement of the racquet, hip alignment, or shoulder alignment at the completion of the backswing; nor did angular displacement vary significantly at impact. Irrespective of the group, different shoulder, hip, and racquet angles were found at impact, depending on the situation. The results should assist coaches when striving to improve their players' forehand.

  3. Bone properties in child and adolescent male hockey and soccer players.

    PubMed

    Falk, Bareket; Braid, Sarah; Moore, Michael; Yao, Matthew; Sullivan, Phil; Klentrou, Nota

    2010-07-01

    Children and adolescents who train extensively in high-impact, weight-bearing activities have enhanced bone mineral density. The purpose of this study was to evaluate bone strength, as reflected by quantitative ultrasound (QUS, Sunlight Omniscence), of child (10-12 yrs old) and adolescent (14-16 yrs old) male soccer and hockey players in comparison with age-matched controls. The groups included 30 child (CH) and 31 adolescent (AH) hockey players, 26 child (CS) and 30 adolescent (AS) soccer players, as well as 34 child (CC) and 31 adolescent (AC) healthy, non-athletic, age-matched controls. All athletes trained at an elite level year-round, with no difference in training volume between groups. Ultrasound speed of sound (SOS) was measured at the distal-radius and mid-tibia. In both age groups, hockey players were the heaviest and had the highest fat-free mass. No differences were found among groups in total energy intake, calcium or vitamin D intake. Radial and tibial SOS increased with age. Hockey players had higher radial SOS in both age groups (children: CH:3763+/-74, CS:3736+/-77, CC:3721+/-88 m/s; adolescents: AH:3809+/-105, AS:3767+/-85, AC:3760+/-94 m/s). Tibial SOS was higher in soccer players compared with controls. In spite of the higher body mass and fat-free mass in hockey players, their tibial SOS was similar to the non-athletes in both age groups. These findings support previous suggestions of sport-specific effects on bone strength. However, they need to be corroborated with longitudinal or prospective intervention studies.

  4. Tournament structure and nations' success in women's professional tennis.

    PubMed

    Reid, Machar; Crespo, Miguel; Atienza, Francisco; Dimmock, James

    2007-09-01

    The relationship between domestic professional tournament structure in women's tennis and the subsequent professional ranking success of a nation's female players is examined. The 2003 women's professional tennis tournament calendar provided the distribution of events in 33 countries. Criteria used to classify nations' success in women's professional tennis were as follows: number of players with Women's Tennis Association (WTA) points, number of players with Top 200 rankings, and the combined WTA ranking of a nation's Top 5 female players. Pearson product - moment correlations were performed between the number of tournaments and the three criteria. Considerable variation was observed in the number of events organized between nations (USA, n = 56; Thailand, n = 3). All countries had internationally ranked female players, and 24 nations had players ranked in the Top 200. Results revealed relationships between a nation's number of women's professional events and both that nation's number of professionally ranked players (r = 0.60; P < 0.01) and Top 200 players (r = 0.60; P < 0.01), as well as the combined ranking of their Top 5 players (r = -0.52; P < 0.01). While a similar association was found between the number of professional events and players ranked in the men's game, there was no significant correlation between events held and the combined standing of nations' best five ranked players. Governing bodies and national associations in tennis should consider the provision of professional, domestic competition as key to the development of female tennis players.

  5. Modern tennis rackets, balls, and surfaces

    PubMed Central

    Miller, S

    2006-01-01

    Modern rackets have facilitated a change in playing style from one of technique to one characterised by power and spin. The combination of the increased stiffness of modern rackets and the tendency for tennis balls to have become harder has led to an increased shock transmission from the racket to the player, which is probably a major contributor to tennis elbow. The paucity of tennis specific research on shoes and surfaces makes it difficult to link their characteristics with lower limb injury, although, as their interaction directly affects the magnitude of the forces to which the player is exposed, such a link seems reasonable. PMID:16632569

  6. Modern tennis rackets, balls, and surfaces.

    PubMed

    Miller, S

    2006-05-01

    Modern rackets have facilitated a change in playing style from one of technique to one characterised by power and spin. The combination of the increased stiffness of modern rackets and the tendency for tennis balls to have become harder has led to an increased shock transmission from the racket to the player, which is probably a major contributor to tennis elbow. The paucity of tennis specific research on shoes and surfaces makes it difficult to link their characteristics with lower limb injury, although, as their interaction directly affects the magnitude of the forces to which the player is exposed, such a link seems reasonable.

  7. Nutrition for Tennis: Practical Recommendations

    PubMed Central

    Ranchordas, Mayur K.; Rogersion, David; Ruddock, Alan; Killer, Sophie C.; Winter, Edward M.

    2013-01-01

    Tennis is a pan-global sport that is played year-round in both hemispheres. This places notable demands on the physical and psychological preparation of players and included in these demands are nutritional and fluid requirements both of training and match- play. Thus, the purpose of this article is to review nutritional recommendations for tennis. Notably, tennis players do not excel in any particular physiological or anthropometric characteristic but are well adapted in all areas which is probably a result of the varied nature of the training demands of tennis match play. Energy expenditures of 30.9 ± 5.5 and 45.3 ± 7.3 kJ·min-1 have been reported in women and men players respectively regardless of court surface. Tennis players should follow a habitually high carbohydrate diet of between 6-10 g·kg-1·d-1 to ensure adequate glycogen stores, with women generally requiring slightly less than men. Protein intake guidelines for tennis players training at a high intensity and duration on a daily basis should be ~1.6 g·kg-1·d-1 and dietary fat intake should not exceed 2 g·kg-1·d-1. Caffeine in doses of 3 mg·kg-1 provides ergogenic benefit when taken before and/or during tennis match play. Depending on environmental conditions, sweat rates of 0.5 to and over 5 L·hr-1 and sodium losses of 0.5 - 1.8 g have been recorded in men and women players. 200 mL of fluid containing electrolytes should be consumed every change-over in mild to moderate temperatures of < 27°C but in temperatures greater than 27°C players should aim for ≤ 400 mL. 30-60 g·hr-1 of carbohydrate should be ingested when match play exceeds 2 hours. Key Points Tennis players should follow a habitually high carbohydrate diet of between 6-10 g·kg-1 to ensure adequate glycogen stores, with women generally requiring slightly less than men. Protein intake guidelines for tennis players training at a high intensity and duration on a daily basis should be ~1.6 g·kg-1·d-1. Dietary fat intake should

  8. Aerobic Tennis.

    ERIC Educational Resources Information Center

    Stewart, Michael J.; Ahlschwede, Robert

    1989-01-01

    Increasing the aerobic nature of tennis drills in the physical education class may be necessary if tennis is to remain a part of the public school curriculum. This article gives two examples of drills that can be modified by teachers to increase activity level. (IAH)

  9. Motion analyses of adolescent rugby union players: a comparison of training and game demands.

    PubMed

    Hartwig, Timothy B; Naughton, Geraldine; Searl, John

    2011-04-01

    This research described the physiological demands of participation in adolescent rugby union including positional differences and the degree to which training practices replicate game demands. Between 2003 and 2008, 118 male adolescent rugby players aged 14 to 18 years were recruited from 10 teams representing 3 levels of adolescent rugby. Time-motion analyses using global positioning satellite tracking devices (SPI10; GPSports Systems Pty Ltd 2003) and computer-based tracking software (Trak Performance; Sports Tec Pty Ltd) applied to video footage determined player movement patterns 161 times during rugby training sessions and 53 times during rugby games. Compared with rugby training, rugby games were consistently characterized by more time spent jogging (14 vs. 8%), striding (3.2 vs. 1.3%), and sprinting (1.3 vs. 0.1%) (p < 0.001). Players also covered greater distances (4000 ± 500 vs. 2710 ± 770 m) and performed more sprints (21.8 vs. 1) during games compared with training (p < 0.001). The average sprint duration of 2 seconds was similar in games and training; however, the frequency of sprint efforts in training sessions was low (1 per hour). A major finding of this study is the disparity between physical game demands and on-field rugby training practices in adolescent players determined using time-motion analyses. Sprint pattern differences between games and training in particular could have important implications for player performance during competition. Results of this study should assist in the development of game-specific training sessions and drills that provide the kinds of physically demanding experiences observed in games. Additionally, coaches could assist in the management of adolescent players' participation loads by increasing the intensity and specificity and decreasing the volume of training.

  10. Reliability and Usefulness of Linear Sprint Testing in Adolescent Rugby Union and League Players.

    PubMed

    Darrall-Jones, Joshua D; Jones, Ben; Roe, Gregory; Till, Kevin

    2016-05-01

    The purpose of this study was to evaluate (a) whether there were differences in sprint times at 5, 10, 20, 30, and 40 m between rugby union and rugby league players, (b) determine the reliability and usefulness of linear sprint testing in adolescent rugby players. Data were collected on 28 rugby union and league academy players over 2 testing sessions, with 3-day rest between sessions. Rugby league players were faster at 5 m than rugby union players, with further difference unclear. Sprint time at 10, 20, 30, and 40 m was all reliable (coefficient of variation [CV] = 3.1, 1.8, 2.0, and 1.3%) but greater than the smallest worthwhile change (SWC [0.2 × between-subject SD]), rating the test as marginal for usefulness. Although the test was incapable of detecting the SWC, we recommend that practitioners and researchers use Hopkins' proposed method; whereby plotting the change score of the individual at each split (±typical error [TE] expressed as a CV) against the SWC and visually inspecting whether the TE crosses into the SWC are capable of identifying whether a change is both real (greater than the noise of the test, i.e., >TE) and of practical significance (>SWC). Researchers and practitioners can use the TE and SWC from this study to assess changes in performance of adolescent rugby players when using single beam timing gates.

  11. Trajectories of Affective States in Adolescent Hockey Players: Turning Point and Motivational Antecedents

    ERIC Educational Resources Information Center

    Gaudreau, Patrick; Amiot, Catherine E.; Vallerand, Robert J.

    2009-01-01

    This study examined longitudinal trajectories of positive and negative affective states with a sample of 265 adolescent elite hockey players followed across 3 measurement points during the 1st 11 weeks of a season. Latent class growth modeling, incorporating a time-varying covariate and a series of predictors assessed at the onset of the season,…

  12. Adolescent Identities and Sexual Behavior: An Examination of Anderson's Player Hypothesis

    ERIC Educational Resources Information Center

    Giordano, Peggy C.; Longmore, Monica A.; Manning, Wendy D.; Northcutt, Miriam J.

    2009-01-01

    We investigate the social and behavioral characteristics of male adolescents who self-identify as players, focusing particularly on Anderson's claim that this social role is inextricably linked with poverty and minority status. Results indicate that black respondents, those affiliated with liberal peers and young men who initially report a…

  13. Comparison of posture among adolescent male volleyball players and non-athletes

    PubMed Central

    2014-01-01

    Due to high training loads and frequently repeated unilateral exercises, several types of sports training can have an impact on the process of posture development in young athletes. The objective of the study was to assess and compare the postures of adolescent male volleyball players and their non-training peers. The study group comprised 104 volleyball players while the control group consisted of 114 non-training individuals aged 14-16 years. Body posture was assessed by the Moiré method. The volleyball players were significantly taller, and had greater body weight and fat-free mass. The analysis of posture relative to symmetry in the frontal and transverse planes did not show any significant differences between the volleyball players and non-athletes. Postural asymmetries were observed in both the volleyball players and the control participants. Lumbar lordosis was significantly less defined in the volleyball players compared to non-training individuals while no difference was observed in thoracic kyphosis. All athletes demonstrated a loss of lumbar lordosis and an increase in thoracic kyphosis. Significant differences in anteroposterior curvature of the spine between the volleyball players and the non-athletes might be associated with both training and body height. Considering the asymmetric spine overloads which frequently occur in sports training, meticulous posture assessment in young athletes seems well justified. PMID:25729154

  14. Performance enhancement among adolescent players after 10 weeks of pitching training with appropriate baseball weights.

    PubMed

    Yang, Wen-Wen; Liu, Ya-Chen; Lu, Lee-Chang; Chang, Hsiao-Yun; Chou, Paul Pei-Hsi; Liu, Chiang

    2013-12-01

    Compared with regulation-weight baseballs, lightweight baseballs generate lower torque on the shoulder and elbow joints without altering the pitching movement and timing. This study investigates the throwing accuracy, throwing velocity, arm swing velocity, and maximum shoulder external rotation (MSER) of adolescent players after 10 weeks of pitching training with appropriate lightweight baseballs. We assigned 24 adolescent players to a lightweight baseball group (group L) and a regulation-weight baseball group (group R) based on their pretraining throwing velocity. Both groups received pitching training 3 times per week for 10 weeks with 4.4- and 5-oz baseballs. The players' throwing accuracy, throwing velocity, arm swing velocity, and MSER were measured from 10 maximum efforts throws using a regulation-weight baseball before and after undergoing the pitching training. The results showed that the players in group L significantly increased their throwing velocity and arm swing velocity (p < 0.05) after 10 weeks of pitching training with the 4.4-oz baseball, whereas group R did not (p > 0.05). Furthermore, the percentage change in the throwing velocity and arm swing velocity of group L was significantly superior to that of group R (p < 0.05). Thus, we concluded that the 10 weeks of pitching training with an appropriate lightweight baseball substantially enhanced the arm swing velocity and throwing velocity of the adolescent baseball players. These findings suggest that using a lightweight baseball, which can reduce the risk of injury without altering pitching patterns, has positive training effects on players in the rapid physical growth and technique development stage.

  15. On the Gender Effects of Handedness in Professional Tennis

    PubMed Central

    Breznik, Kristijan

    2013-01-01

    The aim of this study was to explore the effects of the gender variable in relation to other player and match characteristics on the advantage possessed by left-handed professional tennis players over their right-handed rivals. The data include 16 732 male tennis players and 16 432 female tennis players who played 438 937 and 415 346 matches, respectively, in the period from 1968 to the end of 2011. The results revealed that the advantage of left-handed professional tennis players is higher in males compared to females. The inverse impact of player and match quality on the left- handers’ advantage was clearly confirmed. On the contrary, it seems that the type of court surface does not directly imply this advantage. To obtain an overview on the individual level, directed and weighted networks of tennis matches in both gender categories were constructed. Applying network analytic methods and the PageRank algorithm, the best left and right-handed players in the Open Era of tennis were identified. The top three ranked left-handed players in the male and female categories were found to be far more consistent in their ranks achieved against left and right-handed opponents compared to their right-handed counterparts. Key Points The advantage of left-handed professional tennis players over their right-handed opponents is higher in males compared to females. The quality of player and match is inversely proportional to the advantage of left-handers against their right-handed counterparts. On the contrary, it seems that the type of court surface does not directly imply this advantage. When the tennis talent appears in left-handers it is likely to be an outstanding one, particularly in the female category. PMID:24149815

  16. The effects of rhythm training on tennis performance.

    PubMed

    Söğüt, Mustafa; Kirazci, Sadettin; Korkusuz, Feza

    2012-06-01

    Rhythm training is an integral part of sports. The purposes of the study were to analyze the effects of rhythm training on tennis performance and rhytmic competence of tennis players, to compare the improvement levels of tennis specific and general rhythm training and to examine the effects of shorter and longer tempos on rhythmic competence. Thirty university students whose mean score of International Tennis Number (ITN) was 7.3 (±0.9) were divided randomly into three sub-groups: Tennis Group, General Rhythm Training Group and Tennis-Specific Rhythm Training Group. The experimental procedure lasted 8 weeks. During this period, all groups had the same tennis training twice a week. The Tennis Group had regular tennis training sessions. In addition to regular tennis training sessions, the General Rhythm Training Group followed the general rhythm training sessions and the Tennis-Specific Rhythm Training Group had tennis-specific rhythm training. The measurement instruments were ITN, Rhythmic Competence Analysis Test and Untimed Consecutive Rally Test. The results indicated that participation in tennis-specific or general rhythm training resulted in progress in tennis playing levels, forehand consistency performance and rhythmic competence of the participants. On the other hand, attendance to the regular 8-week tennis training was enough to solely increase the tennis playing level but not sufficient to develop forehand consistency performance and rhythmic competence. Although the participants in the TRTG had better improvement scores than the ones in the GRTG, no significant difference was found between the rhythm training groups. The results also revealed that participants exhibited higher rhythmic competence scores on fast tempo compared to slow tempo.

  17. The Effects of Rhythm Training on Tennis Performance

    PubMed Central

    Söğüt, Mustafa; Kirazci, Sadettin; Korkusuz, Feza

    2012-01-01

    Rhythm training is an integral part of sports. The purposes of the study were to analyze the effects of rhythm training on tennis performance and rhytmic competence of tennis players, to compare the improvement levels of tennis specific and general rhythm training and to examine the effects of shorter and longer tempos on rhythmic competence. Thirty university students whose mean score of International Tennis Number (ITN) was 7.3 (±0.9) were divided randomly into three sub-groups: Tennis Group, General Rhythm Training Group and Tennis-Specific Rhythm Training Group. The experimental procedure lasted 8 weeks. During this period, all groups had the same tennis training twice a week. The Tennis Group had regular tennis training sessions. In addition to regular tennis training sessions, the General Rhythm Training Group followed the general rhythm training sessions and the Tennis-Specific Rhythm Training Group had tennis-specific rhythm training. The measurement instruments were ITN, Rhythmic Competence Analysis Test and Untimed Consecutive Rally Test. The results indicated that participation in tennis-specific or general rhythm training resulted in progress in tennis playing levels, forehand consistency performance and rhythmic competence of the participants. On the other hand, attendance to the regular 8-week tennis training was enough to solely increase the tennis playing level but not sufficient to develop forehand consistency performance and rhythmic competence. Although the participants in the TRTG had better improvement scores than the ones in the GRTG, no significant difference was found between the rhythm training groups. The results also revealed that participants exhibited higher rhythmic competence scores on fast tempo compared to slow tempo. PMID:23486093

  18. Some Remarks on Strategy in Playing Tennis.

    DTIC Science & Technology

    1980-08-01

    ADA096 976 INDIANA UNIV AT BLOOMINGTON DEPT OF MATHEMATICS F/G 12/1 SOME REMARKS ON STRATEGY IN PLAYING TENNIS .(U) AUG 80 R BARTOSZYNSKI. M L PURI...TMIS PA£0 I47.,,- I)a? FIq.P£d) AFOSR-TR. 81-0206 SOME REMARKS ON STRATEGY IN PLAYING TENNIS Robert Bartoszyfiski and Madan L. Puri !j The paper shows...the problem to which degree the scoring system of tennis matches allows the difference in players’ levels to be reflected in the result of the match

  19. Anthropometric profile and body composition of Irish adolescent rugby union players aged 16-18.

    PubMed

    Delahunt, Eamonn; Byrne, Risteard B; Doolin, Rachel K; McInerney, Rory G; Ruddock, Ciaran T J; Green, Brian S

    2013-12-01

    The literature suggests that one of the key determinants of success at rugby union international competitions is the anthropometric profile of players. The Irish Rugby Football Union (IRFU) long-term player development (LTPD) model is a framework designed to guide the development of the tactical, physical, and psychological domains of sporting participation. In Ireland, the Train-to-Train stage of the IRFU model is a critical stage, whereby the next developmental progression would include the transition of players into professional academies. To date, no previously published studies have examined the anthropometric profile of Irish Schools' rugby union players at the Train-to-Train stage of the IRFU model. The anthropometric profile of 136 male adolescent rugby union players at the Train-to-Train stage of the IRFU model was assessed using total-body dual-energy x-ray absorptiometry. Significant differences in height, body mass, body fat percentage, fat mass, lean mass, and fat-free mass were observed between players assigned to the forward and back units, and for specific position categorizations within each unit. Direct logistic regression revealed that body mass was a statistically significant (p < 0.01) predictor of unit position classification, with an odds ratio of 2.35, indicating that the players with a higher body mass were twice as likely to be classified as forwards. The results of this study indicate that at the Train-to-Train stage of the IRFU model, forward and back units have distinctly different anthropometric profiles. Furthermore, anthropometric differentiation also exists within specific position categorizations within each of these playing units. Thus, anthropometric profiling should be carried out on a systematic and periodic basis, because this will allow for the evaluation of the effectiveness of the implementation strategies of the IRFU model on a national basis.

  20. Lumbar facet fracture in an adolescent ice hockey player.

    PubMed

    Shaffer, W O; Taylor, M R; Sundaram, M

    1999-11-01

    A 14-year-old boy was checked hard as he was winding up to shoot in an ice hockey game. He experienced low-back pain during the game but when examined later for complaints of pain and fever, he denied trauma. Plain x-rays were normal, but a bone scan showed increased uptake at L-3. MRI evaluation revealed a lumbar mass; a CT scan showed the mass to be a hematoma and edema secondary to a facet fracture. Acute severe back pain in a hockey player should prompt a careful history and a search for musculoskeletal injury. When trauma in the lumbar spine is suspected and plain radiographs are nondiagnostic, CT scans are more precise than MRI for diagnosing injury.

  1. Tennis Elbow (Lateral Epicondylitis)

    MedlinePlus

    .org Tennis Elbow (Lateral Epicondylitis) Page ( 1 ) Tennis elbow, or lateral epicondyliti s, is a painful condition of the elbow caused by overuse. Not surprisingly, playing tennis or other racquet sports can cause ...

  2. Tennis physiology: training the competitive athlete.

    PubMed

    Kovacs, Mark S

    2007-01-01

    The game of tennis has evolved from the wooden-racket era of long, crafty points based on style and finesse, to the current fast paced, explosive sport based on power, strength and speed, where 210 km/h serves are common. This evolution over the last 20 years has led to an increased interest in tennis research. Competitive tennis athletes need a mixture of anaerobic skills, such as speed, agility and power, combined with high aerobic capabilities. The work-to-rest ratios of competitive tennis athletes range between 1 : 3 and 1 : 5, and fatigue has been shown to greatly reduce the hitting accuracy. Competitive male tennis athletes maintain body fat <12% and have maximal oxygen uptake values >50 mL/kg/min, and as high as 70 mL/kg/min. Results from lactate testing in tennis players are inconclusive as some studies have shown increased levels, whilst other studies have shown little or no change. Further investigation is required to determine the production and utilisation effects of lactate from playing tennis. The average length of time to play a point in tennis is <10 seconds and this has declined substantially in the last 20 years. Further research is needed to investigate tournament performance and its effect on fatigue, recovery, hormonal and injury levels. As the game of tennis continues to change, the physiological parameters must be continually investigated to help provide athletes, coaches and trainers with information that will aid in the development of efficient and productive tennis performance and injury prevention programmes.

  3. Teaching Tennis

    ERIC Educational Resources Information Center

    Breag, Daniel

    2005-01-01

    This article describes an approach to teaching the basic skills of tennis to students in grades 4 and 5. It relates a five-lesson unit suitable to a near-weekly class schedule. The author found it effective when seeing his students as infrequently as once every four days for fifty minutes.

  4. Frostbite in an Adolescent Football Player: A Case Report

    PubMed Central

    Rivlin, Michael; King, Marnie; Kruse, Richard; Ilyas, Asif M.

    2014-01-01

    Objective: To present the case of vascular compromise of a finger from a confluent circumferential blister due to an inappropriately applied commercial cold pack in a high school athlete and to describe the mechanism of iatrogenic injury, acute surgical management, rehabilitation, and pathophysiology of frostbite and constriction injuries. Background: A 17-year-old male football player presented with a frostbite and constriction injury to the index finger secondary to prolonged use of a cooling pack after a mild traumatic injury to the digit. He developed a prolonged sensory deficit from thermal injury, as well as acute vascular compromise requiring urgent operative intervention. Differential Diagnosis: Frostbite and constriction injury to the index finger. Treatment: Emergency surgical decompression and occupational therapy. Uniqueness: Frostbite injuries can occur iatrogenically because of inappropriate use of cooling devices or gel packs. Fingers are commonly injured extremities that are particularly susceptible to frostbite and compression injuries. To our knowledge, no case of vascular compromise from the blister constriction of digits has been reported. Conclusions: Patients and their caregivers must be educated about how to properly use cooling devices. Clinicians need to fully evaluate patients with iatrogenic frostbite injuries, giving particular attention to neurovascular status, and must recognize the need for surgical release of constriction syndrome to prevent substantial morbidity. PMID:24143903

  5. Football injuries in children and adolescent players: are there clues for prevention?

    PubMed

    Faude, Oliver; Rößler, Roland; Junge, Astrid

    2013-09-01

    Football (soccer) is the world's most popular sport with most players being younger than 18 years. Playing football can induce beneficial health effects, but there is also a high risk of injury. Therefore, it is necessary to implement measures for preventing injuries. The present review analyzes and summarizes published scientific information on the incidence and characteristics of football injuries in children and adolescent players to arrive at sound conclusions and valid considerations for the development of injury-prevention programs. A literature search was conducted up to November 2012. Fifty-three relevant scientific publications were detected. Thirty-two studies fulfilled the inclusion criteria for pooled analysis. Additional information from the remaining 21 studies was considered where appropriate to obtain a broader perspective on the injury problem in children and youth football. Training injury incidence was nearly constant for players aged 13-19 years, ranging from 1 to 5 injuries per 1,000 h training. Match injury incidence tended to increase with age through all age groups, with an average incidence of about 15 to 20 injuries per 1,000 match hours in players older than 15 years. Between 60 and 90 % of all football injuries were classified as traumatic and about 10-40 % were overuse injuries. Most injuries (60-90 %) were located at the lower extremities with the ankle, knee, and thigh being mostly affected. The frequency of upper-extremity and head/face injuries was higher in those studies that analyzed match injuries only. The most common injury types were strains, sprains, and contusions (10 up to 40 % each). There is some evidence that the risk of traumatic injuries and, in particular, of sustaining a fracture, contusion, or concussion was higher during match play than in practice sessions. Fractures were more frequent in children younger than 15 years than in older players. About half of all time-loss injuries led to an absence from sport of less

  6. The effect of plyometric training on power and kicking distance in female adolescent soccer players.

    PubMed

    Rubley, Mack D; Haase, Amaris C; Holcomb, William R; Girouard, Tedd J; Tandy, Richard D

    2011-01-01

    The purpose of this study was to measure the effects of low-frequency, low-impact plyometric training on vertical jump (VJ) and kicking distance in female adolescent soccer players. Sixteen adolescent soccer players were studied (age 13.4 ± 0.5 years) across 14 weeks. The control group (general soccer training only) had 6 subjects, and the plyometric training (general soccer training plus plyometric exercise) group had 10 subjects. All subjects were tested for VJ and kicking distance on 3 occasions: pre-test, 7 weeks, and 14 weeks. Data were analyzed using a 2 (Training) × 3 (Test) analysis of variance (ANOVA) with repeated measures on the factor test. No significant difference in kicking distance was found between groups at pre-test (p = 0.688) or 7 weeks (p = 0.117). The plyometric group had significantly greater kicking distance after 14 weeks (p < 0.001). No significant difference in VJ height was found between groups at pre-test (p = 0.837) or 7 weeks (p = 0.108). The plyometric group had a significantly higher VJ after 14 weeks (p = 0.014). These results provide strength coaches with a safe and effective alternative to high-intensity plyometric training. Based on these findings, to increase lower-body power resulting in increased VJ and kicking distance, strength coaches should implement once-weekly, low-impact plyometric training programs with their adolescent athletes.

  7. Vitamin D receptor gene FokI polymorphisms influence bone mass in adolescent football (soccer) players.

    PubMed

    Diogenes, Maria Eduarda L; Bezerra, Flávia Fioruci; Cabello, Giselda M K; Cabello, Pedro H; Mendonça, Laura M C; Oliveira Júnior, Astrogildo V; Donangelo, Carmen M

    2010-01-01

    The genetic influence on bone mineralization during adolescence is unclear possibly due to modifying factors such as skeletal maturation and lifestyle. We evaluated the influence of polymorphisms of the vitamin D receptor (VDR) gene on longitudinal changes in bone mass, bone- and calcium-related hormones in 46 adolescent soccer players (11.8-14.2 years). Total body bone mineral content (TBMC) and density (TBMD) were measured at baseline and after 6 months. Insulin-like growth factor-I (IGF-1), testosterone, intact parathyroid hormone, and activity of plasma bone alkaline phosphatase were measured at baseline and after 3 months. The influence of FokI or TaqI VDR genotypes on changes in the outcome variables were analyzed by univariate ANOVA with adjustment for chronological age, skeletal age and body weight at baseline. At baseline, boys with Ff genotype had higher TBMC, TBMD, TBMD Z-score compared to those with FF genotype (P < 0.05). After 3 months, Ff boys also had higher increment in plasma IGF-1 (P < 0.05). FokI polymorphism did not influence changes in bone mass measurements after 6 months, although differences detected at baseline remained significant after 6 months. There were no differences in the outcome variables according to TaqI genotypes. This study demonstrates that FokI polymorphisms affect bone mass in Brazilian adolescent soccer players and suggests that the FokI effect on bone mineralization occurs during bone maturation, possibly at the initial pubertal stages.

  8. Simplifying Tennis Instruction

    ERIC Educational Resources Information Center

    Vasil, Jay

    2005-01-01

    How many physical education programs incorporate tennis into the curriculum? How many physical educators feel proficient enough to teach tennis? Equally important, do students truly make progress when tennis is taught? Tennis instruction in secondary physical education settings is often frustrating for students and teachers alike. Many physical…

  9. Sports-related acute and chronic avulsion injuries in children and adolescents with special emphasis on tennis.

    PubMed

    Vandervliet, Everhard J M; Vanhoenacker, Filip M; Snoeckx, Annemie; Gielen, Jan L; Van Dyck, Pieter; Parizel, Paul M

    2007-11-01

    Acute and chronic sports-related muscle and tendon injuries are not infrequent in youngsters. In particular, the physis is prone to trauma as it constitutes the weakest part of the immature skeleton. The type of sports activity determines the location of the lesion. Most commonly, apophyses of the hip and pelvis are subject to avulsion. The purpose of this paper is to give a short overview of the pathogenesis, location, prevalence and imaging characteristics of acute and chronic avulsion injuries in the immature skeleton, with special emphasis on tennis-related injuries. Tennis-related injuries particularly involve apophyses of the ischial tuberosity, the anterior inferior or superior iliac spine and the iliac crest.

  10. Ethnicity-related variations of left ventricular remodeling in adolescent amateur football players.

    PubMed

    Pelà, G; Li Calzi, M; Crocamo, A; Pattoneri, P; Goldoni, M; Anedda, A; Musiari, L; Biggi, A; Bonetti, A; Montanari, A

    2015-06-01

    Adult and adolescent elite black athletes display - as compared with their white counterparts - excessively increased left ventricle (LV) wall thickness (LVWT), mass (LVM), and relative wall thickness (RWT). To investigate such ethnicity-related differences in non-professional adolescent athletes, 138 male, amateur football players [age 14.0 ± 1.7 years, 42 West-African blacks (BA) and 96 Italian whites (WA)] underwent an echocardiographic study of LV diameters, LVWT, maximal wall thickness (MWT), LVM, and RWT as remodeling index. BA vs WA exhibited greater thickness of septum and posterior wall, higher MWT (10.3 ± 1.7 vs 8.8 ± 1.1 mm), and higher LVM (117 ± 27 vs 101 ± 20 g/m(2)) and RWT (0.44 ± 0.07 vs 0.35 ± 0.04). Age, systolic blood pressure, body mass index, and ethnicity predicted MWT and LVM, whereas ethnicity was the sole strong predictor of RWT. The greater MWT, LVWT, and LVM of 14-year-old, amateur-level BA vs WA indicates that ethnicity substantially affects LV structure in adolescent, non-professional athletes. In contrast with MWT and LVM, elevated RWT was predicted by black ethnicity only. We suggest that concentric-type LV remodeling is a peculiar LV phenotype in adolescent African athletes.

  11. Good maintenance of exercise-induced bone gain with decreased training of female tennis and squash players: a prospective 5-year follow-up study of young and old starters and controls.

    PubMed

    Kontulainen, S; Kannus, P; Haapasalo, H; Sievänen, H; Pasanen, M; Heinonen, A; Oja, P; Vuori, I

    2001-02-01

    This prospective 5-year follow-up study of 64 adult female racquet sports players and 27 controls assessed the changes in the playing-to-nonplaying arm bone mineral content (BMC) differences to answer three questions: (1) Are training-induced bone gains lost with decreased training? (2) Is the bone response to decreased training different if the playing career has been started before or at puberty rather than after it? (3) Are the possible bone changes related to the changes in training? The players were divided into two groups according to the starting age of their tennis or squash playing. The mean starting age was 10.5 years (SD, 2.2) among the players who had started training before or at menarche (young starters; n = 36) while 26.4 years (SD, 8.0) among those players who had begun training a minimum of 1 year after menarche (old starters; n = 28). At baseline of the 5-year follow-up, the mean age of the young starters was 21.6 years (SD, 7.6) and that of old starters was 39.4 years (SD, 10.5). During the follow-up, the young starters had reduced the average training frequency from 4.7 times a week (2.7) to 1.4 times a week (1.3) and the old starters from 4.0 times a week (1.4) to 2.0 times a week (1.4), respectively. The 5-year follow-up revealed that despite reduced training the exercise-induced bone gain was well maintained in both groups of players regardless of their clearly different starting age of activity and different amount of exercise-induced bone gain. The gain was still 1.3-2.2 times greater in favor of the young starters (at the follow-up, the dominant-to-nondominant arm BMC difference was 22% [8.4] in the humeral shaft of the young starters versus 10% [3.8] in the old starters, and 3.5% [2.4] in controls). In the players, changes in training were only weakly related to changes in the side-to-side BMC difference (r(s) = 0.05-0.34, all NS), and this was true even among the players who had stopped training completely a minimum 1 year before the

  12. Epidemiological analysis of doping offences in the professional tennis circuit

    PubMed Central

    2010-01-01

    Introduction Tennis is a professional sport under a strict anti-doping control. However, since the first violation of the code, the positive cases have not been statistically studied. The objective of this study was to analyze doping offences in the international professional tennis circuit. Methods All offences to the Doping Code committed by tennis players during 2003-2009 were collected from the ITF official webpage, registered and analyzed. Results An average of 1905.7 (±174.5) samples was obtained per year. Fifty-two doping offences were reported and the overall incidence of positive doping samples accounted for 0.38% and 7.4 (±4.1) cases/year. Male players showed higher incidence doping offences than females (p = 0.0004). The incidence in wheelchair players was higher than in non-handicapped subjects (p = 0.0001) Banned substance distribution showed: stimulants 32.69%, cannabis 23.07%; anabolic 11.53%, diuretics and masking agents 11.53, β2-agonists 9.61%; corticosteroids 3.84%, others 3.84%. The overall incidence of 'social drugs' (cocaine, cannabis) was 36.53%. All EPO and blood samples were normal, while the incidence of 'out-of-competition' offences was 0.12%. The lower incidence of doping was found in Grand Slams tournaments. Conclusions The incidence of positive doping samples among professional tennis players is quite low supporting the assumption that there is no evidence of systematic doping in Tennis. "Social drugs" misuse constitutes the main problem of doping in tennis. Male and wheelchair tennis players showed higher risk of infringing the doping code than their females and non-handicapped counterparts. Findings of this study should help to determine the direction of the ongoing strategy in the fight against doping in Tennis. PMID:21159201

  13. Strength and conditioning in tennis: current research and practice.

    PubMed

    Reid, Machar; Schneiker, Knut

    2008-06-01

    Virtually all professional tennis players are in continuous pursuit of enhanced performance. With the modern game becoming increasingly dynamic and tournament schedules no less demanding, the importance of physical fitness is well accepted. Indeed, most professional tennis players resource strength and conditioning specialists on a full- or part-time basis. As tennis play is characterised by intricate bio-energetics, planning specific strength and conditioning interventions represents a significant challenge for the specialist. Further, where game physiology and mechanics have been described extensively, critiques of the efficacy of different training initiatives are far less common. This review therefore considers the current scientific, tennis-specific fitness training evidence base in light of contemporary conditioning, and more particularly resistance training, practices.

  14. Tennis elbow surgery

    MedlinePlus

    Lateral epicondylitis - surgery; Lateral tendinosis - surgery; Lateral tennis elbow - surgery ... Surgery to repair tennis elbow is usually an outpatient surgery. This means you will not stay in the hospital overnight. You will be given ...

  15. Tennis elbow surgery - discharge

    MedlinePlus

    ... epicondylitis surgery - discharge; Lateral tendinosis surgery - discharge; Lateral tennis elbow surgery - discharge ... long as you are told. This helps ensure tennis elbow will not return. You may be prescribed a ...

  16. Validity and usefulness of the Line Drill test for adolescent basketball players: a Bayesian multilevel analysis.

    PubMed

    Carvalho, Humberto M; Gonçalves, Carlos E; Grosgeorge, Bernard; Paes, Roberto R

    2017-04-10

    The study examined the validity of the Line Drill test (LD) in male adolescent basketball players (10-15 years). Sensitiveness of the LD to changes in performance across a training and competition season (4 months) was also considered. Age, maturation, body size and LD were measured (n = 57). Sensitiveness of the LD was examined pre- and post-competitive season in a sub-sample (n = 44). The time at each of the four shuttle sprints of the LD (i.e. four stages) was modelled with Bayesian multilevel models. We observed very large correlation of performance at stage 4 (full LD protocol) with stage 3, but lower correlations with the early LD stages. Players' performance by somatic maturity differed substantially only when considering full LD protocol performance. Substantial improvements in all stages of the protocol were observed across the 4-month competitive season. The LD protocol should be shortened by the last full court shuttle sprint, remaining sensitive to training exposure, and independent of maturity status and body size.

  17. A rare cause of chronic elbow pain in an adolescent baseball player: a case report

    PubMed Central

    Wasylynko, David

    2016-01-01

    Objective: To present a case of chronic elbow pain as a result of a hidden underlying osteochondral defect. Clinical Features: A 17-year old baseball player presented with chronic lateral elbow pain. Examination revealed swelling of the elbow with signs of possible ligament, muscle, and tendon injury. Diagnosis and Treatment: Although there was apparent soft-tissue injury, the elbow swelling created immediate suspicion of a more serious underlying condition. Examination revealed a swollen and tender elbow, with plain x-ray confirming a subchondral bone disorder (osteochondral defect) of the capitellum. Surgical repair was performed by an orthopedic surgeon using DeNovo NT Natural Tissue Grafts: the implantation of small pieces of juvenile joint cartilage into the affected area, using glue-like fibrin. Rehabilitation of the elbow began immediately following surgery. Summary: Examination and imaging indicated that elbow pain in an adolescent baseball player could be from multiple sources, however, the chronic swelling raised suspicion of a condition requiring immediate and further investigation. PMID:27713578

  18. Eating behaviors, nutritional status, and menstrual function in elite female adolescent volleyball players.

    PubMed

    Beals, Katherine A

    2002-09-01

    Nutritional status, eating behaviors and menstrual function was examined in 23 nationally ranked female adolescent volleyball players using a health/weight/ dieting/menstrual history questionnaire, the Eating Disorder Inventory (EDI), and the Body Shape Questionnaire (BSQ). Nutrient and energy intakes (El) and energy expenditure (EE) were determined by 3-d weighed food records and activity logs. Iron (Fe), vitamins C, B12, and Folate status were assessed using serum and whole blood. Mean El (2248 +/- 414 kcal/d) was less than EE (2815 +/- 306 kcal/d). Mean carbohydrate (5.4 +/-1.0g/kg/d) and protein (1.1+/-0.3g/kg/d) intakes were below recommended levels for highly active women. Mean intakes for folate, Fe, Ca, Mg, and Zn were less than the respective RDAs/DRIs and almost 50% of the athletes were consuming less than the RDAs/DRIs for the B-complex vitamins and vitamin C. Three athletes presented with Fe deficiency anemia (Hb <12 mg/dL), while marginal vitamin B12 status (<200 pg/ml) and vitamin C status (<28 mmol/L) were found in 1 and 4 athletes, respectively. Approximately 1/2 of the athletes reported actively "dieting". Mean BSQ and EDI subscales scores were within the normal ranges; yet, elevated scores on these scales were reported by 26% and 35% of athletes, respectively. Past or present amenorrhea was reported by 17% of the athletes and 13% and 48%, reported past or present oligomenorrhea and "irregular" menstrual cycles, respectively. These results indicate that elite adolescent volleyball players are at risk for menstrual dysfunction and have energy and nutrient intakes that place them at risk for nutritional deficiencies and compromised performance.

  19. THE RELATIONSHIP BETWEEN TRUNK ENDURANCE PLANK TESTS AND ATHLETIC PERFORMANCE TESTS IN ADOLESCENT SOCCER PLAYERS

    PubMed Central

    Kaneoka, Koji

    2016-01-01

    Background Although it is believed that trunk function is important for athletic performance, few researchers have demonstrated a significant relationship between the trunk function and athletic performance. Recently, the prone plank and side plank tests have been used to assess trunk function. Purpose The purpose of this study was to investigate the relationships between trunk endurance plank tests and athletic performance tests, including whether there is a relationship between long distance running and trunk endurance plank tests in adolescent male soccer players. Study design Cross sectional study design. Methods Fifty-five adolescent male soccer players performed prone and side plank tests and seven performance tests: the Cooper test, the Yo-Yo intermittent recovery test, the step 50 agility test, a 30-m sprint test, a vertical countermovement jump, a standing five-step jump, and a rebound jump. The relationships between each individual plank test, the combined score of both plank tests, and performance tests were analyzed using the Pearson correlation coefficient. Results The combined score of plank tests was highly correlated with the Yo-Yo intermittent recovery test (r = 0.710, p < 0.001), and was moderately correlated with the Cooper test (r = 0.567, p < 0.001). Poor correlation was observed between the prone plank test and step 50 agility test (r = -0.436, p = 0.001) and no significant correlations were observed between plank tests and jump performance tests. Conclusions The results suggest that trunk endurance plank tests are positively correlated with the Yo-Yo intermittent recovery test, the Cooper test, and the step 50 agility test. Level of Evidence Level 2 PMID:27757284

  20. Comparison of segmental linear and angular momentum transfers in two-handed backhand stroke stances for different skill level tennis players.

    PubMed

    Wang, Lin-Hwa; Lin, Hwai-Ting; Lo, Kuo-Cheng; Hsieh, Yung-Chun; Su, Fong-Chin

    2010-07-01

    The purpose of this study was to investigate the differences of momentum transfer from the trunk and upper extremities to the racket between open and square stances for different skill levels players in the two-handed backhand stroke. The motion capture system with twenty-one reflective markers attached on anatomic landmarks of the subject was used for two-handed backhand stroke motion data collection. Twelve subjects were divided into an advanced group and an intermediate group based on skill level. The three-dimensional linear and angular momentums of the trunk, upper arm, forearm, hand and racket were used for kinetic chain analysis. Results showed that all players with the square stance had significantly larger backward linear momentum contribution in trunk and upper arm than with the open stance (p<.05) irrespective of playing level. However, the external rotation angular momentum of the shoulder joint was significantly larger with an open stance than with a square stance (p=.047). Comparison of playing levels showed that the intermediate group performed higher linear momentum in three components of the trunk, upper arm backward linear momentum, and trunk right bending angular momentum than the advanced group significantly (p<.05). The advanced group reduces trunk linear movement to keep stability and applies trunk and linkage segment rotation to generate backhand stroke power. The advanced group also has a quick backswing for increasing acceleration and maintains longer in the follow-through phase for shock energy absorption. This information could improve training protocol design for teaching the two-handed backhand stroke and teaching players, especially beginners, how to make an effective stroke.

  1. Agreement between Two Methods of Dietary Data Collection in Male Adolescent Academy-Level Soccer Players

    PubMed Central

    Briggs, Marc A.; Rumbold, Penny L. S.; Cockburn, Emma; Russell, Mark; Stevenson, Emma J.

    2015-01-01

    Collecting accurate and reliable nutritional data from adolescent populations is challenging, with current methods providing significant under-reporting. Therefore, the aim of the study was to determine the accuracy of a combined dietary data collection method (self-reported weighed food diary, supplemented with a 24-h recall) when compared to researcher observed energy intake in male adolescent soccer players. Twelve Academy players from an English Football League club participated in the study. Players attended a 12 h period in the laboratory (08:00 h–20:00 h), during which food and drink items were available and were consumed ad libitum. Food was also provided to consume at home between 20:00 h and 08:00 h the following morning under free-living conditions. To calculate the participant reported energy intake, food and drink items were weighed and recorded in a food diary by each participant, which was supplemented with information provided through a 24-h recall interview the following morning. Linear regression, limits of agreement (LOA) and typical error (coefficient of variation; CV) were used to quantify agreement between observer and participant reported 24-h energy intake. Difference between methods was assessed using a paired samples t-test. Participants systematically under-reported energy intake in comparison to that observed (p < 0.01) but the magnitude of this bias was small and consistent (mean bias = −88 kcal·day−1, 95% CI for bias = −146 to −29 kcal·day−1). For random error, the 95% LOA between methods ranged between −1.11 to 0.37 MJ·day−1 (−256 to 88 kcal·day−1). The standard error of the estimate was low, with a typical error between measurements of 3.1%. These data suggest that the combined dietary data collection method could be used interchangeably with the gold standard observed food intake technique in the population studied providing that appropriate adjustment is made for the systematic under-reporting common to such

  2. The Diet Quality of Competitive Adolescent Male Rugby Union Players with Energy Balance Estimated Using Different Physical Activity Coefficients

    PubMed Central

    Burrows, Tracy; Harries, Simon K.; Williams, Rebecca L.; Lum, Cheryl; Callister, Robin

    2016-01-01

    Objectives: The aims of the current study were to comprehensively assess the dietary intakes and diet quality of a sample of Australian competitive adolescent rugby union players and compare these intakes with National and Sports Dietitians Association (SDA) Recommendations for adolescent athletes. A secondary aim investigated applying different physical activity level (PAL) coefficients to determine total energy expenditure (TEE) in order to more effectively evaluate the adequacy of energy intakes. Design: Cross-sectional. Methods: Anthropometrics and dietary intakes were assessed in 25 competitive adolescent male rugby union players (14 to 18 years old). Diet was assessed using the validated Australian Eating Survey (AES) food frequency questionnaire and diet quality was assessed through the Australian Recommended Food Score. Results: The median dietary intakes of participants met national recommendations for percent energy (% E) from carbohydrate, protein and total fat, but not carbohydrate intake when evaluated as g/day as proposed in SDA guidelines. Median intakes of fibre and micronutrients including calcium and iron also met national recommendations. Overall diet quality was classified as ‘good’ with a median diet quality score of 34 (out of a possible 73); however, there was a lack of variety within key food groups including carbohydrates and proteins. Non-core food consumption exceeded recommended levels at 38% of the daily total energy intake, with substantial contributions from takeaway foods and sweetened beverages. A PAL coefficient of 1.2–1.4 was found to best balance the energy intakes of these players in their pre-season. Conclusions: Adolescent rugby players met the percent energy recommendations for macronutrients and attained an overall ‘good’ diet quality score. However, it was identified that when compared to specific recommendations for athletes, carbohydrate intakes were below recommendations and these players in their pre

  3. Comparing 9 to 10 Years Old Children's Performance in Tennis and Physical Fitness Activities

    ERIC Educational Resources Information Center

    Olcucu, Burcin

    2013-01-01

    The aim of the study is to determine the degree of performance-related physical coordination of elementary education children (male and female) that play tennis according to their age and gender and to investigate the relationship between their motor ability tests and performances. A total of 210 children tennis players (9 to 10 years; 105 males…

  4. Pseudonephritis is associated with high urinary osmolality and high specific gravity in adolescent soccer players.

    PubMed

    Van Biervliet, Stephanie; Van Biervliet, Jean Pierre; Watteyne, Karel; Langlois, Michel; Bernard, Dirk; Vande Walle, Johan

    2013-08-01

    The study aimed to evaluate the effect of exercise on urine sediment in adolescent soccer players. In 25 15-year-old (range 14.4-15.8 yrs) athletes, urinary protein, osmolality and cytology were analyzed by flow cytometry and automated dipstick analysis before (T(0)), during (T(1)), and after a match (T(2)). All athletes had normal urine analysis and blood pressure at rest, tested before the start of the soccer season. Fifty-eight samples were collected (T(0): 20, T(1): 17, T(2): 21). Proteinuria was present in 20 of 38 samples collected after exercise. Proteinuria was associated with increased urinary osmolality (p < .001) and specific gravity (p < .001). Hyaline and granular casts were present in respectively 8 of 38 and 8 of 38 of the urinary samples after exercise. The presence of casts was associated with urine protein concentration, osmolality, and specific gravity. This was also the case for hematuria (25 of 38) and leucocyturia (9 of 38). Squamous epithelial cells were excreted in equal amounts to white and red blood cells. A notable proportion of adolescent athletes developed sediment abnormalities, which were associated with urinary osmolality and specific gravity.

  5. Expert-novice differences in cognitive and execution skills during tennis competition.

    PubMed

    Del Villar, Fernando; García González, Luis; Iglesias, Damián; Perla Moreno, M; Cervelló, Eduardo M

    2007-04-01

    This study deals with decision and execution behavior of tennis players during competition. The study is based on the expert-novice paradigm and aims to identify differences between both groups in the decision-making and execution variables in serve and shot actions in tennis. Six expert players (elite Spanish tennis players) and six novice players (grade school tennis players) took part in this study. To carry out this study, the observation protocol defined by McPherson and Thomas in 1989, in which control, decision-making and execution variables were included, was used, where it was applied to the performance of the tennis player in a real match situation. In the analysis, significant differences between experts and novices in decision-making and execution variables are found wherein it can be observed that experts display a greater ability to make the appropriate decisions, selecting the most tactical responses to put pressure on the opponent. Expert tennis players were also able to carry out forceful executions to their opponent with greater efficiency, making the opponent's response to a large extent more difficult. These findings are in accordance with those of McPherson and colleagues.

  6. The physiological demands of table tennis: a review.

    PubMed

    Kondrič, Miran; Zagatto, Alessandro Moura; Sekulić, Damir

    2013-01-01

    Although table tennis has a tradition lasting more than 100 years, relatively little is known about players' physiological requirements - especially during competition. In this review we discuss research studies that have led to our current understanding of how the body functions during table tennis training and competition and how this is altered by training. Match and practice analysis of the table tennis game indicates that during intense practice and competition it is predominantly the anaerobic alactic system that is called into play, while the endurance system is relied on to recovery the anaerobic stores used during such effort. It is thus important for coaches to keep in mind that, while the anaerobic alactic system is the most energetic system used during periods of exertion in a table tennis game, a strong capacity for endurance is what helps a player recover quicker for the following match and the next day of competition. This paper provides a review of specific studies that relate to competitive table tennis, and highlights the need for training and research programs tailored to table tennis. Key PointsMatch and practice analysis of the table tennis game indicates that during intense practice and competition it is predominantly the anaerobic alactic system that is called into play.The endurance system is relied on to recovery the anaerobic stores used during hard practice and competition effort.It is important for coaches to keep in mind that, while the anaerobic alactic system is the most energetic system used during periods of exertion in a table tennis game, a strong capacity for endurance is what helps a player recover quicker for the following match and the next day of competition.

  7. Knee movement patterns of injured and uninjured adolescent basketball players when landing from a jump: A case-control study

    PubMed Central

    Louw, Quinette; Grimmer, Karen; Vaughan, Christopher

    2006-01-01

    Background A common knee injury mechanism sustained during basketball is landing badly from a jump. Landing is a complex task and requires good coordination, dynamic muscle control and flexibility. For adolescents whose coordination and motor control has not fully matured, landing badly from a jump can present a significant risk for injury. There is currently limited biomechanical information regarding the lower limb kinetics of adolescents when jumping, specifically regarding jump kinematics comparing injured with uninjured adolescents. This study reports on an investigation of biomechanical differences in landing patterns of uninjured and injured adolescent basketball players. Methods A matched case-control study design was employed. Twenty-two basketball players aged 14–16 years participated in the study: eleven previously knee-injured and eleven uninjured players matched with cases for age, gender, weight, height and years of play, and playing for the same club. Six high-speed, three-dimensional Vicon 370 cameras (120 Hz), Vicon biomechanical software and SAS Version 8 software were employed to analyse landing patterns when subjects performed a "jump shot". Linear correlations determined functional relationships between the biomechanical performance of lower limb joints, and paired t-tests determined differences between the normalised peak biomechanical parameters. Results The average peak vertical ground reaction forces between the cases and controls were similar. The average peak ground reaction forces between the cases and controls were moderately correlated (r = -0.47). The control (uninjured) players had significantly greater hip and knee flexion angles and significantly greater eccentric activity on landing than the uninjured cases (p < 0.01). Conclusion The findings of the study indicate that players with a history of knee injuries had biomechanically compromised landing techniques when compared with uninjured players matched for gender, age and club

  8. Low Compression Tennis Balls and Skill Development

    PubMed Central

    Hammond, John; Smith, Christina

    2006-01-01

    Coaching aims to improve player performance and coaches have a number of coaching methods and strategies they use to enhance this process. If new methods and ideas can be determined to improve player performance they will change coaching practices and processes. This study investigated the effects of using low compression balls (LCBs) during coaching sessions with beginning tennis players. In order to assess the effectiveness of LCBs on skill learning the study employed a quasi-experimental design supported by qualitative and descriptive data. Beginner tennis players took part in coaching sessions, one group using the LCBs while the other group used standard tennis balls. Both groups were administered a skills at the beginning of a series of coaching sessions and again at the end. A statistical investigation of the difference between pre and post-test results was carried out to determine the effect of LCBs on skill learning. Additional qualitative data was obtained through interviews, video capture and the use of performance analysis of typical coaching sessions for each group. The skill test results indicated no difference in skill learning when comparing beginners using the LCBs to those using the standard balls. Coaches reported that the LCBs appeared to have a positive effect on technique development, including aspects of technique that are related to improving power of the shot. Additional benefits were that rallies went on longer and more opportunity for positive reinforcement. In order to provide a more conclusive answer to the effects of LCBs on skill learning and technique development recommendations for future research were established including a more controlled experimental environment and larger sample sizes across a longer period of time. Key Points LCB may aid skill learning in tennis. Qualitative indicators. Statistical evidence not conclusive. Further studies of larger groups recommended. PMID:24357952

  9. Validity of the jump-and-reach test in sub-elite adolescent handball players.

    PubMed

    Muehlbauer, Thomas; Pabst, Jan; Granacher, Urs; Büsch, Dirk

    2016-08-18

    The primary purpose of this study was to examine concurrent validity of the jump-and-reach (JaR) test using the Vertec system and a criterion device (i.e., Optojump system). In separate sub-analyses, we investigated the influence of gym floor condition and athletes' sex on the validity of vertical jump height. Four hundred and forty sub-elite adolescent female (n = 222, mean age: 14 ± 1 years, age range: 13-15 years) and male (n = 218, mean age: 15 ± 1 years, age range: 14-16 years) handball players performed the JaR test in gyms with region or point elastic floors. Maximal vertical jump height was simultaneously assessed using the Vertec and the Optojump system. In general, significantly higher jump heights were obtained for the Vertec compared to the Optojump system (11.2 cm, [INCREMENT]31%, Cohen´s d = 2.58). The sub-analyses revealed significantly larger jump heights for the Vertec compared to the Optojump system irrespective of gym floor condition and players' sex. The association between Optojump and Vertec-derived vertical jump height amounted to rP = 0.84, with a coefficient of determination (R) of 0.71. The sub-analyses indicated significantly larger correlations in males (rP = 0.75, R = 0.56) than in females (rP = 0.63, R = 0.40). Yet, correlations were not significantly different between region (rP = 0.83, R = 0.69) as opposed to point elastic floor (rP = 0.87, R = 0.76). Our findings indicate that the two apparatus cannot be used interchangeably. Consequently, gym floor and sex specific regression equations were provided to estimate true (Optojump system) vertical jump height from Vertec-derived data.

  10. Prevalence of Musculoskeletal Conditions in Tennis-Teaching Professionals

    PubMed Central

    Colberg, Ricardo E.; Aune, Kyle T.; Propst, Matthew S.

    2016-01-01

    Background: Tennis-teaching professionals represent a significant proportion of all avid tennis players worldwide, with 15,000 belonging to the largest professional organization, the United States Professional Tennis Association (USPTA). However, there is no epidemiologic study to date reporting the prevalence of musculoskeletal conditions in these tennis-teaching professionals. Purpose: To investigate the prevalence of musculoskeletal conditions in tennis-teaching professionals following the International Tennis Federation’s (ITF) guidelines for epidemiologic studies. Study Design: Descriptive epidemiology study. Methods: Electronic surveys were distributed to 13,500 American members of the USPTA. The prevalence of musculoskeletal conditions was calculated. Results: A total of 1176 USPTA members completed the survey. Most participants reported teaching more than 5 days per week and more than 2 hours per day. The prevalence of musculoskeletal injury secondary to teaching tennis was 42%. The most affected area was the lower extremities (43% of all injuries) followed by the upper extremities (37%). The most commonly injured structures were muscles or tendons (36% of all injuries) and joints or ligaments (28%). The majority of injuries did not cause participants to miss more than 24 hours of teaching (57%). Conclusion: This is the first epidemiologic study on the occupational risk of musculoskeletal injuries and conditions in tennis-teaching professionals. Tennis-teaching professionals have a significant risk of musculoskeletal injuries or conditions related to their occupation. The prevalence of injury is consistent with previously published studies of injury prevalence among other tennis-playing populations. The proportions of upper and lower extremity injuries were fairly equitable. PMID:27790624

  11. Skill acquisition in tennis: research and current practice.

    PubMed

    Reid, Machar; Crespo, Miguel; Lay, Brendan; Berry, Jason

    2007-02-01

    Common to most tennis players is the desire to improve performance. Equipped with the necessary motivation, these players can spend countless hours rehearsing tennis' skills under the guidance of a coach. Often, these practices feature repetitious hitting, with little consideration given to the actual context in which the game's skills are expressed. Alternatively, training sessions that amount to little more than poorly structured game-play, devoid of any specific goals or objectives, are also discernible. Either way, player learning and long-term performance are unlikely to be optimised. So, where tennis coaches have long relied on certain instructional approaches and types of practices to enhance player performance, their efficacy is uncertain. Indeed, a growing body of research suggests that players stand to benefit from the earlier introduction of variable and random practices and feedback that is more intrinsic in nature rather than time-honoured overly prescriptive coaching. This review considers contemporary skill acquisition research in relation to current tennis coaching practice.

  12. An 8-Stage Model for Evaluating the Tennis Serve

    PubMed Central

    Kovacs, Mark; Ellenbecker, Todd

    2011-01-01

    Background: The tennis serve is a complex stroke characterized by a series of segmental rotations involving the entire kinetic chain. Many overhead athletes use a basic 6-stage throwing model; however, the tennis serve does provide some differences. Evidence Acquisition: To support the present 8-stage descriptive model, data were gathered from PubMed and SPORTDiscus databases using keywords tennis and serve for publications between 1980 and 2010. Results: An 8-stage model of analysis for the tennis serve that includes 3 distinct phases—preparation, acceleration, and follow-through—provides a more tennis-specific analysis than that previously presented in the clinical tennis literature. When a serve is evaluated, the total body perspective is just as important as the individual segments alone. Conclusion: The 8-stage model provides a more in-depth analysis that should be utilized in all tennis players to help better understand areas of weakness, potential areas of injury, as well as components that can be improved for greater performance. PMID:23016050

  13. Shoulder proprioception is not related to throwing speed or accuracy in elite adolescent male baseball players.

    PubMed

    Freeston, Jonathan; Adams, Roger D; Rooney, Kieron

    2015-01-01

    Understanding factors that influence throwing speed and accuracy is critical to performance in baseball. Shoulder proprioception has been implicated in the injury risk of throwing athletes, but no such link has been established with performance outcomes. The purpose of this study was to describe any relationship between shoulder proprioception acuity and throwing speed or accuracy. Twenty healthy elite adolescent male baseball players (age, 19.6 ± 2.6 years), who had represented the state of New South Wales in the past 18 months, were assessed for bilateral active shoulder proprioception (shoulder rotation in 90° of arm abduction moving toward external rotation using the active movement extent discrimination apparatus), maximal throwing speed (MTS, meters per second measured via a radar gun), and accuracy (total error in centimeters determined by video analysis) at 80 and 100% of MTS. Although proprioception in the dominant and nondominant arms was significantly correlated with each other (r = 0.54, p < 0.01), no relationship was found between shoulder proprioception and performance. Shoulder proprioception was not a significant determinant of throwing performance such that high levels of speed and accuracy were achieved without a high degree of proprioception. There is no evidence to suggest therefore that this particular method of shoulder proprioception measurement should be implemented in clinical practice. Consequently, clinicians are encouraged to consider proprioception throughout the entire kinetic chain rather than the shoulder joint in isolation as a determining factor of performance in throwing athletes.

  14. The Physiological Demands of Table Tennis: A Review

    PubMed Central

    Kondrič, Miran; Zagatto, Alessandro Moura; Sekulić, Damir

    2013-01-01

    Although table tennis has a tradition lasting more than 100 years, relatively little is known about players’ physiological requirements – especially during competition. In this review we discuss research studies that have led to our current understanding of how the body functions during table tennis training and competition and how this is altered by training. Match and practice analysis of the table tennis game indicates that during intense practice and competition it is predominantly the anaerobic alactic system that is called into play, while the endurance system is relied on to recovery the anaerobic stores used during such effort. It is thus important for coaches to keep in mind that, while the anaerobic alactic system is the most energetic system used during periods of exertion in a table tennis game, a strong capacity for endurance is what helps a player recover quicker for the following match and the next day of competition. This paper provides a review of specific studies that relate to competitive table tennis, and highlights the need for training and research programs tailored to table tennis. Key Points Match and practice analysis of the table tennis game indicates that during intense practice and competition it is predominantly the anaerobic alactic system that is called into play. The endurance system is relied on to recovery the anaerobic stores used during hard practice and competition effort. It is important for coaches to keep in mind that, while the anaerobic alactic system is the most energetic system used during periods of exertion in a table tennis game, a strong capacity for endurance is what helps a player recover quicker for the following match and the next day of competition. PMID:24149139

  15. Body mass index and body fat percentage are associated with decreased physical fitness in adolescent and adult female volleyball players

    PubMed Central

    Nikolaidis, Pantelis Theo

    2013-01-01

    Background: The objectives of this study were to examine (a) the prevalence of overweight/obesity, and (b) the relationship between body mass index (BMI), body fat percentage (BF) and physical fitness in adolescent and adult female volleyball players. Materials and Methods: Adolescent (n = 102, aged 15.2 ± 2.0 year) and adult (n = 57, 25.9 ± 5.0 year) players were examined for anthropometric characteristics and body composition, and performed the physical working capacity in heart rate 170 min-1 test, a force-velocity test, the Wingate anaerobic test (WAnT), sit-and-reach test (SAR), handgrip strength test (HST) and countermovement vertical jump (CVJ). Results: Based on international BMI cut-off points, 27.5% (n = 28) of adolescent and 12.3% (n = 7) of adult participants were classified as overweight, with the prevalence of overweight being higher in girls than in women (χ2 = 4.90, P = 0.027). BMI was correlated with BF in both age groups (r = 0.72, P < 0.001 in girls; r = 0.75, P < 0.001 in women). Normal participants had superior certain physical and physiological characteristics than those who were overweight. For instance, normal girls and women had higher mean power during WAnT than their overweight counterparts (P = 0.003 and P = 0.009 respectively). Except for flexibility, BMI and BF were inversely related with physical fitness (e.g., BMI vs. HST r = -0.39, P < 0.001 in girls; BF vs. CVJ r = -0.45, P < 0.001 in women). Conclusion: The findings confirmed the negative effect of overweight and fatness on selected parameters of physical fitness. The prevalence of overweight in adolescent volleyball players was higher than in general population, which was a novel finding, suggesting that proper exercise interventions should be developed to target the excess of body mass in youth volleyball clubs. PMID:23900100

  16. Scapulothoracic kinematics during tennis forehand drive.

    PubMed

    Rogowski, Isabelle; Creveaux, Thomas; Chèze, Laurence; Dumas, Raphaël

    2014-06-01

    Scapular dyskinesis is recognized as an abnormality in the kinetic chain; yet, there has been little research quantifying scapular motion during sport tasks. Tennis forehand drives of eight highly skilled tennis players were studied to assess the scapulothoracic kinematics and evaluate repeatability using video-based motion analysis. Scapulothoracic downward/upward rotation, posterior/anterior tilt, and internal/external rotation were computed using an acromial marker cluster. On average, the upward rotation, anterior tilt, and internal rotation varied from 1 degrees to 26 degrees, from 7 degrees to 32 degrees, and from 42 degrees to 100 degrees, respectively, during the tennis forehand drive. During the backswing and forward swing phases of the forehand stroke, small changes were observed for the three scapular angle values, while all angles increased rapidly during the follow-through phase. This suggests that the tennis forehand drive may contribute to scapula dyskinesis, mainly due to the great amplitude in scapulothoracic anterior tilt and internal rotation observed during the follow-through phase. Knowledge of normal scapula motion during sport tasks performed at high velocity could improve the understanding of various sport-specific adaptations and pathologies.

  17. Tennis: Applied Examples of a Game-Based Teaching Approach

    ERIC Educational Resources Information Center

    Crespo, Miguel; Reid, Machar M.; Miley, Dave

    2004-01-01

    In this article, the authors reveal that tennis has been increasingly taught with a tactical model or game-based approach, which emphasizes learning through practice in match-like drills and actual play, rather than in practicing strokes for exact technical execution. Its goal is to facilitate the player's understanding of the tactical, physical…

  18. Tennis: Course Proposal.

    ERIC Educational Resources Information Center

    Yeo, David G.

    A proposal is presented for a Community College of Philadelphia Life Sciences and Allied Health Services course in tennis. Following a standard cover form, a statement of purpose explains that the course is designed to provide instruction and practice in the basic tennis techniques of the forehand, backhand, serve, volley, and overhead. Next,…

  19. The effect of deprivation on the developmental activities of adolescent rugby union players in Wales.

    PubMed

    Winn, Charles O N; Ford, Paul R; McNarry, Melitta A; Lewis, Jason; Stratton, Gareth

    2016-12-26

    The developmental activities of rugby union players and their interaction with deprivation remain to be elucidated. Five-hundred and ninety elite junior rugby union players (14.8 ± 0.5 years) were split into deprivation quintiles. These players subsequently completed a participant history questionnaire to record their involvement in rugby and other sports. Players accumulated 1987 ± 1297 h in rugby between 6 and 15 years of age. During the mini rugby stage (6-10 years of age), players accumulated an average of 113 ± 105, 89 ± 69 and 43 ± 19 h per year in rugby play, practice and competition, respectively. Moreover, 461 players engaged in an average of two other sports during the mini rugby stage. During the junior rugby stage (11-15 years of age), players accumulated 179 ± 98, 115 ± 90 and 64 ± 26 h per year in rugby practice, play and competition, respectively, and 538 players took part in three other sports. Players who were more deprived accumulated less rugby hours and participated in fewer other sports, but age milestones were not different between deprivation quintiles. There were no differences within developmental activities in rugby between deprivation groups.

  20. You Can't Be Serious, that Ball Was IN: An Investigation of Junior Tennis Cheating Behavior

    ERIC Educational Resources Information Center

    Casper, Jonathan

    2006-01-01

    Because junior tennis players have to enforce the rules of the game against each other, cheating to give a player an unfair advantage is common. While this deviant behavior is found to be commonplace in the sport, there is little research to investigate its cause or influences. Results indicated that junior players felt that personal and parental…

  1. Influence of a Prolonged Tennis Match Play on Serve Biomechanics

    PubMed Central

    Martin, Caroline; Bideau, Benoit; Delamarche, Paul; Kulpa, Richard

    2016-01-01

    The aim of this study was to quantify kinematic, kinetic and performance changes that occur in the serve throughout a prolonged tennis match play. Serves of eight male advanced tennis players were recorded with a motion capture system before, at mid-match, and after a 3-hour tennis match. Before and after each match, electromyographic data of 8 upper limb muscles obtained during isometric maximal voluntary contraction were compared to determine the presence of muscular fatigue. Vertical ground reaction forces, rating of perceived exertion, ball speed, and ball impact height were measured. Kinematic and upper limb kinetic variables were computed. The results show decrease in mean power frequency values for several upper limb muscles that is an indicator of local muscular fatigue. Decreases in serve ball speed, ball impact height, maximal angular velocities and an increase in rating of perceived exertion were also observed between the beginning and the end of the match. With fatigue, the majority of the upper limb joint kinetics decreases at the end of the match. No change in timing of maximal angular velocities was observed between the beginning and the end of the match. A prolonged tennis match play may induce fatigue in upper limb muscles, which decrease performance and cause changes in serve maximal angular velocities and joint kinetics. The consistency in timing of maximal angular velocities suggests that advanced tennis players are able to maintain the temporal pattern of their serve technique, in spite of the muscular fatigue development. PMID:27532421

  2. Influence of a Prolonged Tennis Match Play on Serve Biomechanics.

    PubMed

    Martin, Caroline; Bideau, Benoit; Delamarche, Paul; Kulpa, Richard

    2016-01-01

    The aim of this study was to quantify kinematic, kinetic and performance changes that occur in the serve throughout a prolonged tennis match play. Serves of eight male advanced tennis players were recorded with a motion capture system before, at mid-match, and after a 3-hour tennis match. Before and after each match, electromyographic data of 8 upper limb muscles obtained during isometric maximal voluntary contraction were compared to determine the presence of muscular fatigue. Vertical ground reaction forces, rating of perceived exertion, ball speed, and ball impact height were measured. Kinematic and upper limb kinetic variables were computed. The results show decrease in mean power frequency values for several upper limb muscles that is an indicator of local muscular fatigue. Decreases in serve ball speed, ball impact height, maximal angular velocities and an increase in rating of perceived exertion were also observed between the beginning and the end of the match. With fatigue, the majority of the upper limb joint kinetics decreases at the end of the match. No change in timing of maximal angular velocities was observed between the beginning and the end of the match. A prolonged tennis match play may induce fatigue in upper limb muscles, which decrease performance and cause changes in serve maximal angular velocities and joint kinetics. The consistency in timing of maximal angular velocities suggests that advanced tennis players are able to maintain the temporal pattern of their serve technique, in spite of the muscular fatigue development.

  3. The relationship between professional tournament structure on the national level and success in men's professional tennis.

    PubMed

    Crespol, M; Reid, M; Miley, D; Atienza, F

    2003-03-01

    This article discusses the relationship between a nation's men's professional tennis tournament structure and that nation's success in the international men's game. The 2002 men's professional tennis tournament calendar provided the distribution of events on the top thirty nations. Criteria for a nation's success in men's professional tennis were: nation's number of players with ATP points, nation's number of players in the top 200 ranking, and the combined ATP ranking of a nation's top 5 male players. Pearson correlations were performed between the number of tournaments and each criterion. Results showed a considerable variation in the number of events ranging between 67 (United States) and 4 (Sweden). On the other hand, 29 of the 30 countries had Internationally ranked male player/s and 22 had player/s ranked inside the top 200. Results also showed that: 1. nations with a high number of men's professional events are best positioned to provide for more professionally ranked players, 2. nations with more professional men's tournaments are likely to experience success in the men's international game, and 3. having a high number of tournaments is not a prerequisite to having a group of players ranked among the game's elite. It can be concluded that competition is an important factor in player development and that countries who want to be successful at the professional level should try to provide best competitive progression for their players.

  4. A practical method of estimating energy expenditure during tennis play.

    PubMed

    Novas, A M P; Rowbottom, D G; Jenkins, D G

    2003-03-01

    This study aimed to develop a practical method of estimating energy expenditure (EE) during tennis. Twenty-four elite female tennis players first completed a tennis-specific graded test in which five different Intensity levels were applied randomly. Each intensity level was intended to simulate a "game" of singles tennis and comprised six 14 s periods of activity alternated with 20 s of active rest. Oxygen consumption (VO2) and heart rate (HR) were measured continuously and each player's rate of perceived exertion (RPE) was recorded at the end of each intensity level. Rate of energy expenditure (EE(VO2)) during the test was calculated using the sum of VO2 during play and the 'O2 debt' during recovery, divided by the duration of the activity. There were significant individual linear relationships between EE(VO2) and RPE, EE(VO2) and HR (r > or = 0.89 & r > or = 0.93; p < 0.05). On a second occasion, six players completed a 60-min singles tennis match during which VO2, HR and RPE were recorded; EE(VO2) was compared with EE predicted from the previously derived RPE and HR regression equations. Analysis found that EE(VO2) was overestimated by EE(RPE) (92 +/- 76 kJ x h(-1)) and EE(HR) (435 +/- 678 kJ x h(-1)), but the error of estimation for EE(RPE) (t = -3.01; p = 0.03) was less than 5% whereas for EE(HR) such error was 20.7%. The results of the study show that RPE can be used to estimate the energetic cost of playing tennis.

  5. Cumulative Incidence of Osteochondritis Dissecans of the Capitellum in Child and Adolescent Baseball Players

    PubMed Central

    Iwame, Toshiyuki; Matsuura, Tetsuya; Suzue, Naoto; Sairyo, Koichi

    2016-01-01

    Objectives: Prevalence of osteochondritis dissecans (OCD) of the capitellum is high among individuals who have played baseball since childhood. Recently two cross-sectional studies according to prevalence of OCD have been published. In a study of 1040 baseball players aged 10 to 12 years, Matsuura et al found that 2.1% of players had OCD, with no differences in prevalence according to age or player position. Kida et al., in their study of 2433 baseball players aged 12 to 18 years, found OCD in 3.4% of subjects. Furthermore, they found that players with OCD began playing baseball at earlier ages, had played for longer periods, and had experienced more elbow pain. The player’s current baseball position may not be related to the existence of OCD lesions. Together, these findings led us to examine the longitudinal study for examining the risk factors for occurrence of OCD. Our objectives were to determine (1) cumulative incidence rates of OCD in the school child players aged 6-11 years old, (2) the relative risk of OCD by age, beginning age playing baseball, playing period, experimental hours per week, playing position, and elbow pain. Methods: A total of 1,275 players aged 6-11 years (mean, 9.4 years) belonged to youth baseball teams without OCD lesions received examination in the next year and were the subjects of this investigation. Subjects were examined by questionnaire, and ultrasonographic and radiographic examination. Questionnaire items included age, player position, beginning age of playing baseball, playing period of baseball, number of training hours per week and history of elbow pain. Ultrasonography of the lateral aspect of the elbow was performed. An irregularity of the subchondral bone of the capitellum was regarded as an abnormality. Radiographic examination was recommended to players who had an abnormal finding on ultrasonographic examination. We investigated the following risk factors for occurrence of OCD: age, player position, beginning age of

  6. Relationships between the yo-yo intermittent recovery test and anaerobic performance tests in adolescent handball players.

    PubMed

    Hermassi, Souhail; Aouadi, Ridha; Khalifa, Riadh; van den Tillaar, Roland; Shephard, Roy J; Chelly, Mohamed Souhaiel

    2015-03-29

    The aim of the present study was to investigate relationships between a performance index derived from the Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IR1) and other measures of physical performance and skill in handball players. The other measures considered included peak muscular power of the lower limbs (Wpeak), jumping ability (squat and counter-movement jumps (SJ, CMJ), a handball skill test and the average sprinting velocities over the first step (VS) and the first 5 m (V5m). Test scores for 25 male national-level adolescent players (age: 17.2 ± 0.7 years) averaged 4.83 ± 0.34 m·s(-1) (maximal velocity reached at the Yo-Yo IR1); 917 ± 105 Watt, 12.7 ± 3 W·kg(-1) (Wpeak); 3.41 ± 0.5 m·s(-1) and 6.03 ± 0.6 m·s(-1) (sprint velocities for Vs and V5m respectively) and 10.3 ± 1 s (handball skill test). Yo-Yo IR1 test scores showed statistically significant correlations with all of the variables examined: Wpeak (W and W·kg(-1)) r = 0.80 and 0.65, respectively, p≤0.001); sprinting velocities (r = 0.73 and 0.71 for VS and V5m respectively; p≤0.001); jumping performance (SJ: r = 0.60, p≤0.001; CMJ: r= 0.66, p≤0.001) and the handball skill test (r = 0.71; p≤0.001). We concluded that the Yo-Yo test score showed a sufficient correlation with other potential means of assessing handball players, and that intra-individual changes of Yo-Yo IR1 score could provide a useful composite index of the response to training or rehabilitation, although correlations lack sufficient precision to help in players' selection.

  7. Tennis elbow: a review.

    PubMed

    Noteboom, T; Cruver, R; Keller, J; Kellogg, B; Nitz, A J

    1994-06-01

    Tennis elbow is a common yet sometimes complex musculoskeletal condition affecting many patients treated by physical therapists. The purpose of this article is to review the anatomy, clinical examination, differential diagnosis, conservative care, and surgical treatment for tennis elbow or lateral epicondylitis. Particular attention is given to determining the precise pathological cause of lateral epicondylitis, with consideration of intrinsic and extrinsic factors associated with this condition. This information should assist health care practitioners who treat patients with this disorder.

  8. The Variability of the Serve Toss in Tennis Under the Influence of Artificial Crosswind

    PubMed Central

    Mendes, Pedro C.; Fuentes, Juan P.; Mendes, Rui; Martins, Fernando M.L.; Clemente, Filipe M.; Couceiro, Micael S.

    2013-01-01

    This study was made to analyze the variability and stability of the serve toss in tennis, on the x (side-to-side), y (back-to-front) and z (vertical) axes, with 12 experienced players under the influence of crosswind (induced aerodynamic flow) produced by an industrial ventilator. The players were analyzed individually after serving at maximum speed and accuracy to the intersection point of the centre line and service line (“T ”point). The results allow us to conclude that the experienced players tend to stabilize the vertical dimension of the service (z axis). Additionally, this study confirms the invariability of the player height ratio: height of impact (1:1.5) in experienced players even when constrained by the “artificial crosswind. ”Given the above, the vertical dimension of the tennis serve is assumed as a constant feature, which is guaranteed in the remaining varying dimensions (y and x axes) of the ball toss. Thus, the variability should be seen as part of the solution and not as something to be avoided by players and coaches. Key Points Analysis of the tennis serve variability under the effect of artificial crosswind Twelve experienced tennis players performed a set of 20 free serves (without wind constraints), and four other sets of 20 serves under different practice conditions (with different crosswind intensities) The players tend to stabilize in the z axis and vary in the y- (back-to-front) and x-axes (side-to-side) during the ball toss tennis serve in all the practice conditions (with and without crosswind) The maintenance of a player height ratio: impact height of approximately 1:1.5 in experienced players, even when constrained by “artificial crosswind”. PMID:24149810

  9. Tennis service stroke benefits humerus bone: is torsion the cause?

    PubMed

    Ireland, Alex; Degens, Hans; Maffulli, Nicola; Rittweger, Jörn

    2015-08-01

    Regular tennis play is associated with impressive asymmetries in bone strength in favor of the racquet arm, particularly in the humerus. However, the relative effects of service and ground strokes are not known. Serendipitously, we encountered a 46-year-old regular tennis player who has played service and ground strokes with different arms for over 30 years, and thus allowed differentiation of stroke effects. Grip strength and peripheral quantitative computed tomography scans of both arms of radius at 4 % distal-proximal ulna length, radius and ulna at 60 % distal-proximal ulna length, and at distal (35 % length) humerus were analyzed in this player, and 12 male veteran players of similar age, height, and mass who played a conventional single-sided style. Confidence intervals (95 %) were calculated for asymmetries and bone, muscle and force parameters in the control players-values in the case study player were compared to these intervals. Sizeable differences in bone strength in favor of the serving arm humerus were observed in this player-comparable to those found in the control players. While asymmetries in favor of the ground stroke arm ulna were also evident, no sizeable asymmetry was found in proximal or distal radius, forearm or upper arm muscle size or hand grip force. These results suggest that the service stroke is responsible for the humeral hypertrophy observed in tennis players, and that ulna adaptation may be attributable to the ground strokes. The osteogenic potential of the service stroke may be related to the large torsional stresses it produces.

  10. Rhabdomyolysis After Out-of-Water Exercise in an Elite Adolescent Water Polo Player Carrying the IL-6 174C Allele Single-Nucleotide Polymorphism.

    PubMed

    Eliakim, Alon; Ben Zaken, Sigal; Meckel, Yoav; Yamin, Chen; Dror, Nitzan; Nemet, Dan

    2015-12-01

    We present an adolescent elite water polo player who despite a genetic predisposition to develop exercise-induced severe muscle damage due to carrying the IL-6 174C allele single-nucleotide polymorphism, developed acute rhabdomyolysis only after a vigorous out-of-water training, suggesting that water polo training may be more suitable for genetically predisposed athletes.

  11. [Nutritional status and physical condition of adolescent football players after consuming fishmeal as a nutritional complement].

    PubMed

    Accinelli-Tanaka, Roberto; López-Oropeza, Lidia

    2013-03-01

    The objective of the study is to identify the changes in the nutritional parameters and the physical condition of teenage players after eating fishmeal as a nutritional complement. For this purpose, a quasi-experimental study, blinded for investigators, was conducted, involving 100 teenage football players, divided in two groups, homogeneous in terms of all study parameters, one of which received fishmeal for four months. After evaluating the nutritional status and physical condition, before and after the intervention, no change was found in the nutritional and anthropometric status or laboratory results, or in the physical condition. However, those who received fishmeal did report a change in their hemoglobin and hematocrit levels in comparison to the control group. In conclusion, the consumption of fishmeal did not lead to changes in the nutritional status or the physical condition of teenage football players.

  12. Physical characteristics of elite adolescent female basketball players and their relationship to match performance

    PubMed Central

    Montalvo, Alicia; Latinjak, Alexander; Unnithan, Viswanath

    2016-01-01

    Abstract There were two aims of this study: first, to investigate physical fitness and match performance differences between under-16 (U16) and under-18 (U18) female basketball players, and second, to evaluate the relationship between physical fitness and game-related performances. Twenty-three young, female, elite Spanish basketball players (16.2 1.2 years) participated in the study. The sample was divided into two groups: U16 and U18 players. The average scores from pre- and post-season physical fitness measurements were used for subsequent analyses. Anthropometric variables were also measured. To evaluate game performance, game-related statistics, including the number of games and minutes played, points, rebounds, assists, steals and blocks per game, were recorded for every competitive match in one season. When anthropometric and physical performance variables were compared between groups, the U18 group demonstrated significantly (p<0.05) higher values in upper (+21.2%) and lower (+27.11%) limb strength compared to the U16 group. Furthermore, no significant differences between groups were observed in match performance outcomes. Only two performance variables, steals and assists per game, correlated significantly with jump capacity, speed, agility, anaerobic power, repeated sprint ability and aerobic power (p ≤ 0.005). These findings can help optimize training programs for young, elite female basketball players. PMID:28149421

  13. Tennis, incidence of URTI and salivary IgA.

    PubMed

    Novas, A M P; Rowbottom, D G; Jenkins, D G

    2003-04-01

    Tennis played at an elite level requires intensive training characterized by repeated bouts of brief intermittent high intensity exercise over relatively long periods of time (1 - 3 h or more). Competition can place additional stress on players. The purpose of this study was to investigate the temporal association between specific components of tennis training and competition, the incidence of upper respiratory tract infections (URTI), and salivary IgA, in a cohort of seventeen elite female tennis players. Timed, whole unstimulated saliva samples were collected before and after selected 1-h training sessions at 2 weekly intervals, over 12 weeks. Salivary IgA concentration was measured by ELISA and IgA secretion rate calculated (microg IgA x ml -1 x ml saliva x min -1). Players reported URTI symptoms and recorded training and competition in daily logs. Data analysis showed that higher incidence of URTI was significantly associated with increased training duration and load, and competition level, on a weekly basis. Salivary IgA secretion rate (S-IgA) dropped significantly after 1 hour of tennis play. Over the 12-week period, pre-exercise salivary IgA concentration and secretion rate were directly associated with the amount of training undertaken during the previous day and week (p < 0.05). However, the decline in S-IgA after 1 h of intense tennis play was also positively related to the duration and load of training undertaken during the previous day and week (p < 0.05). Although exercise-induced suppression of salivary IgA may be a risk factor, it could not accurately predict the occurrence of URTI in this cohort of athletes.

  14. Basketball Performance Is Related to Maturity and Relative Age in Elite Adolescent Players.

    PubMed

    Torres-Unda, Jon; Zarrazquin, Idoia; Gravina, Leyre; Zubero, Jaime; Seco, Jesús; Gil, Susana M; Gil, Javier; Irazusta, Jon

    2016-05-01

    During a national championship, the anthropometric, physiological, and maturation characteristics of 13- to 14-year-old players of elite basketball teams and their association with sport performance were analyzed. Body parameters (weight, height, skinfold thicknesses, and lengths) were measured and physiological capacities assessed by sprint (20 m) and jump tests (i.e., countermovement jump with arm swing). Chronological age (CA) and maturity offset (years from age at peak height velocity; YAPHV) were calculated, and then predicted age at peak height velocity, as the difference between CA and YAPHV. Game performance was assessed with point averages and the performance index rating (PIR). The birth-date distribution of players was biased, those born early in the selection year outnumbering those born later. Anthropometric analysis indicated that players who performed better had longer body lengths. Physiological testing showed that semi-finalists had better sprint performance than quarter-finalists and those players with greater jump capacity scored more points. Early maturation and advanced maturity status were also associated with better PIR and scored points per game. Multiple blockwise regression analysis showed that, among the factors analyzed, YAPHV was the best predictor of basketball performance. In conclusion, around puberty, physical and physiological parameters associated with maturity and CA are important in determining the success of elite basketball players. Consequently, boys who are born in the second half of the year and/or late maturing tend to be marginalized or totally excluded, and not given the chance to play under equal conditions; their careers may then be held back by the relative disadvantage associated with inexperience.

  15. Leaving the professional tennis circuit: exploratory study of experiences and reactions from elite female athletes

    PubMed Central

    Young, J A; Pearce, A J; Kane, R; Pain, M

    2006-01-01

    In 2002, Tennis Australia commissioned a report into the experiences of elite female past players on leaving the professional tennis circuit. Australian players who were in the top 800 of the Women's Tennis Association (WTA) end of year rankings and who had left the professional circuit within the previous 15 years were asked by mail to respond to a questionnaire. The questionnaire asked players to describe their feelings about leaving the tour during the time leading up to leaving the tour to two years after retirement. The main findings of the study suggested that those who planned to leave the tour found the transition process easy, whereas those who did not plan to leave the tour found the process difficult. Most players (66%) did not regret leaving the tour, and, although the remaining players responded that they regretted leaving, none attempted a comeback. Tennis Australia has implemented strategies to assist current players on the professional tour based on the results of this study. PMID:16632584

  16. Comparison of Lateral Abdominal Muscle Thickness and Cross Sectional Area of Multifidus in Adolescent Soccer Players with and without Low Back Pain: A Case Control Study

    PubMed Central

    Noormohammadpour, Pardis; Hosseini Khezri, Alireza; Linek, Paweł; Mansournia, Mohammad Ali; Hassannejad, Alireza; Younesian, Ali; Farahbakhsh, Farzin; Kordi, Ramin

    2016-01-01

    Background Low back pain (LBP) is a common complaint amongst adolescent athletes. While different studies have shown association between LBP and trunk muscle thickness in the general population, few articles have studied it in adolescent athletes. Objectives The aim of this study is to compare lateral abdominal muscle thickness and function, and cross sectional area (CSA) of lumbar multifidus (LM) in adolescent soccer players with and without LBP. Methods In total, 28 adolescent soccer players with and without LBP, from the premier league participated in this study. The thickness of external oblique, internal oblique and transversus abdominis and the CSA of the LM muscles at L4 level on both sides were measured at rest and contraction via ultrasound imaging (USI). In addition, leg length discrepancy, hamstring flexibility, active lumbar forward flexion, and isometric muscle endurance of trunk extensors were measured in both groups. (study design/setting: case control study). Results The mean (SD) age in LBP group and non-LBP group were 14.0 (1.1) and 14.1 (0.9) years, respectively. There was no significant difference in baseline characteristics of participants between groups. Findings showed no significant difference between LBP and non-LBP groups comparing all measured variables. Conclusions The data obtained support that there is not a correlation between abdominal muscle thickness and CSA of the lumbar multifidi and LBP in adolescent soccer players. These findings suggest that other factors rather than the thickness of deep trunk muscles may play a more significant role in the etiology of LBP in adolescent soccer players. PMID:28144414

  17. Quantitative Evaluation of Growth Plates around the Knees of Adolescent Soccer Players by Diffusion-Weighted Magnetic Resonance Imaging

    PubMed Central

    Krajnc, Zmago; Rupreht, Mitja; Drobnič, Matej

    2015-01-01

    Purpose. To quantitatively evaluate growth plates around the knees in adolescent soccer players utilizing the diffusion-weighted MR imaging (DWI). Methods. The knees and adjacent growth plates of eleven 14-year-old male soccer players were evaluated by MRI before (end of season's summer break) and after two months of intense soccer training. MRI evaluation was conducted in coronal plane by PD-FSE and DWI. All images were screened for any major pathological changes. Later, central growth plate surface area (CGPSA) was measured and the apparent diffusion coefficient (ADC) values were calculated in two most central coronal slices divided into four regions: distal femur medial (DFM), distal femur lateral (DFL), proximal tibia medial (PTM), and proximal tibia lateral (PTL). Results. No gross pathology was diagnosed on MRI. CGPSA was not significantly reduced: DFM 278 versus 272, DFL 265 versus 261, PTM 193 versus 192, and PTL 214 versus 210. ADC decrease was statistically significant only for PTM: DFM 1.27 versus 1.22, DFL 1.37 versus 1.34, PTM 1.13 versus 1.03 (p = 0.003), and PTL 1.28 versus 1.22. Conclusions. DWI measurements indicate increased cellularity in growth plates around knees in footballers most prominent in PTM after intense training. No detectable differences on a standard PD-FSE sequence were observed. PMID:26693482

  18. Why bigger may in fact be better... in the context of table tennis

    NASA Astrophysics Data System (ADS)

    Truscott, Tadd; Pan, Zhao; Belden, Jesse

    2014-11-01

    We submit that table tennis is too fast. Because of the high ball velocities relative to the small table size, players are required to act extremely quickly, often exceeding the limits of human reaction time. Additionally, the Magnus effect resulting from large rotation rates introduces dramatically curved paths and causes rapid direction changes after striking the table or paddle, which effectively reduces reaction time further. Moreover, watching a professional game is often uninteresting and even tiring because the ball is moving too quickly to follow with the naked eye and the action of the players is too subtle to resolve from a distance. These facts isolate table tennis from our quantitatively defined ``fun game club,'' and make it less widely appealing than sports like baseball and soccer. Over the past 100 years, the rules of table tennis have changed several times in an effort to make the game more attractive to players and spectators alike, but the game continues to lose popularity. Here, we experimentally quantify the historic landmark equipment changes of table tennis from a fluid dynamics perspective. Based on theory and observation, we suggest a larger diameter ball for table tennis to make the game more appealing to both spectators and amateur players.

  19. Effects of pre-exercise, endurance, and recovery designer sports drinks on performance during tennis tournament simulation.

    PubMed

    Peltier, Sébastien L; Leprêtre, Pierre-Marie; Metz, Lore; Ennequin, Gael; Aubineau, Nicolas; Lescuyer, Jean-François; Duclos, Martine; Brink, Thibault; Sirvent, Pascal

    2013-11-01

    Sports drinks are often used before, during, and after tennis tournaments, but their ability to influence physiological and psychological variables and the characteristics of tennis match play remains uncertain. The objective of this study was to evaluate the impact of ingesting specially formulated pre-exercise, endurance, and recovery sports drinks on glycemia and performance indices during a simulated tennis tournament. Eight well-trained male tennis players performed two 3-match round-robin tennis tournaments although ingesting sports drinks (SPDs) or placebos (PLAs) before, during, and after each match (crossover study design). Before the first tournament, match and drink order were randomized (SPDs or PLAs first) and players were placed under controlled nutritional and hydration conditions. Glycemia, heart rate response, rate of perceived exertion, and notational/match analysis were assessed during each match. Sports drinks maintained higher glycemia levels during match 2 and 3 of the tennis tournament compared with PLAs (p < 0.01). Moreover, higher mean heart rates (p < 0.01) and stroke frequencies (p < 0.01) concomitantly with lower rates of perceived exertion (p < 0.01) were recorded throughout the duration of the tournament, when players used the SPDs. During a 3-match tennis tournament, SPDs allow higher stroke frequency during play, with decreased rates of perceived exertion.

  20. Mental Toughness in Competitive Tennis: Relationships with Resilience and Stress

    PubMed Central

    Cowden, Richard G.; Meyer-Weitz, Anna; Oppong Asante, Kwaku

    2016-01-01

    The present study investigated the relationships between mental toughness (MT), resilience, and stress among competitive South African tennis players. A total of 351 tennis players participating at various competitive standards completed the Sports Mental Toughness Questionnaire, the Resilience Scale for Adults, and a modified version of the Recovery-Stress Questionnaire for Athletes. The results indicated that total MT was positively associated with total resilience (r = 0.59), but negatively associated with total stress (r = -0.44). The resilience subscales of perception of self, perception of future, social competence, and social resources, but not family cohesion, significantly predicted total MT (R2 = 0.35). Both total resilience and total MT significantly predicted total stress (R2 = 0.21). Based on the findings, interrelations between MT and resilience are explored, implications outlined, and additional research is suggested to ascertain the contextual relevance and outcomes associated with each construct in sport. PMID:27014132

  1. Mental Toughness in Competitive Tennis: Relationships with Resilience and Stress.

    PubMed

    Cowden, Richard G; Meyer-Weitz, Anna; Oppong Asante, Kwaku

    2016-01-01

    The present study investigated the relationships between mental toughness (MT), resilience, and stress among competitive South African tennis players. A total of 351 tennis players participating at various competitive standards completed the Sports Mental Toughness Questionnaire, the Resilience Scale for Adults, and a modified version of the Recovery-Stress Questionnaire for Athletes. The results indicated that total MT was positively associated with total resilience (r = 0.59), but negatively associated with total stress (r = -0.44). The resilience subscales of perception of self, perception of future, social competence, and social resources, but not family cohesion, significantly predicted total MT (R (2) = 0.35). Both total resilience and total MT significantly predicted total stress (R (2) = 0.21). Based on the findings, interrelations between MT and resilience are explored, implications outlined, and additional research is suggested to ascertain the contextual relevance and outcomes associated with each construct in sport.

  2. Effects of Plyometric and Sprint Training on Physical and Technical Skill Performance in Adolescent Soccer Players.

    PubMed

    Sáez de Villarreal, Eduardo; Suarez-Arrones, Luis; Requena, Bernardo; Haff, Gregory G; Ferrete, Carlos

    2015-07-01

    To determine the influence of a short-term combined plyometric and sprint training (9 weeks) within regular soccer practice on explosive and technical actions of pubertal soccer players during the in-season. Twenty-six players were randomly assigned to 2 groups: control group (CG) (soccer training only) and combined group (CombG) (plyometric + acceleration + dribbling + shooting). All players trained soccer 4 times per week and the experimental groups supplemented the soccer training with a proposed plyometric-sprint training program for 40 minutes (2 days per weeks). Ten-meter sprint, 10-m agility with and without ball, CMJ and Abalakov vertical jump, ball-shooting speed, and Yo-Yo intermittent endurance test were measured before and after training. The experimental group followed a 9-week plyometric and sprint program (i.e., jumping, hurdling, bouncing, skipping, and footwork) implemented before the soccer training. Baseline-training results showed no significant differences between the groups in any of the variables tested. No improvement was found in the CG; however, meaningful improvement was found in all variables in the experimental group: CMJ (effect size [ES] = 0.9), Abalakov vertical jump (ES = 1.3), 10-m sprint (ES = 0.7-0.9), 10-m agility (ES = 0.8-1.2), and ball-shooting speed (ES = 0.7-0.8). A specific combined plyometric and sprint training within regular soccer practice improved explosive actions compared with conventional soccer training only. Therefore, the short-term combined program had a beneficial impact on explosive actions, such as sprinting, change of direction, jumping, and ball-shooting speed which are important determinants of match-winning actions in soccer performance. Therefore, we propose modifications to current training methodology for pubertal soccer players to include combined plyometric and speed training for athlete preparation in this sport.

  3. Anyone for Tennis?

    ERIC Educational Resources Information Center

    de Mestre, Neville

    2004-01-01

    Tennis is a sport in which the mathematics involves an unusual scoring system together with other applications pertinent to the draw for different types of tournaments and the relative ratios of points won and lost. The name of the sport is thought to have originated from the French word "tenez", which translates roughly as "to receive (the…

  4. Biomechanical analysis of abdominal injury in tennis serves. A case report.

    PubMed

    Tubez, François; Forthomme, Bénédicte; Croisier, Jean-Louis; Cordonnier, Caroline; Brüls, Olivier; Denoël, Vincent; Berwart, Gilles; Joris, Maurice; Grosdent, Stéphanie; Schwartz, Cédric

    2015-06-01

    The serve is an important stroke in any high level tennis game. A well-mastered serve is a substantial advantage for players. However, because of its repeatability and its intensity, this stroke is potentially deleterious for upper limbs, lower limbs and trunk. The trunk is a vital link in the production and transfer of energy from the lower limbs to the upper limbs; therefore, kinematic disorder could be a potential source of risk for trunk injury in tennis. This research studies the case of a professional tennis player who has suffered from a medical tear on the left rectus abdominis muscle after tennis serve. The goal of the study is to understand whether the injury could be explained by an inappropriate technique. For this purpose, we analyzed in three dimensions the kinematic and kinetic aspects of the serve. We also performed isokinetic tests of the player's knees. We then compared the player to five other professional players as reference. We observed a possible deficit of energy transfer because of an important anterior pelvis tilt. Some compensation made by the player during the serve could be a possible higher abdominal contraction and a larger shoulder external rotation. These particularities could induce an abdominal overwork that could explain the first injury and may provoke further injuries. Key pointsIn the proximal-distal sequence, energy is transmitted from lower limbs to upper limps via trunk.The 3D analysis tool is an indispensable test for an objective evaluation of the kinematic in the tennis serve.Multiple evaluations techniques are useful for fuller comprehension of the kinematics and contribute to the awareness of the player's staff concerning pathologies and performance.

  5. Collision avoidance behavior as a function of aging and tennis playing.

    PubMed

    Lobjois, Régis; Benguigui, Nicolas; Bertsch, Jean; Broderick, Michael P

    2008-02-01

    Daily living often requires pedestrians and drivers to adapt their behavior to the displacement of other objects in their environment in order to avoid collision. Yet little research has paid attention to the effect of age on the completion of such a challenging task. The purpose of this study was to examine the relationship between age and collision avoidance skill and whether a sporting activity affects this. Three age groups (20-30, 60-70, and 70-80 years) of tennis players and non-players launched a projectile toward a target in order to hit it before it was hit by another "object" (a stimulus represented by apparent motion of lights). If the participant judged that time-to-collision (TTC) of the moving stimulus was not long enough for him/her to launch the projectile in time to arrive before the stimulus, the participant had to inhibit the launching. Results showed that for the non-players the number of errors in the 70-80 year-old group was significantly higher than those of the 20-30 and 60-70 year-old groups, which did not differ from each other. However, this increase was not observed in the 70-80 year-old tennis players, demonstrating a beneficial effect of playing tennis on collision avoidance skill. Results also revealed that the older groups of both tennis players and non-players were subject to the typical age-related increase in response time. Additional analyses indicated that the 70-80 year-old non-players did not adjust their actions to these age-related changes in response time. The older tennis-playing participants, however, were more likely to adjust collision avoidance behavior to their diminished response times.

  6. Posttraumatic fat necrosis presenting as prepatellar loose bodies in an adolescent football player.

    PubMed

    Sole, Joshua S; Wisniewski, Steve J; Dahm, Diane L; Bond, Jeffrey; Smith, Jay

    2014-08-01

    A 16-year-old high school football player presented with 4 months of anterior knee pain and small, mobile, prepatellar "lumps" after falling onto an opponent's cleat. He reported knee pain primarily during knee flexion and direct pressure during squatting and kneeling. Knee radiographs were unremarkable. Ultrasonography revealed multiple, freely mobile, subcutaneous nodules of variable size and echogenicity in the prepatellar region. Analysis of magnetic resonance imaging suggested possible fat necrosis but was nondiagnostic. The patient opted for surgical exploration, at which time multiple, opalescent subcutaneous nodules were removed. Pathology was consistent with encapsulated fat necrosis. After surgery, his symptoms resolved, and he returned to sports without restrictions.

  7. On- and Off-Field Antisocial and Prosocial Behavior in Adolescent Soccer Players: A Multilevel Study

    ERIC Educational Resources Information Center

    Rutten, Esther A.; Dekovic, Maja; Stams, Geert Jan J. M.; Schuengel, Carlo; Hoeksma, Jan B.; Biesta, Gert J. J.

    2008-01-01

    This study investigated to what extent team membership predicts on- and off-field antisocial and prosocial behavior in (pre)adolescent athletes. Effects of team-membership were related to characteristics of the team environment, such as relational support from the coach towards team members, fair play attitude and sociomoral reasoning within the…

  8. Effects of an off-season conditioning program on the physical characteristics of adolescent rugby union players.

    PubMed

    Smart, Daniel J; Gill, Nicholas D

    2013-03-01

    The aims of the study were to determine if a supervised off-season conditioning program enhanced gains in physical characteristics compared with the same program performed in an unsupervised manner and to establish the persistence of the physical changes after a 6-month unsupervised competition period. Forty-four provincial representative adolescent rugby union players (age, mean ± SD, 15.3 ± 1.3 years) participated in a 15-week off-season conditioning program either under supervision from an experienced strength and conditioning coach or unsupervised. Measures of body composition, strength, vertical jump, speed, and anaerobic and aerobic running performance were taken, before, immediately after, and 6 months after the conditioning. Post conditioning program the supervised group had greater improvements in all strength measures than the unsupervised group, with small, moderate and large differences between the groups\\x{2019} changes for chin-ups (9.1%; ± 11.6%), bench-press (16.9%; ± 11.7%) and box-squat (50.4%; ± 20.9%) estimated 1RM respectively. Both groups showed trivial increases in mass; however increases in fat free mass were small and trivial for supervised and unsupervised players respectively. Strength declined in the supervised group while the unsupervised group had small increases during the competition phase, resulting in only a small difference between the long-term changes in box-squat 1RM (15.9%; ± 13.2%). The supervised group had further small increases in fat free mass resulting in a small difference (2.4%; ± 2.7%) in the long-term changes. The postconditioning differences between the 2 groups may have been a result of increased adherence and the attainment of higher training loads during supervised training. The lack of differences in strength after the competition period indicates that supervision should be maintained to reduce substantial decrements in performance.

  9. Training increases anabolic response and reduces inflammatory response to a single practice in elite male adolescent volleyball players.

    PubMed

    Nemet, Dan; Portal, Shawn; Zadik, Zvi; Pilz-Burstein, Rutie; Adler-Portal, Dana; Meckel, Yoav; Eliakim, Alon

    2012-01-01

    We examined the effect of training on hormonal and inflammatory response to a single volleyball practice in elite adolescent players. Fourteen male, elite, national team-level, Israeli volleyball players (age, 16.3±1.1 years, Tanner stage 4-5) participated in the study. Blood samples were collected before and immediately after a typical 60-min volleyball practice, before and after 7 weeks of training during the initial phases of the volleyball season. Hormonal measurements included the anabolic hormones growth hormone (GH), insulin-like growth factor 1 (IGF-1), IGF-binding protein 3, and testosterone; the catabolic hormone cortisol; the pro-inflammatory markers interleukin (IL) 6, and the anti-inflammatory marker IL-1 receptor antagonist. Training led to a significant improvement of both anaerobic and aerobic properties. Before the training intervention, the typical volleyball practice was associated with a significant increase of GH and testosterone and also with a significant increase of IL-6. Training resulted in a significantly greater GH response (ΔGH, 2.5±2.4 vs. 4.7±3.0 ng/mL, before and after training, respectively; p<0.02) and reduced IL-6 response (ΔIL-6, 2.0±1.6 vs. 0.6±0.7 pg/mL, before and after training, respectively; p<0.01) to the same relative intensity volleyball practice. The results suggest that, along with the improvement of anaerobic and aerobic characteristics, training leads to a greater anabolic and reduced inflammatory response to exercise.

  10. Training Level Does Not Affect Auditory Perception of The Magnitude of Ball Spin in Table Tennis.

    PubMed

    Santos, Daniel P R; Barbosa, Roberto N; Vieira, Luiz H P; Santiago, Paulo R P; Zagatto, Alessandro M; Gomes, Matheus M

    2017-01-01

    Identifying the trajectory and spin of the ball with speed and accuracy is critical for good performance in table tennis. The aim of this study was to analyze the ability of table tennis players presenting different levels of training/experience to identify the magnitude of the ball spin from the sound produced when the racket hit the ball. Four types of "forehand" contact sounds were collected in the laboratory, defined as: Fast Spin (spinning ball forward at 140 r/s); Medium Spin (105 r/s); Slow Spin (84 r/s); and Flat Hit (less than 60 r/s). Thirty-four table tennis players of both sexes (24 men and 10 women) aged 18-40 years listened to the sounds and tried to identify the magnitude of the ball spin. The results revealed that in 50.9% of the cases the table tennis players were able to identify the ball spin and the observed number of correct answers (10.2) was significantly higher (χ(2) = 270.4, p <0.05) than the number of correct answers that could occur by chance. On the other hand, the results did not show any relationship between the level of training/experience and auditory perception of the ball spin. This indicates that auditory information contributes to identification of the magnitude of the ball spin, however, it also reveals that, in table tennis, the level of training does not interfere with the auditory perception of the ball spin.

  11. Relationships Between the Yo-Yo Intermittent Recovery Test and Anaerobic Performance Tests in Adolescent Handball Players

    PubMed Central

    Hermassi, Souhail; Aouadi, Ridha; Khalifa, Riadh; van den Tillaar, Roland; Shephard, Roy J.; Chelly, Mohamed Souhaiel

    2015-01-01

    The aim of the present study was to investigate relationships between a performance index derived from the Yo-Yo Intermittent Recovery Test level 1 (Yo-Yo IR1) and other measures of physical performance and skill in handball players. The other measures considered included peak muscular power of the lower limbs (Wpeak), jumping ability (squat and counter-movement jumps (SJ, CMJ), a handball skill test and the average sprinting velocities over the first step (VS) and the first 5 m (V5m). Test scores for 25 male national-level adolescent players (age: 17.2 ± 0.7 years) averaged 4.83 ± 0.34 m·s−1 (maximal velocity reached at the Yo-Yo IR1); 917 ± 105 Watt, 12.7 ± 3 W·kg−1 (Wpeak); 3.41 ± 0.5 m·s−1 and 6.03 ± 0.6 m·s−1 (sprint velocities for Vs and V5m respectively) and 10.3 ± 1 s (handball skill test). Yo-Yo IR1 test scores showed statistically significant correlations with all of the variables examined: Wpeak (W and W·kg−1) r = 0.80 and 0.65, respectively, p≤0.001); sprinting velocities (r = 0.73 and 0.71 for VS and V5m respectively; p≤0.001); jumping performance (SJ: r = 0.60, p≤0.001; CMJ: r= 0.66, p≤0.001) and the handball skill test (r = 0.71; p≤0.001). We concluded that the Yo-Yo test score showed a sufficient correlation with other potential means of assessing handball players, and that intra-individual changes of Yo-Yo IR1 score could provide a useful composite index of the response to training or rehabilitation, although correlations lack sufficient precision to help in players’ selection. PMID:25964822

  12. Aging and Tennis Playing in a Coincidence-Timing Task with an Accelerating Object: The Role of Visuomotor Delay

    ERIC Educational Resources Information Center

    Lobjois, Regis; Benguigui, Nicolas; Bertsch, Jean

    2005-01-01

    The purpose of the present study was to determine whether playing a specific ball sport, such as tennis, could maintain the coincidence-timing (CT) performance of older adults at a similar level to that of younger ones. To address this question, tennis players and nonplayers of three different age ranges (ages 20-30, 60-70, and 70-80 years)…

  13. Increased Training Volume Improves Bone Density and Cortical Area in Adolescent Football Players.

    PubMed

    Varley, Ian; Hughes, David C; Greeves, Julie P; Fraser, William D; Sale, Craig

    2017-03-01

    Habitual football participation has been shown to be osteogenic, although the specific volume of football participation required to cause bone adaptations are not well established. The aim of the present study is to investigate tibial bone adaptations in response to 12 weeks of increased training volume in elite adolescents who are already accustomed to irregular impact training. 99 male adolescent elite footballers participated (age 16±0 y; height 1.76±0.66 m; body mass 70.2±8.3 kg). Tibial scans were performed using peripheral quantitative computed tomography immediately before and 12 weeks after an increase in football training volume. Scans were obtained at 4, 14, 38 and 66% of tibial length. Trabecular density (mg/cm(3)), cortical density (mg/cm(3)), cross-sectional area, cortical area (mm(2)), cortical thickness (mm) and strength strain index (mm(3)) were assessed. Trabecular (4%) and cortical density (14, 38%), cortical cross-sectional area (14, 38%), total cross-sectional area (66%), cortical thickness (14, 38%) and strength strain index (14, 38%) increased following 12 weeks of augmented volume training (P<0.05). Increased density of trabecular and cortical compartments and cortical thickening were shown following an increased volume of training. These adaptive responses may have been enhanced by the adolescent status of the cohort, supporting the role of early exercise intervention in improving bone strength.

  14. A Shot Number Based Approach to Performance Analysis in Table Tennis

    PubMed Central

    Yoshida, Kazuto; Yamada, Koshi

    2017-01-01

    Abstract The current study proposes a novel approach that improves the conventional performance analysis in table tennis by introducing the concept of frequency, or the number of shots, of each shot number. The improvements over the conventional method are as follows: better accuracy of the evaluation of skills and tactics of players, additional insights into scoring and returning skills and ease of understanding the results with a single criterion. The performance analysis of matches played at the 2012 Summer Olympics in London was conducted using the proposed method. The results showed some effects of the shot number and gender differences in table tennis. Furthermore, comparisons were made between Chinese players and players from other countries, what threw light on the skills and tactics of the Chinese players. The present findings demonstrate that the proposed method provides useful information and has some advantages over the conventional method. PMID:28210334

  15. Teaching and Coaching Tennis Using System 5

    ERIC Educational Resources Information Center

    Helfrich, Janet

    2006-01-01

    The United States Professional Tennis Association (USPTA) has developed a universal language for tennis instruction entitled System 5: The Five Keys to Tennis, which is extremely easy to teach and learn and covers court positioning, strategy, and stroke selection. Many professional tennis instructors have used System 5 since its inception but…

  16. The prevalence of musculoskeletal pain and use of painkillers among adolescent male ice hockey players in Finland.

    PubMed

    Selanne, Harri; Ryba, Tatiana V; Siekkinen, Kirsti; Kyröläinen, Heikki; Kautiainen, Hannu; Hakonen, Harto; Mikkelsson, Marja; Kujala, Urho M

    2014-01-01

    Participating in competitive sport increases the risk for injuries and musculoskeletal pain among adolescent athletes. There is also evidence that the use of prescription drugs has increased among sport club athletes. The purpose of this study was to evaluate the use of painkillers among young male ice hockey players (IHP) in comparison to schoolboys (controls) and its relation to the prevalence of musculoskeletal pain and problems during activities and sleeping. Information was gathered through a questionnaire, completed by 121 IHP and compared to the responses of 618 age-matched controls. Results showed that monthly existing pain was at 82% for IHP, and 72% for controls, though IHP had statistically more musculoskeletal pain in their lower limbs (56% vs. 44%), lower back (54% vs. 35%), and buttocks (26% vs. 11%). There were no group differences in the neck, upper back, upper limb, or chest areas. The disability index was statistically similar for both groups, as musculoskeletal pain causing difficulties in daily activities and sleeping was reported by a minority of subjects. Despite this similarity, IHP used more painkillers than controls (18% vs. 10%). Further nuanced research is encouraged to compare athletes and non-athletes in relation to painkillers.

  17. A caffeinated energy drink improves jump performance in adolescent basketball players.

    PubMed

    Abian-Vicen, Javier; Puente, Carlos; Salinero, Juan José; González-Millán, Cristina; Areces, Francisco; Muñoz, Gloria; Muñoz-Guerra, Jesús; Del Coso, Juan

    2014-05-01

    This study aimed at investigating the effects of a commercially available energy drink on shooting precision, jump performance and endurance capacity in young basketball players. Sixteen young basketball players (first division of a junior national league; 14.9 ± 0.8 years; 73.4 ± 12.4 kg; 182.3 ± 6.5 cm) volunteered to participate in the research. They ingested either (a) an energy drink that contained 3 mg of caffeine per kg of body weight or (b) a placebo energy drink with the same appearance and taste. After 60 min for caffeine absorption, they performed free throw shooting and three-point shooting tests. After that, participants performed a maximal countermovement jump (CMJ), a repeated maximal jumps test for 15 s (RJ-15), and the Yo-Yo intermittent recovery test level 1 (Yo-Yo IR1). Urine samples were obtained before and 30 min after testing. In comparison to the placebo, the ingestion of the caffeinated energy drink did not affect precision during the free throws (Caffeine = 70.7 ± 11.8 % vs placebo = 70.3 ± 11.0 %; P = 0.45), the three-point shooting test (39.9 ± 11.8 vs 38.1 ± 12.8 %; P = 0.33) or the distance covered in the Yo-Yo IR1 (2,000 ± 706 vs 1,925 ± 702 m; P = 0.19). However, the energy drink significantly increased jump height during the CMJ (38.3 ± 4.4 vs 37.5 ± 4.4 cm; P < 0.05) mean jump height during the RJ-15 (30.2 ± 3.6 vs 28.8 ± 3.4 cm; P < 0.05) and the excretion of urinary caffeine (1.2 ± 0.7 vs 0.1 ± 0.1 μg/mL; P < 0.05). The intake of a caffeine-containing energy drink (3 mg/kg body weight) increased jump performance although it did not affect basketball shooting precision.

  18. Perception of Kinematic Characteristics of Tennis Strokes for Anticipating Stroke Type and Direction

    ERIC Educational Resources Information Center

    Shim, Jaeho; Carlton, Les G.; Kwon, Young-Hoo

    2006-01-01

    The purpose of this study was to determine the sources of visual information used by highly skilled tennis players in anticipating their opponent's shots. In Experiment 1, motion analysis of the strokes showed that the relative motion between the racquet and forearm was different between the ground strokes and lobs, but there were no reliable…

  19. Mechanism of Tennis Racket Spin Performance

    NASA Astrophysics Data System (ADS)

    Kawazoe, Yoshihiko; Okimoto, Kenji; Okimoto, Keiko

    Players often say that some strings provide a better grip and more spin than others, but ball spin did not depend on string type, gauge, or tension in pervious laboratory experiments. There was no research work on spin to uncover what is really happening during an actual tennis impact because of the difficulty of performing the appropriate experiments. The present paper clarified the mechanism of top spin and its improvement by lubrication of strings through the use of high-speed video analysis. It also provided a more detailed explanation of spin behavior by comparing a racket with lubricated strings with the famous “spaghetti” strung racket, which was banned in 1978 by the International Tennis Federation because it used plastic spaghetti tubing over the strings to reduce friction, resulting in excessive ball spin. As the main strings stretch and slide sideways more, the ball is given additional spin due to the restoring force parallel to the string face when the main strings spring back and the ball is released from the strings. Herein, we also showed that the additional spin results in a reduction of shock vibrations of the wrist joint during impact.

  20. The development of fatigue during match-play tennis

    PubMed Central

    Reid, Machar; Duffield, Rob

    2014-01-01

    Data describing the activity profile and physiological characteristics of tennis match-play are extensive. However, these data have generally provided descriptive accounts of the one-off match-play of amateur or lowly ranked professional players lasting <3 h. Accordingly, these research efforts have likely failed to fully capture the demands of Grand Slam tennis match-play, particularly in the men's game where matches can last >5 h. Furthermore, there is a distinct lack of evidence-based insight regarding the manifestation of fatigue within and between tennis matches, notwithstanding that skeletal muscle function has been reported to reduce following prolonged match-play. Moreover, it is evident that match-play evokes pronounced and prolonged physiological, neuromuscular and psychological perturbations that may be exacerbated with consecutive days of match-play. Separate to these internal load responses, a collection of non-uniform movement and technical performance changes are reported, though rarely from match-play data. Consequently, direct or causal links between altered physiological or muscle contractile function and subsequent match-play outcomes are lacking. Indeed, emerging evidence seems to infer that players adjust their game strategy, and the resultant execution of stroke play, to accommodate any such deterioration in physiological function. The purpose of this review was to discuss the available literature in terms of the physiological, mechanical and psychological responses that occur during prolonged match-play in the context of their likely effect on match-play performance. PMID:24668384

  1. Learning strategies in table tennis using inverse reinforcement learning.

    PubMed

    Muelling, Katharina; Boularias, Abdeslam; Mohler, Betty; Schölkopf, Bernhard; Peters, Jan

    2014-10-01

    Learning a complex task such as table tennis is a challenging problem for both robots and humans. Even after acquiring the necessary motor skills, a strategy is needed to choose where and how to return the ball to the opponent's court in order to win the game. The data-driven identification of basic strategies in interactive tasks, such as table tennis, is a largely unexplored problem. In this paper, we suggest a computational model for representing and inferring strategies, based on a Markov decision problem, where the reward function models the goal of the task as well as the strategic information. We show how this reward function can be discovered from demonstrations of table tennis matches using model-free inverse reinforcement learning. The resulting framework allows to identify basic elements on which the selection of striking movements is based. We tested our approach on data collected from players with different playing styles and under different playing conditions. The estimated reward function was able to capture expert-specific strategic information that sufficed to distinguish the expert among players with different skill levels as well as different playing styles.

  2. Glenohumeral contact force during flat and topspin tennis forehand drives.

    PubMed

    Blache, Yoann; Creveaux, Thomas; Dumas, Raphaël; Chèze, Laurence; Rogowski, Isabelle

    2017-03-01

    The primary role of the shoulder joint in tennis forehand drive is at the expense of the loadings undergone by this joint. Nevertheless, few studies investigated glenohumeral (GH) contact forces during forehand drives. The aim of this study was to investigate GH compressive and shearing forces during the flat and topspin forehand drives in advanced tennis players. 3D kinematics of flat and topspin forehand drives of 11 advanced tennis players were recorded. The Delft Shoulder and Elbow musculoskeletal model was implemented to assess the magnitude and orientation of GH contact forces during the forehand drives. The results showed no differences in magnitude and orientation of GH contact forces between the flat and topspin forehand drives. The estimated maximal GH contact force during the forward swing phase was 3573 ± 1383 N, which was on average 1.25 times greater than during the follow-through phase, and 5.8 times greater than during the backswing phase. Regardless the phase of the forehand drive, GH contact forces pointed towards the anterior-superior part of the glenoid therefore standing for shearing forces. Knowledge of GH contact forces during real sport tasks performed at high velocity may improve the understanding of various sport-specific adaptations and causative factors for shoulder problems.

  3. Reducing the likelihood of long tennis matches.

    PubMed

    Barnett, Tristan; Alan, Brown; Pollard, Graham

    2006-01-01

    Long matches can cause problems for tournaments. For example, the starting times of subsequent matches can be substantially delayed causing inconvenience to players, spectators, officials and television scheduling. They can even be seen as unfair in the tournament setting when the winner of a very long match, who may have negative aftereffects from such a match, plays the winner of an average or shorter length match in the next round. Long matches can also lead to injuries to the participating players. One factor that can lead to long matches is the use of the advantage set as the fifth set, as in the Australian Open, the French Open and Wimbledon. Another factor is long rallies and a greater than average number of points per game. This tends to occur more frequently on the slower surfaces such as at the French Open. The mathematical method of generating functions is used to show that the likelihood of long matches can be substantially reduced by using the tiebreak game in the fifth set, or more effectively by using a new type of game, the 50-40 game, throughout the match. Key PointsThe cumulant generating function has nice properties for calculating the parameters of distributions in a tennis matchA final tiebreaker set reduces the length of matches as currently being used in the US OpenA new 50-40 game reduces the length of matches whilst maintaining comparable probabilities for the better player to win the match.

  4. Effects of A 6-Week Junior Tennis Conditioning Program on Service Velocity

    PubMed Central

    Fernandez-Fernandez, Jaime; Ellenbecker, Todd; Sanz-Rivas, david; Ulbricht, Alexander; Ferrautia, lexander

    2013-01-01

    This study examined the effects of a 6-week strength-training program on serve velocity in youth tennis players. Thirty competitive healthy and nationally ranked male junior tennis players (13 years of age) were randomly and equally divided into control and training groups. The training group performed 3 sessions (60-70 min) weekly for 6 weeks, comprising core strength, elastic resistance and medicine ball exercises. Both groups (control and training) also performed a supervised stretching routine at the end of each training session, during the 6 week intervention. Service velocity, service accuracy and shoulder internal/external rotation were assessed initially and at the end of the 6-week conditioning program for both, control and training groups. There was a significant improvement in the serve velocity for the training group (p = 0. 0001) after the intervention, whereas in the control group there were no differences between pre and post-tests (p = 0.29). Serve accuracy was not affected in the training group (p = 0.10), nor in the control group (p = 0.15). Shoulder internal/external rotation ROM significantly improved in both groups, training (p = 0.001) and control (p = 0.0001). The present results showed that a short- term training program for young tennis players, using minimum equipment and effort, can result in improved tennis performance (i.e., serve velocity) and a reduction in the risk of a possible overuse injury, reflected by an improvement in shoulder external/internal range of motion. Key Points A short-term training program for young tennis players, using minimum equipment and effort, can result in improved tennis performance and a reduction in the risk of a possible overuse injury, reflected by an improvement in shoulder external/internal range of motion A combination of core stabilization, elastic resistance exercises, and upper body plyometric exercises (i.e., medicine ball throws), focussing on the primary muscle groups and stabilizers involved

  5. The beneficial effects of game-based exercise using age-appropriate tennis lessons on the executive functions of 6-12-year-old children.

    PubMed

    Ishihara, Toru; Sugasawa, Shigemi; Matsuda, Yusuke; Mizuno, Masao

    2017-03-06

    This study evaluated the effects of two different types of tennis lessons-those involving a technique-based approach (TBA) and those involving a game-based approach (PLAY+STAY [P+S])-on the executive functions (EFs) of junior tennis players. Eighty-one tennis players (6-12 years old) were recruited and assigned to one of three groups: TBA, P+S, or watching TV (CONT). Subjects completed evaluations of EFs (inhibitory control, working memory, and cognitive flexibility) before and after 50min programs. The overall score for EFs improved significantly for both the P+S and TBA groups but not for the CONT group; indeed the CONT group showed no improvement in overall EFs. Furthermore, the overall EF score improved more for P+S participants than for those in TBA. Looking at components of EFs, the pattern for inhibitory control reflected the pattern for the overall EF index: Improvement in the P+S and TBA groups but not in the CONT group. Only the P+S group improved in working memory. Thus, playing tennis and practicing isolated tennis skills both improved EFs of junior players more than did watching TV, and game-based tennis lessons seem to hold more promise for improving EFs than drills of tennis skills.

  6. The Activity Profile of Young Tennis Athletes Playing on Clay and Hard Courts: Preliminary Data

    PubMed Central

    Adriano Pereira, Lucas; Freitas, Victor; Arruda Moura, Felipe; Saldanha Aoki, Marcelo; Loturco, Irineu

    2016-01-01

    Abstract The aim of this study was to compare the kinematic characteristics of tennis matches between red clay and hard courts in young tennis players. Eight young tennis players performed two tennis matches on different court surfaces. The match activities were monitored using GPS units. The distance covered in different velocity ranges and the number of accelerations were analyzed. The paired t test and inference based on magnitudes were used to compare the match physical performance between groups. The total distance (24% of difference), high-intensity running distance (15 - 18 km/h) (30% of difference), the number of high-intensity activities (44% of difference), the body load (1% of difference), and accelerations >1.5 g (1.5-2 g and >2 g 7.8 and 8.1 % of difference, respectively) were significantly greater in clay court than hard court matches (p < 0.05). Matches played on the red clay court required players to cover more total and high-intensity running distances and engage in more high-intensity activities than the matches played on the hard court. Finally, on the clay court the body load and the number of accelerations performed (>1.5 g) were possibly higher than on the hard court. PMID:28149359

  7. The Activity Profile of Young Tennis Athletes Playing on Clay and Hard Courts: Preliminary Data.

    PubMed

    Adriano Pereira, Lucas; Freitas, Victor; Arruda Moura, Felipe; Saldanha Aoki, Marcelo; Loturco, Irineu; Yuzo Nakamura, Fábio

    2016-04-01

    The aim of this study was to compare the kinematic characteristics of tennis matches between red clay and hard courts in young tennis players. Eight young tennis players performed two tennis matches on different court surfaces. The match activities were monitored using GPS units. The distance covered in different velocity ranges and the number of accelerations were analyzed. The paired t test and inference based on magnitudes were used to compare the match physical performance between groups. The total distance (24% of difference), high-intensity running distance (15 - 18 km/h) (30% of difference), the number of high-intensity activities (44% of difference), the body load (1% of difference), and accelerations >1.5 g (1.5-2 g and >2 g 7.8 and 8.1 % of difference, respectively) were significantly greater in clay court than hard court matches (p < 0.05). Matches played on the red clay court required players to cover more total and high-intensity running distances and engage in more high-intensity activities than the matches played on the hard court. Finally, on the clay court the body load and the number of accelerations performed (>1.5 g) were possibly higher than on the hard court.

  8. Epidemiology of tennis injuries: An eight-year review of Davis Cup retirements.

    PubMed

    Maquirriain, Javier; Baglione, Roberto

    2016-01-01

    Tennis practice, especially at elite levels, may place players at risk for debilitating musculoskeletal injuries. The aim of this study was to analyse the epidemiological pattern of retirements due to medical conditions sustained by tennis players during Davis Cup matches in the 2006-2013 period. All uncompleted matches due to a medical condition (injuries and illnesses) occurred in the above-mentioned competition were collected from the official source, registered and analysed according to published guidelines. The overall incidence of match retirements was 1.66% (12/719). The injury rate was 6.05/1000 playing hours; and 6.64/1000 match exposures. Musculotendinous lesions were the most common type of injury (66.66%). The incidence of lower-limb injuries was higher than upper-limb and trunk lesions. The incidence of retired matches due to medical conditions was higher in hard courts than in clay courts (2.97% and 0.90%, respectively; p = 0.04), while the median value of inactivity of injuries was 32.0 days (range 3-297). In conclusion, the incidence of retirements due to medical conditions in Davis Cup matches was low supporting the assumption that elite tennis is a low-risk sport activity. Findings provided scientific evidences of injury patterns among male professional tennis players and may contribute to conduct better injury prevention strategies.

  9. Effects of sports drinks on the maintenance of physical performance during 3 tennis matches: a randomized controlled study

    PubMed Central

    2014-01-01

    Background Tennis tournaments often involve playing several consecutive matches interspersed with short periods of recovery. Objective The objective of this study was firstly to assess the impact of several successive tennis matches on the physical performance of competitive players and secondly to evaluate the potential of sports drinks to minimize the fatigue induced by repeated matches. Methods This was a crossover, randomized controlled study. Eight male regionally-ranked tennis players participated in this study. Players underwent a series of physical tests to assess their strength, speed, power and endurance following the completion of three tennis matches each of two hours duration played over three consecutive half-days (1.5 day period for each condition). In the first condition the players consumed a sports drink before, during and after each match; in the second, they drank an identical volume of placebo water. The results obtained were compared with the third ‘rest’ condition in which the subjects did not play any tennis. Main outcomes measured were maximal isometric strength and fatigability of knee and elbow extensors, 20-m sprint speed, jumping height, specific repeated sprint ability test and hand grip strength. Results The physical test results for the lower limbs showed no significant differences between the three conditions. Conversely, on the upper limbs the EMG data showed greater fatigue of the triceps brachii in the placebo condition compared to the rest condition, while the ingestion of sports drinks attenuated this fatigue. Conclusions This study has demonstrated for the first time that, when tennis players are adequately hydrated and ingest balanced meals between matches, then no large drop in physical performance is observed even during consecutive competitive matches. Trial registration ClinicalTrials.gov: NCT01353872. PMID:25302057

  10. The Whys of Teaching Tennis

    ERIC Educational Resources Information Center

    Davis, Brett R.; Brusseau, Timothy A.; Hannon, James C.

    2013-01-01

    This article addresses the importance of clearly defining tennis terms and explaining the reasons behind certain techniques so that students will learn and apply the material taught and enjoy the game more fully. (Contains 4 figures.)

  11. Effects of heavy resistance training on maximal and explosive force production, endurance and serum hormones in adolescent handball players.

    PubMed

    Gorostiaga, E M; Izquierdo, M; Iturralde, P; Ruesta, M; Ibáñez, J

    1999-10-01

    To determine the effects of 6-weeks of heavy-resistance training on physical fitness and serum hormone status in adolescents (range 14-16 years old) 19 male handball players were divided into two different groups: a handball training group (NST, n = 10), and a handball and heavy-resistance strength training group (ST, n = 9). A third group of 4 handball goalkeepers of similar age served as a control group (C, n = 4). After the 6-week training period, the ST group showed an improvement in maximal dynamic strength of the leg extensors (12.2%; P < 0.01) and the upper extremity muscles (23%; P < 0.01), while no changes were observed in the NST and C groups. Similar differences were observed in the maximal isometric unilateral leg extension forces. The height of the vertical jump increased in the NST group from 29.5 (SD 4) cm to 31.4 (SD 5) cm (P < 0.05) while no changes were observed in the ST and C groups. A significant increase was observed in the ST group in the velocity of the throwing test [from 71.7 (SD 7) km x h(-1) to 74.0 (SD 7) km x h(-1); P < 0.001] during the 6-week period while no changes were observed in the NST and C groups. During a submaximal endurance test running at 11 km x h(-1), a significant decrease in blood lactate concentration occurred in the NST group [from 3.3 (SD 0.9) mmol x l(-1) to 2.4 (SD 0.8) mmol x l(-1); P < 0.01] during the experiment, while no change was observed in the ST or C groups. Finally, a significant increase (P < 0.01) was noted in the testosterone:cortisol ratio in the C group, while the increase in the NST group approached statistical significance (P < 0.08) and no changes in this ratio occurred in the ST group. The present findings suggested that the addition of 6-weeks of heavy resistance training to the handball training resulted in gains in maximal strength and throwing velocity but it compromised gains in leg explosive force production and endurance running. The tendency for a compromised testosterone:cortisol ratio

  12. The most important points in grand slam singles tennis.

    PubMed

    O'Donoghue, P G

    2001-06-01

    A computerized data management system was used to enter details of points played in 252 tennis matches from the men's and women's singles events of all four Grand Slam tournaments over a 2-year period. A supplementary data analysis system was developed to determine the proportion of points won by each player on serve at each game score from love all to deuce as well as the proportion of games the player went on to win from each score. Analysis of the 43 matches in which both players served at each score from love all to deuce revealed that the proportion of points won by the server was not significantly influenced by score, F(15, 495) = 0.8, p > .05. A further analysis of the 175 matches consisting of at least 100 points revealed that the proportion of points won by the superior player was not significantly influenced by gender, F(1, 165) = 0.1, p > .05, or surface, F(3, 165) = 0.1, p > .05. However, the proportion of points won when serving was significantly greater in men's singles than women's singles, F(1, 165) = 69.7, p < .001, R2 = .30. Surface also had a significant influence on the proportion of points won when serving, F(3, 165) = 8.1, p < .001, R2 = .13, with a significantly greater proportion of points won when serving by both winning and losing players at Wimbledon than at the Australian and French Opens, p < .05. This suggests that gender and surface should be accounted for when determining the importance of points in Grand Slam tennis.

  13. McNeese's Community Tennis Program.

    ERIC Educational Resources Information Center

    Brown, Jim

    1981-01-01

    A year-round tennis instruction program was developed to provide an alternative to private club and municipal programs of tennis instruction. Private and group lessons were given at moderate prices. Other benefits of the program include improved community relations and more opportunities for experience for young tennis instructors. (JN)

  14. Relationship between motor variability, accuracy, and ball speed in the tennis serve.

    PubMed

    Antúnez, Ruperto Menayo; Hernández, Francisco Javier Moreno; García, Juan Pedro Fuentes; Vaíllo, Raúl Reina; Arroyo, Jesús Sebastián Damas

    2012-06-01

    The main objective of this study was to analyze the motor variability in the performance of the tennis serve and its relationship to performance outcome. Seventeen male tennis players took part in the research, and they performed 20 serves. Linear and non-linear variability during the hand movement was measured by 3D Motion Tracking. Ball speed was recorded with a sports radar gun and the ball bounces were video recorded to calculate accuracy. The results showed a relationship between the amount of variability and its non-linear structure found in performance of movement and the outcome of the serve. The study also found that movement predictability correlates with performance. An increase in the amount of movement variability could affect the tennis serve performance in a negative way by reducing speed and accuracy of the ball.

  15. Relationship Between Motor Variability, Accuracy, and Ball Speed in the Tennis Serve

    PubMed Central

    Antúnez, Ruperto Menayo; Hernández, Francisco Javier Moreno; García, Juan Pedro Fuentes; Vaíllo, Raúl Reina; Arroyo, Jesús Sebastián Damas

    2012-01-01

    The main objective of this study was to analyze the motor variability in the performance of the tennis serve and its relationship to performance outcome. Seventeen male tennis players took part in the research, and they performed 20 serves. Linear and non-linear variability during the hand movement was measured by 3D Motion Tracking. Ball speed was recorded with a sports radar gun and the ball bounces were video recorded to calculate accuracy. The results showed a relationship between the amount of variability and its non-linear structure found in performance of movement and the outcome of the serve. The study also found that movement predictability correlates with performance. An increase in the amount of movement variability could affect the tennis serve performance in a negative way by reducing speed and accuracy of the ball. PMID:23486998

  16. Validity of critical frequency test for measuring table tennis aerobic endurance through specific protocol

    PubMed Central

    Zagatto, Alessandro M.; Papoti, Marcelo; Gobatto, Claudio A.

    2008-01-01

    The aim of this study was to validate critical frequency specific test (critf) for the estimation of the aerobic endurance in table tennis players. Methods: Eight male international-level table tennis players participated of this study. Specific tests were applied by using a mechanical ball thrower to control the intensity of the exercise. The critf was determined by applying three or four series of exercises to exhaustion (Tlim). The critf was evaluated by using lactate steady state test (90, 100, and 106 % of critf intensity). The other specific test was an incremental protocol used to determine the anaerobic threshold (AnTBI) and the onset of blood lactate accumulation (OBLA) using a ball thrower. Results: The critf (39.87 ± 3.31 balls·min-1) was not significantly different among AnTBI (48.11 ± 7.36 balls·min- 1) and OBLA3.5 (49.36 ± 12.04 balls·min-1) frequencies and it was correlated with AnTBI parameter (r = 0.78). At frequencies of the 90 and 100% of critf a dynamic equilibrium was verified in lactate concentration between the eighth and twentieth minutes. However, this dynamic equilibrium was not found at 106% intensity. Conclusion: The data indicate that in table tennis the critf model can be used for measuring the aerobic endurance. Key pointsIn table tennis is need the use of a specific protocol for evaluation of the aerobic endurance.The critical frequency test in table tennis seems to represent the intensity of maximal equilibrium of lactatemia.The critical frequency test can be used for measuring table tennis aerobic endurance through specific protocol. PMID:24149951

  17. Shoulder joint kinetics of the elite wheelchair tennis serve

    PubMed Central

    Reid, Machar; Elliott, Bruce; Alderson, Jacque

    2007-01-01

    Background The shoulder is a key joint in wheelchair locomotion and commonly implicated in injury among virtually all wheelchair populations. In tennis, quantification of the shoulder joint kinetics that characterise the wheelchair serve could enhance injury prevention and rehabilitation practices as well as assist coaches evaluate the efficacy of their current technical instruction. Methods A 12‐camera, 250 Hz Vicon motion analysis system (Oxford Metrics Inc., UK) recorded the 3D flat (WFS) and kick serve (WKS) motions of two male top 30‐ranked international wheelchair players. Mechanical comparisons between wheelchair players, as well as to the previously captured data of 12 high‐performance able‐bodied players executing the same types of serves, were undertaken. Results Without the benefit of a propulsive leg action, wheelchair players developed lower peak absolute (∼32 m/s) and horizontal (∼28 m/s) pre‐impact racquet velocities than able‐bodied players (∼42 m/s, ∼38 m/s). Wheelchair serve tactics nevertheless necessitated that higher pre‐impact horizontal and right lateral racquet velocities characterised the WFS (∼29 m/s, WKS: ∼26 m/s) and WKS (∼4 m/s, WFS: ∼11 m/s) respectively. The shoulder joint kinetics that contributed to the differential racquet velocity profiles were mostly developed independent of wheelchair serve type, but varied with and were likely related to the level and severity of spinal cord injury of the individual players. Conclusions Compared with able‐bodied players, wheelchair players experienced matching pre‐ and post‐impact shoulder joint loads, such that wheelchair and able‐bodied playing populations appear subject to similar shoulder joint injury risk. PMID:17957009

  18. Training Level Does Not Affect Auditory Perception of The Magnitude of Ball Spin in Table Tennis

    PubMed Central

    Santos, Daniel P. R.; Barbosa, Roberto N.; Vieira, Luiz H. P.; Santiago, Paulo R. P.; Zagatto, Alessandro M.

    2017-01-01

    Abstract Identifying the trajectory and spin of the ball with speed and accuracy is critical for good performance in table tennis. The aim of this study was to analyze the ability of table tennis players presenting different levels of training/experience to identify the magnitude of the ball spin from the sound produced when the racket hit the ball. Four types of “forehand” contact sounds were collected in the laboratory, defined as: Fast Spin (spinning ball forward at 140 r/s); Medium Spin (105 r/s); Slow Spin (84 r/s); and Flat Hit (less than 60 r/s). Thirty-four table tennis players of both sexes (24 men and 10 women) aged 18-40 years listened to the sounds and tried to identify the magnitude of the ball spin. The results revealed that in 50.9% of the cases the table tennis players were able to identify the ball spin and the observed number of correct answers (10.2) was significantly higher (χ2 = 270.4, p <0.05) than the number of correct answers that could occur by chance. On the other hand, the results did not show any relationship between the level of training/experience and auditory perception of the ball spin. This indicates that auditory information contributes to identification of the magnitude of the ball spin, however, it also reveals that, in table tennis, the level of training does not interfere with the auditory perception of the ball spin. PMID:28210335

  19. Tennis injury data from The Championships, Wimbledon, from 2003 to 2012

    PubMed Central

    Smith, S; Bell, P H; Batt, M E

    2017-01-01

    Objective The primary aims of this retrospective study were to describe the burden of injury presenting to the medical team and the changes in injury profile over 10 years (2003–2012) at The Championships, Wimbledon. Secondary aims included description of gender difference in rates, distribution and pathology of injuries. Design Retrospective observational cohort of player injury presentations over 10 years (2003–2012) at The Championships, Wimbledon. Results The overall rate of presentation of injury for all players over the 10-year period was 20.7 per 1000 sets played. Injury rates were lower for male players (17.7 injuries per 1000 sets played) than female players (23.4 injuries per 1000 sets played). There was variability in the numbers of injuries reported by men and women players over the 10-year period. Conclusions The rates of presentation of injury at this Grand Slam tennis tournament varied between male and female players, and between years. More robust systems of data collection are required in professional tennis to enable more sophisticated injury data analysis between sexes, years and different playing surfaces. PMID:26755678

  20. The Relationship Between Stress and Coping in Table Tennis

    PubMed Central

    Pope-Rhodius, Alison; Kondric, Miran

    2017-01-01

    Abstract The aim of this study was to examine the relationship between cognitive competitive anxiety intensity and coping strategies in table tennis players. One hundred and two (102) US competitive table tennis players of age range from 10 to 60 filled out a Revised Competitive State Anxiety Inventory-2 (CSAI-2R, Cox et al., 2003) at least 30 minutes before the start of their tournament match and a Modified Cope questionnaire (MCOPE; Crocker and Graham, 1995) 15 minutes after they finished their match. Our study found significant differences between low and high cognitive competitive anxiety groups with regard to the use of coping strategies. The high cognitive competitive anxiety intensity group used significantly more behavioral disengagement (avoidance coping, p ≤ 0.05), denial coping strategies (emotion focused coping, p ≤ 0.01) compared to the low cognitive anxiety intensity group. Our results suggest that there is some connection between anxiety intensity and coping strategies. If the cognitive anxiety intensity (for example, intensity from worrying) is very high, an athlete might be more likely to use avoidance coping (such as behavioral disengagement) and emotion-focused coping (such as denial and venting of emotions) compared to athletes who have low cognitive competitive anxiety. Furthermore, gender differences in cognitive anxiety and direction were found. Confidence management techniques such as positive self-talk, breathing techniques and visualization should be taught to athletes to assist them in coping with their competitive anxiety better and to enhance their performance. PMID:28210340

  1. Does an eye-hand coordination test have added value as part of talent identification in table tennis? A validity and reproducibility study.

    PubMed

    Faber, Irene R; Oosterveld, Frits G J; Nijhuis-Van der Sanden, Maria W G

    2014-01-01

    This study investigated the added value, i.e. discriminative and concurrent validity and reproducibility, of an eye-hand coordination test relevant to table tennis as part of talent identification. Forty-three table tennis players (7-12 years) from national (n = 13), regional (n = 11) and local training centres (n = 19) participated. During the eye-hand coordination test, children needed to throw a ball against a vertical positioned table tennis table with one hand and to catch the ball correctly with the other hand as frequently as possible in 30 seconds. Four different test versions were assessed varying the distance to the table (1 or 2 meter) and using a tennis or table tennis ball. 'Within session' reproducibility was estimated for the two attempts of the initial tests and ten youngsters were retested after 4 weeks to estimate 'between sessions' reproducibility. Validity analyses using age as covariate showed that players from the national and regional centres scored significantly higher than players from the local centre in all test versions (p<0.05). The tests at 1 meter demonstrated better discriminative ability than those at 2 meter. While all tests but one had a positive significant association with competition outcome, which were corrected for age influences, the version with a table tennis ball at 1 meter showed the highest association (r = 0.54; p = 0.001). Differences between the first and second attempts were comparable for all test versions (between -8 and +7 repetitions) with ICC's ranging from 0.72 to 0.87. The smallest differences were found for the test with a table tennis ball at 1 meter (between -3 and +3 repetitions). Best test version as part of talent identification appears to be the version with a table tennis ball at 1 meter regarding the psychometric characteristics evaluated. Longitudinal studies are necessary to evaluate the predictive value of this test.

  2. TENNIS ELBOW IN INDUSTRY

    PubMed Central

    Sinclair, A.

    1965-01-01

    This paper briefly reviews the present state of knowledge concerning the various factors involved in the aetiology of tennis elbow and the possible pathological lesions underlying the condition. Two series of cases are considered in greater detail. The first series, consisting of 37 cases, was treated by physical methods only, viz., manipulation, ultrasonic radiation, and short wave diathermy. The results were disappointing since little more than half the number were improved by sonation although subsequent diathermy did improve the majority of those who did not respond. But physical treatment is shown to be time consuming and variable in its results. The second series was treated by local infiltration of the painful area by hydrocortisone and, of the 38 cases, only one proved unsuccessful after one or two injections. The reduction in treatment-time and the fact that no special equipment is necessary are some of the obvious advantages in this form of treatment. The paper concludes with a discussion on the rationale of treatment and some additional aetiological factors which are in favour of an inflammatory, rather than a traumatic, basis for the condition. PMID:14278802

  3. Playing vs. nonplaying aerobic training in tennis: physiological and performance outcomes.

    PubMed

    Pialoux, Vincent; Genevois, Cyril; Capoen, Arnaud; Forbes, Scott C; Thomas, Jordan; Rogowski, Isabelle

    2015-01-01

    This study compared the effects of playing and nonplaying high intensity intermittent training (HIIT) on physiological demands and tennis stroke performance in young tennis players. Eleven competitive male players (13.4 ± 1.3 years) completed both a playing and nonplaying HIIT session of equal distance, in random order. During each HIIT session, heart rate (HR), blood lactate, and ratings of perceived exertion (RPE) were monitored. Before and after each HIIT session, the velocity and accuracy of the serve, and forehand and backhand strokes were evaluated. The results demonstrated that both HIIT sessions achieved an average HR greater than 90% HRmax. The physiological demands (average HR) were greater during the playing session compared to the nonplaying session, despite similar lactate concentrations and a lower RPE. The results also indicate a reduction in shot velocity after both HIIT sessions; however, the playing HIIT session had a more deleterious effect on stroke accuracy. These findings suggest that 1) both HIIT sessions may be sufficient to develop maximal aerobic power, 2) playing HIIT sessions provide a greater physiological demand with a lower RPE, and 3) playing HIIT has a greater deleterious effect on stroke performance, and in particular on the accuracy component of the ground stroke performance, and should be incorporated appropriately into a periodization program in young male tennis players.

  4. Playing vs. Nonplaying Aerobic Training in Tennis: Physiological and Performance Outcomes

    PubMed Central

    Pialoux, Vincent; Genevois, Cyril; Capoen, Arnaud; Forbes, Scott C.; Thomas, Jordan; Rogowski, Isabelle

    2015-01-01

    This study compared the effects of playing and nonplaying high intensity intermittent training (HIIT) on physiological demands and tennis stroke performance in young tennis players. Eleven competitive male players (13.4 ± 1.3 years) completed both a playing and nonplaying HIIT session of equal distance, in random order. During each HIIT session, heart rate (HR), blood lactate, and ratings of perceived exertion (RPE) were monitored. Before and after each HIIT session, the velocity and accuracy of the serve, and forehand and backhand strokes were evaluated. The results demonstrated that both HIIT sessions achieved an average HR greater than 90% HRmax. The physiological demands (average HR) were greater during the playing session compared to the nonplaying session, despite similar lactate concentrations and a lower RPE. The results also indicate a reduction in shot velocity after both HIIT sessions; however, the playing HIIT session had a more deleterious effect on stroke accuracy. These findings suggest that 1) both HIIT sessions may be sufficient to develop maximal aerobic power, 2) playing HIIT sessions provide a greater physiological demand with a lower RPE, and 3) playing HIIT has a greater deleterious effect on stroke performance, and in particular on the accuracy component of the ground stroke performance, and should be incorporated appropriately into a periodization program in young male tennis players. PMID:25816346

  5. Extraction of Knowledge from the Topographic Attentive Mapping Network and its Application in Skill Analysis of Table Tennis

    PubMed Central

    Fujii, Masanori; Maeda, Toshiyuki; Leveille, Jasmin; Tasaka, Tokio

    2017-01-01

    Abstract The Topographic Attentive Mapping (TAM) network is a biologically-inspired classifier that bears similarities to the human visual system. In case of wrong classification during training, an attentional top-down signal modulates synaptic weights in intermediate layers to reduce the difference between the desired output and the classifier’s output. When used in a TAM network, the proposed pruning algorithm improves classification accuracy and allows extracting knowledge as represented by the network structure. In this paper, sport technique evaluation of motion analysis modelled by the TAM network was discussed. The trajectory pattern of forehand strokes of table tennis players was analyzed with nine sensor markers attached to the right upper arm of players. With the TAM network, input attributes and technique rules were extracted in order to classify the skill level of players of table tennis from the sensor data. In addition, differences between the elite player, middle level player and beginner were clarified; furthermore, we discussed how to improve skills specific to table tennis from the view of data analysis. PMID:28210337

  6. Development of the parents' perception of their involvement in their child's tennis activity questionnaire (Q-PPICTA).

    PubMed

    Hurtel, V; Lacassagne, M-F

    2013-08-01

    The purpose of this study was to develop and validate a questionnaire for assessing parents' perception of their involvement in their children's tennis activity (Q-PPICTA). The validation required four successive studies. In study 1, a preliminary version of the questionnaire was formulated after selecting and adapting items taken from existing questionnaires and interviews conducted with the parents of 36 young tennis players. Three factors for measuring parental involvement in sport were identified and retained: emotional, logistic, and informational supports. In study 2, exploratory factor analyses were performed on data collected from 214 parents of tennis players. Results attested the questionnaire's three-factor structure and ascertained its internal consistency. In study 3, a confirmatory factor analysis as well as tests on convergent and discriminant validity were carried out on data gathered from a different sample of 220 parents of tennis players. Statistics confirmed the questionnaire's three-factor structure and reliability. In study 4, the questionnaire's external construct validity was compared with another sample consisting of 192 parents and their children. Overall, results underlined satisfactory psychometric properties for the Q-PPICTA. Nevertheless, further studies are required to confirm the questionnaire's accuracy, reliability, and temporal validity.

  7. Ball Machine Usage in Tennis: Movement Initiation and Swing Timing While Returning Balls from a Ball Machine and from a Real Server

    PubMed Central

    Carboch, Jan; Süss, Vladimir; Kocib, Tomas

    2014-01-01

    Practicing with the use of a ball machine could handicap a player compared to playing against an actual opponent. Recent studies have shown some differences in swing timing and movement coordination, when a player faces a ball projection machine as opposed to a human opponent. We focused on the time of movement initiation and on stroke timing during returning tennis serves (simulated by a ball machine or by a real server). Receivers’ movements were measured on a tennis court. In spite of using a serving ball speed from 90 kph to 135 kph, results showed significant differences in movement initiation and backswing duration between serves received from a ball machine and serves received from a real server. Players had shorter movement initiation when they faced a ball machine. Backswing duration was longer for the group using a ball machine. That demonstrates different movement timing of tennis returns when players face a ball machine. Use of ball machines in tennis practice should be limited as it may disrupt stroke timing. Key points Players have shorter initial move time when they are facing the ball machine. Using the ball machine results in different swing timing and movement coordination. The use of the ball machine should be limited. PMID:24790483

  8. Ball machine usage in tennis: movement initiation and swing timing while returning balls from a ball machine and from a real server.

    PubMed

    Carboch, Jan; Süss, Vladimir; Kocib, Tomas

    2014-05-01

    Practicing with the use of a ball machine could handicap a player compared to playing against an actual opponent. Recent studies have shown some differences in swing timing and movement coordination, when a player faces a ball projection machine as opposed to a human opponent. We focused on the time of movement initiation and on stroke timing during returning tennis serves (simulated by a ball machine or by a real server). Receivers' movements were measured on a tennis court. In spite of using a serving ball speed from 90 kph to 135 kph, results showed significant differences in movement initiation and backswing duration between serves received from a ball machine and serves received from a real server. Players had shorter movement initiation when they faced a ball machine. Backswing duration was longer for the group using a ball machine. That demonstrates different movement timing of tennis returns when players face a ball machine. Use of ball machines in tennis practice should be limited as it may disrupt stroke timing. Key pointsPlayers have shorter initial move time when they are facing the ball machine.Using the ball machine results in different swing timing and movement coordination.The use of the ball machine should be limited.

  9. Body composition assessment of paddle and tennis adult male players.

    PubMed

    Martínez-Rodríguez, Alejandro; Roche Collado, Enrique; Vicente-Salar, Néstor

    2014-09-12

    Introducción: los deportistas que practican disciplinas deportivas de raqueta necesitan mejorar constantemente sus cualidades físicas con el fin de competir al máximo nivel. Por lo tanto, es necesario conseguir y mantener en dichos jugadores una óptima composición corporal, pero no obstante, existen pocos estudios publicados relacionados con esta temática. Objetivo: el presente trabajo trata de ofrecer un perfil antropométrico completo, incluyendo el somatotipo y la composición corporal de jugadores varones adultos de pádel y tenis. Material y métodos: se realizaron diversas medidas antropométricas, incluyendo peso corporal total, estatura, pliegues cutáneos, perímetros y diámetros, en 21 jugadores de pádel y 26 jugadores de tenis. Los resultados obtenidos de cada grupo de jugadores se compararon entre ellos y frente a un grupo control que no practicaba deportes de raqueta. Resultados: no se encontraron diferencias significativas en cuanto a las variables de composición corporal analizadas entre los grupos de jugadores de pádel y tenis, mostrando ambos grupos un somatotipo meso-endomófico. Los jugadores presentaron una menor masa muscular, y por tanto un menor componente mesomórfico, cuando se compararon con el grupo control. Conclusión: ya que la composición corporal es determinante en el rendimiento de los jugadores de deportes de raqueta, es imprescindible realizar un control de la grasa y masa muscular mediante herramientas dietético-nutricionales así como de programas de entrenamiento adecuados.

  10. Video modeling and imaging training on performance of tennis service of 9- to 12-year-old children.

    PubMed

    Atienza, F L; Balaguer, I; García-Merita, M L

    1998-10-01

    The purpose of this work is to analyze, in a pilot study, the effects of video modeling and imagery training over 24 weeks on tennis service performance. Three groups of 9- to 12-yr.-old tennis players participated: (a) a physical practice group, who received physical training, (b) a physical practice + video group who received physical training plus watched a video modeling mental training, and (c) a physical practice + video + imagery group who received physical training plus video modeling and imagery mental training. The results for the intragroup pre-post-test comparisons showed that tennis performance did not significantly improve for the physical training group. The groups given mental training showed improvement from pre- to postintervention. Finally, the posttest comparison between groups indicated that there were significant differences between the group given physical training only compared to the groups given mental training but that the latter two did not differ significantly from each other.

  11. The Effect of Specific Sling Exercises on the Functional Movement Screen Score in Adolescent Volleyball Players: A Preliminary Study

    PubMed Central

    Saulicz, Edward; Myśliwiec, Andrzej; Wójtowicz, Monika; Wolny, Tomasz

    2016-01-01

    Abstract The existing data indicate that the result of the Functional Movement Screen (FMS) test influences the likelihood of subsequent injury in professional athletes. Therefore, exercises increasing test scores of the FMS may be useful at various stages of sports activity. This study evaluated the effects of the NEURAC sling exercises method on the FMS test score in teenage volleyball players. The study was conducted on 15 volleyball players aged 14 years. The FMS test was performed three times interspersed with a two-month interval. Between the first and the second assessment, neither additional treatment nor training was applied, while between the second and the third assessment, the participants performed stabilisation exercises based on the NEURAC method. Training was carried out twice a week, for eight weeks. The analysis showed that between the first and the second measurement, no significant differences occurred. The use of specific sling exercises caused a significant improvement in FMS results (p ≤ 0.01) between the first and the third, as well as the second and the third measurement. The applied stabilisation exercises based on the NEURAC method positively influenced the FMS test result in male subjects practicing volleyball. Performance of such exercises also resulted in more than 90% of the subjects having a total FMS test score ≥ 17, which may be important in the prevention of injuries. The preliminary results indicate that this type of exercise should be included in a teenage volleyball training routine. PMID:28031760

  12. An integrated physiological and performance profile of professional tennis

    PubMed Central

    Hornery, Daniel J; Farrow, Damian; Mujika, Iñigo

    2007-01-01

    Objective To describe the physiological responses to tournament tennis in relation to prevailing environmental conditions, match notation, and skills that underpin performance. Design 14 male professional tennis players (mean (SD) age, 21.4 (2.6) years; height, 183.0 (6.9) cm; body mass, 79.2 (6.4) kg) were studied while contesting international tennis tournaments. Environmental conditions, match notation, physiological (core temperature, hydration status, heart rate, blood variables), and performance indices (serve kinematics, serve velocity, error rates) were recorded. Results Hard and clay court tournaments elicited similar peak core temperature (38.9 (0.3) v 38.5 (0.6)°C) and average heart rate (152 (15) v 146 (19) beats/min) but different body mass deficit (1.05 (0.49) v 0.32 (0.56)%, p<0.05). Average pre‐match urine specific gravity was 1.022 (0.004). Time between points was longer during hard court matches (25.1 (4.3) v 17.2 (3.3) s, p<0.05). Qualitative analysis of first and second serves revealed inverse relations between the position of the tossing arm at ball release and the position of the ball toss and progressive match time (respectively, r = −0.74 and r = −0.73, p<0.05) and incurred body mass deficit (r = 0.73 and r = 0.73, p<0.05). Conclusions Participants began matches in a poor state of hydration, and experienced moderate thermoregulatory strain and dehydration during competition. These adverse physiological conditions may compromise performance and influence notational analyses. PMID:17472999

  13. Relationship between anaerobic parameters provided from MAOD and critical power model in specific table tennis test.

    PubMed

    Zagatto, A M; Gobatto, C A

    2012-08-01

    The aim of this study was to verify the validity of the curvature constant parameter (W'), calculated from 2-parameter mathematical equations of critical power model, in estimating the anaerobic capacity and anaerobic work capacity from a table tennis-specific test. Specifically, we aimed to i) compare constants estimated from three critical intensity models in a table tennis-specific test (Cf); ii) correlate each estimated W' with the maximal accumulated oxygen deficit (MAOD); iii) correlate each W' with the total amount of anaerobic work (W ANAER) performed in each exercise bout performed during the Cf test. Nine national-standard male table tennis players participated in the study. MAOD was 63.0(10.8) mL · kg - 1 and W' values were 32.8(6.6) balls for the linear-frequency model, 38.3(6.9) balls for linear-total balls model, 48.7(8.9) balls for Nonlinear-2 parameter model. Estimated W' from the Nonlinear 2-parameter model was significantly different from W' from the other 2 models (P<0.05). Also, none W' values were significantly correlated with MAOD or W ANAER (r ranged from - 0.58 to 0.51; P>0.13). Thus, W' estimated from the 2-parameter mathematical equations did not correlate with MAOD or W ANAER in table tennis-specific tests, indicating that W' may not provide a strong and valid estimation of anaerobic capacity and anaerobic capacity work.

  14. Improved executive functions in 6-12-year-old children following cognitively engaging tennis lessons.

    PubMed

    Ishihara, Toru; Sugasawa, Shigemi; Matsuda, Yusuke; Mizuno, Masao

    2016-11-16

    The aim of this cross-sectional study was to evaluate the relationships between cognitively engaging exercise (i.e., game-based and coordination exercises), executive functions (i.e., inhibitory control and working memory), and physical fitness. Forty junior tennis players (6-12 years old), who regularly participated in tennis lessons (2.55 years, SD = 1.61) prior to the study, were investigated. All participants completed evaluations of executive functions (inhibitory control and working memory) at rest. The duration of each lessons' instructional activities, including coordination training, game-based exercise, rallying, and non-physical activity (explanations and breaks), was recorded. Physical fitness was evaluated using the Tennis Field Test. A longer duration of game-based exercise was positively correlated with inhibitory control and physical fitness. Coordination training was associated with improved working memory. Non-physical activity was inversely correlated with inhibitory control, working memory, and physical fitness. The results suggest that game-based tennis lessons have beneficial effects on inhibitory control and physical fitness levels, and a longer duration of coordination training is associated with better working memory. The present study indicates that shortened non-physical activity time within a sports setting is associated with the development of executive functions and physical fitness.

  15. Effects of the Racket Polar Moment of Inertia on Dominant Upper Limb Joint Moments during Tennis Serve

    PubMed Central

    Rogowski, Isabelle; Creveaux, Thomas; Chèze, Laurence; Macé, Pierre; Dumas, Raphaël

    2014-01-01

    This study examined the effect of the polar moment of inertia of a tennis racket on upper limb loading in the serve. Eight amateur competition tennis players performed two sets of 10 serves using two rackets identical in mass, position of center of mass and moments of inertia other than the polar moment of inertia (0.00152 vs 0.00197 kg.m2). An eight-camera motion analysis system collected the 3D trajectories of 16 markers, located on the thorax, upper limbs and racket, from which shoulder, elbow and wrist net joint moments and powers were computed using inverse dynamics. During the cocking phase, increased racket polar moment of inertia was associated with significant increases in the peak shoulder extension and abduction moments, as well the peak elbow extension, valgus and supination moments. During the forward swing phase, peak wrist extension and radial deviation moments significantly increased with polar moment of inertia. During the follow-through phase, the peak shoulder adduction, elbow pronation and wrist external rotation moments displayed a significant inverse relationship with polar moment of inertia. During the forward swing, the magnitudes of negative joint power at the elbow and wrist were significantly larger when players served using the racket with a higher polar moment of inertia. Although a larger polar of inertia allows players to better tolerate off-center impacts, it also appears to place additional loads on the upper extremity when serving and may therefore increase injury risk in tennis players. PMID:25117871

  16. Effects of the racket polar moment of inertia on dominant upper limb joint moments during tennis serve.

    PubMed

    Rogowski, Isabelle; Creveaux, Thomas; Chèze, Laurence; Macé, Pierre; Dumas, Raphaël

    2014-01-01

    This study examined the effect of the polar moment of inertia of a tennis racket on upper limb loading in the serve. Eight amateur competition tennis players performed two sets of 10 serves using two rackets identical in mass, position of center of mass and moments of inertia other than the polar moment of inertia (0.00152 vs 0.00197 kg.m2). An eight-camera motion analysis system collected the 3D trajectories of 16 markers, located on the thorax, upper limbs and racket, from which shoulder, elbow and wrist net joint moments and powers were computed using inverse dynamics. During the cocking phase, increased racket polar moment of inertia was associated with significant increases in the peak shoulder extension and abduction moments, as well the peak elbow extension, valgus and supination moments. During the forward swing phase, peak wrist extension and radial deviation moments significantly increased with polar moment of inertia. During the follow-through phase, the peak shoulder adduction, elbow pronation and wrist external rotation moments displayed a significant inverse relationship with polar moment of inertia. During the forward swing, the magnitudes of negative joint power at the elbow and wrist were significantly larger when players served using the racket with a higher polar moment of inertia. Although a larger polar of inertia allows players to better tolerate off-center impacts, it also appears to place additional loads on the upper extremity when serving and may therefore increase injury risk in tennis players.

  17. The Dutch Technical-Tactical Tennis Test (D4T) for Talent Identification and Development: Psychometric Characteristics

    PubMed Central

    Kolman, Nikki; Kramer, Tamara; Elferink-Gemser, Marije; Visscher, Chris

    2017-01-01

    Abstract This study examined the test-retest reliability, validity and feasibility of the newly developed Dutch Technical-Tactical Tennis Test (D4T). This new test is relevant for talent identification and development in tennis. Thirty-two youth male tennis players (age 13.4 ± 0.5) were classified as elite (n = 15) or sub-elite (n = 17) according to their position on the national youth ranking list under 15 years (cut-off rank 50) in the Netherlands. Games, rallies and different tactical situations (i.e. offensive, neutral and defensive) were simulated with a ball machine. Players had to return 72 balls to predetermined target areas. Stroke quality was recorded based on ball velocity and accuracy (VA-index), as well as percentage errors. Test-retest reliability was assessed by comparing differences between the first and second test-session (n = 10). An intraclass-correlation coefficient of .78 for the VA-index was found (p < .05), indicating excellent test-retest reliability. Independent t-tests revealed that elite players outscored sub-elite players for the VA-index, ball velocity, accuracy and percentage errors (p < .05), supporting good validity. Furthermore, a high correlation was found between the VA-index and individual positions on the youth ranking list (p = -.75; p < .001). The assessment of feasibility indicated that the D4T was applicable for instructors and coaches. In conclusion, the D4T was shown to be a reliable, valid and feasible test to measure technical-tactical characteristics of tennis performance in youth players. PMID:28210345

  18. The Dutch Technical-Tactical Tennis Test (D4T) for Talent Identification and Development: Psychometric Characteristics.

    PubMed

    Kolman, Nikki; Huijgen, Barbara; Kramer, Tamara; Elferink-Gemser, Marije; Visscher, Chris

    2017-01-01

    This study examined the test-retest reliability, validity and feasibility of the newly developed Dutch Technical-Tactical Tennis Test (D4T). This new test is relevant for talent identification and development in tennis. Thirty-two youth male tennis players (age 13.4 ± 0.5) were classified as elite (n = 15) or sub-elite (n = 17) according to their position on the national youth ranking list under 15 years (cut-off rank 50) in the Netherlands. Games, rallies and different tactical situations (i.e. offensive, neutral and defensive) were simulated with a ball machine. Players had to return 72 balls to predetermined target areas. Stroke quality was recorded based on ball velocity and accuracy (VA-index), as well as percentage errors. Test-retest reliability was assessed by comparing differences between the first and second test-session (n = 10). An intraclass-correlation coefficient of .78 for the VA-index was found (p < .05), indicating excellent test-retest reliability. Independent t-tests revealed that elite players outscored sub-elite players for the VA-index, ball velocity, accuracy and percentage errors (p < .05), supporting good validity. Furthermore, a high correlation was found between the VA-index and individual positions on the youth ranking list (p = -.75; p < .001). The assessment of feasibility indicated that the D4T was applicable for instructors and coaches. In conclusion, the D4T was shown to be a reliable, valid and feasible test to measure technical-tactical characteristics of tennis performance in youth players.

  19. Technique effects on upper limb loading in the tennis serve.

    PubMed

    Elliott, B; Fleisig, G; Nicholls, R; Escamilia, R

    2003-03-01

    The purpose of this study was to compare the shoulder and elbow joint loads during the tennis serve. Two synchronised 200 Hz video cameras were used to record the service action of 20 male and female players at the Sydney 2000 Olympics. The displacement histories of 20 selected landmarks, were calculated using the direct linear transformation approach. Ball speed was recorded from the stadium radar gun. The Peak Motus system was used to smooth displacements, while a customised inverse-dynamics program was used to calculate 3D shoulder and elbow joint kinematics and kinetics. Male players, who recorded significantly higher service speeds (male = 183 km hr(-1): female = 149 km hr(-1)) recorded significantly higher normalised and absolute internal rotation shoulder torque at the position when the arm was maximally externally rotated (MER) (male = 4.6% and 64.9 Nm: female = 3.5% and 37.5 Nm). A higher absolute elbow varus torque (67.6 Nm) was also recorded at MER, when compared with the female players (41.3 Nm). Peak normalised horizontal adduction torque (male = 7.6%: female = 6.5%), normalised shoulder compressive force (male = 79.6%: female = 59.1%) and absolute compressive force (male = 608.3 N: female = 363.7 N), were higher for the male players. Players who flexed at the front knee by 7.6 degrees, in the backswing phase of the serve, recorded a similar speed (162 km hr(-1)), and an increased normalised internal rotation torque at MER (5.0%), when compared with those who flexed by 14.7 degrees. They also recorded a larger normalised varus torque at MER (5.3% v 3.9%) and peak value (6.3% v 5.2%). Players who recorded a larger knee flexion also recorded less normalised and absolute (4.3%, 55.6 Nm) peak internal rotation torque compared with those with less flexion (5.6%, 63.9 Nm). Those players who used an abbreviated backswing were able to serve with a similar speed and recorded similar kinetic values. Loading on the shoulder and elbow joints is higher for the male

  20. Comparison of Heart Rate Response to Tennis Activity between Persons with and without Spinal Cord Injuries: Implications for a Training Threshold

    ERIC Educational Resources Information Center

    Barfield, J. P.; Malone, Laurie A.; Coleman, Tristica A.

    2009-01-01

    The purpose of this study was to evaluate the ability of individuals with spinal cord injury (SCI) to reach a training threshold during on-court sport activity. Monitors collected heart rate (HR) data every 5 s for 11 wheelchair tennis players (WCT) with low paraplegia and 11 able-bodied controls matched on experience and skill level (ABT).…

  1. Tennis Courts: A Construction and Maintenance Manual.

    ERIC Educational Resources Information Center

    United States Tennis Court & Track Builders Association.

    This manual addresses court design and planning; the construction process; court surface selection; accessories and amenities; indoor tennis court design and renovation; care and maintenance tips; and court repair, reconstruction, and renovation. General and membership information is provided on the U.S. Tennis Court and Track Builders Association…

  2. Tennis injuries: occurrence, aetiology, and prevention

    PubMed Central

    Pluim, B M; Staal, J B; Windler, G E; Jayanthi, N

    2006-01-01

    A systematic search of published reports was carried out in three electronic databases from 1966 on to identify relevant articles relating to tennis injuries. There were 39 case reports, 49 laboratory studies, 28 descriptive epidemiological studies, and three analytical epidemiological studies. The principal findings of the review were: first, there is a great variation in the reported incidence of tennis injuries; second, most injuries occur in the lower extremities, followed by the upper extremities and then the trunk; third, there have been very few longitudinal cohort studies that investigated the association between risk factors and the occurrence of tennis injuries (odds ratios, risk ratios, hazard ratios); and fourth, there were no randomised controlled trials investigating injury prevention measures in tennis. More methodologically sound studies are needed for a better understanding of risk factors, in order to design useful strategies to prevent tennis injuries. PMID:16632572

  3. Tennis Racket Vibrations and Shock Transmission to the Wrist during Forehand Drive.

    PubMed

    Rogowski, Isabelle; Creveaux, Thomas; Triquigneaux, Sylvain; Macé, Pierre; Gauthier, Fabien; Sevrez, Violaine

    2015-01-01

    This study aimed to investigate the effects of two different racket models and two different forehand drive velocities on the three-dimensional vibration behavior of the racket and shock transmission to the player's wrist under real playing conditions. Nine tennis players performed a series of crosscourt flat forehand drives at two velocities, using a lightly and a highly vibrant racket. Two accelerometers were fixed on the racket frame and the player's wrist. The analysis of vibration signals in both time and frequency domains showed no interaction effect of velocity and racket conditions either on the racket vibration behavior or on shock transmission. An increase in playing velocity enlarged the amount of vibrations at the racket and wrist, but weakly altered their frequency content. As compared to a racket perceived as highly vibrating, a racket perceived as lightly vibrating damped longer in the out-of-plane axis of the racket and shorter on the other axis of the racket and on the wrist, and displayed a lower amount of energy in the high frequency of the vibration signal at the racket and wrist. These findings indicated that the playing velocity must be controlled when investigating the vibration loads due to the racket under real playing conditions. Similarly, a reduced perception of vibration by the tennis player would be linked to decreased amplitude of the racket vibration signal, which may concentrate the signal energy in the low frequencies.

  4. A Multidisciplinary Investigation of the Effects of Competitive State Anxiety on Serve Kinematics in Table Tennis.

    PubMed

    Ngo, Vuong; Richards, Hugh; Kondric, Miran

    2017-01-01

    Displays of anxiety in table tennis were assessed through subjective (a self-report questionnaire), physiological (heart-rate variability) and kinematic variables. Using a within-group crossover design, 9 university-level table tennis players completed a series of serves under low- and high-anxiety conditions. Anxiety manipulation was achieved through the introduction of a national standard table tennis player, known to the participants, to receive serves in the high-anxiety condition, whilst serves were received by no opponent in the low-anxiety condition. Automated motion capture systems consisting of high-speed 3D motion cameras and analytical software (QUALISYS) determined the subject's movement kinematics: bat face angle (degrees) and serve routine duration (s). Self-reported state anxiety (MRF-Likert) and heart rate measurements were collected to examine changes between conditions. Contrary to the hypothesis, bat face angles did not change significantly between anxiety conditions (F (1.8) = 2.791, p = 0.133) and movement times were faster in the high-anxiety condition. In light of these findings, research into other facets of movement behaviour must be analysed to gain further understanding of the effects of anxiety on performance, which remain unclear.

  5. A Multidisciplinary Investigation of the Effects of Competitive State Anxiety on Serve Kinematics in Table Tennis

    PubMed Central

    Ngo, Vuong; Richards, Hugh; Kondric, Miran

    2017-01-01

    Abstract Displays of anxiety in table tennis were assessed through subjective (a self-report questionnaire), physiological (heart-rate variability) and kinematic variables. Using a within-group crossover design, 9 university-level table tennis players completed a series of serves under low- and high-anxiety conditions. Anxiety manipulation was achieved through the introduction of a national standard table tennis player, known to the participants, to receive serves in the high-anxiety condition, whilst serves were received by no opponent in the low-anxiety condition. Automated motion capture systems consisting of high-speed 3D motion cameras and analytical software (QUALISYS) determined the subject’s movement kinematics: bat face angle (degrees) and serve routine duration (s). Self-reported state anxiety (MRF-Likert) and heart rate measurements were collected to examine changes between conditions. Contrary to the hypothesis, bat face angles did not change significantly between anxiety conditions (F (1.8) = 2.791, p = 0.133) and movement times were faster in the high-anxiety condition. In light of these findings, research into other facets of movement behaviour must be analysed to gain further understanding of the effects of anxiety on performance, which remain unclear. PMID:28210341

  6. A stochastic Markov chain approach for tennis: Monte Carlo simulation and modeling

    NASA Astrophysics Data System (ADS)

    Aslam, Kamran

    This dissertation describes the computational formulation of probability density functions (pdfs) that facilitate head-to-head match simulations in tennis along with ranking systems developed from their use. A background on the statistical method used to develop the pdfs , the Monte Carlo method, and the resulting rankings are included along with a discussion on ranking methods currently being used both in professional sports and in other applications. Using an analytical theory developed by Newton and Keller in [34] that defines a tennis player's probability of winning a game, set, match and single elimination tournament, a computational simulation has been developed in Matlab that allows further modeling not previously possible with the analytical theory alone. Such experimentation consists of the exploration of non-iid effects, considers the concept the varying importance of points in a match and allows an unlimited number of matches to be simulated between unlikely opponents. The results of these studies have provided pdfs that accurately model an individual tennis player's ability along with a realistic, fair and mathematically sound platform for ranking them.

  7. Mechanical energy generation and transfer in the racket arm during table tennis topspin backhands.

    PubMed

    Iino, Yoichi; Kojima, Takeji

    2016-06-01

    The ability to generate a high racket speed and a large amount of racket kinetic energy on impact is important for table tennis players. The purpose of this study was to understand how mechanical energy is generated and transferred in the racket arm during table tennis backhands. Ten male advanced right-handed table tennis players hit topspin backhands against pre-impact topspin and backspin balls. The joint kinetics at the shoulder, elbow and wrist of the racket arm was determined using inverse dynamics. A majority of the mechanical energy of the racket arm acquired during forward swing (65 and 77% against topspin and backspin, respectively) was due to energy transfer from the trunk. Energy transfer by the shoulder joint force in the vertical direction was the largest contributor to the mechanical energy of the racket arm against both spins and was greater against backspin than against topspin (34 and 28%, respectively). The shoulder joint force directed to the right, which peaked just before impact, transferred additional energy to the racket. Our results suggest that the upward thrust of the shoulder and the late timing of the axial rotation of the upper trunk are important for an effective topspin backhand.

  8. Medical assistance at the Brazilian juniors tennis circuit--a one-year prospective study.

    PubMed

    Silva, R T; Takahashi, R; Berra, B; Cohen, M; Matsumoto, M H

    2003-03-01

    A prospective study was conducted during one year to evaluate injuries in Brazilian Junior tennis players during the national circuit, in 2001. Male and female athletes in the age categories under 12, under 14, under 16 and under 18 years, all members of The Brazilian Tennis Confederation, participated in the study. Two physiotherapists and/or one physician evaluated the athletes. A total of 280 medical examinations were performed in 151 tennis players who needed medical treatment during the tournaments. The 151 athletes had 1-6 medical treatments during the tournaments and the mean was 1.8 treatment per athlete. The overall incidence was 6.9 medical treatments for every 1,000 games played. Medical assistance tothe athletes was performed on court in 83 (29.6%) occasions, 185 (66.1%) at the medical department and in both in 12 (4.3%) occasions. Retirement of the match was reported in 9 (3.2%) lesions. The most frequent injuries were: muscle contractures (76 - 27.14%), muscle pain/fatigue (36-12.85%), muscle strain (35-12.52%), tendinopathies (20 - 7.14%), cramps (16 -5.71%), ankle sprain (12 -4.28%) and low back pain (10-3.57%). Muscle pathology was the major source of injuries causing the athlete to seek medical assistance. Preventative measures are important to reduce the number of injuries, which may include muscle stretching programs and adequate nutrition and hydration.

  9. The one- and two-handed backhands in tennis.

    PubMed

    Reid, Machar; Elliott, Bruce

    2002-01-01

    The study investigated differences in the one- (SH) and two-handed (DH) backhands when hit flat, across-court (AC) and down-the-line (DL), and with heavy topspin DL (TDL). The ability to disguise each of these backhands when hitting the above strokes was also assessed. Eighteen college-level male tennis players, identified as having a high performance topspin SH (n = 6) or DH (n = 12) backhand drive, participated in the study. Players were required to hit three AC, DL and TDL backhands from the baseline with their preferred technique, while being filmed with two high-speed video cameras operating at 200 Hz. The highest horizontal velocity backhand for each stroke was analysed. Results indicated that the sequential coordination of five body segments (hips, shoulder, upper arm, forearm, and hand/racquet rotations) was required for the execution of the SH stroke. The same number of segments were generally coordinated in the DH stroke (hips, shoulders, and varying degrees of upper arm and forearm rotations followed by hand/racquet movement). Mature players produced comparable racquet horizontal velocities 0.005 s prior to impact using either the SH or DH backhand technique. The SH backhand was characterised by a more rotated shoulder alignment than the DH stroke (SH: 119.1 degrees; DH: 83.4 degrees) at the completion of the backswing. At impact the ball was impacted further in front (SH: 0.59 m: DH: 0.40 m) and a similar distance to the side of the body (SH: 0.75 m: DH: 0.70 m). Players using the DH backhand technique delayed the horizontal acceleration of the racquet towards the ball (SH: 0.13 s: DH: 0.08 s prior to impact) and thus were capable of displaying a similar hitting motion closer to impact than players with a SH technique.

  10. Leadership and satisfaction in tennis: examination of congruence, gender, and ability.

    PubMed

    Riemer, H A; Toon, K

    2001-09-01

    The study investigated: (a) the congruency hypothesis, and (b) the member characteristics hypotheses relating to ability and gender, of Chelladurai's (1978) Multidimensional Model of Leadership. One hundred forty-eight tennis players (77 women) competing at the NCAA Division I and II Tennis Championship level participated in the study. Results indicated athlete satisfaction (Athlete Satisfaction Scale; Riemer & Chelladurai, 1998) was not dependent on the congruence between preferred and perceived leadership behavior. Other results indicated that an athlete's level of ability did affect preferences for leadership behavior. Further, while athlete gender was responsible for some variance in preferences for autocratic behavior and positive feedback behavior, the gender of the athlete's coach had a significant effect on the athlete's preferences for social support behavior.

  11. Real-time interaction with a humanoid avatar in an immersive table tennis simulation.

    PubMed

    Rusdorf, Stephan; Brunnett, Guido; Lorenz, Mario; Winkler, Tobias

    2007-01-01

    In this paper, we report on the realization of an immersive table tennis simulation. After describing the hardware necessities of our system, we give insight into different aspects of the simulation. In particular, the developed methods for collision detection and physical simulation are presented. The design of the virtual opponent is of crucial importance to realize an enjoyable game. Therefore, we report on the implemented game strategy and the animation of the opponent. Since table tennis is one of the fastest sports, the synchronization of the human player's movements and the visual output on the projection wall is a very challenging problem to solve. To overcome the latencies in our system, we designed a prediction method that allows high speed interaction with our application.

  12. Importance of Hierarchical Structure Determining Tennis Performance for Modern Defensive Baseliner.

    PubMed

    Đurović, Nikša; Dizdar, Dražan; Zagorac, Nebojša

    2015-07-01

    Hierarchies are present everywhere (physics, medicine, nature, human needs, etc.) and tennis is no exception. Is counterpuncher's goal just to chase down every ball and force the opponents into long rallies? The aim of this first empirical study is integrate theory and practice about overall quality evaluation and accurately analyze offensive and defensive tennis priorities for counterpunchers. Weight of each criterion was obtained using AHP technique in Expert Choice software. The results indicate that this model is able to provide important training variables in order to control and manipulate training process. Also, issues prior to research indicate that sports scientists and expert coaches need to learn from each other in order to help players maximizing their performance.

  13. Ratings of perceived exertion-lactate association during actual singles tennis match play.

    PubMed

    Mendez-Villanueva, Alberto; Fernandez-Fernández, Jaime; Bishop, David; Fernandez-Garcia, Benjamin

    2010-01-01

    To examine the relationship between metabolic (i.e., blood lactate concentration) and perceptual (ratings of perceived exertion, RPE) responses and their association with variables describing the characteristics of the singles tennis match play. Eight trained and internationally ranked (Association of Tennis Professionals rankings) male tennis players were studied during singles matches (best of 3 sets) played on an outdoor clay court surface during a professional invitational tournament. Ratings of perceived exertion and blood lactate concentrations were determined at selected change overs during the game. The variables describing the characteristics of the matches, (a) duration of rallies (DR), (b) rest time, (c) effective playing time, and (d) strokes per rally (SR), were determined from video recordings. Significant correlations (r = 0.57-0.48; p < 0.01) were found for RPE-blood lactate responses during the games. Both RPE and blood lactate concentration values were significantly correlated with SR and DR (r = 0.80-0.61; p < 0.001) in service games. Average RPE was significantly higher (p < 0.05) following service games (13.5 +/- 1.9; n = 24) than following receiving games (12.2 +/- 2.0; n = 22). Mean blood lactate concentrations were significantly higher (p < 0.05) following service games (4.4 +/- 2.4 mmol.L; n = 24) than following receiving games (3.0 +/- 1.3 mmol.L; n = 22). These results indicate that monitoring RPE may be a useful technique for regulating on-court tennis training intensity. Moreover, blood lactate may mediate the relation between RPE and tennis match play intensity.

  14. Intention understanding over T: a neuroimaging study on shared representations and tennis return predictions

    PubMed Central

    Cacioppo, Stephanie; Fontang, Frederic; Patel, Nisa; Decety, Jean; Monteleone, George; Cacioppo, John T.

    2014-01-01

    Studying the way athletes predict actions of their peers during fast-ball sports, such as a tennis, has proved to be a valuable tool for increasing our knowledge of intention understanding. The working model in this area is that the anticipatory representations of others' behaviors require internal predictive models of actions formed from pre-established and shared representations between the observer and the actor. This model also predicts that observers would not be able to read accurately the intentions of a competitor if the competitor were to perform the action without prior knowledge of their intention until moments before the action. To test this hypothesis, we recorded brain activity from 25 male tennis players while they performed a novel behavioral tennis intention inference task, which included two conditions: (i) one condition in which they viewed video clips of a tennis athlete who knew in advance where he was about to act/serve (initially intended serves) and (ii) one condition in which they viewed video clips of that same athlete when he did not know where he was to act/serve until the target was specified after he had tossed the ball into the air to complete his serve (non-initially intended serves). Our results demonstrated that (i) tennis expertise is related to the accuracy in predicting where another server intends to serve when that server knows where he intends to serve before (but not after) he tosses the ball in the air; and (ii) accurate predictions are characterized by the recruitment of both cortical areas within the human mirror neuron system (that is known to be involved in higher-order (top-down) processes of embodied cognition and shared representation) and subcortical areas within brain regions involved in procedural memory (caudate nucleus). Interestingly, inaccurate predictions instead recruit areas known to be involved in low-level (bottom-up) computational processes associated with the sense of agency and self-other distinction

  15. The effect of a novel movement strategy in decreasing ACL risk factors in female adolescent soccer players

    PubMed Central

    Celebrini, Richard G.; Eng, Janice J.; Miller, William C.; Ekegren, Christina L.; Johnston, James D.; MacIntyre, Donna L.

    2015-01-01

    There is a need to investigate the effect of specific movement strategies in reducing biomechanical risk factors for ACL injury in young female athletes. The purpose of this study was 1) to determine the feasibility of implementing a novel movement strategy (Core-PAC) into a team warm-up prior to soccer training based on subject compliance and integration of the Core-PAC into the warm-up and 2) to determine whether the Core-PAC would improve peak knee flexion angles and peak abduction moments at the knee during a side-cut (SC) and an unanticipated side-cut (USC) prior to kicking a soccer ball, and a side-hop (SH) task after immediate instruction and after a four-week training program. A convenience sample of ten 14–16 year old female soccer players were instructed in the Core-PAC immediately after baseline testing and during a training program consisting of a 20-minute warm-up, two-times per week. The Core-PAC was understood and accepted by the subjects and incorporated into their warm-up activities with good compliance. After the immediate instruction, there were significant increases in peak knee flexion angles of a mean 6.4° during the SC (p = 0.001), 3.5° during the USC (p = 0.007), and 5.8° during the SH (p < 0.001) tasks. Peak knee abduction moments decreased by a mean of 0.25 Nm/kg during the SC (p < 0.03), 0.17 Nm/kg during the USC (p = 0.05), and 0.27 Nm/kg during the SH (p = 0.04) tasks. After the 4-week training program, some individuals showed improvement. The results of this study suggest that the Core-PAC may be one method of modifying high-risk movements for ACL injury such as side-cutting and single-leg landing. PMID:22210470

  16. Tennis: for the health of it!

    PubMed

    Groppel, Jack; DiNubile, Nicholas

    2009-06-01

    Tennis is a sport with numerous health benefits for individuals of all ages. It is also a tremendously effective fitness activity. Regular participants experience a wide variety of health-related physical and mental benefits, from improved cardiovascular, metabolic, and bone health to improved agility, coordination, and even stress and anxiety management. Physicians and other health care professionals can play an important role in educating patients and the public about the health benefits of tennis as well as motivating them to take up this activity as part of an overall exercise prescription. Based on the scientific evidence available, it is difficult to find an activity that offers as wide a range of overall health benefits as tennis, and individuals who take up tennis reap tremendous rewards.

  17. Spatial characteristics of professional tennis serves with implications for serving aces: A machine learning approach.

    PubMed

    Whiteside, David; Reid, Machar

    2017-04-01

    This study sought to determine the features of an ideal serve in men's professional tennis. A total of 25,680 first serves executed by 151 male tennis players during Australian Open competition were classified as either aces or returned into play. Spatiotemporal (impact location, speed, projection angles, landing location and relative player locations) and contextual (score) features of each serve were extracted from Hawk-Eye data and used to construct a classification tree model (with decision rules) that predicted serve outcome. k-means clustering was applied to the landing locations to quantify optimal landing locations for aces. The classification tree revealed that (1) serve directionality, relative to the returner; (2) the ball's landing proximity to the nearest service box line and (3) serve speed classified aces with an accuracy of 87.02%. Hitting aces appeared more contingent on accuracy than speed, with serves directed >5.88° from the returner and landing <15.27 cm from a service box line most indicative of an ace. k-means clustering revealed four distinct locations (≈0.73 m wide × 2.35 m deep) in the corners of the service box that corresponded to aces. These landing locations provide empirically derived target locations for players to adhere to during practice and competition.

  18. WEST TENNIS COURTS AND NONCOMMISSIONED OFFICER'S HOUSING, FROM SOUTH OAKWOOD ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    WEST TENNIS COURTS AND NON-COMMISSIONED OFFICER'S HOUSING, FROM SOUTH OAKWOOD DRIVE - Hamilton Field, Tennis Courts, Escolta Avenue at Sixth Street, & Crescent Drive near South Oakwood Drive, Novato, Marin County, CA

  19. Tomographical description of tennis-loaded radius: reciprocal relation between bone size and volumetric BMD.

    PubMed

    Ashizawa, N; Nonaka, K; Michikami, S; Mizuki, T; Amagai, H; Tokuyama, K; Suzuki, M

    1999-04-01

    Effects of long-term tennis loading on volumetric bone mineral density (vBMD) and geometric properties of playing-arm radius were examined. Paired forearms of 16 tennis players (10 women) and 12 healthy controls (7 women), aged 18-24 yr, were scanned at mid and distal site by using peripheral quantitative computerized tomography. Tomographic data at midradius showed that tennis playing led to a slight decrease in cortical vBMD (-0.8% vs. nonplaying arm, P < 0. 05) and increase both in periosteal and endocoritcal bone area (+15. 2% for periosteal bone, P < 0.001; and +18.8% for endocortical bone, P < 0.001). These data suggest that, together with an increase in cortical thickness (+6.4%, P < 0.01), cortical drift toward periosteal direction resulted in improvement of mechanical characteristics of the playing-arm midradius. Enlargement of periosteal bone area was also observed at distal radius (+6.8%, P < 0.01), and the relative side-to-side difference in periosteal bone area was inversely related to that in trabecular vBMD (r = -0.53, P < 0.05). We conclude that an improvement of mechanical properties of young adult bone in response to long-term exercise is related to geometric adaptation but less to changes in vBMD.

  20. Biomarkers of exposure to organic solvents from glues used in table tennis bats.

    PubMed

    Karacić, V; Skender, L; Kruslin, E

    1995-09-01

    In nine samples of the glues used to glue rubber onto the table tennis bats, benzene, toluene, xylene, trichloroethene (TRI) and tetrachloroethene (TETRA) were determined by head-space gas chromatography. The analyses demonstrated the presence of benzene (1.8-4.8% (w/w)), toluene (0.32-33.90% (w/w)) and TRI (0.0006-0.280% (w/w)) in seven samples and of toluene only (22.50-67.20% (w/w)) in two samples. Xylene and TETRA were not detected in any of the glue samples analysed. Benzene, toluene and TRI in blood, as a measure of body burden, were determined in four table tennis players (aged 11-14 years) and five volunteers (aged 26-38 years). They were at the same level as in the general population. The aim of the study was to draw attention to the possibility of exposure to organic solvents from glues used in table tennis bats, particularly as it is very often a question of child exposure.

  1. Heart rate deflection point relates to second ventilatory threshold in a tennis test.

    PubMed

    Baiget, Ernest; Fernández-Fernández, Jaime; Iglesias, Xavier; Rodríguez, Ferran A

    2015-03-01

    The relationship between heart rate deflection point (HRDP) and the second ventilatory threshold (VT2) has been studied in continuous sports, but never in a tennis-specific test. The aim of the study was to assess the relationships between HRDP and the VT2, and between the maximal test performance and the maximal oxygen uptake ((Equation is included in full-text article.)) in an on-court specific endurance tennis test. Thirty-five high-level tennis players performed a progressive tennis-specific field test to exhaustion to determine HRDP, VT2, and (Equation is included in full-text article.). Ventilatory gas exchange parameters were continuously recorded by a portable telemetric breath-by-breath gas exchange measurement system. Heart rate deflection point was identified at the point at which the slope values of the linear portion of the time/heart rate (HR) relationship began to decline and was successfully determined in 91.4% of the players. High correlations (r = 0.79-0.96; p < 0.001) between physiological (HR and oxygen uptake [(Equation is included in full-text article.)]) and performance (Time, Stage, and Frequency of balls [Ballf]) variables corresponding to HRDP and VT2 were observed. Frequency of balls at the HRDP (BallfHRDP) was detected at 19.8 ± 1.7 shots per minute. Paired t-test showed no significant differences in HR (178.9 ± 8.5 vs. 177.9 ± 8.7 b·min for HRDP vs. HRVT2, respectively) at intensities corresponding to HRDP and VT2. Maximal test performance and (Equation is included in full-text article.)were moderately correlated (r = 0.56; p < 0.001). Heart rate deflection point obtained from this specific tennis test can be used to determine the VT2, and the BallfHRDP can be used as a practical performance variable to prescribe on-court specific aerobic training at or near VT2.

  2. Activity patterns, blood lactate concentrations and ratings of perceived exertion during a professional singles tennis tournament

    PubMed Central

    Mendez‐Villanueva, Alberto; Fernandez‐Fernandez, Jaime; Bishop, David; Fernandez‐Garcia, Benjamin; Terrados, Nicolas

    2007-01-01

    Objective To examine the game characteristics and physiological (ie, blood lactate concentration) and perceptual (ie, rating of perceived exertion, RPE) responses during actual tennis competition in professional performers. Methods Eight trained and internationally ranked (Association of Tennis Professionals rankings) male tennis players were studied during singles matches (best of three sets) played on an outdoor clay court surface during a professional, invitational tournament. Blood lactate concentrations (n = 53) and RPE (n = 113) were determined at selected changeovers during the game. The variables describing the characteristics of the matches, (a) duration of rallies (DRs); (b) rest time (RT); (c) effective playing time (EPT); and (d) shots per rally (SR), were determined from video recordings. Results The mean (SD) values for the match‐play activity variables were DR 7.5 (7.3) s, RT 16.2 (5.2) s, EPT 21.5 (4.9%), SR 2.7 (2.2) shots. Average blood lactate concentration and RPE values were 3.8 (2.0) mmol/l and 13 (2). Blood lactate concentrations and RPE values were significantly higher (p<0.01) in service games than in receiving games. Both blood lactate concentration and RPE values were significantly correlated with SR and DR (r = 0.80 to 0.28; p<0.001). Conclusions Blood lactate concentrations and RPE were found to be influenced by the characteristics of the match and the playing situation (ie, serving or returning). These specific situations might be used to alter the overload training stimulus during tennis on‐court practice. PMID:17237121

  3. The Dutch motor skills assessment as tool for talent development in table tennis: a reproducibility and validity study.

    PubMed

    Faber, Irene R; Nijhuis-Van Der Sanden, Maria W G; Elferink-Gemser, Marije T; Oosterveld, Frits G J

    2015-01-01

    A motor skills assessment could be helpful in talent development by estimating essential perceptuo-motor skills of young players, which are considered requisite to develop excellent technical and tactical qualities. The Netherlands Table Tennis Association uses a motor skills assessment in their talent development programme consisting of eight items measuring perceptuo-motor skills specific to table tennis under varying conditions. This study aimed to investigate this assessment regarding its reproducibility, internal consistency, underlying dimensions and concurrent validity in 113 young table tennis players (6-10 years). Intraclass correlation coefficients of six test items met the criteria of 0.7 with coefficients of variation between 3% and 8%. Cronbach's alpha valued 0.853 for internal consistency. The principal components analysis distinguished two conceptually meaningful factors: "ball control" and "gross motor function." Concurrent validity analyses demonstrated moderate associations between the motor skills assessment's results and national ranking; boys r = -0.53 (P < 0.001) and girls r = -0.45 (P = 0.015). In conclusion, this evaluation demonstrated six test items with acceptable reproducibility, good internal consistency and good prospects for validity. Two test items need revision to upgrade reproducibility. Since the motor skills assessment seems to be a reproducible, objective part of a talent development programme, more longitudinal studies are required to investigate its predictive validity.

  4. Management of tennis elbow by Agnikarma.

    PubMed

    Mahanta, Vyasadeva; Dudhamal, Tukaram S; Gupta, Sanjay Kumar

    2013-01-01

    Tennis elbow is a painful condition and causes restricted movement of forearm which requires treatment for long period. Till date only symptomatic treatments are available like use of anti-inflammatory analgesic drugs, steroids injection, physiotherapy, exercise etc. But none of these provide satisfactory result. Long term use of anti-inflammatory, analgesic drugs and steroids injection is also not free from the adverse effects. Usually, 'wait-and-see policy' of treatment guideline is recommended in most of medical texts. According to Ayurveda, snayugata vata can be correlated with the condition of tennis elbow. Sushruta has advised Agnikarma for disorders of snayu (ligaments and tendons), asthi (bone), siddhi (joints) etc. Hence, in this study a case of tennis elbow (snayugata vata) was treated by Agnikarma, along with administration of powder of Ashwagandha and Navajivana Rasa orally, for a period of 03 weeks. This combination therapy provided considerable relief in pain and movement of the elbow joint.

  5. Management of tennis elbow by Agnikarma

    PubMed Central

    Mahanta, Vyasadeva; Dudhamal, Tukaram S.; Gupta, Sanjay Kumar

    2013-01-01

    Tennis elbow is a painful condition and causes restricted movement of forearm which requires treatment for long period. Till date only symptomatic treatments are available like use of anti-inflammatory analgesic drugs, steroids injection, physiotherapy, exercise etc. But none of these provide satisfactory result. Long term use of anti-inflammatory, analgesic drugs and steroids injection is also not free from the adverse effects. Usually, ‘wait-and-see policy’ of treatment guideline is recommended in most of medical texts. According to Ayurveda, snayugata vata can be correlated with the condition of tennis elbow. Sushruta has advised Agnikarma for disorders of snayu (ligaments and tendons), asthi (bone), siddhi (joints) etc. Hence, in this study a case of tennis elbow (snayugata vata) was treated by Agnikarma, along with administration of powder of Ashwagandha and Navajivana Rasa orally, for a period of 03 weeks. This combination therapy provided considerable relief in pain and movement of the elbow joint. PMID:23741162

  6. Joint Kinetics to Assess the Influence of the Racket on a Tennis Player’s Shoulder

    PubMed Central

    Creveaux, Thomas; Dumas, Raphaël; Hautier, Christophe; Macé, Pierre; Chèze, Laurence; Rogowski, Isabelle

    2013-01-01

    This study aimed at investigating the influence of three rackets on shoulder net joint moments, power and muscle activity during the flat tennis serve under field- conditions. A 6-camera Eagle® motion analysis system, operating at 256 Hz, captured racket and dominant upper limb kinematics of the serve in five tennis players under three racket conditions (A: low mass, high balance and polar moment, B: low three moments of inertia, and C: high mass, swingweight and twistweight). The electromyographic activity of six trunk and arm muscles was simultaneously recorded. Shoulder net joint moments and power were computed by 3D inverse dynamics. The results showed that greater shoulder joint power and internal/external rotation peak moments were found to accelerate and decelerate racket A in comparison with the racket C. Moreover, serving with the racket A resulted in less activity in latissimus dorsi muscle during the acceleration phase, and biceps brachii muscle during the follow-through phase when compared with racket C. These initial findings encourage studying the biomechanical measurements to quantify the loads on the body during play in order to reduce them, and then prevent shoulder injuries. Racket specifications may be a critical point for coaches who train players suffering from shoulder pain and chronic upper limb injuries should be considered in relation to the racket specifications of the players. Key Points Light racket required more joint power than heavy one to achieve similar post impact ball velocity. Serving with a light racket resulted in higher shoulder internal and external rotation moments than using a heavy one for similar performance. Chronic shoulder pain should encourage coaches to check for potentially inappropriate racket specifications of their players. PMID:24149804

  7. Energy expenditure during tennis play: a preliminary video analysis and metabolic model approach.

    PubMed

    Botton, Florent; Hautier, Christophe; Eclache, Jean-Paul

    2011-11-01

    The aim of this study was to estimate, using video analysis, what proportion of the total energy expenditure during a tennis match is accounted for by aerobic and anaerobic metabolism, respectively. The method proposed involved estimating the metabolic power (MP) of 5 activities, which are inherent to tennis: walking, running, hitting the ball, serving, and sitting down to rest. The energy expenditure concerned was calculated by sequencing the activity by video analysis. A bioenergetic model calculated the aerobic energy expenditure (EEO2mod) in terms of MP, and the anaerobic energy expenditure was calculated by subtracting this (MP - EEO2mod). Eight tennis players took part in the experiment as subjects (mean ± SD: age 25.2 ± 1.9 years, weight 79.3 ± 10.8 kg, VO2max 54.4 ± 5.1 ml·kg(-1)·min(-1)). The players started off by participating in 2 games while wearing the K4b2, with their activity profile measured by the video analysis system, and then by playing a set without equipment but with video analysis. There was no significant difference between calculated and measured oxygen consumptions over the 16 games (p = 0.763), and these data were strongly related (r = 0.93, p < 0.0001). The EEO2mod was quite weak over all the games (49.4 ± 4.8% VO2max), whereas the MP during points was up to 2 or 3 times the VO2max. Anaerobic metabolism reached 32% of the total energy expenditure across all the games 67% for points and 95% for hitting the ball. This method provided a good estimation of aerobic energy expenditure and made it possible to calculate the anaerobic energy expenditure. This could make it possible to estimate the metabolic intensity of training sessions and matches using video analysis.

  8. Brain regions concerned with perceptual skills in tennis: an fMRI study.

    PubMed

    Wright, Michael J; Jackson, Robin C

    2007-02-01

    Sporting performance makes special demands on perceptual skills, but the neural mechanisms underlying such performance are little understood. We address this issue, making use of fMRI to identify the brain areas activated in viewing and responding to video sequences of tennis players, filmed from the opponent's perspective. In a block-design, fMRI study, 9 novice tennis players watched video clips of tennis play. The main stimulus conditions were (1) serve sequences, (2) non-serve behaviour (ball bouncing) and (3) static control sequences. A button response was required indicating the direction of serve (left or right for serve sequences, middle button for non-serve and static sequences). By comparing responses to the three stimulus conditions, it was possible to identify two groups of brain regions responsive to different components of the task. Areas MT/MST and STS in the posterior part of the temporal lobe responded either to serve and to non-serve stimuli, relative to static controls. Serve sequences produced additional regions of activation in the parietal lobe (bilateral IPL, right SPL) and in the right frontal cortex (IFGd, IFGv), and these areas were not activated by non-serve sequences. These regions of the parietal and frontal cortex have been implicated in a "mirror neuron" network in the human brain. It is concluded that the task of judgement of serve direction produces two different patterns of response: activations in the MT/MST and STS concerned with primarily with the analysis of motion and body actions, and activations in the parietal and frontal cortex associated specifically with the task of identification of direction of serve.

  9. The Relationship Between Maximum Isometric Strength and Ball Velocity in the Tennis Serve

    PubMed Central

    Corbi, Francisco; Fuentes, Juan Pedro; Fernández-Fernández, Jaime

    2016-01-01

    Abstract The aims of this study were to analyze the relationship between maximum isometric strength levels in different upper and lower limb joints and serve velocity in competitive tennis players as well as to develop a prediction model based on this information. Twelve male competitive tennis players (mean ± SD; age: 17.2 ± 1.0 years; body height: 180.1 ± 6.2 cm; body mass: 71.9 ± 5.6 kg) were tested using maximum isometric strength levels (i.e., wrist, elbow and shoulder flexion and extension; leg and back extension; shoulder external and internal rotation). Serve velocity was measured using a radar gun. Results showed a strong positive relationship between serve velocity and shoulder internal rotation (r = 0.67; p < 0.05). Low to moderate correlations were also found between serve velocity and wrist, elbow and shoulder flexion – extension, leg and back extension and shoulder external rotation (r = 0.36 – 0.53; p = 0.377 – 0.054). Bivariate and multivariate models for predicting serve velocity were developed, with shoulder flexion and internal rotation explaining 55% of the variance in serve velocity (r = 0.74; p < 0.001). The maximum isometric strength level in shoulder internal rotation was strongly related to serve velocity, and a large part of the variability in serve velocity was explained by the maximum isometric strength levels in shoulder internal rotation and shoulder flexion. PMID:28149411

  10. Tennis Racket Vibrations and Shock Transmission to the Wrist during Forehand Drive

    PubMed Central

    Rogowski, Isabelle; Creveaux, Thomas; Triquigneaux, Sylvain; Macé, Pierre; Gauthier, Fabien; Sevrez, Violaine

    2015-01-01

    This study aimed to investigate the effects of two different racket models and two different forehand drive velocities on the three-dimensional vibration behavior of the racket and shock transmission to the player’s wrist under real playing conditions. Nine tennis players performed a series of crosscourt flat forehand drives at two velocities, using a lightly and a highly vibrant racket. Two accelerometers were fixed on the racket frame and the player’s wrist. The analysis of vibration signals in both time and frequency domains showed no interaction effect of velocity and racket conditions either on the racket vibration behavior or on shock transmission. An increase in playing velocity enlarged the amount of vibrations at the racket and wrist, but weakly altered their frequency content. As compared to a racket perceived as highly vibrating, a racket perceived as lightly vibrating damped longer in the out-of-plane axis of the racket and shorter on the other axis of the racket and on the wrist, and displayed a lower amount of energy in the high frequency of the vibration signal at the racket and wrist. These findings indicated that the playing velocity must be controlled when investigating the vibration loads due to the racket under real playing conditions. Similarly, a reduced perception of vibration by the tennis player would be linked to decreased amplitude of the racket vibration signal, which may concentrate the signal energy in the low frequencies. PMID:26177373

  11. The Relationship Between Maximum Isometric Strength and Ball Velocity in the Tennis Serve.

    PubMed

    Baiget, Ernest; Corbi, Francisco; Fuentes, Juan Pedro; Fernández-Fernández, Jaime

    2016-12-01

    The aims of this study were to analyze the relationship between maximum isometric strength levels in different upper and lower limb joints and serve velocity in competitive tennis players as well as to develop a prediction model based on this information. Twelve male competitive tennis players (mean ± SD; age: 17.2 ± 1.0 years; body height: 180.1 ± 6.2 cm; body mass: 71.9 ± 5.6 kg) were tested using maximum isometric strength levels (i.e., wrist, elbow and shoulder flexion and extension; leg and back extension; shoulder external and internal rotation). Serve velocity was measured using a radar gun. Results showed a strong positive relationship between serve velocity and shoulder internal rotation (r = 0.67; p < 0.05). Low to moderate correlations were also found between serve velocity and wrist, elbow and shoulder flexion - extension, leg and back extension and shoulder external rotation (r = 0.36 - 0.53; p = 0.377 - 0.054). Bivariate and multivariate models for predicting serve velocity were developed, with shoulder flexion and internal rotation explaining 55% of the variance in serve velocity (r = 0.74; p < 0.001). The maximum isometric strength level in shoulder internal rotation was strongly related to serve velocity, and a large part of the variability in serve velocity was explained by the maximum isometric strength levels in shoulder internal rotation and shoulder flexion.

  12. Standoffish perhaps, but successful as well: evidence that avoidant attachment can be beneficial in professional tennis and computer science.

    PubMed

    Ein-Dor, Tsachi; Reizer, Abira; Shaver, Phillip R; Dotan, Eyal

    2012-06-01

    Attachment-related avoidance and anxiety have repeatedly been associated with poorer adjustment in various social, emotional, and behavioral domains. We examined 2 domains in which avoidant individuals might be better equipped than their less avoidant peers to succeed and be satisfied--professional singles tennis and computer science. These fields may reward self-reliance, independence, and the ability to work without proximal social support from loved ones. In study 1, we followed 58 professional singles tennis players for 16 months and found that scores on attachment-related avoidance predicted a higher ranking, above and beyond the contributions of training and coping resources. In study 2, we sampled 100 students and found that those who scored higher on avoidance were happier with their choice of computer science as a career than those who scored lower on avoidance. Results are discussed in relation to the possible adaptive functions of certain personality characteristics often viewed as undesirable.

  13. Fractal Aggregates in Tennis Ball Systems

    ERIC Educational Resources Information Center

    Sabin, J.; Bandin, M.; Prieto, G.; Sarmiento, F.

    2009-01-01

    We present a new practical exercise to explain the mechanisms of aggregation of some colloids which are otherwise not easy to understand. We have used tennis balls to simulate, in a visual way, the aggregation of colloids under reaction-limited colloid aggregation (RLCA) and diffusion-limited colloid aggregation (DLCA) regimes. We have used the…

  14. Tennis Rackets and the Parallel Axis Theorem

    ERIC Educational Resources Information Center

    Christie, Derek

    2014-01-01

    This simple experiment uses an unusual graph straightening exercise to confirm the parallel axis theorem for an irregular object. Along the way, it estimates experimental values for g and the moment of inertia of a tennis racket. We use Excel to find a 95% confidence interval for the true values.

  15. [A world record in marathon tennis: sleep deprivation and performance].

    PubMed

    Tafti, M; Vergé, M; Besset, A; Billiard, M

    1989-01-01

    We studied the effects of marked sleep deprivation on the EEG patterns and performance of a physically fit man (age 26) on the occasion of the world record continuous marathon tennis play (147 hours, 20 minutes). Before and immediately after the marathon, the sleep patterns of the player were recorded in our laboratory. After playing for 40 and 80 hours and within 24 hours, the performance changes were evaluated each hour. Amounts of the different sleep stages during the first recovery night compared with those of the baseline indicate an increase of 56% for total sleep time, 54% for stages 1 and 2, 154% for stages 3 and 4 and 20% for REM sleep. During the second recovery night, only REM sleep showed an increase. Activity index showed a marked decrease after 80 hours of sleep deprivation compared with that after 40 hours and was dramatically worsened during nighttime. The number of faults and pauses was also increased after 80 hours, suggesting a clear performance deterioration. Our results confirmed the effects of sleep deprivation on the recovery and performance deterioration.

  16. Pre‐ and post‐impact muscle activation in the tennis volley: effects of ball speed, ball size and side of the body

    PubMed Central

    Chow, John W; Knudson, Duane V; Tillman, Mark D; Andrew, Damon P S

    2007-01-01

    Aim To examine the pre‐ and post‐impact activation of five upper extremity muscles in the tennis volley across conditions of ball speed, ball type and side of the body. Methods A repeated measures design in a biomechanics laboratory setting was used. A total of 24 recreational tennis players (mean (SD) age 24 (5) years, height 176 (10) cm, mass 76 (13) kg) were recruited from a university. Participants performed tennis volleys under 18 ball conditions: three ball speeds (slow, medium and fast), with three ball types (two oversize and one regular size) each from two sides (forehand and backhand). Average normalised electromyographic levels of the flexor carpi radialis, extensor carpi radialis, triceps brachii, anterior/middle deltoid and posterior/middle deltoid of the hitting arm during pre‐ and post‐impact phases (200 ms before and after ball–racquet impact, respectively) were assessed. Results For the pre‐impact phase, a significant muscle and side interaction (p<0.001) and significant main effects for speed (p = 0.002) and muscle (p<0.001) were observed. For the post‐impact phase, significant interactions were observed for ball type and side (p = 0.002), ball speed and side (p = 0.011) and muscle and side (p = 0.001), as well significant main effects for muscle (p<0.001), speed (p = 0.035) and side (p<0.001). Conclusion Oversize tennis balls do not significantly increase upper extremity muscle activation compared to regular size balls during a tennis volley. The highest post‐impact activation was observed in the ECR indicating a vigorous wrist stabilisation role that could irritate players with lateral epicondylalgia. PMID:17957013

  17. Effect of Notched Strings on Tennis Racket Spin Performance: Ultrahigh-Speed Video Analysis of Spin Rate, Contact Time, and Post-Impact Ball Velocity

    NASA Astrophysics Data System (ADS)

    Kawazoe, Yoshihiko; Takeda, Yukihiro; Nakagawa, Masamichi

    While some tennis racket strings have more grip than others do, this does not guarantee that they will impart more spin to a tennis ball. Experiments with hand-held rackets are required to determine the longstanding question of how players can discern that different strings behave differently when laboratory tests indicate that they should play the same. In a previous study, we clarified the top-spin mechanism of a tennis racket by using high-speed video analysis on a tennis court for the first time. Furthermore, we improved it by using lubricated notched nylon strings. These experiments revealed that the more the main strings stretch and bend laterally, the more spin is imparted to the ball. This is due to the restoring force being parallel to the string face when the main strings spring back and the ball is released from the strings. Notched strings reduce the spin rate, but this can be effectively counteracted by employing lubricants. Furthermore, we found that imparting more spin reduces shock vibrations on the wrist during impact. The present study revealed that a ball has a 40% lower spin rate when hit with a racket with notched strings than with one with unnotched strings in the case of nylon (it had to be determined whether new strings or lubricated used strings give more spin). The experiments also showed that 30% more spin is imparted to a ball when the string intersections are lubricated by oil than when notched used nylon strings are used. Furthermore, we found that used natural gut notched strings reduced the spin rate by 70% compared to when new natural gut unnotched strings are used. We also investigated different top-spin behaviors obtained when professional and amateur tennis players hit a ball.

  18. Natural course in tennis elbow--lateral epicondylitis after all?

    PubMed

    Zeisig, Eva

    2012-12-01

    Tennis elbow is a common and difficult-to-treat condition largely because of lack of evidence. The natural history is unknown, but the condition is described as self-limiting. The objective of this case report is to describe the natural course of two control participants (pain free), who later developed tennis elbow, patient history, clinical findings, and ultrasound and colour Doppler examination before, during and after a period of tennis elbow.

  19. Menstrual cycle disorders in female volleyball players.

    PubMed

    Wodarska, M; Witkoś, J; Drosdzol-Cop, A; Dąbrowska, J; Dąbrowska-Galas, M; Hartman, M; Plinta, R; Skrzypulec-Plinta, V

    2013-07-01

    The aim of this study was to examine the relation between increased physical activity and menstrual disorders in adolescent female volleyball players. The study was conducted on 210 Polish female volleyball players, aged 13-17 years, the authorship questionnaire was used. The results of the study showed that irregular menstruation occurred in 19% of girls, spotting between menstrual periods in 27% and heavy menstruation was reported in 33% of girls. Out of all volleyball female players participating in the study, 94 girls (45%) declared absence of menstrual periods after regular cycles. Statistical analysis showed that the more training hours per week, the bigger probability of the occurrence of irregular menstruation. It was concluded that the number of hours of volleyball training per week affects regularity of menstrual cycles in female volleyball players. The absence of menstruation might be caused by the duration of training per week or years of training.

  20. A double pendulum model of tennis strokes

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2011-05-01

    The physics of swinging a tennis racquet is examined by modeling the forearm and the racquet as a double pendulum. We consider differences between a forehand and a serve, and show how they differ from the swing of a bat and a golf club. It is also shown that the swing speed of a racquet, like that of a bat or a club, depends primarily on its moment of inertia rather than on its mass.

  1. Modifying Equipment in Early Skill Development: A Tennis Perspective

    ERIC Educational Resources Information Center

    Buszard, Tim; Farrow, Damian; Reid, Machar; Masters, Rich S. W.

    2014-01-01

    Purpose: The International Tennis Federation recently launched a worldwide campaign advocating the use of equipment scaling for children learning to play tennis. The aim of this study was to investigate the influence that varying racquet sizes and ball compressions had on children's ability to play a forehand groundstroke. Method: This was a…

  2. "New Balls, Please!"--The Prosody of Tennis Scores

    ERIC Educational Resources Information Center

    Swerts, Marc; van Wijk, Carel

    2010-01-01

    Tennis scores represent a natural language domain that offers the unique opportunity to study the effects of discourse constraints on prosody with strict control over syntactic and lexical variation. This study analyzed a set of tennis scores, such as "30-15," from live recordings of several Wimbledon and Davis Cup matches. The objective was to…

  3. Effects of a Simulated Tennis Match on Lymphocyte Subset Measurements

    ERIC Educational Resources Information Center

    Schafer, Mark; Kell, Holly; Navalta, James; Tibana, Ramires; Lyons, Scott; Arnett, Scott

    2014-01-01

    Tennis is an activity requiring both endurance and anaerobic components, which could have immunosuppressive effects postexercise. Purpose: The purpose of this investigation was to determine the effect of a simulated tennis match on apoptotic and migratory markers on lymphocyte subsets. Method: Male high school (n = 5) and college (n = 3) tennis…

  4. USTC & TBA Guidelines for Tennis Court & Running Track Construction.

    ERIC Educational Resources Information Center

    United States Tennis Court & Track Builders Association.

    Guidelines are presented on tennis court and track and field construction that reflect the latest developments in construction technology, methodology, and practice. Based on contributions from experienced certified tennis court and track builders, material suppliers and design professionals, this manual examines each of the critical areas of…

  5. Table Top Tennis: A Vehicle for Teaching Sportspersonship and Responsibility

    ERIC Educational Resources Information Center

    Schwager, Susan; Stylianou, Michalis

    2012-01-01

    Table top tennis is a game that can be played in the classroom or lunchroom when the gymnasium is unavailable. It is a good activity for developing sportspersonship and responsibility in students in grades four and up. This article provides a description of table top tennis, including basic rules and strategies; an explanation of how it can…

  6. Keys to a Winning High School Tennis Team.

    ERIC Educational Resources Information Center

    Scoda, Leo

    1982-01-01

    A successful year-round tennis program developed in a high school as a result of community interest in tennis. Important factors in creating the school's winning varsity team were: (1) establishing a year-round program; (2) an organized team practice program; (3) professional approach to coaching; and (4) developing individual and team pride. (FG)

  7. Tennis Enhances Well-being in University Students

    PubMed Central

    Yazici, Ahmet Bulent; Gul, Mine; Yazici, Esra; Gul, Gazanfer Kemal

    2016-01-01

    Sports and physical activity are widely recommended, both as guidelines and in clinical practice, because of their broad range of positive effects on health, depression, anxiety, and psychological well-being. While several studies have examined the anti-depressive and anxiolytic effects of physical activity in clinical populations, and fewer studies have focused on the nonclinical populations, the relationship between tennis and well-being has not been clearly investigated. This study was carried out with 76 student volunteers from Kocaeli University (Turkey) who had chosen tennis lessons as their University. The tennis exercise program consisted of 90-minute basic tennis skills lessons for 13 weeks. At the beginning and at the end of the study, the students were given the Symptom Checklist-90-Revised (SCL-90-R), the Beck Anxiety Inventory (BAI), and the Beck Depression Inventory (BDI) scales, and were evaluated by the DeWitt-Dugan Tennis Service Test, the DeWitt-Dugan Speed Test, and the Dyer Backboard Tennis Test. Upon evaluating the students’ pre- and post-test scores, we concluded that their BDI and BAI scores had significantly decreased, with the most significant decreases seen in several sub-scores of the SCL-90-R; their tennis skills, meanwhile, increased significantly. This study shows that partaking in tennis exercise once a week decreases depression and anxiety symptoms and enhances well-being in healthy young people. PMID:27403277

  8. Reliability and Factorial Validity of Non-Specific and Tennis-Specific Pre-Planned Agility Tests; Preliminary Analysis

    PubMed Central

    Sekulic, Damir; Uljevic, Ognjen; Peric, Mia; Spasic, Miodrag; Kondric, Miran

    2017-01-01

    Abstract Agility is an important quality in tennis, yet there is an evident lack of studies focussing on the applicability of tennis-specific agility performances and comparing them to equivalent non-specific agility performances. The aim of this study was to evaluate the reliability and factorial validity of three tests of pre-planned agility, performed in specific (with a tennis racquet) and non-specific (without a tennis racquet) conditions. The sample consisted of 33 tennis players (13 males and 20 females; age: 18.3 ± 1.1 years and 18.6 ± 1.3 years; body height: 185.4 ± 51 cm and 169.3 ± 4.2 cm, 74.0 ± 4.4 kg and 61.2 ± 3.1 kg, respectively). The variables comprised three agility tests: a 20-yard test, a T-test and the Illinois test, all performed in both specific and non-specific conditions. Between-subject and within-subject reliability were found to be high (Cronbach Alpha: 0.93 to 0.98; Coefficient of Variation: 3 to 8%), with better within-subject reliability and stability of the measurement for specific tests. Pearson’s product moment correlations between the non-specific and specific agility performances were high (r ≥0.84), while factor analysis extracted only one significant latent dimension on the basis of the Guttman-Kaiser criterion. The results of the 20-yard test were better when the test was conducted in the specific conditions (t-test = 2.66; p < 0.05). For the Illinois test, superior results were recorded in the non-specific conditions (t-test = 2.96; p < 0.05), which can be explained by the test duration (about 20 s) and non-specific locomotion forms such as rotational movements. Considering the findings of the present study, when testing tennis-specific pre-planned agility, we suggest using tests of short duration (less than 10 s) and sport-specific types of locomotion. PMID:28210343

  9. A study of kinematic cues and anticipatory performance in tennis using computational manipulation and computer graphics.

    PubMed

    Ida, Hirofumi; Fukuhara, Kazunobu; Kusubori, Seiji; Ishii, Motonobu

    2011-09-01

    Computer graphics of digital human models can be used to display human motions as visual stimuli. This study presents our technique for manipulating human motion with a forward kinematics calculation without violating anatomical constraints. A motion modulation of the upper extremity was conducted by proportionally modulating the anatomical joint angular velocity calculated by motion analysis. The effect of this manipulation was examined in a tennis situation--that is, the receiver's performance of predicting ball direction when viewing a digital model of the server's motion derived by modulating the angular velocities of the forearm or that of the elbow during the forward swing. The results showed that the faster the server's forearm pronated, the more the receiver's anticipation of the ball direction tended to the left side of the serve box. In contrast, the faster the server's elbow extended, the more the receiver's anticipation of the ball direction tended to the right. This suggests that tennis players are sensitive to the motion modulation of their opponent's racket-arm.

  10. Rectus abdominis overuse injury in a tennis athlete treated with traumeel

    PubMed Central

    Natsis, Konstantinos; Lyrtzis, Christos; Papathanasiou, Efthymia; Anastasopoulos, Nikos

    2012-01-01

    Summary Background: Rectus abdominis injuries are common in tennis players at all levels of competition. Traumeel® injection can be used for treatment of muscle strains and hematomas. Case Report: A 21-year-old female tennis athlete was injured on the non-dominant rectus abdominis during the cocking phase of the service motion. She suffered from pain and tenderness. One week later, during a serve, she experienced severe pain on the contralateral side of her abdomen. Conservative treatment was performed by the team physician with rest, ice therapy and analgesics for 20 days, but she had recurrent injuries. The ultrasonography and MRI showed hematoma of the rectus abdominis muscle. She was treated with 2 injections of Traumeel® on the 2nd, 4th, 6th post-traumatic day and received 1 injection on the 10th post-traumatic day. She also modified her serve technique. On the fourth post-treatment week the athlete had pain-free function and both the MRI appearance and the size of rectus abdominal muscle were normal. She returned to her sport activities. There is no recurrence of her injury 2 years later. Conclusions: Rectus abdominis hematoma must be diagnosed early. Traumeel® injections are effective, safe and well-tolerated for the treatment of overuse injury of the rectus abdominis following strain. PMID:23569472

  11. Fluid Mechanics of Cricket and Tennis Balls

    NASA Astrophysics Data System (ADS)

    Mehta, Rabindra D.

    2009-11-01

    Aerodynamics plays a prominent role in defining the flight of a ball that is struck or thrown through the air in almost all ball sports. The main interest is in the fact that the ball can often deviate from its initial straight path, resulting in a curved, or sometimes an unpredictable, flight path. It is particularly fascinating that that not all the parameters that affect the flight of a ball are always under human influence. Lateral deflection in flight, commonly known as swing, swerve or curve, is well recognized in cricket and tennis. In tennis, the lateral deflection is produced by spinning the ball about an axis perpendicular to the line of flight, which gives rise to what is commonly known as the Magnus effect. It is now well recognized that the aerodynamics of sports balls are strongly dependent on the detailed development and behavior of the boundary layer on the ball's surface. A side force, which makes a ball curve through the air, can also be generated in the absence of the Magnus effect. In one of the cricket deliveries, the ball is released with the seam angled, which trips the laminar boundary layer into a turbulent state on that side. The turbulent boundary layer separates relatively late compared to the laminar layer on the other side, thereby creating a pressure difference and hence side force. The fluid mechanics of a cricket ball become very interesting at the higher Reynolds numbers and this will be discussed in detail. Of all the round sports balls, a tennis ball has the highest drag coefficient. This will be explained in terms of the contribution of the ``fuzz" drag and how that changes with Reynolds number and ball surface wear. It is particularly fascinating that, purely through historical accidents, small disturbances on the ball surface, such as the stitching on cricket balls and the felt cover on tennis balls are all about the right size to affect boundary layer transition and development in the Reynolds numbers of interest. The fluid

  12. Physiological, perceptual, and technical responses to on-court tennis training on hard and clay courts.

    PubMed

    Reid, Machar M; Duffield, Rob; Minett, Geoffrey M; Sibte, Narelle; Murphy, Alistair P; Baker, John

    2013-06-01

    The aim of this study was to investigate the effect of court surface (clay vs. hard court) on technical, physiological, and perceptual responses to on-court tennis training. Four high-performance junior male players performed 2 identical training sessions on hard and clay courts, respectively. Sessions included both physical conditioning and technical elements as led by the coach. Each session was filmed for later notational analysis of stroke count and error rates. Furthermore, players wore a global positioning satellite device to measure distance covered during each session, while heart rate, countermovement jump distance, and capillary blood measures of metabolites were measured before, during, and after each session. Additionally, a respective coach and athlete rating of perceived exertion (RPE) were measured after each session. Total duration and distance covered during each session were comparable (p > 0.05; d < 0.20). Although forehand and backhands stroke volume did not differ between sessions (p > 0.05; d < 0.30), large effects for increased unforced and forced errors were present on the hard court (p > 0.05; d > 0.90). Furthermore, large effects for increased heart rate, blood lactate, and RPE values were evident on clay compared with hard courts (p > 0.05; d > 0.90). Additionally, although player and coach RPE on hard courts were similar, there were large effects for coaches to underrate the RPE of players on clay courts (p > 0.05; d > 0.90). In conclusion, training on clay courts results in trends for increased heart rate, lactate, and RPE values, suggesting that sessions on clay courts tend towards higher physiological and perceptual loads than hard courts. Furthermore, coaches seem effective at rating player RPE on hard courts but may underrate the perceived exertion of sessions on clay courts.

  13. Pelvic Rotation and Lower Extremity Motion with Two Different Front Foot Directions in the Tennis Backhand Groundstroke

    PubMed Central

    Iwamoto, Sayumi; Fukubayashi, Toru; Hume, Patria

    2013-01-01

    When a tennis player steps forward to hit a backhand groundstroke in closed stance, modifying the direction of the front foot relative to the net may reduce the risk of ankle injury and increase performance. This study evaluated the relationship between pelvic rotation and lower extremity movement during the backhand groundstroke when players stepped with toes parallel to the net (Level) or with toes pointed towards the net (Net). High school competitive tennis players (eleven males and seven females, 16.8 ± 0.8 years, all right- handed) performed tennis court tests comprising five maximum speed directional runs to the court intersection line to hit an imaginary ball with forehand or backhand swings. The final backhand groundstroke for each player at the backcourt baseline was analyzed. Pelvic rotation and lower extremity motion were quantified using 3D video analysis from frontal and sagittal plane camera views reconstructed to 3D using DLT methods. Plantar flexion of ankle and supination of the front foot were displayed for both Net and Level groups during the late phase of the front foot step. The timings of the peak pelvis rotational velocity and peak pelvis rotational acceleration showed different pattern for Net and Level groups. The peak timing of the pelvis rotational velocity of the Level group occurred during the late phase of the step, suggesting an increase in the risk of inversion ankle sprain and a decrease in stroke power compared to the Net group. Key Points Regarding the movement of the forefoot, the Net group and the Level group showed a pattern of supination-pronation-supination during the front stepping foot contact phase (FSFCP). However, the Level group showed only supination of various degrees during FSFCP. For the Net group, the maximum angular velocity of pelvis occurred in the early phase of FSFCP before impact; however, for the Level group, the maximum angular velocity of pelvis occurred in the latter phase of FSFCP after impact. The

  14. Inducing Attitude Change toward Online Gaming among Adolescent Players Based on Dissonance Theory: The Role of Threats and Justification of Effort

    ERIC Educational Resources Information Center

    Wan, Chin-Sheng; Chiou, Wen-Bin

    2010-01-01

    The negative impact of online gaming on adolescents has received much attention. The question of how to reduce their pathological use of online gaming is a critical issue. Based on the concept of external justification in dissonance theory, this experimental study aimed to examine whether severity of threat and justification of effort would impact…

  15. Comparison of laboratory and "on-court" endurance testing in tennis.

    PubMed

    Smekal, G; Pokan, R; von Duvillard, S P; Baron, R; Tschan, H; Bachl, N

    2000-05-01

    Treadmill testing (TT) commonly used in endurance testing is often not sport-specific. Therefore a field test (FT) for tennis players was developed. The purpose was 1) to compare metabolic and cardiorespiratory response between TT and FT and 2) to assess tennis stroke ratings during FT. In both tests ventilatory variables (VO2, VE, VT, Bf, VE x VO2(-1)), heart rate (HR), and lactate (LA) were measured. For both tests an "individual anaerobic threshold" (IAT) was calculated. The comparison of TT and FT yielded significant differences in cardiorespiratory and metabolic response. LA and VE were significantly higher in TT compared to FT at VO2 of 35, 40, and 45 ml x kg(-1) x min(-1). There were statistical differences between IAT resulting from both tests (TT vs. FT): HR (165+/-16, 175+/-11, p<0.001), VO2 (44.4+/-4.3, 47.8+/-4.8, p<0.05), LA (3.1+/-0.5, 2.5+/-0.4, p < 0.001), VE (97.0+/-15.6, 89.1+/-14.9, p < 0.05), VT (2.66+/-0.34, 2.34+/-0.47, p<0.05), VE/VO2 (27.9+/-3.9, 23.9+/-2.9, p<0.01). High correlation was found between stroke ratings and the national ranking of the players. We concluded that 1) metabolic, ventilatory, and cardiorespiratory demands of TT vs. FT were (semi)sport-specific and significantly different and 2) that the stroke rating in our study was a good predictor for tournament performance (r = 0.94). This type of stroke rating can be implemented in a FT.

  16. Recovery interventions and strategies for improved tennis performance

    PubMed Central

    Kovacs, Mark S; Baker, Lindsay B

    2014-01-01

    Improving the recovery capabilities of the tennis athlete is receiving more emphasis in the research communities, and also by practitioners (coaches, physical trainers, tennis performance specialists, physical therapists, etc). The purpose of this article was to review areas of recovery to limit the severity of fatigue and/or speed recovery from fatigue. This review will cover four broad recovery techniques commonly used in tennis with the belief that the interventions may improve athlete recovery and therefore improve adaptation and future performance. The four areas covered are: (1) temperature-based interventions, (2) compressive clothing, (3) electronic interventions and (4) nutritional interventions. PMID:24668374

  17. View of foundation, looking southeast. Note tennis courts in background ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of foundation, looking southeast. Note tennis courts in background facing southeast, see HABS No. CA-2716 - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA

  18. View of foundation, looking south. Note tennis courts in background ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of foundation, looking south. Note tennis courts in background facing south, see HABS no. CA-2716 - Presidio of San Francisco, Officers' Vehicles Garage, 1055 General Kennedy Avenue, Letterman Hospital Complex, San Francisco, San Francisco County, CA

  19. Brain Jogging Training to Improve Motivation and Learning Result of Tennis Skills

    NASA Astrophysics Data System (ADS)

    Tafaqur, M.; Komarudin; Mulyana; Saputra, M. Y.

    2017-03-01

    This research is aimed to determine the effect of brain jogging towards improvement of motivation and learning result of tennis skills. The method used in this research is experimental method. The population of this research is 15 tennis athletes of Core Siliwangi Bandung Tennis Club. The sampling technique used in this research is purposive sampling technique. Sample of this research is the 10 tennis athletes of Core Siliwangi Bandung Tennis Club. Design used for this research is pretest-posttest group design. Data analysis technique used in this research is by doing Instrument T-test to measure motivation using The Sport Motivation Scale questionnaire (SMS-28) and Instrument to measure learning result of tennis skill by using tennis skills test, which include: (1) forehand test, (2) backhand test, and (3) service placement test. The result of this research showed that brain jogging significantly impact the improvement of motivation and learning result of tennis skills.

  20. The Effect of a Novel Movement Strategy in Decreasing ACL Risk Factors in Female Adolescent Soccer Players: A Randomized Controlled Trial

    PubMed Central

    Celebrini, Richard G.; Eng, Janice J.; Miller, William C.; Ekegren, Christina L.; Johnston, James D.; Depew, Thomas A.; MacIntyre, Donna L.

    2015-01-01

    Objective To determine the effect of a novel movement strategy incorporated within a soccer warm-up on biomechanical risk factors for ACL injury during three sport-specific movement tasks. Design Single-blind, randomized controlled clinical trial. Setting Laboratory setting. Participants 20 top-tier female teenage soccer players. Interventions Subjects were randomized to the Core Position and Control movement strategy (Core-PAC) warm-up or standard warm-up which took place prior to their regular soccer practice over a 6-week period. The Core-PAC focuses on getting the centre of mass closer to the plant foot or base of support. Main Outcome Measures Peak knee flexion angle and abduction moments during a side-hop (SH), side-cut (SC) and unanticipated side-cut (USC) task after the 6-weeks with (intervention group only) and without a reminder to use the Core-PAC strategy. Results The Core-PAC group increased peak flexion angles during the SH task (Mean difference = 6.2°, 95% CI: 1.9–10.5°, effect size = 1.01, P = 0.034) after the 6-week warm-up program without a reminder. In addition, the Core-PAC group demonstrated increased knee flexion angles for the side-cut (Mean difference = 8.5°, 95% CI: 4.8–12.2°, ES = 2.02, P = 0.001) and side-hop (Mean difference = 10.0°, 95% CI: 5.7–14.3°, ES = 1.66, P = 0.001) task after a reminder. No changes in abduction moments were found. Conclusions The results of this study suggest that the Core-PAC may be one method of modifying high-risk soccer-specific movements and can be implemented within a practical, team-based soccer warm-up. The results should be interpreted with caution due to the small sample size. PMID:24184850

  1. Effects that different types of sports have on the hearts of children and adolescents and the value of two-dimensional strain-strain-rate echocardiography.

    PubMed

    Binnetoğlu, Fatih Köksal; Babaoğlu, Kadir; Altun, Gürkan; Kayabey, Özlem

    2014-01-01

    Whether the hypertrophy found in the hearts of athletes is physiologic or a risk factor for the progression of pathologic hypertrophy remains controversial. The diastolic and systolic functions of athletes with left ventricular (LV) hypertrophy usually are normal when measured by conventional methods. More precise assessment of global and regional myocardial function may be possible using a newly developed two-dimensional (2D) strain echocardiographic method. This study evaluated the effects that different types of sports have on the hearts of children and adolescents and compared the results of 2D strain and strain-rate echocardiographic techniques with conventional methods. Athletes from clubs for five different sports (basketball, swimming, football, wrestling, and tennis) who had practiced regularly at least 3 h per week during at least the previous 2 years were included in the study. The control group consisted of sedentary children and adolescents with no known cardiac or systemic diseases (n = 25). The athletes were grouped according to the type of exercise: dynamic (football, tennis), static (wrestling), or static and dynamic (basketball, swimming). Shortening fraction and ejection fraction values were within normal limits for the athletes in all the sports disciplines. Across all 140 athletes, LV geometry was normal in 58 athletes (41.4 %), whereas 22 athletes (15.7 %) had concentric remodeling, 20 (14.3 %) had concentric hypertrophy, and 40 (28.6 %) had eccentric hypertrophy. Global LV longitudinal strain values obtained from the average of apical four-, two-, and three-chamber global strain values were significantly lower for the basketball players than for all the other groups (p < 0.001).

  2. Assessing personal talent determinants in young racquet sport players: a systematic review.

    PubMed

    Faber, Irene R; Bustin, Paul M J; Oosterveld, Frits G J; Elferink-Gemser, Marije T; Nijhuis-Van der Sanden, Maria W G

    2016-01-01

    Since junior performances have little predictive value for future success, other solutions are sought to assess a young player's potential. The objectives of this systematic review are (1) to provide an overview of instruments measuring personal talent determinants of young players in racquet sports, and (2) to evaluate these instruments regarding their validity for talent development. Electronic searches were conducted in PubMed, PsychINFO, Web of Knowledge, ScienceDirect and SPORTDiscus (1990 to 31 March 2014). Search terms represented tennis, table tennis, badminton and squash, the concept of talent, methods of testing and children. Thirty articles with information regarding over 100 instruments were included. Validity evaluation showed that instruments focusing on intellectual and perceptual abilities, and coordinative skills discriminate elite from non-elite players and/or are related to current performance, but their predictive validity is not confirmed. There is moderate evidence that the assessments of mental and goal management skills predict future performance. Data on instruments measuring physical characteristics prohibit a conclusion due to conflicting findings. This systematic review yielded an ambiguous end point. The lack of longitudinal studies precludes verification of the instrument's capacity to forecast future performance. Future research should focus on instruments assessing multidimensional talent determinants and their predictive value in longitudinal designs.

  3. Tennis: a physiological profile during match play.

    PubMed

    Bergeron, M F; Maresh, C M; Kraemer, W J; Abraham, A; Conroy, B; Gabaree, C

    1991-10-01

    Heart rate (HR), hematocrit, hemoglobin, blood glucose, and plasma concentrations of lactate, cortisol, and testosterone were monitored in 10 male subjects (Division I, 20.3 +/- 2.5 yrs, VO2max: 58.5 +/- 9.4 ml.kg-1.min-1) during singles tennis and a treadmill test. During the on-court session, HR was 144.6 +/- 13.2 beats.min-1 for the 85 min of play. Plasma lactate rose 50% from a post-warmup value of 1.6 +/- 0.6 mmol.l-1 to 2.3 +/- 1.2 mmol.l-1 during play (p greater than 0.05). Blood glucose slightly decreased (8%, p greater than 0.05) from a pre-exercise value of 4.6 +/- 0.8 mmol.l-1 as a result of the 10-min warmup. This was followed by a 23% rise (p less than 0.05) from 4.2 +/- 1.0 mmol.l-1 to 5.2 +/- 0.6 mmol.l-1, measured after the first 30 min of play. Blood glucose subsequently remained steady at slightly above the pre-exercise value. Plasma cortisol rose (9%, p greater than 0.05) during the warmup and subsequently decreased (p less than 0.05) from a post-warmup value of 558.2 +/- 285.2 nmol.l-1 to 337.1 +/- 173.3 nmol.l-1 (a 40% decrease), and remained decreased during recovery. Plasma testosterone rose 22% (p less than 0.05) from pre-exercise to recovery (13.5 +/- 3.8 nmol.l-1 and 16.5 +/- 2.6 nmol.l-1, respectively). Although tennis is characterized by periods of high-intensity exercise, the overall metabolic response resembles prolonged moderate-intensity exercise.

  4. Impact of fluid restriction and ad libitum water intake or an 8% carbohydrate-electrolyte beverage on skill performance of elite adolescent basketball players.

    PubMed

    Carvalho, Pedro; Oliveira, Bruno; Barros, Renata; Padrão, Patricia; Moreira, Pedro; Teixeira, Vitor Hugo

    2011-06-01

    Twelve adolescent athletes underwent, in a crossover-design study, 3 separate 90-min training sessions in the following conditions: no fluid ingestion allowed (NF), ad libitum ingestion of water (W), and ad libitum ingestion of a commercial 8% carbohydrate-electrolyte sports beverage (CSB). After each session athletes performed a set of basketball drills (2-point, 3-point, and free-throw shootout, suicide sprints, and defensive zigzags). Body weight (before and after sessions), rating of perceived exertion (RPE), urine color, and beverage acceptability were determined in each session. Athletes also completed a survey about their knowledge and behaviors regarding hydration and fluid replacement. The percentage of weight loss was significantly higher in NF (2.46% ± 0.87%) than in the other 2 conditions (W, 1.08% ± 0.67%, p = .006; CSB, 0.65% ± 0.62%, p = .001) but also higher in W than CSB (p = .012). RPE was higher in NF (16.8 ± 1.96) than in the W (14.2 ± 1.99, p = .004) and CSB (13.3 ± 2.06, p = .002) trials. Athletes' fluid intake was positively correlated with proper self-reported behaviors (r = .75, p = .005) and knowledge (r = .76, p = .004) about fluid and hydration. In conclusion, fluid restriction during exercise was associated with a greater level of dehydration and increased perceived exertion but had no impact on basketball performance compared with ad libitum drinking of water or a CSB. Athletes with more knowledge about hydration and better self-reported hydration behaviors ingested more fluids during training sessions.

  5. Performance Factors Related to the Different Tennis Backhand Groundstrokes: A Review

    PubMed Central

    Genevois, Cyril; Reid, Machar; Rogowski, Isabelle; Crespo, Miguel

    2015-01-01

    The backhand is one of the two basic groundstrokes in tennis and can be played both with one or two hands, with topspin or backspin. Despite its variety of derivatives, the scientific literature describing the backhand groundstroke production has not been reviewed as extensively as with the serve and the forehand. The purpose of this article is to review the research describing the mechanics of one and two-handed backhands, with a critical focus on its application to clinicians and coaches. One hundred and thirty four articles satisfied a key word search (tennis, backhand) in relevant databases and manual search, with only 61 of those articles considered directly relevant to our review. The consensus of this research supports major differences between both the one- and two-handed strokes, chiefly about their respective contributions of trunk rotation and the role of the non-dominant upper extremity. Two-handed backhand strokes rely more on trunk rotation for the generation of racquet velocity, while the one-handed backhands utilize segmental rotations of the upper limb to develop comparable racquet speeds. There remains considerable scope for future research to examine expertise, age and/or gender-related kinematic differences to strengthen the practitioner’s understanding of the key mechanical considerations that may shape the development of proficient backhand strokes. Key points One-and two-handed backhands require different motor coordination Two-handed backhand strokes rely more on trunk rotation for racquet velocity generation, whereas one-handed backhand strokes rely more on segmental rotations of the upper limb Players using a two-handed backhand should learn early a slice one-handed backhand because of the different co-ordination pattern involved Equipment scaling is a great tool for coaches to learn early proper one-handed backhand strokes Future research related to the interaction between backhand technique, gender and skill level is needed PMID

  6. Heat stress does not exacerbate tennis-induced alterations in physical performance

    PubMed Central

    Girard, Olivier; Christian, Ryan J; Racinais, Sébastien; Périard, Julien D

    2014-01-01

    Objectives To assess the time course of changes in physical performance in response to match-play tennis under heat stress. Methods Two matches consisting of 20 min of effective playing time (2×10 min segments) were played in COOL (∼102 min; ∼22°C and 70% relative humidity (RH)) and HOT (∼119 min; ∼36°C and 35% RH) environments. Repeated-sprint ability (3×15 m, 15 s rest), 15 m sprint time with a direction change (180°), vertical jump height (squat and countermovement jumps) and leg stiffness (multirebound jumps) were assessed in 12 competitive male players prematch, midmatch and postmatch, and 24 and 48 h after match completion. Results During the repeated-sprint ability test, initial (+2.3% and +3.1%) and cumulated sprint (+1.5% and +2.8%) times increased from prematch to midmatch and postmatch, respectively (p<0.001), while the sprint decrement score did not change. Match-play tennis induced a slowing (average of both conditions: +1.1% and +1.3% at midmatch and postmatch time points; p=0.05) of 15 m sprint time with direction change. Compared with prematch, leg stiffness (−6.4% and −6.5%; p<0.001) and squat jump height (−1.5% and −2.4%; p=0.05), but not countermovement jump height (−0.7% and −1.3%; p>0.05), decreased midmatch and postmatch, respectively, regardless of the condition. Complete recovery in all physical performance markers occurred within 24 h. Conclusions In tennis, match-related fatigue is characterised by impaired repeated-sprint ability, explosive power and leg stiffness at midmatch and postmatch, with values restored to prematch baseline 24 h into recovery. In addition, physical performance responses (match and recovery kinetics) are identical when competing in cool and hot environments. PMID:24668378

  7. Key Factors and Timing Patterns in the Tennis Forehand of Different Skill Levels

    PubMed Central

    Landlinger, Johannes; Lindinger, Stefan; Stöggl, Thomas; Wagner, Herbert; Müller, Erich

    2010-01-01

    The main purpose of the present study was to quantify and compare selected kinematic variables and their timing during the tennis forehand of different skill levels. An eight-camera 400 Hz, Vicon motion analysis system recorded kinematic data of six ATP- professionals (elite) and seven high performance (HP) players when shots were played cross court and down the line. Timing of the maximum angles, linear and angular velocities was measured prior to and after impact. A total of twelve strokes per subject were analyzed from the beginning to the end of horizontal racquet movement. Significant differences (p < 0.01) and large effect sizes were observed between elite and HP players in the timing of maximum pelvis (-0.075 ± 0.008 vs. -0.093 ± 0.012 s) and trunk angular velocities (-0.057 ± 0.004 vs. -0.075 ± 0.011 s) before impact. The elite group showed a tendency (p < 0.05) towards higher peak horizontal shoulder (3.0 ± 0.4 vs. 2.5 ± 0.4 m·s-1) and racquet velocities (33.1 ± 2.4 vs. 31.1 ± 1.9 m·s-1) compared to the HP players. Depending on the situation (cross court vs. down the line), different peak hip, racquet and separation angles were found for both groups. Similar peak values were detected between groups for maximum angular velocities and displacement of key variables that had been selected for analysis. The findings of this study can be vital for successful player development, improved performance or injury prevention. The later occurrence of maximum angular pelvis and trunk rotations were the main reasons for the tendency towards higher horizontal shoulder and racquet velocities in the elite group. Key points Different timing of maximum angular pelvis and trunk rotations separated the elite from the high performance players. The elite group tended to reach higher horizontal shoulder and racquet velocities than the high performance group. In addition to maximum angular velocities, maximum racquet, shoulder, and hip alignment angles were similar

  8. Expert-novice differences in performance skills and problem representations of youth and adults during tennis competition.

    PubMed

    McPherson, S L

    1999-09-01

    Expert and novice tennis players selected from three different age groups (i.e., 10-11 years, 12-13 years, and collegiate adults) were examined for differences in performance skills (i.e., behavioral analyses of video recordings) and problem representations (i.e., verbal report analyses of tape recordings) during matched competition. Factorial analyses of variance on behavioral measures indicated that experts' performances exhibited higher levels of decision and execution than novices, regardless of age. Kruskal-Wallis tests on verbal report measures indicated that experts generated more total, varied, and sophisticated condition and action concepts than novices. Within experts, adults accessed more sophisticated problem representations than youth. Both current event and action plan profiles guided and mediated adult experts' response selections and executions, respectively. Youth experts primarily used action plan profiles to guide their response selections. Novices, regardless of age, accessed weak problem representations.

  9. 3D technology of Sony Bloggie has no advantage in decision-making of tennis serve direction: A randomized placebo-controlled study.

    PubMed

    Liu, Sicong; Ritchie, Jason; Sáenz-Moncaleano, Camilo; Ward, Savanna K; Paulsen, Cody; Klein, Tyler; Gutierrez, Oscar; Tenenbaum, Gershon

    2017-06-01

    This study aimed at exploring whether 3D technology enhances tennis decision-making under the conceptual framework of human performance model. A 3 (skill-level: varsity, club, recreational) × 3 (experimental condition: placebo, weak 3D [W3D], strong 3D [S3D]) between-participant design was used. Allocated to experimental conditions by a skill-level stratified randomization, 105 tennis players judged tennis serve direction from video scenarios and rated their perceptions of enjoyment, flow, and presence during task performance. Results showed that varsity players made more accurate decisions than less skilled ones. Additionally, applying 3D technology to typical video displays reduced tennis players' decision-making accuracy, although wearing the 3D glasses led to a placebo effect that shortened the decision-making reaction time. The unexpected negative effect of 3D technology on decision-making was possibly due to participants being more familiar to W3D than to S3D, and relatedly, a suboptimal task-technology match. Future directions for advancing this area of research are offered. Highlights 3D technology augments binocular depth cues to tradition video displays, and thus results in the attainment of more authentic visual representation. This process enhances task fidelity in researching perceptual-cognitive skills in sports. The paper clarified both conceptual and methodological difficulties in testing 3D technology in sports settings. Namely, the nomenclature of video footage (with/without 3D technology) and the possible placebo effect (arising from wearing glasses of 3D technology) merit researchers' attention. Participants varying in level of domain-specific expertise were randomized into viewing conditions using a placebo-controlled design. Measurement consisted of both participants' subjective experience (i.e., presence, flow, and enjoyment) and objective performance (i.e., accuracy and reaction time) in a decision-making task. Findings revealed that

  10. Cross-sectional area of psoas major muscle and hip flexion strength in youth soccer players.

    PubMed

    Hoshikawa, Yoshihiro; Iida, Tomomi; Ii, Nozomi; Muramatsu, Masataka; Nakajima, Yoshiharu; Chumank, Kentaro; Kanehisa, Hiroaki

    2012-10-01

    This study aimed to clarify the differences in the cross-sectional area (CSA) of the psoas major (PM) muscle and hip flexion force (HFF) of the right (dominant) side between adolescent male soccer players and age-matched non-athletes. PM CSA at L4–L5 and HFF at 1.05 rad/s were determined in 22 early (12.8–13.6 years) and 27 late (16.1–17.9 years) adolescent soccer players and 11 early (12.6–13.5 years) and 20 late (16.0–17.7 years) adolescent non-athletes. Fat-free mass (FFM) was greater in late adolescent soccer players than in late adolescent non-athletes, but was similar between the two early adolescent groups. Without the effect of age, PM CSA and HFF were greater in soccer players than in non-athletes. PM CSA and HFF were significantly correlated to FFM (soccer players, r = 0.860, P < 0.0001; non-athletes, r = 0.709, P < 0.0001) and PM CSA (soccer players, r = 0.760, P < 0.0001; non-athletes, r = 0.777, P < 0.0001), respectively. The difference between soccer players and non-athletes in PM CSA was still significant even when PM CSA was covaried for FFM. On the other hand, HFF covaried for PM CSA was similar between the two groups. The current results indicate that, as compared to age-matched non-athletes: (1) not only late, but also early adolescent soccer players have a greater PM CSA even when the difference in FFM was adjusted, and (2) their superiority in hip flexion force can be attributed to the difference in PM CSA.

  11. The Perception of Leader Behaviors upon the Satisfaction of College Tennis Players

    ERIC Educational Resources Information Center

    Adams, Orville Moses

    2009-01-01

    During the past 30 years, the discipline of Leadership Studies has pervaded several academic domains including business management. Recently, leadership theory has been applied to sports management. The current study sought to inform this line of inquiry and was based on Chelladurai (1979), multidimensional model of leadership. The purpose of the…

  12. Rectus abdominis muscle injuries in elite handball players: management and rehabilitation.

    PubMed

    Balius, Ramon; Pedret, Carles; Pacheco, Laura; Gutierrez, Josep Antoni; Vives, Joan; Escoda, Jaume

    2011-01-01

    Muscle injuries generally occur in two-joint muscles with a high percentage of type II fibers during the performance of eccentric activity. Some muscle injuries, such as those located in the adductor longus, a monoarticular muscle, as well as rectus abdominis do not fully comply with these requirements. This study examines five cases of elite handball players with ruptured rectus abdominals. Sonographically, lesions in rectus abdominis are shown as a disruption of the fibrillar pattern with a hematic suffusion that invades the entire lesion. In some of the cases, the ultrasound study was complemented with a MRI. A unified rehabilitation protocol was applied and the return to play time of each handball player ranged between 16 and 22 days, with an average of 18.2 days. Follow-up at 15 months showed no evidence of re-injury or residual discomfort and all of them are playing at their highest level. The aim of this study was to illustrate a feature of handball injury that, as in tennis and volleyball, is uncommon and so far has not been specifically reported. The phenomenon of contralateral abdominal hypertrophy in handball appears in the dominant arm as in tennis and volleyball.

  13. Rectus abdominis muscle injuries in elite handball players: management and rehabilitation

    PubMed Central

    Balius, Ramon; Pedret, Carles; Pacheco, Laura; Gutierrez, Josep Antoni; Vives, Joan; Escoda, Jaume

    2011-01-01

    Muscle injuries generally occur in two-joint muscles with a high percentage of type II fibers during the performance of eccentric activity. Some muscle injuries, such as those located in the adductor longus, a monoarticular muscle, as well as rectus abdominis do not fully comply with these requirements. This study examines five cases of elite handball players with ruptured rectus abdominals. Sonographically, lesions in rectus abdominis are shown as a disruption of the fibrillar pattern with a hematic suffusion that invades the entire lesion. In some of the cases, the ultrasound study was complemented with a MRI. A unified rehabilitation protocol was applied and the return to play time of each handball player ranged between 16 and 22 days, with an average of 18.2 days. Follow-up at 15 months showed no evidence of re-injury or residual discomfort and all of them are playing at their highest level. The aim of this study was to illustrate a feature of handball injury that, as in tennis and volleyball, is uncommon and so far has not been specifically reported. The phenomenon of contralateral abdominal hypertrophy in handball appears in the dominant arm as in tennis and volleyball. PMID:24198573

  14. Thigh muscularity and strength in teenage soccer players.

    PubMed

    Hoshikawa, Y; Iida, T; Muramatsu, M; Ii, N; Nakajima, Y; Chumank, K; Kanehisa, H

    2013-05-01

    This study examined the thigh muscularity and strength capability in early adolescent soccer players. The cross-sectional areas (CSAs) of the thigh muscles and dynamic strength during knee extension and flexion at 1.05 rad/s were determined twice at an interval of 6 months in 24 male soccer players aged 12-13 years and 11 age- and body height-matched non-athletes. After 6 months, muscle CSA and dynamic strength increased without significant interaction of time and group. Thigh total muscle CSA was not significantly affected by group, but the value relative to either thigh CSA or body mass was higher in soccer players. While knee flexion strength was similar between the 2 groups, knee extension strength was greater in soccer players than in non-athletes, even in terms of strength relative to CSA. The current results indicate that, compared with age- and body height-matched non-athletes, early adolescent soccer players are characterized by higher relative distribution of muscle mass within the thigh and higher knee extension strength relative to the quadriceps CSA. During the growth stage in which body height begins to increase markedly, however, participation in competitive soccer training does not increase the rate of development in thigh muscularity and strength.

  15. Hybridized Tennis Games for Utilization-Level and Higher Learners

    ERIC Educational Resources Information Center

    Kahan, David

    2006-01-01

    Over the past 10 years a number of articles pertaining to teaching tennis to elementary and middle school students have appeared (see Resources at the end of this article). These articles have focused on topics such as tactical play, basic skill instruction and drill, teaching progressions, organizational methods, and fitness development. While…

  16. Effects of Play Practice on Teaching Table Tennis Skills

    ERIC Educational Resources Information Center

    Zhang, Peng; Ward, Phillip; Li, Weidong; Sutherland, Sue; Goodway, Jackie

    2012-01-01

    The purpose of this study was to examine the effects of Play Practice (PP) instruction on the performance of table tennis skills. Fifty-six college students in four intact classes were taught by two instructors using PP and Skill-focused Instruction (SI). A nonequivalent control/comparison group experimental design with pre and post measures was…

  17. Surgical Treatment of Tennis Elbow; Minimal Incision Technique

    PubMed Central

    Amroodi, Morteza Nakhaei; Mahmuudi, Ali; Salariyeh, Mostafa; Amiri, Arash

    2016-01-01

    Background: When non-operative treatment of tennis elbow fails; a surgical procedure can be performed to improve the associated symptoms. Different surgical techniques for treatment of lateral epicondylitis are prescribed. The purpose of this study was to evaluate the clinical outcomes of surgical treatment for tennis elbow based on small incision techniques. Methods: This technique was performed on 24 consecutive patients between June 2011 and July 2013. Outcomes were assessed using the Patient-Rated Tennis Elbow Evaluation (PRTEE), Nirschl’s staging system and visual analog scale (VAS) for pain and satisfaction criteria. Results: There were 15 female and 9 male patients in the study. The mean duration of symptoms before surgery was 3.7 years. The average duration of follow-up was 34.8 months. The post-operative outcome was good to excellent in most patients. The mean VAS score improved from 7.2 to 3.5 points. The total PRTEE improved from 68.7 to 15.8 points. Conclusion: This procedure provides a low complication rate which is associated with a high rate of patient satisfaction. Therefore, we suggest this option after failed conservative management of tennis elbow. PMID:27847851

  18. The Table Tennis Triathlon: An Integrated Sport Education Season

    ERIC Educational Resources Information Center

    Buchanan, Alice M.; Barrow, Brook

    2016-01-01

    This article describes an integrated, 10-day unit that was designed using the sport education model in physical education. English language arts and social responsibility were integrated into a unit of table tennis in fifth-grade physical education. The student roles were adapted to best fit the needs of the unit. Through the integration of three…

  19. MedlinePlus: Viewers & Players

    MedlinePlus

    ... Player Play video and audio files on Apple operating systems. mov Apple iTunes Download NLM podcasts and applications. ... Player Play video and audio files on PC operating systems. mp3 wav wmz Microsoft Excel Viewer Open, view ...

  20. Shoulder Disease Patterns of the Wheelchair Athletes of Table-Tennis and Archery: A Pilot Study

    PubMed Central

    2016-01-01

    Objective To investigate the shoulder disease patterns for the table-tennis (TT) and archery (AR) wheelchair athletes via ultrasonographic evaluations. Methods A total of 35 wheelchair athletes were enrolled, made up of groups of TT (n=19) and AR (n=16) athletes. They were all paraplegic patients and were investigated for their wheelchair usage duration, careers as sports players, weekly training times, the Wheelchair User's Shoulder Pain Index (WUSPI) scores and ultrasonographic evaluation. Shoulders were divided into playing arm of TT, non-playing arm of TT, bow-arm of AR, and draw arm of AR athletes. Shoulder diseases were classified into five entities of subscapularis tendinopathy, supraspinatus tendinopathy, infraspinatus tendinopathy, biceps long head tendinopathy, and subacromial-subdeltoid bursitis. The pattern of shoulder diseases were compared between the two groups using the Mann-Whitney and the chi-square tests Results WSUPI did not significantly correlate with age, wheelchair usage duration, career as players or weekly training times for all the wheelchair athletes. For the non-playing arm of TT athletes, there was a high percentage of subscapularis (45.5%) and supraspinatus (40.9%) tendinopathy. The percentage of subacromial-subdeltoid bursitis showed a tendency to be present in the playing arm of TT athletes (20.0%) compared with their non-playing arm (4.5%), even though this was not statistically significant. Biceps long head tendinopathy was the most common disease of the shoulder in the draw arm of AR athletes, and the difference was significant when compared to the non-playing arm of TT athletes (p<0.05). Conclusion There was a high percentage of subscapularis and supraspinatus tendinopathy cases for the non-playing arm of TT wheelchair athletes, and a high percentage of biceps long head tendinopathy for the draw arm for the AR wheelchair athletes. Consideration of the biomechanical properties of each sport may be needed to tailor specific

  1. Kinetics of the upper extremity in the open and square stance tennis forehand.

    PubMed

    Bahamonde, R E; Knudson, D

    2003-03-01

    Seven right-handed teaching professionals and eight intermediate tennis players were filmed using two high-speed cameras (100 Hz) as they performed open and square stance forehand drives. Three-dimensional coordinates (3D) were reconstructed using the DLT method. A three-segment rigid body model of the racket and upper extremity was used to calculate the kinetics of the wrist, elbow, and shoulder joints up to impact. The open stance created lower resultant velocities of the racket at impact (21.2 and 15.8 m/s) than the square stance (22.3 and 16.4 m/s) for professional and intermediate subjects, respectively. The largest components of the resultant joint torques were generated by the shoulder horizontal adductors, followed by elbow varus torques, and shoulder internal rotation torques. Torques were similar across stance and skill level except for significantly (p < 0.05) greater peak shoulder internal rotation torques in the square compared to the open stance, greater peak wrist flexion torques in the intermediate compared to the professionals, and greater peak wrist flexion torques in the square stance compared to the open stance. The data did not support the hypothesis that the open stance technique creates greater loading throughout the upper extremity than the square stance technique. Peak upper extremity torques were similar to peak torques reported for baseball pitching and represent loads that could contribute to strength imbalances and overuse injuries.

  2. Teaching Beginning Trombone Players.

    ERIC Educational Resources Information Center

    Fallis, Todd L.

    2001-01-01

    Discusses the process of introducing the trombone to beginning students and addresses the issue of warming-up. Provides resources for beginning trombone methods, band methods, and daily warm-up studies. Includes resources for scale studies and etudes for beginning to intermediate trombone players. (CMK)

  3. Comparison of body composition and nutrients' deficiencies between Portuguese rink-hockey players.

    PubMed

    Silva, Maria-Raquel G; Silva, Hugo-Henrique

    2017-01-01

    We evaluated dietary intake and body composition of child and adolescent rink-hockey players and controls. Seventy-two male rink-hockey players (38 children and 34 adolescents) and 79 male controls (43 children and 36 adolescents) were evaluated in order to collect training data, detailed dietary intake and body composition. Rink-hockey players presented significantly lower body fat (BF) and higher fat-free mass (FFM) than controls. Mean intakes of carbohydrate and protein were considered to be adequate, but mean intakes of fat were above the recommended levels in athletes. Significant differences were found for energy intake (EI) and exercise energy expenditure (EEE) between athletes and controls (P < 0.05), resulting in some cases of low energy availability in rink-hockey players. Significant group differences (P < 0.05) were also observed for vitamins and mineral intakes in child and adolescent rink-hockey players due to higher mean intakes in control groups. Low intakes of vitamins D, E and K, calcium, iron, boron and magnesium were reported in athletes, with exception for thiamine (P = 0.449), riboflavin (P = 0.246), pantothenic acid (P = 0.065), magnesium (P = 0.061) and phosphorus (P = 0.051) in children and for niacin (P = 0.652), vitamin D (P = 0.406) and zinc (P = 0.783) in adolescents.

  4. The activity intensities reached when playing active tennis gaming relative to sedentary gaming, tennis game-play, and current activity recommendations in young adults.

    PubMed

    Scanlan, Aaron T; Arkinstall, Hayley; Dalbo, Vincent J; Humphries, Brendan J; Jennings, Cameron T; Kingsley, Michael I C

    2013-09-01

    Although active gaming is popular and can increase energy expenditure in young adults, its efficacy as a prescriptive exercise tool is not well understood. This study aimed to: (a) compare the activity intensities experienced by young adults while playing active tennis gaming with conventional sedentary gaming, tennis game-play, and current activity recommendations for health; and (b) identify changes in activity intensities across playing time. After habitualization, 10 active young adults (age: 20.2 ± 0.4 years; stature: 1.74 ± 0.03 m; body mass: 67.7 ± 3.3 kg) completed 3 experimental trials (sedentary gaming, active tennis gaming, and tennis game-play) on separate days in a randomized order. Heart rate (HR) and metabolic equivalents (METs) were averaged across 5 minutes and 10 minutes intervals, and the entire 20 minutes bout within each condition. Active gaming produced greater intensities across 5-10, 10-15, and 15-20 minutes time intervals compared with sedentary gaming (p < 0.01). Tennis game-play elicited greater HR (67 ± 5% HR(max)) and METs (5.0 ± 0.2) responses than both sedentary (40 ± 2% HR(max), 1.1 ± 0.1 METs) and active gaming (45 ± 2% HR(max), 1.4 ± 0.1 METs) (p < 0.001). Only tennis game-play produced activity intensities meeting current recommendations for health benefit. Lower HR intensities were reached across 0-5 minutes than during later time intervals during active gaming (6%) and tennis game-play (9%) (p < 0.01). Activity intensities elicited by active gaming were greater than sedentary gaming but less than tennis game-play and insufficient to contribute toward promoting and maintaining good health in young adults. These data suggest that active tennis gaming should not be recommended by exercise professionals as a substitute for actual sports participation in young adults.

  5. STS-44 OV-104's airlock hatch with tennis shoes and Presidential Sports Award

    NASA Technical Reports Server (NTRS)

    1991-01-01

    STS-44 airlock hatch is decorated with two pairs of tennis shoes and a Presidential Sports Award Jogging patch (insignia) on the middeck of Atlantis, Orbiter Vehicle (OV) 104. With the crew having a treadmill-like device onboard for exercise and biomedical testing, tennis shoes were in plentiful stock on the eight-day mission.

  6. Eating and nutrition habits in young competitive athletes: a comparison between soccer players and cyclists.

    PubMed

    Galanti, Giorgio; Stefani, Laura; Scacciati, Irene; Mascherini, Gabriele; Buti, Gabriella; Maffulli, Nicola

    2015-01-01

    The study evaluated the dietary habits in two groups of young athletes, practicing two different sports: soccer players and cycling. The dietary habits of 47 athletes were investigated by questionnaire. Body Mass Index, Fat Mass, Free Fat Mass, Total Body, Intracellular, Extracellular Water and Phase Angle were measured by bioimpedance. The t-Student test for unpaired data was used. Significance was set at P < 0.05. Body Mass Index was similar between the groups, while total body water and extracellular water were significantly higher in the soccer player group (soccer players: 63.8±1.96%; cyclists : 59.8 ± 8.7%; and soccer players 43.9±3.1%, cyclists 43.8 ±2.1%, respectively). Fatty mass of the soccer player group (14.5±2.9%) was significantly lower than that of the cyclist group (19.5±3.6%). Daily food intake was similar between the two groups (2844 kCal/die for soccer players /2630 kcal/die for cyclists), and lower than recommended. There was a low intake of Calcium (soccer players 1120±128.9 mg/die, cyclists 718±309 mg/die) for both groups, and a low intake of Potassium for soccer player (2576 mg/die ± 52.4) The caloric intake of adolescent athletes is lower than recommended. Body composition is significantly different between soccer players and cyclists.

  7. SteroMoviePlayer

    SciTech Connect

    Hodson, Steve; Pugmire, Dave

    2005-03-14

    StereoMoviePlayer StereoMoviePlayer (SMP) is a software package for creating and displaying stereo movies on a variety of computer architectures and display configuations. SMP is capable of running in serial, or in parallel to facilitate multiple computers driving a collection of display surfaces. SMP utilizes the standatd openGL gaphics library for display of both monoscopic and stereoscopic images and MPI for parallel communication and sychronization between multiple computers. SMP uses standard IO methods for loading movie files into memory and, when compressed movies are being displayed uses zLIB (which is standard in most Linux/Unix;/IRIX distributions) for decompression. A movie file is simply a concatenation of each frame. Each frame is a raw red/green/blue encoding. For stereoscopic movies, concatenation is left followed by right, as follows; Frame0-Left, Frame0-Right, Frame1-Left, Frame1-Right .... FrameN-Left, FrameN-Right To enhance performance, this concatenation of frames can be compressed using the aforementioned zLib compression/decompression library. ConvertMovie is a utility that converts between compressed and uncompressed movie formats. ConvertMovie uses zLib, which is included in most standard Linux/Unix/IRIX distributions for compression and decompression. StereoMoviePlayer consists of 3 main parts: 1-Initialization. Information is parsed from a configuration script that specifies machines on which to run, the movie file and the parameters for each graphics display. MPI is then used to instantiate a movie player on each specified computer. 2-Per-node initialization. Each parallel node creates 2 threads of execution, an IO thread and a display and communication thread. 3-Execution: The IO thread reads movie frames from disk, decompresses if necessary and places the frames in main memory. The display thread copies fromes from main memory to the graphics card for display. The display thread also handles synchronization among the other nodes

  8. Comparison of heart rate response to tennis activity between persons with and without spinal cord injuries: implications for a training threshold.

    PubMed

    Barfield, J P; Malone, Laurie A; Coleman, Tristica A

    2009-03-01

    The purpose of this study was to evaluate the ability of individuals with spinal cord injury (SCI) to reach a training threshold during on-court sport activity. Monitors collected heart rate (HR) data every 5 s for 11 wheelchair tennis players (WCT) with low paraplegia and 11 able-bodied controls matched on experience and skill level (ABT). Average HR was determined for time spent in practice (e.g, drills) and game (i.e., a competitive set), and the ability to surpass 50% peak HR (HRpeak) and 64% HRpeak in each condition was evaluated. Average exercise intensity (%HRpeak) was not significantly different between the groups during practice (M WCT = 68.18, SD = 7.53%, M ABT = 68.78, SD = 5.44%; t = .22, p = .83) or game (M WCT = 68.17, SD = .17%, M ABT = 71.55, SD = 4.75%; t = 1.12, p =.28). Allparticipants averaged an intensity > or = 50% HR-peak during practice and game, and the difference between group participants averaging an intensity > or = 64% HRpeak was not significant during practice (chi2 = .92, p = .34) or game (chi2 = 3.85, p = .05). In terms of reaching a health and fitness training threshold during tennis, individuals with low-level SCI are similar to matched controls.

  9. Fitness Profiles of Elite Portuguese Rugby Union Players

    PubMed Central

    Vaz, Luís; Morais, Tomaz; Rocha, Henrique; James, Nic

    2014-01-01

    The aim of this study was to describe the fitness profiles of senior elite Portuguese rugby players. Forty-six senior Portuguese rugby players, classified as backs (n=22; age 26.2±2.8) and forwards (n=24; age 26.7±2.9) were assessed during physical testing sessions carried out for the Portuguese National rugby team. The body composition, maximum strength and anaerobic capacity of players are hypothesized to be important physical characteristics as successful performance in rugby is predicated on the ability to undertake skilled behaviours both quickly and whilst withstanding large forces when in contact situations. No absolute differences were found between the backs and forwards for the speed performance variables although positional differences were found across all speeds when assessed relative to body mass since the forwards were significantly heavier. Coaches and the management team can use this information for monitoring progressive improvements in the physiological capacities of rugby players. These physical characteristics of elite rugby players provide normative profiles for specific positions and should form the basis of developmental programmes for adolescents. PMID:25114750

  10. Development of Body Composition, Hormone Profile, Physical Fitness, General Perceptual Motor Skills, Soccer Skills and On-The-Ball Performance in Soccer-Specific Laboratory Test Among Adolescent Soccer Players

    PubMed Central

    Vänttinen, Tomi; Blomqvist, Minna; Häkkinen, Keijo

    2010-01-01

    The aim of the present study was to examine the development of on-the-ball skills in soccer-specific laboratory test and to examine how traditional measures of body composition, hormone profile, physical fitness, general perceptual motor skills and soccer skills were related to performance measured in open skill environment among 10, 12, and 14-year-old regional male soccer players (n = 12/group). The measured variables were height, weight, fat, muscle mass, testosterone, 10m sprint, agility, counter movement jump, peripheral awareness, Eye- Hand-Foot coordination, passing skill, dribbling skill and on-the-ball skills (performance time and passing accuracy) in soccer-specific laboratory test. A significant main effect by age was found in all measured variables except in fat, in peripheral awareness and in passing accuracy. In discriminant analysis 63.9% (λ = 0.603, F = 4.600, p < 0.01) of the players were classified correctly based on physical fitness and general perceptual motor skills into three ability groups originally classified with performance time in soccer-specific laboratory test. Correlation co- efficient analysis with-in age groups revealed that variables associated with performance time in soccer-specific laboratory test were peripheral awareness (r = 0.72, p < 0.01) in 10-year-olds; testosterone (r = -0.70, p < 0.05), dribbling skill (r = 0.73, p < 0.01) and passing skill (r = 0.73, p < 0.01) in 12-year-olds; agility (r = 0.79, p < 0.01), counter movement jump (r = - 0.62, p < 0.01), dribbling skill (r = 0.80, p < 0.01) and passing skill (r = 0.58, p < 0. 05) in 14-year olds. Corresponding relationships with passing accuracy were weight (r = 0.59, p < 0.05), fat (r = 0.66, p < 0.05), 10m sprint (r = 0.71, p < 0.01) and countermovement jump (r = -0.64, p < 0.05) in 10-year-olds; Eye-Hand-Foot coordination (r = 0.63, p < 0.05) in 14-year- olds. The relationship between soccer-specific anticipation time and performance time in soccer- specific

  11. Communicative Competency among Poker Players.

    ERIC Educational Resources Information Center

    Hayano, David M.

    1980-01-01

    Discusses the use of specific styles of strategic interaction among professional poker players in their attempts to conceal, distort, or discover useful information about their opponents in order to maximize some gain. (JMF)

  12. Lift crisis of a spinning table tennis ball

    NASA Astrophysics Data System (ADS)

    Miyazaki, T.; Sakai, W.; Komatsu, T.; Takahashi, N.; Himeno, R.

    2017-03-01

    The aerodynamic properties of a spinning table tennis ball were investigated using flight experiments. Using high-speed video cameras, the trajectory and rotation of an official ball (Nittaku 3-Star Premium), which was launched by a three rotor machine, were recorded. The drag and lift coefficients (C D and C L) were determined by analysing the video images. The measurements covered the speed and rotation range of typical table tennis shots in the form of the Reynolds number (Re) and dimensionless spin rate (SP), i.e. 3.0 × 104 < Re < 9.0 × 104 and 0 < SP < 1.0, and C D and C L were obtained as functions of Re and SP. We determined that the lift coefficient C L is not a monotonically increasing function of SP. A deep valley of C L was found around SP = 0.5, and the lift force exerted on a spinning ball almost vanished at Re = 9.0 × 104 and 0.48 < SP < 0.5. These results qualitatively agree with the results from recent wind tunnel tests, but quantitative differences owing to the unsteady nature of the flight experiments remain. This anomaly in the lift coefficient should be called the ‘lift crisis’.

  13. Elastic Properties of Plasticine, Silly Putty, and Tennis Strings

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2012-12-01

    How would a physicist describe the elastic properties of an apple or a banana? Physics students and teachers are familiar with the elastic properties of metal springs, but are likely to be less familiar with the elastic properties of other common materials. The behavior of a metal spring is commonly examined in the laboratory by adding masses to measure the change in the extension or compression. A banana or an apple or any other relatively soft material could just as easily be examined in the same way, as an additional and entertaining exercise. Even if an apparatus is not readily available to undertake such an experiment, it can easily be constructed.1,2 In this article I compare the elastic properties of Plasticine (a brand of modeling clay), Silly Putty, and tennis strings. All three materials behave in the same qualitative manner when stretched or compressed slowly, despite the fact that they are quite different when stretched or compressed rapidly and despite the fact that Plasticine and Silly Putty are both much softer than a tennis string. Typical results for a slow deformation are shown in Fig. 1.

  14. Freedom between the Lines: Clothing Behavior and Identity Work among Young Female Soccer Players

    ERIC Educational Resources Information Center

    Hendley, Alexandra; Bielby, Denise D.

    2012-01-01

    Our research examines the relationship among identity, age, gender and athleticism through a study of the association between sports clothing and the identity work of pre-adolescent female soccer players. Based on participant-observation and interviews conducted at three co-ed youth soccer camps, we find that age is an important element of…

  15. A Newly Designed Tennis Elbow Orthosis With a Traditional Tennis Elbow Strap in Patients With Lateral Epicondylitis

    PubMed Central

    Saremi, Hossein; Chamani, Vahid; Vahab-Kashani, Reza

    2016-01-01

    Background Lateral epicondylitis is a common cause of pain and upper limb dysfunction. The use of counterforce straps for treatment of lateral epicondylitis is widespread. This kind of orthosis can be modified to have a greater effect on relieving pain by reducing tension on the origin of the extensor pronator muscles. Objectives To determine the immediate effects of a newly designed orthosis on pain and grip strength in patients with lateral epicondylitis. Materials and Methods Twelve participants (six men and six women) were recruited (mean age = 41 ± 6.7 years) and evaluated for pain and grip strength in three sessions. A 48-hour break was taken between each session. The first session was without any orthosis, the second session was with the new modified tennis elbow orthosis, and the third session was with a conventional tennis elbow strap. Results Both counterforce straps were effective. However, significantly more improvement was observed in pain and grip strength after using the newly modified orthosis (P < 0.05). Conclusions The newly designed strap reduces pain more effectively and improves grip strength by causing greater localized pressure on two regions with different force applications (two component vectors versus one). PMID:28180116

  16. Online Computer Gaming: A Comparison of Adolescent and Adult Gamers

    ERIC Educational Resources Information Center

    Griffiths, M. D.; Davies, Mark N. O.; Chappell, Darren

    2004-01-01

    Despite the growing popularity of online game playing, there have been no surveys comparing adolescent and adult players. Therefore, an online questionnaire survey was used to examine various factors of online computer game players (n=540) who played the most popular online game Everquest. The survey examined basic demographic information, playing…

  17. Multiple Past Concussions in High School Football Players

    PubMed Central

    Brooks, Brian L.; Mannix, Rebekah; Maxwell, Bruce; Zafonte, Ross; Berkner, Paul D.; Iverson, Grant L.

    2017-01-01

    Background There is increasing concern about the possible long-term effects of multiple concussions, particularly on the developing adolescent brain. Whether the effect of multiple concussions is detectable in high school football players has not been well studied, although the public health implications are great in this population. Purpose To determine if there are measureable differences in cognitive functioning or symptom reporting in high school football players with a history of multiple concussions. Study Design Cross-sectional study; Level of evidence, 3. Methods Participants included 5232 male adolescent football players (mean [±SD] age, 15.5 ± 1.2 years) who completed baseline testing between 2009 and 2014. On the basis of injury history, athletes were grouped into 0 (n = 4183), 1 (n = 733), 2 (n = 216), 3 (n = 67), or ≥4 (n = 33) prior concussions. Cognitive functioning was measured by the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) battery, and symptom ratings were obtained from the Post-Concussion Symptom Scale. Results There were no statistically significant differences between groups (based on the number of reported concussions) regarding cognitive functioning. Athletes with ≥3 prior concussions reported more symptoms than did athletes with 0 or 1 prior injury. In multivariate analyses, concussion history was independently related to symptom reporting but less so than developmental problems (eg, attention or learning problems) or other health problems (eg, past treatment for psychiatric problems, headaches, or migraines). Conclusion In the largest study to date, high school football players with multiple past concussions performed the same on cognitive testing as those with no prior concussions. Concussion history was one of several factors that were independently related to symptom reporting. PMID:27474382

  18. The aerodynamics of tennis balls-The topspin lob

    NASA Astrophysics Data System (ADS)

    Štěpánek, Antonín

    1988-02-01

    A general description is presented of the calculation of the ballistic trajectory of a flying spinning ball acted on, in addition to the forces of gravity and drag, by the so-called Magnus force. By applying the regression analysis to results of wind-tunnel measurement of the drag and lift coefficients of a spinning ball, a calculation of the nonlinear differential equation of the hodograph was carried out by means of the Runge-Kutta method. The theoretical results that can be used to calculate the ballistic trajectories for any ball game were applied to one of the most difficult and most interesting tennis strokes, i.e., to the topspin lob. Practical results obtained for various distances are presented in a table as well as in graphical form. UFAJP

  19. Long term results in refractory tennis elbow using autologous blood.

    PubMed

    Gani, Naseem Ul; Khan, Hayat Ahmad; Kamal, Younis; Farooq, Munir; Jeelani, Hina; Shah, Adil Bashir

    2014-10-27

    Tennis elbow (TE) is one of the commonest myotendinosis. Different treatment options are available and autologous blood injection has emerged as the one of the acceptable modalities of treatment. Long term studies over a larger group of patients are however lacking. The purpose of this study was to evaluate these patients on longer durations. One-hundred and twenty patients of TE, who failed to respond to conventional treatment including local steroid injections were taken up for this prospective study over the period from year 2005 to 2011 and were followed up for the minimum of 3 years (range 3-9 years). Two mL of autologous blood was taken from the ipsilateral limb and injected into the lateral epicondyle. The effectiveness of the procedure was assessed by Pain Rating Sscale and Nirschl Staging, which was monitored before the procedure, at first week, monthly for first three months, at 6 months and then 3 monthly for first year, six monthly for next 2 years and then yearly. Statistical analysis was done and a P value of <0.05 was taken as significant. The patients (76 females and 44 males) were evaluated after procedure. The mean age group was 40.67±8.21. The mean follow up was 5.7±1.72 (range 3 to 9 years). The mean pain score and Nirschl stage before the procedure was 3.3±0.9 and 6.2±0.82 respectively. At final follow up the pain score and Nirschl were 1.1±0.9 and 1.5±0.91 respectively. Autologous blood injection was found to be one of the modalities for treatment of TE. Being cheap, available and easy method of treatment, it should be considered as a treatment modality before opting for the surgery. Universal guidelines for the management of tennis elbow should be made as there is lot of controversy regarding the treatment.

  20. Decreased Brain Neurokinin-1 Receptor Availability in Chronic Tennis Elbow

    PubMed Central

    Linnman, Clas; Catana, Ciprian; Svärdsudd, Kurt; Appel, Lieuwe; Engler, Henry; Långström, Bengt; Sörensen, Jens; Furmark, Tomas; Fredrikson, Mats; Borsook, David; Peterson, Magnus

    2016-01-01

    Substance P is released in painful and inflammatory conditions, affecting both peripheral processes and the central nervous system neurokinin 1 (NK1) receptor. There is a paucity of data on human brain alterations in NK1 expression, how this system may be affected by treatment, and interactions between central and peripheral tissue alterations. Ten subjects with chronic tennis elbow (lateral epicondylosis) were selected out of a larger (n = 120) randomized controlled trial evaluating graded exercise as a treatment for chronic tennis elbow (lateral epicondylosis). These ten subjects were examined by positron emission tomography (PET) with the NK1-specific radioligand 11C-GR205171 before, and eight patients were followed up after treatment with graded exercise. Brain binding in the ten patients before treatment, reflecting NK1-receptor availability (NK1-RA), was compared to that of 18 healthy subjects and, longitudinally, to the eight of the original ten patients that agreed to a second PET examination after treatment. Before treatment, patients had significantly lower NK1-RA in the insula, vmPFC, postcentral gyrus, anterior cingulate, caudate, putamen, amygdala and the midbrain but not the thalamus and cerebellum, with the largest difference in the insula contralateral to the injured elbow. No significant correlations between brain NK1-RA and pain, functional severity, or peripheral NK1-RA in the affected limb were observed. In the eight patients examined after treatment, pain ratings decreased in everyone, but there were no significant changes in NK1-RA. These findings indicate a role for the substance P (SP) / NK1 receptor system in musculoskeletal pain and tissue healing. As neither clinical parameters nor successful treatment response was reflected in brain NK1-RA after treatment, this may reflect the diverse function of the SP/NK1 system in CNS and peripheral tissue, or a change too small or slow to capture over the three-month treatment. PMID:27658244

  1. Shoulder injuries in soccer players

    PubMed Central

    Longo, Umile Giuseppe; Loppini, Mattia; Berton, Alessandra; Martinelli, Nicolò; Maffulli, Nicola; Denaro, Vincenzo

    2012-01-01

    Summary Even though soccer is the most popular sport of the world, no review is available at present to resume the available data on shoulder injuries in soccer. The aim of this review is to report the available epidemiological data on shoulder specific injuries in soccer players and to describe the common mechanisms of shoulder injuries in soccer. Studies published through September 15, 2011, were identified by using MEDLINE, EMBASE, CINAHL and Pre-CINAHL, Pub-Med, Web of Science, and the full Cochrane Library. Reference lists of included studies were searched by hand. Studies were included if they reported on shoulder injuries in soccer players. Limits were not placed on year of publication, status of publication, or language. The journal, authors, and author affiliations of included studies were masked from 2 reviewers. We planned to perform a study on the epidemiology, mechanisms and management of shoulder injuries in elite soccer players. We also planned to use Review Manager (RevMan. Version 5 for Windows) to calculate the magnitude of treatment effect. No studies on clinical outcome of shoulder injuries in elite soccer athletes were found. No studies on the mechanism of shoulder injury in elite soccer players were found. The results of the available studies on epidemiology are reported. Despite soccer is the world’s game, few studies focused on shoulder injuries in soccer players, and therefore no definitive conclusions can be drawn. Further research is warranted to clarify the epidemiology, mechanisms and management of shoulder injuries in elite soccer players. PMID:23289025

  2. Sport injuries aligned to peak height velocity in talented pubertal soccer players.

    PubMed

    van der Sluis, A; Elferink-Gemser, M T; Coelho-e-Silva, M J; Nijboer, J A; Brink, M S; Visscher, C

    2014-04-01

    In young athletes, demands of sports are superimposed on normal growth and maturation. It has been suggested that this causes a temporarily increased vulnerability for injuries. We followed 26 talented soccer players (mean age 11.9±0.84 years) longitudinally for 3 years around their adolescent growth spurt, called Peak Height Velocity, to identify differences in number of traumatic and overuse injuries and days missed due to injuries. Peak Height Velocity was calculated according to the Maturity Offset Protocol. The number of injuries was calculated for each player per year. A repeated measurement analysis showed that athletes had significantly more traumatic injuries in the year of Peak Height Velocity (1.41) than in the year before Peak Height Velocity (0.81). A moderate effect size of 0.42 was found for the difference in number of overuse injuries per player per year before (0.81) and after Peak Height Velocity (1.41), respectively. Finally, a moderate effect size of 0.55 was found for difference between days missed due to injuries before (7.27 days per player per year) and during Peak Height Velocity (15.69 days per player per year). Adolescent growth spurt seems to result in increased vulnerability for traumatic injuries. Afterwards athletes seem to be susceptible to overuse injuries.

  3. Who Are the Players in Canadian Curriculum?

    ERIC Educational Resources Information Center

    Milburn, Geoffrey

    1987-01-01

    Labels range of persons advocating different theoretical positions of Canadian curriculum as "players." Describes players as "managers,""predictors,""transformers,""sleuths,""analysts." Values varied viewpoints for attention to language regarding curriculum, critical review of…

  4. The Effectiveness Evaluation among Different Player-Matching Mechanisms in a Multi-Player Quiz Game

    ERIC Educational Resources Information Center

    Tsai, Fu-Hsing

    2016-01-01

    This study aims to investigate whether different player-matching mechanisms in educational multi-player online games (MOGs) can affect students' learning performance, enjoyment perception and gaming behaviors. Based on the multi-player quiz game, TRIS-Q, developed by Tsai, Tsai and Lin (2015) using a free player-matching (FPM) mechanism, the same…

  5. The Relation between Self Esteem Levels and Life Quality Levels of Disabled and Non-Disabled Tennis Sportsmen

    ERIC Educational Resources Information Center

    Civan, Adem

    2015-01-01

    This research was carried out to determine the self-esteem and life quality levels of disabled and non-disabled tennis sportsmen; and also to set forth the relation between their self-esteem and life quality levels. The research group consists of total 44 sportsmen including 22 disabled tennis sportsmen (n[subscript (female)]=9, n[subscript…

  6. [Hemodynamic Status of Prepubertal and Pubertal Hockey Players].

    PubMed

    Shayhelislamova, M V; Sitdikov, F G; Zefirov, T L; Dikopolskaya, N B

    2015-01-01

    The hemodynamic status of 11-15-year-old hockey players depending on their age and puberty stage were studied and compared with hemodynamic parameters of the control group. It was found that regular muscle training has a dominant effect on the functional state of cardiovascular system (CVS) in prepuberty and puberty. It was proved that in hockey players a decrease in the heart rate (H R) and an increase in the stroke volume (SV) result in a significant increase in systolic blood pressure (SBP) at the age of 11-14 years and a progressive increase in total peripheral vascular resistance (PVR), in contrast to significantly lower values in the control group. The urgent adaptation of CVS to graduated physical activities at the age of 11-13 years leads to an enhancement of vascular spasmodic reactions while SV remains constant. It was found that in adolescent hockey players have consistently high SV and SBP; at the same time, maximal values of HR, cardiac output (CO) and diastolic blood pressure (DBP) were observed at the stages I and II of the puberty period; then, at the stage III, these parameters decrease. I n the control group, hymodinamic status changed in an opposite way. This may be an evidence of the stress effect of physical activities which results in the adaptive reactions of CVS rather than reactions typical of the puberty period.

  7. Upper limb muscle imbalance in tennis elbow: a functional and electromyographic assessment.

    PubMed

    Alizadehkhaiyat, Omid; Fisher, Anthony C; Kemp, Graham J; Vishwanathan, Karthik; Frostick, Simon P

    2007-12-01

    The purpose of this study was to investigate strength, fatigability, and activity of upper limb musculature to elucidate the role of muscular imbalance in the pathophysiology of tennis elbow. Sixteen patients clinically diagnosed with tennis elbow, recruited from a university hospital upper limb orthopedic clinic, were compared with 16 control subjects with no history of upper limb musculoskeletal problem, recruited from university students and staff. Muscle strength was measured for grip, metacarpophalangeal, wrist, and shoulder on both sides. Electromyographic activity (RMS amplitude) and fatigue characteristics (median frequency slope) of five forearm and two shoulder muscles were measured during isometric contraction at 50% maximum voluntary contraction. All strength measurements showed dominance difference in C, but none in TE. In tennis elbow compared to controls, hand/wrist and shoulder strength and extensor carpi radialis (ECR) activity were reduced (p < 0.05), while fatigue was normal. A global upper limb weakness exists in tennis elbow. This may be due to disuse and deconditioning syndrome caused by fear avoidance, and needs to be addressed in prevention and treatment. Activation imbalance among forearm muscles (reduced extensor carpi radialis activity) in tennis elbow, probably due to protective pain-related inhibition, could lead to a widespread upper limb muscle imbalance.

  8. Long Term Results in Refractory Tennis Elbow Using Autologous Blood

    PubMed Central

    Gani, Naseem ul; Khan, Hayat Ahmad; Kamal, Younis; Farooq, Munir; Jeelani, Hina; Shah, Adil Bashir

    2014-01-01

    Tennis elbow (TE) is one of the commonest myotendinosis. Different treatment options are available and autologous blood injection has emerged as the one of the acceptable modalities of treatment. Long term studies over a larger group of patients are however lacking. The purpose of this study was to evaluate these patients on longer durations. One-hundred and twenty patients of TE, who failed to respond to conventional treatment including local steroid injections were taken up for this prospective study over the period from year 2005 to 2011 and were followed up for the minimum of 3 years (range 3-9 years). Two mL of autologous blood was taken from the ipsilateral limb and injected into the lateral epicondyle. The effectiveness of the procedure was assessed by Pain Rating Sscale and Nirschl Staging, which was monitored before the procedure, at first week, monthly for first three months, at 6 months and then 3 monthly for first year, six monthly for next 2 years and then yearly. Statistical analysis was done and a P value of <0.05 was taken as significant. The patients (76 females and 44 males) were evaluated after procedure. The mean age group was 40.67±8.21. The mean follow up was 5.7±1.72 (range 3 to 9 years). The mean pain score and Nirschl stage before the procedure was 3.3±0.9 and 6.2±0.82 respectively. At final follow up the pain score and Nirschl were 1.1±0.9 and 1.5±0.91 respectively. Autologous blood injection was found to be one of the modalities for treatment of TE. Being cheap, available and easy method of treatment, it should be considered as a treatment modality before opting for the surgery. Universal guidelines for the management of tennis elbow should be made as there is lot of controversy regarding the treatment. PMID:25568727

  9. Analgesic effect of extracorporeal shock wave therapy versus ultrasound therapy in chronic tennis elbow

    PubMed Central

    Lizis, Paweł

    2015-01-01

    [Purpose] This study compared the analgesic effects of extracorporeal shock wave therapy with those of ultrasound therapy in patients with chronic tennis elbow. [Subjects] Fifty patients with tennis elbow were randomized to receive extracorporeal shock wave therapy or ultrasound therapy. [Methods] The extracorporeal shock wave therapy group received 5 treatments once per week. Meanwhile, the ultrasound group received 10 treatments 3 times per week. Pain was assessed using the visual analogue scale during grip strength evaluation, palpation of the lateral epicondyle, Thomsen test, and chair test. Resting pain was also recorded. The scores were recorded and compared within and between groups pre-treatment, immediately post-treatment, and 3 months post-treatment. [Results] Intra- and intergroup comparisons immediately and 3 months post-treatment showed extracorporeal shock wave therapy decreased pain to a significantly greater extent than ultrasound therapy. [Conclusion] Extracorporeal shock wave therapy can significantly reduce pain in patients with chronic tennis elbow. PMID:26357440

  10. Selective enhancement of attentional networks in college table tennis athletes: a preliminary investigation

    PubMed Central

    Wang, Biye; Guo, Wei

    2016-01-01

    The purpose of the study was to investigate the characteristics of the attentional network in college table tennis athletes. A total of 65 college students categorized as table tennis athlete group or non-athlete group participated in the study. All participants completed the attentional network test (ANT) which measured the alerting, orienting and executive control networks. The results showed a significant difference between the athlete and non-athlete group for executive control network (p < 0.01), while no differences were observed for alerting (p > 0.05) or orienting (p > 0.05) networks. These results combined suggest that college table tennis athletes exhibited selectively enhanced executive control of attentional networks. PMID:27957396

  11. Modelling and simulation for table tennis referee regulation based on finite state machine.

    PubMed

    Cui, Jianjiang; Liu, Zixuan; Xu, Long

    2016-10-13

    As referee's decisions are made artificially in traditional table tennis matches, many factors in a match, such as fatigue and subjective tendency, may lead to unjust decision. Based on finite state machine (FSM), this paper presents a model for table tennis referee regulation to substitute manual decisions. In this model, the trajectory of the ball is recorded through a binocular visual system while the complete rules extracted from the International Table Tennis Federation (ITTF) rules are described based on FSM. The final decision for the competition is made based on expert system theory. Simulation result shows that the proposed model has high accuracy, and can be generalised to other similar games such as badminton, volleyball, etc.

  12. Physiological alterations consequent to 20-week conditioning programs of bicycling, tennis, and jogging.

    PubMed

    Wilmore, J H; Davis, J A; O'Brien, R S; Vodak, P A; Walder, G R; Amsterdam, E A

    1980-01-01

    This study investigated the efficacy of free-wheel bicycling and tennis as endurance conditioning activities. The subjects were 38 sedentary, middle-aged male volunteers, who were randomly assigned to one of four groups: bicyling (N=9); tennis (N=10); jogging (N=9); and control (N=10). Each subject was tested twice at the beginning and once at the conclusion of the 20-week study. Each training group exercised 3 days/week for 30 min/day, following 15 minutes of formal warm-up. The bicycling, tennis and jogging groups had an average attendance of 3.0, 2.7, and 2.8 days/week, and maintained theri exercise intensity at 83, 65, and 85% of HR max respectively. Using analysis of covariance, only the bicycle and jogging groups significantly increased treadmill Vo2max (14.8 and 13.3% respectively) even though there was a 5.7% improvement for the tennis group. The control group did not change. Vo2max was also assessed on a cycle ergometer for the bicycle and jogging groups, and increased significantly by 17.4 and 14.0% respectively, thus, specificity of the training response was not identified. VEmax increased significantly in the bicycling and jogging groups, while resting blood pressure did not change for any of the four groups. Relative to body composition, only the bicycle group increased lean body weight. The bicycle and jogging groups had substantial decreases in relative and absolute body fat, but these changes were not statistically significant due to changes in the control group. In conclusion, bicycling and jogging appear to provide comparable physiological benefits. Tennis produced only modest increases in endurance capacity but, since the duration of each training session was only 30 to 50% of a typical time period for playing tennis, the results of the present study may, in fact, be underestimating changes in Vo2max due to the interaction of intensity and duration in facilitating change.

  13. [Feet dermatophytosis in soccer players].

    PubMed

    Purim, Kátia Sheylla Malta; de Freitas, Camila Fernanda Novak Pinheiro; Leite, Neiva

    2009-01-01

    Athletes present risk of cutaneous mycosis. A study was carried out with 23 soccer players using clinical and mycological examination (direct microscopic examination and culture) and nail clipping. Eighteen (78.26%) did not present mycosis; two (8.70%) presented tinea pedis, and three (13.04%) presented onychomycosis associated to tinea pedis, mainly for Trichophyton mentagrophytes. Infected tinea pedis has produced cellulitis in one of the athletes. It is necessary to create an educative program of skin care during sports practice.

  14. Two-Player Graph Pebbling

    NASA Astrophysics Data System (ADS)

    Prudente, Matthew James

    Given a graph G with pebbles on the vertices, we define a pebbling move as removing two pebbles from a vertex u, placing one pebble on a neighbor v, and discarding the other pebble, like a toll. The pebbling number pi( G) is the least number of pebbles needed so that every arrangement of pi(G) pebbles can place a pebble on any vertex through a sequence of pebbling moves. We introduce a new variation on graph pebbling called two-player pebbling. In this, players called the mover and the defender alternate moves, with the stipulation that the defender cannot reverse the previous move. The mover wins only if they can place a pebble on a specified vertex and the defender wins if the mover cannot. We define η(G), analogously, as the minimum number of pebbles such that given every configuration of the η( G) pebbles and every specified vertex r, the mover has a winning strategy. First, we will investigate upper bounds for η( G) on various classes of graphs and find a certain structure for which the defender has a winning strategy, no matter how many pebbles are in a configuration. Then, we characterize winning configurations for both players on a special class of diameter 2 graphs. Finally, we show winning configurations for the mover on paths using a recursive argument.

  15. Effect of tennis racket parameters on a simulated groundstroke.

    PubMed

    Allen, Tom B; Haake, Steve J; Goodwill, Simon R

    2011-02-01

    Composite materials have given manufacturers the freedom to develop a broad range of tennis rackets, allowing them to change key parameters such as the structural stiffness, mass, and position of the balance point. The aim of this research was to determine how changing these parameters could affect ball resultant rebound velocity and spin for a simulated groundstroke. A finite element model of a freely suspended racket and strings was used to determine the effect of racket parameters for oblique spinning impacts at a range of locations on the stringbed. The finite element simulations were conducted in the laboratory frame of reference, where the ball is projected onto an initially stationary racket. The mean rebound velocity of the ball was 9% higher for a structurally stiff racket, 37% higher for a heavy racket, and 32% higher for a head-heavy racket. In addition, the mean rebound topspin of the ball was 23% higher for a heavy racket and 21% higher for a head-heavy racket. Therefore, in relation to a groundstroke with an impact location away from the node, the rebound velocity of the ball is likely to increase with the structural stiffness of a racket. The effect of changing the mass and position of the balance point is more complex, as it is dependent on the relationship between the transverse moment of inertia and maximum pre-impact swing velocity.

  16. Adolescent development

    MedlinePlus

    Development - adolescent; Growth and development - adolescent ... During adolescence, children develop the ability to: Understand abstract ideas. These include grasping higher math concepts, and developing moral ...

  17. Longitudinal Study of Repeated Sprint Performance in Youth Soccer Players of Contrasting Skeletal Maturity Status

    PubMed Central

    Valente-dos-Santos, João; Coelho-e-Silva, Manuel J.; Severino, Vítor; Duarte, João; Martins, Raúl S.; Figueiredo, António J.; Seabra, André T.; Philippaerts, Renaat M.; Cumming, Sean P; Elferink-Gemser, Marije; Malina, Robert M.

    2012-01-01

    The purpose of the study was to evaluate the developmental changes in performance in a repeated-sprint ability (RSA) test in young soccer players of contrasting maturity status. A total of 83 regional level Portuguese youth soccer players, aged 11-13 years at baseline was assessed annually. Stature, body mass, 7x34.2-m sprint protocol (25-s active recovery), 20-m multi-stage continuous shuttle endurance run and counter-movement jump (CMJ) without the use of the arms were measured. Fat-free mass (FFM) was determined by age and gender-specific formulas. Developmental changes in total sprint time across ages were predicted using multilevel modeling. Corresponding measurements were performed on an independent cross-sectional subsample of 52 youth soccer players 11-17 years to evaluate the predictive model. CA, CA2, maturational status (SA-CA), body size (mass and stature), FFM, aerobic endurance, lower limb explosive strength and annual volume training significantly improved the statistical fit of the RSA multilevel model. In ‘late’ maturing athletes, the best model for predicting change in RSA was expressed by the following equation: 86.54 - 2.87 x CA + 0.05 x CA2 - 0.25 x FFM + 0.15 x body mass + 0.05 x stature - 0.05 x aerobic endurance - 0.09 x lower limb explosive strength - 0.01 x annual volume training. The best fitting models for players who were ‘on time’ and ‘early’ maturing were identical to the best model for late maturing players, less 0.64 seconds and 1.74 seconds, respectively. Multilevel modeling provided performance curves that permitted the prediction of individual RSA performance across adolescent years in regional level soccer players. Key pointsRepeated-sprint ability tests are a valuable sport-specific field test of sprint performance in youth soccer players. Here, the test had reasonable reliability and can be useful to trainers and coaches in the assessment of young athletes and in monitoring changes over time.The total sprint time

  18. Vitamin D Deficiency Among Professional Basketball Players

    PubMed Central

    Fishman, Matthew P.; Lombardo, Stephen J.; Kharrazi, F. Daniel

    2016-01-01

    Background: Vitamin D plays an important role in several systems of the human body. Various studies have linked vitamin D deficiency to stress and insufficiency fractures, muscle recovery and function, and athletic performance. The prevalence of vitamin D deficiency in the elite athletic population has not been extensively studied, and very few reports exist among professional athletes. Hypothesis: There is a high prevalence of vitamin D deficiency or insufficiency among players attending the National Basketball Association (NBA) Combine. Study Design: Cross-sectional study; Level of evidence, 3. Methods: This is a retrospective review of data previously collected as part of the routine medical evaluation of players in the NBA Combines from 2009 through 2013. Player parameters evaluated were height, weight, body mass index (BMI), and vitamin D level. Statistical analysis using t tests and analysis of variance was used to detect any correlation between the player parameters and vitamin D level. Vitamin D levels were categorized as deficient (<20 ng/mL), insufficient (20-32 ng/mL), and sufficient (>32 ng/mL). Results: After institutional review board approval was submitted to the NBA, the NBA released deidentified data on 279 players who participated in the combines from 2009 through 2013. There were 90 players (32.3%) who were deficient, 131 players (47.0%) who were insufficient, and 58 players (20.8%) who were sufficient. A total of 221 players (79.3%) were either vitamin D deficient or insufficient. Among all players included, the average vitamin D level was 25.6 ± 10.2 ng/mL. Among the players who were deficient, insufficient, and sufficient, the average vitamin D levels were 16.1 ± 2.1 ng/mL, 25.0 ± 3.4 ng/mL, and 41.6 ± 8.6 ng/mL, respectively. Player height and weight were significantly increased in vitamin D–sufficient players compared with players who were not sufficient (P = .0008 and .009, respectively). Player age and BMI did not significantly

  19. The Prevalence of Injuries in Professional Turkish Soccer Players

    ERIC Educational Resources Information Center

    Yamaner, Faruk; Gumusdag, Hayrettin; Kartal, Alparslan; Gumus, M.; Gullu, A.; Imamoglu, O.

    2011-01-01

    Study aim: To assess the prevalence and anatomical sites of injuries in professional soccer players in one game season. Material and methods: A cohort of 510 professional male soccer players consisting of 48 goalkeepers, 194 defence players, 189 mid-field players and 79 forward players of the 1st and 2nd Turkish Professional Soccer Leagues in…

  20. Adolescent Images of Adolescence.

    ERIC Educational Resources Information Center

    Falchikov, Nancy

    1989-01-01

    Examined extent to which Scottish adolescents (N=40) were influenced by negative images of adolescence present in the culture, investigating self-images by means of Q sort. Eleven factors emerged from analysis, six of which met criterion that distinguishes common factors. Little evidence was found to suggest that adolescents were influenced by…

  1. Bourdieu Knew More than How to Play Tennis! An Empirically Based Discussion of Habituation and Reflexivity

    ERIC Educational Resources Information Center

    Strandbu, Åse; Steen-Johnsen, Kari

    2014-01-01

    This paper explores the role of reflexivity in habituation by contrasting the learning of aerobics and basketball with the acquisition of gendered bodily skills. The discussion is inspired by the paper "So, how did Bourdieu learn to play tennis? Habitus, consciousness and habituation," by Noble and Watkins (2003), which represents a…

  2. The effect of equipment scaling on children's sport performance: the case for tennis.

    PubMed

    Timmerman, Ewout; De Water, Joel; Kachel, Kim; Reid, Machar; Farrow, Damian; Savelsbergh, Geert

    2015-01-01

    The influence of scaling court-size and net height on children's tennis performance was examined. Sixteen boys (9.7 ± 0.5 years) had to perform a 30-min match in four different conditions, where court-size and/or net height were scaled by using a scaling ratio based on the differences in temporal demands between the children and the adult game. These 30-min matches were analysed using Tennis Analyst (FairPlay Ltd., Jindalee, QLD, Australia) software to determine typical tennis match performance characteristics. Children hit more winners, more forced errors, played more volleys, struck more shots from a comfortable height and played in a more forward court position when the net was scaled. Scaling both the court and net lead to a faster children's game, more closely approximating what is typical of the adult game. The differences between the typical tennis performance variables recorded suggested that scaling the net led to a more aggressive way of playing. Further, children enjoyed playing on the standard court-scaled net condition more than standard adult conditions. It is suggested that optimising the scaling of net height may be as critical as other task constraints, such as racquet length or court-size, as it leads to a more engaging learning environment for experienced children.

  3. The Tennis Ball Bomb Incident or the Safety Plan as "Shelf Document"

    ERIC Educational Resources Information Center

    Fast, Jonathan; Fanelli, Rossella

    2003-01-01

    This article presents a case study of a single incident involving a high school student who brought a "tennis ball" bomb to school. Although the district had recently created a safety plan, with a specific protocol for the discovery of a bomb in the building, the principal and the crises team ignored it. The principal did not refer to…

  4. Motivational Factors Affecting Athletes in Selecting the Sport Branches of Athletics, Ski and Tennis

    ERIC Educational Resources Information Center

    Akyüz, Murat; Agar, Muharrem; Akyüz, Öznur; Dogru, Yeliz

    2016-01-01

    The aim of this study is to research the motivational factors affecting athletes to select the branches of athletics, ski and tennis. Within the scope of the research, the survey developed by H. Sunay in 1996 was implemented and solution for the problem of the research was searched through the findings that were obtained from the survey. SPSS…

  5. Effects of Peer Mediated Instruction with Task Cards on Motor Skill Acquisition in Tennis

    ERIC Educational Resources Information Center

    Iserbyt, Peter; Madou, Bob; Vergauwen, Lieven; Behets, Daniel

    2011-01-01

    This study compared the motor skill effects of a peer teaching format by means of task cards with a teacher-centered format. Tennis performance of eighth grade students (n = 55) was measured before and after a four week intervention period in a regular physical education program. Results show that peer mediated learning with task cards…

  6. Benefits of Exercise with Mini Tennis in Intellectual Disabilities: Effects on Body Image and Psychopathology

    PubMed Central

    Hardoy, Maria Carolina; Seruis, Maria Luisa; Floris, Francesca; Sancassiani, Federica; Moro, Maria Francesca; Mellino, Gisa; Lecca, Maria Efisia; Adamo, Siria; Carta, Mauro Giovanni

    2011-01-01

    The present study is aimed at evaluating the efficacy of an introductory mini tennis programme as a therapeutic aid in the psychosocial rehabilitation of participants affected by mild/moderate intellectual disability in semi-residential care. Two groups (N=12) of participants diagnosed with intellectual disability, one of which followed the mini tennis rehabilitation programme, were compared at time t0, t1 (after 2 months) and t2 (after 6 months). Psychopathological status was assessed by means of the Italian version of the Assessment and Information Rating Profile (AIRP). Motor coordination, lateral dominance and body scheme were assessed by means of structured tools. Psychopathological total scores showed a statistically significant decrease in the experimental group in comparison with the control group. A statistical decrease in the group with the mini tennis rehabilitation programme was found also in the anxiety sub-scale while the sub-scales schizophrenia, depression, adjustment disorder, personality problems, somatoform disorders and psychosexual disorders did not reach any statistical difference between groups. A statistically significant increase in the visuo manual coordination was highlighted in the experimental versus the control group. No statistically significant differences were reported with regard to general movement skills, dynamic balance and coordination. In spite of the limitations of this study, the results obtained are encouraging and suggest the potential efficacy of mini tennis as an auxiliary aid in rehabilitation programmes, particularly to improve visuo manual coordination skills and to boost the patient/participants' self esteem. These findings warrant confirmation by further research studies. PMID:22016751

  7. Scaling Tennis Racquets during PE in Primary School to Enhance Motor Skill Acquisition

    ERIC Educational Resources Information Center

    Buszard, Tim; Reid, Machar; Masters, Rich S. W.; Farrow, Damian

    2016-01-01

    Purpose: Research supporting the skill acquisition benefits of scaling sports equipment for children in a real-world setting where child-to-coach ratios are high is scarce. Thus, the aim of this study was to examine the influence of scaling the tennis racquet on children's skill acquisition in a primary school setting. Method: Children aged 6 to 7…

  8. Relation of Knowledge and Performance in Boys' Tennis: Age and Expertise.

    ERIC Educational Resources Information Center

    McPherson, Sue L.; Thomas, Jerry R.

    1989-01-01

    Examined 10- to 13-year-old boys' development of knowledge structure and sport performance in tennis by comparing skills and knowledge of experts and novices. Experts focused on higher concepts and exhibited greater decision-making ability because of their more highly developed knowledge structure. (SAK)

  9. Anthropometric Characteristics of Columbia, South Carolina, Youth Baseball Players and Dixie Youth World Series Players

    ERIC Educational Resources Information Center

    French, Karen E.; Spurgeon, John H.; Nevett, Michael E.

    2007-01-01

    The purpose of this study was to compare measures of body size in two samples of youth baseball players with normative data from the United States National Center for Health Statistics (NCHS) growth charts. One sample of youth baseball players participated in a local little league. The second sample of youth baseball players were members of eight…

  10. Interaction with the game and motivation among players of massively multiplayer online role-playing games.

    PubMed

    Fuster, Héctor; Carbonell, Xavier; Chamarro, Andrés; Oberst, Ursula

    2013-01-01

    Knowledge about users interacting with Massively Multiplayer Online Role-Playing Games (MMORPG) is fundamental in order to prevent their potential negative effects on behavior. For this reason, the present study analyzed the relationship between styles of play and motivations. An online questionnaire asking for socio-demographic details, playing style, characteristics of the game played and motivations for playing, was answered by 430 Spanish-speaking MMORPG players (45.1% males). The identified profile for players, far away from the stereotype of an adolescent, consisted in a person who mainly plays on PvP (Player versus Player) servers, choosing the type of game according to his experience. Regarding motivations, they were interested in relating with other players through the game (Socialization), in discovering the game's possibilities and development of its adventures (Exploration), to a lesser extent in leadership and prestige (Achievement) and, lastly, identification with an avatar and escape from reality (Dissociation). Although part of the reason for playing was escapism and/or stress relief, the main motivation had a social nature. We conclude that MMORPG offer an attractive environment for a broad spectrum of people, and we have not been able to confirm the stereotype of a loner avoiding reality, taking refuge in games.

  11. Importance of peak height velocity timing in terms of injuries in talented soccer players.

    PubMed

    van der Sluis, A; Elferink-Gemser, M T; Brink, M S; Visscher, C

    2015-04-01

    The purpose of this study was to identify differences in traumatic and overuse injury incidence between talented soccer players who differ in the timing of their adolescent growth spurt. 26 soccer players (mean age 11.9 ± 0.84 years) were followed longitudinally for 3 years around Peak Height Velocity, calculated according to the Maturity Offset Protocol. The group was divided into an earlier and later maturing group by median split. Injuries were registered following the FIFA consensus statement. Mann-Whitney tests showed that later maturing players had a significantly higher overuse injury incidence than their earlier maturing counterparts both in the year before Peak Height Velocity (3.53 vs.0.49 overuse injuries/1 000 h of exposure,U = 49.50, z = − 2.049, p < 0.05) and the year of Peak Height Velocity (3.97 vs. 1.56 overuse injuries/1 000 h of exposure, U = 50.5, z = − 1.796,p < 0.05). Trainers and coaches should be careful with the training and match load they put on talented soccer players, especially those physically not (yet) able to handle that load. Players appear to be especially susceptible to injury between 13.5 and 14.5 years of age. Training and match load should be structured relative to maturity such that athletic development is maximized and the risk of injury is minimized.

  12. Tennis Training Sessions as a Rehabilitation Instrument for Patients after Acute Myocardial Infarction

    PubMed Central

    García, Juan P. F.; Giraldo, Víctor M. A.; Barrado, José J. G.; Casasola, César D.

    2013-01-01

    The aims of this study were to measure the effects of a cardiac rehabilitation program based on a modification of a sport (tennis) on quality of life, on various laboratory test parameters and on an exercise stress test, and to determine if the results of this novel activity are equivalent to those of traditional programs (i.e., the use of the bicycle ergometer). The sample consisted of 79 patients with a low-risk acute coronary syndrome. They were divided into three groups: two experimental groups and one control group. One of the experimental groups used the bicycle ergometer as its main physical activity, whereas the other received training in a modified form of tennis lesson. By the end of the 3-month program, triglycerides, cholesterol LDL, cholesterol HDL, (-25 mg·dl-1 and 32.3 mg·dl-1 final, and 15.7 mg·dl-1 and 23.3 mg·dl-1 LDL final, respectively) and exercise capacity improved significantly (by 1.1 metabolic equivalents (METs) and 1.2 METs, respectively), in both experimental groups. We conclude that the application of a comprehensive cardiac rehabilitation program in patients with low-risk acute coronary syndrome based on a program of modified tennis improves exercise tolerance and metabolic parameters, as well as certain physical characteristics that reduce cardiovascular risk. Key Points Cardiac rehabilitation of low risk patients with acute coronary syndrome based on a program of modified tennis produces an improvement in quality of life, lipid profiles and in exercise tolerance A cardiac rehabilitation program based on a modification of tennis produces favourable changes in various anthropometric parameters related to the reduction of cardiovascular risk The development of programs of cardiac rehabilitation based on modified versions of various sports would advantage the adherence to physical exercise. PMID:24149811

  13. [Almaty club "KAIRAT" young football players' health].

    PubMed

    Kausova, G K; Karabaeva, A I

    2013-10-01

    The aim of the investigation was to study young football players' health. The study was conducted on 161 football players (mean age 12.3) of six children football teams of Almaty club "KAIRAT" during the competition period. It was found that 55,5% of the football players are practically healthy; 18,6% of football players have iron deficiency anemia. 32,6% of football players have caries; 5% of football players have problems of cardiopulmonary system. Investigation reveal, that in a junior sportsman was body weigh surging with downtrend during contest, testify to portability of aerobic load and in childhood unconformable of metabolism' level. This tendency was retain also in the oldest sportsman, this testify to most emulative aerobic load in comparison with junior sportsman. According as the age increases it is emulative load's extension and free occurrence of body weigh subsequent reduction but in the oldest sportsman with prevalence macrosomia. Concurrently with improvement of the anthropometric profile as far as increase of age in soccer players it is forming of a high training level. In spite of lowering of energy resources and the physical load organism's adaptation there are these phenomena. According as the age increases in a soccer player's performance of cardiac and respiratory system are improved.

  14. N-player stochastic differential games

    NASA Technical Reports Server (NTRS)

    Varaiya, P.

    1976-01-01

    The paper presents conditions which guarantee that the control strategies adopted by N players constitute an efficient solution, an equilibrium, or a core solution. The system dynamics are described by an Ito equation, and all players have perfect information. When the set of instantaneous joint costs and velocity vectors is convex, the conditions are necessary.

  15. Quantum Two Player Game in Thermal Environment

    PubMed Central

    Dajka, Jerzy; Kłoda, Dawid; Łobejko, Marcin; Sładkowski, Jan

    2015-01-01

    A two-player quantum game is considered in the presence of thermal decoherence. It is shown how the thermal environment modeled in terms of rigorous Davies approach affects payoffs of the players. The conditions for either beneficial or pernicious effect of decoherence are identified. The general considerations are exemplified by the quantum version of Prisoner Dilemma. PMID:26322833

  16. Executive functioning in highly talented soccer players.

    PubMed

    Verburgh, Lot; Scherder, Erik J A; van Lange, Paul A M; Oosterlaan, Jaap

    2014-01-01

    Executive functions might be important for successful performance in sports, particularly in team sports requiring quick anticipation and adaptation to continuously changing situations in the field. The executive functions motor inhibition, attention and visuospatial working memory were examined in highly talented soccer players. Eighty-four highly talented youth soccer players (mean age 11.9), and forty-two age-matched amateur soccer players (mean age 11.8) in the age range 8 to 16 years performed a Stop Signal task (motor inhibition), the Attention Network Test (alerting, orienting, and executive attention) and a visuospatial working memory task. The highly talented soccer players followed the talent development program of the youth academy of a professional soccer club and played at the highest national soccer competition for their age. The amateur soccer players played at a regular soccer club in the same geographical region as the highly talented soccer players and play in a regular regional soccer competition. Group differences were tested using analyses of variance. The highly talented group showed superior motor inhibition as measured by stop signal reaction time (SSRT) on the Stop Signal task and a larger alerting effect on the Attention Network Test, indicating an enhanced ability to attain and maintain an alert state. No group differences were found for orienting and executive attention and visuospatial working memory. A logistic regression model with group (highly talented or amateur) as dependent variable and executive function measures that significantly distinguished between groups as predictors showed that these measures differentiated highly talented soccer players from amateur soccer players with 89% accuracy. Highly talented youth soccer players outperform youth amateur players on suppressing ongoing motor responses and on the ability to attain and maintain an alert state; both may be essential for success in soccer.

  17. Executive Functioning in Highly Talented Soccer Players

    PubMed Central

    Verburgh, Lot; Scherder, Erik J. A.; van Lange, Paul A.M.; Oosterlaan, Jaap

    2014-01-01

    Executive functions might be important for successful performance in sports, particularly in team sports requiring quick anticipation and adaptation to continuously changing situations in the field. The executive functions motor inhibition, attention and visuospatial working memory were examined in highly talented soccer players. Eighty-four highly talented youth soccer players (mean age 11.9), and forty-two age-matched amateur soccer players (mean age 11.8) in the age range 8 to 16 years performed a Stop Signal task (motor inhibition), the Attention Network Test (alerting, orienting, and executive attention) and a visuospatial working memory task. The highly talented soccer players followed the talent development program of the youth academy of a professional soccer club and played at the highest national soccer competition for their age. The amateur soccer players played at a regular soccer club in the same geographical region as the highly talented soccer players and play in a regular regional soccer competition. Group differences were tested using analyses of variance. The highly talented group showed superior motor inhibition as measured by stop signal reaction time (SSRT) on the Stop Signal task and a larger alerting effect on the Attention Network Test, indicating an enhanced ability to attain and maintain an alert state. No group differences were found for orienting and executive attention and visuospatial working memory. A logistic regression model with group (highly talented or amateur) as dependent variable and executive function measures that significantly distinguished between groups as predictors showed that these measures differentiated highly talented soccer players from amateur soccer players with 89% accuracy. Highly talented youth soccer players outperform youth amateur players on suppressing ongoing motor responses and on the ability to attain and maintain an alert state; both may be essential for success in soccer. PMID:24632735

  18. Validity of the V-cut Test for Young Basketball Players.

    PubMed

    Gonzalo-Skok, O; Tous-Fajardo, J; Suarez-Arrones, L; Arjol-Serrano, J L; Casajús, J A; Mendez-Villanueva, A

    2015-11-01

    The aim of the present study was to assess the reliability, usefulness, validity, age-related differences and responsiveness of a 25- m side-step cutting maneuver test (V-cut test). Fifty young male basketball players performed the V-cut test on 2 occasions separated by 5-7 days to assess test-retest reliability and determine a priori usefulness. Twenty subjects also completed both the L-Run and 505 test to analyze the possible relationships among these 3 tests. Furthermore, 33 players performed the V-cut test 4 times throughout the season to analyze responsiveness. Finally, 53 players (U-14 to U-20) were assessed in the V-cut test to examine the age-related differences. Reliability scores showed high intraclass correlation coefficient (ICC=0.90) and low coefficient of variation (CV=1.4%). The responsiveness of the V-cut test was good, as the typical short- (1.5-1.7%), mid- (1.6-3.1%) and long-term (3.3%) changes in V-cut performance were higher than the CV. Low (r=0.64; CL90%: 0.34; 0.82) to moderate (r=0.76; CL90%: 0.53; 0.88) relationships were found between the V-cut test with the 505 and L-Run test, respectively. Age-related differences analysis showed better V-cut test performance as age increased in adolescent basketball players. The V-cut test is reliable to assess change of direction ability (CODA) and it could be used to monitor CODA in adolescent basketball players.

  19. The Presence of Bilateral Imbalance of the Lower Limbs in Elite Youth Soccer Players of Different Ages.

    PubMed

    Atkins, Stephen J; Bentley, Ian; Hurst, Howard T; Sinclair, Jonathan K; Hesketh, Christopher

    2016-04-01

    The aim of this study was to examine bilateral differences in ground reaction forces (GRF), measured during a deep squat (DS) exercise, in a population of elite youth soccer players. Bilateral muscle balance is a key component in promoting musculoskeletal health of performers, yet there is a limited evidence base investigating such imbalances in youth. Seventy-four subjects were assigned to performance groups according to chronological age (younger than 13, 14, 15, 16, 17 years). Analysis of physical maturity status revealed that very few players were classified as "early" or "late" maturers. Players completed an overhead DS exercise, as part of preseason functional movement screening. Peak GRF were assessed using a twin force plate system. Significant differences (p ≤ 0.05) were identified between right and left side peak GRF for all groups except the youngest (U13) and oldest (U17). Nondominant "sides" showed the highest levels of PGRF across all groups. The magnitude of PGRF was not significantly different both within and between groups, except for the left side in the U13 to U15 groups (p = 0.04). Results from this study show that performance asymmetry is marked in adolescence. There seems a "trigger point" during the early stage of adolescence, when bilateral imbalances become marked. These differences do seem to reduce during the later stages of adolescence. Correct attention to focussed training, designed to remediate any imbalance, is warranted in adolescent groups. This is important with respect of the key associations between bilateral asymmetry and risk of injury.

  20. Using cognitive dissonance to induce adolescents' escaping from the claw of online gaming: the roles of personal responsibility and justification of cost.

    PubMed

    Chiou, Wen-Bin; Wan, Chin-Sheng

    2007-10-01

    The negative impact of the Internet on adolescents has received much attention. How to reduce their pathological use of online gaming is also a critical issue. Based on cognitive dissonance theory, two experiments were conducted to examine whether personal responsibility and justification of cost may play crucial factors in impacting adolescent players' attitude change and their willingness to engage in attitude-discrepant behavior. The results of Experiment 1 revealed that adolescent players who felt a strong sense of responsibility appeared to exhibit greater attitude change. In Experiment 2, the findings indicated that players tended to employ justification of cost in order to reduce or eliminate the dissonance between their attitude toward online gaming and invested cost. Adolescent players who perceived a higher cost in online gaming were less willing to engage in attitude-discrepant behavior. Reducing adolescents ' overuse of online gaming can be appreciated through the perspective of cognitive dissonance.

  1. Anthropometric and Somatotype Characteristics of Young Soccer Players: Differences Among Categories, Subcategories, and Playing Position.

    PubMed

    Perroni, Fabrizio; Vetrano, Mario; Camolese, Giancarlo; Guidetti, Laura; Baldari, Carlo

    2015-08-01

    Considering that anthropometric parameters are important factors in the performance of the soccer players, the aim of this study was to explore the differences in anthropometric and somatotype characteristics of Italian young soccer players. Weight, height, body mass index, and somatotype of 112 young soccer players, grouped in Giovanissimi "A" (14 years), "B" (13 years), and "C" (12 years) as well as Allievi "B" (15 years) and "A" (16 years) and "Juniores" (older than 17 years), were evaluated. Statistical analysis tests were computed at p ≤ 0.05, and an analysis of variance for each somatotype was calculated to analyze the main effects and interactions of the factors: categories, subcategories, and playing position. Bonferroni's post hoc analysis was used to identify differences among mean values. Considering all subjects, we have found significant differences in categories, subcategories, and playing position between anthropometric values and a somatotype value of 2.8-3.8-2.9. Significant differences have found among goalkeepers and the others playing position in endomorphy (p ≤ 0.001) and with defenders and midfielders in ectomorphy (p < 0.01) components, whereas no differences in mesomorphy. Analyzing the interaction between subcategories and playing position factors, a significant effect was found only in the endomorphy component (p = 0.05). The analysis of anthropometric characteristic of Italian young soccer players indicates that players have high muscularity value and low adiposity. This study showed the presence of somatotype differences for playing position within categories also in the youngest categories and subcategories, in particular, in the endomorphy component. Young soccer players should be trained with more appropriate and specific training load to avoid the increased injury risk during adolescence.

  2. The Effects of Individualized Resistance Strength Programs on Knee Muscular Imbalances in Junior Elite Soccer Players.

    PubMed

    Śliwowski, Robert; Jadczak, Łukasz; Hejna, Rafał; Wieczorek, Andrzej

    2015-01-01

    The purpose of this study was to investigate the effects of a resistance training program on the muscular strength of soccer players' knees that initially presented unilateral and bilateral differences. For this study, a team of 24 male well-trained junior soccer players was divided into two strength program training groups: a Resistance Training Control Group (RTCG) composed of 10 players that did not have muscular imbalances and a Resistance Training Experimental Group (RTEG) composed of 14 players that had muscular imbalances. All players followed a resistance training program for six weeks, two times per week, during the transition period. The program of individualized strength training consisted of two parts. The first part, which was identical in terms of the choice of training loads, was intended for both training groups and contained two series of exercises including upper and lower body exercises. The second part of the program was intended only for RTEG and consisted of two additional series for the groups of muscles that had identified unilateral and bilateral differences. The applied program showed various directions in the isokinetic profile of changes. In the case of RTCG, the adaptations related mainly to the quadriceps muscle (the peak torque (PT) change for the dominant leg was statistically significant (p < 0.05)). There were statistically significant changes in RTEG (p < 0.05) related to PT for the hamstrings in both legs, which in turn resulted in an increase in the conventional hamstring/quadriceps ratio (H/Q). It is interesting that the statistically significant (p < 0.05) changes were noted only for the dominant leg. No statistically significant changes in bilateral differences (BD) were noted in either group. These results indicate that individualized resistance training programs could provide additional benefits to traditional strength training protocols to improve muscular imbalances in post-adolescent soccer players.

  3. Longitudinal Development of Explosive Leg Power from Childhood to Adulthood in Soccer Players.

    PubMed

    Deprez, D; Valente-Dos-Santos, J; Coelho-E-Silva, M J; Lenoir, M; Philippaerts, R; Vaeyens, R

    2015-07-01

    The aim of the this study was to investigate the development of explosive leg power by using 2 similar jumping protocols (countermovement jump and standing broad jump) in 555 Belgian, high-level young soccer players, aged between 7 and 20 years. The total sample was divided into 3 longitudinal samples related to growth and maturation (pre-teenchildhood: (6-10 years;), early adolescence: (11-16 years;) and late adolescence: (17-20 years)), and 6 multilevel regression models were obtained. Generally, both jumping protocols emphasized that chronological age, body size dimensions (by means of fat mass in the late childhood and early adolescence groups, fat-free mass in the late adolescence group and stature--(not for CMJ in late childhood group) and fat mass in the late childhood and early adolescence groups, and fat-free mass in the late adolescence group) and motor coordination (one item of a 3-component test battery) are longitudinal predictors of explosive leg power from childhood to young adulthood. The contribution of maturational status was not investigated in this study. The present findings highlight the importance of including non-specific motor coordination in soccer talent development programs.

  4. Development of a table tennis robot for ball interception using visual feedback

    NASA Astrophysics Data System (ADS)

    Parnichkun, Manukid; Thalagoda, Janitha A.

    2016-07-01

    This paper presents a concept of intercepting a moving table tennis ball using a robot. The robot has four degrees of freedom(DOF) which are simplified in such a way that The system is able to perform the task within the bounded limit. It employs computer vision to localize the ball. For ball identification, Colour Based Threshold Segmentation(CBTS) and Background Subtraction(BS) methodologies are used. Coordinate Transformation(CT) is employed to transform the data, which is taken based on camera coordinate frame to the general coordinate frame. The sensory system consisted of two HD Web Cameras. The computation time of image processing from web cameras is long .it is not possible to intercept table tennis ball using only image processing. Therefore the projectile motion model is employed to predict the final destination of the ball.

  5. Survival estimates for elite male and female Olympic athletes and tennis championship competitors.

    PubMed

    Coate, D; Sun, R

    2013-12-01

    In this paper, we report survival estimates for male and female Olympic medal winners and for male and female finalists at the British and U S national tennis championships. We find a consistent longevity advantage of Olympic medal-winning female athletes over Olympic medal-winning male athletes competing separately in the same events since 1900 and for female finalists over male finalists competing separately in the finals of the national tennis championships of Britain and of the United States since the 1880s. This is the case for sample mean comparisons, for Kaplan-Meier survival function estimates, including life expectancy, and for Cox proportional hazard estimates, which show statistically significant lower hazard rates for women with birth year and other variables constant. The female longevity advantage over males is similar in the early period samples (birth years before 1920) and in the full period samples, and is 5-7 years.

  6. Criterion validity and accuracy of global positioning satellite and data logging devices for wheelchair tennis court movement

    PubMed Central

    Sindall, Paul; Lenton, John P.; Whytock, Katie; Tolfrey, Keith; Oyster, Michelle L.; Cooper, Rory A.; Goosey-Tolfrey, Victoria L.

    2013-01-01

    Purpose To compare the criterion validity and accuracy of a 1 Hz non-differential global positioning system (GPS) and data logger device (DL) for the measurement of wheelchair tennis court movement variables. Methods Initial validation of the DL device was performed. GPS and DL were fitted to the wheelchair and used to record distance (m) and speed (m/second) during (a) tennis field (b) linear track, and (c) match-play test scenarios. Fifteen participants were monitored at the Wheelchair British Tennis Open. Results Data logging validation showed underestimations for distance in right (DLR) and left (DLL) logging devices at speeds >2.5 m/second. In tennis-field tests, GPS underestimated distance in five drills. DLL was lower than both (a) criterion and (b) DLR in drills moving forward. Reversing drill direction showed that DLR was lower than (a) criterion and (b) DLL. GPS values for distance and average speed for match play were significantly lower than equivalent values obtained by DL (distance: 2816 (844) vs. 3952 (1109) m, P = 0.0001; average speed: 0.7 (0.2) vs. 1.0 (0.2) m/second, P = 0.0001). Higher peak speeds were observed in DL (3.4 (0.4) vs. 3.1 (0.5) m/second, P = 0.004) during tennis match play. Conclusions Sampling frequencies of 1 Hz are too low to accurately measure distance and speed during wheelchair tennis. GPS units with a higher sampling rate should be advocated in further studies. Modifications to existing DL devices may be required to increase measurement precision. Further research into the validity of movement devices during match play will further inform the demands and movement patterns associated with wheelchair tennis. PMID:23820154

  7. Does Education Matter? Major League Baseball Players and Longevity

    ERIC Educational Resources Information Center

    Kalist, David E.; Peng, Yingwei

    2007-01-01

    The authors used duration analysis to examine the longevity of Major League Baseball players. Using data on players who were born between 1945 and 1964, the authors found that the hazard rate of death for players who only attended high school was almost 2.0 times higher than those players who attended a 4-year university, evidence that the…

  8. Technical, perceptual and motor skills in novice-expert water polo players: an individual discriminant analysis for talent development.

    PubMed

    DʼErcole, Alessandro A; DʼErcole, Cristina; Gobbi, Massimo; Gobbi, Fabio

    2013-12-01

    The 4 tasks (A, B, C, and Y) have the characteristic of containing one more element than the task performed before it. In fact, task B introduces the slalom which is not present in task A. Task C introduces the ball control that are not present in tasks A and B, whereas task Y introduces the slalom and ball control in a visual dual task situation developed in horizontal swimming over a distance of 20 m at maximum speed. This exercise not included in task C. These tasks were performed by a group of pre-adolescent players and national under 18 water polo players. The novice players showed that tasks B and C are predictors of task Y. Such characteristics were not present in the expert players. The novice players also had difficulty in performing task Y because of the visual-attention overload, a difficulty that was not present in the expert players. To improve the 4 skills, the coach of the novice players developed a technical-didactic program, which was checked 6 months after the pretest. The posttest was not significantly different from the pretest while the individual discriminant analysis identified the improvements in some novice players, which on elaboration proved significant, enabling us to distinguish 2 subgroups, one with higher learning rates and the other with lower learning rates. In the practical applications, we describe the didactic tools (task analysis) and the different levels of development of technical skills in water polo. Improvements in these skills are explained through computational models like the HMOSAIC (Hierarchical, Modular, Selection and Identification for Control) while the individual discriminant analysis enables us to do a longitudinal analysis that is not possible with cross-sectional models.

  9. Multi-player games on the cycle

    PubMed Central

    van Veelen, Matthijs; Nowak, Martin

    2011-01-01

    In multi-player games n individuals interact in any one encounter and derive a payoff from that interaction. We assume that individuals adopt one of two strategies, and we consider symmetric games, which means the payoff depends only on the number of players using either strategy, but not on any particular configuration of the encounter. On the cycle we assume that any string of n neighbouring players interacts. We study fixation probabilities of stochastic evolutionary dynamics. We derive analytical results on the cycle both for linear and exponential fitness for any intensity of selection, and compare those to results for the well-mixed population. As particular examples we study multi-player public goods games, stag hunt games and snowdrift games. PMID:21907215

  10. Experienced poker players are emotionally stable.

    PubMed

    Laakasuo, Michael; Palomäki, Jussi; Salmela, Mikko

    2014-10-01

    Online poker and poker subcultures have become exceedingly popular. Previous studies assessing experience and skill in poker have revealed that proficiency in emotion regulation is a consequential factor in explaining financial success in the game. We assessed (N=478) the associations between poker players' (recruited from online poker forums) level of poker experience and HEXACO-PI-R personality traits. The results indicate that a predisposition for emotional stability-that is, lower scores on emotionality-is linked to high levels of poker experience. Thus, in order to become a successful and experienced poker player, it helps to be able to "keep cool" under pressure. Further exploratory analyses suggest that players who prefer live play to online play are more likely to be extroverted and open to experiences. The results contribute to the extant literature on individual differences in personality in poker players, and in particular help to fill the interdisciplinary gap between personality and gambling research.

  11. Video Player Keyboard Shortcuts: MedlinePlus

    MedlinePlus

    ... of this page: https://medlineplus.gov/hotkeys.html Video Player Keyboard Shortcuts To use the sharing features ... of accessible keyboard shortcuts for our latest Health videos on the MedlinePlus site. These shortcuts allow you ...

  12. Replicator dynamics with turnover of players

    NASA Astrophysics Data System (ADS)

    Juul, Jeppe; Kianercy, Ardeshir; Bernhardsson, Sebastian; Pigolotti, Simone

    2013-08-01

    We study adaptive dynamics in games where players abandon the population at a given rate and are replaced by naive players characterized by a prior distribution over the admitted strategies. We demonstrate how such a process leads macroscopically to a variant of the replicator equation, with an additional term accounting for player turnover. We study how Nash equilibria and the dynamics of the system are modified by this additional term for prototypical examples such as the rock-paper-scissors game and different classes of two-action games played between two distinct populations. We conclude by showing how player turnover can account for nontrivial departures from Nash equilibria observed in data from lowest unique bid auctions.

  13. The hospital manager and game theory: chess master, poker player, or cooperative game player?

    PubMed

    Dowd, Steven B; Root, Alexey

    2003-01-01

    Hospital management can be seen as a game, and doctors, nurses, and health maintenance organizations are its players. The astute hospital manager realizes the interdependence of individual career strategies and the hospital's success, just as players in a game are interdependent on each other. Managers familiar with game theory may successfully transfer that knowledge to the hospital realm. They may recognize patterns and calculate outcomes like chess players, bluff other hospitals into folding services as poker players do, and cooperate with their own team to maximize productivity. Knowledge of game theory may also make the hospital manager's job.

  14. High School Football Players Use Their Helmets to Tackle Other Players Despite Knowing the Risks

    PubMed Central

    Kuriyama, Andrew M; Nakatsuka, Austin S

    2017-01-01

    There is greater attention to head-related injuries and concussions in American football. The helmet's structural safety and the way that football players use their helmets are important in preventing head injuries. Current strategies include penalizing players for high-risk behavior such as leading with their helmet or hitting an opposing player above the shoulder. Passive strategies include helmet modification to better protect the head of the players or to change the playing style of the players. Hawai‘i high school varsity football players were surveyed to determine how they use their helmets and how a new helmet design would affect their style of play. One hundred seventy-seven surveys were completed; 79% said that they used their helmet to hit an opposing player during a tackle and 46% said they made this contact intentionally. When asked about modifying helmets with a soft material on the outside, 48% said they thought putting a soft cover over a regular helmet would protect their head better. However, many participants said that putting a soft cover over their regular helmet was a bad idea for various reasons. Most young football players use their helmets to block or tackle despite being taught they would be penalized or potentially injured if they did so. By gaining a better understanding of why and how players use their helmets and how they would respond to new helmet designs, steps can be taken to reduce head injuries for all levels of play. PMID:28352493

  15. Explosive Strength Imbalances in Professional Basketball Players

    PubMed Central

    Schiltz, Marc; Lehance, Cédric; Maquet, Didier; Bury, Thierry; Crielaard, Jean-Michel; Croisier, Jean-Louis

    2009-01-01

    Context: Despite the high rate of lower limb injuries in basketball players, studies of the dominant-limb effect in elite athletes often neglect injury history. Objective: To determine lower limb explosive-strength asymmetries in professional basketball players compared with junior basketball players and control participants. Design: Cohort study. Setting: Academic medical institution. Patients or Other Participants: 15 professional basketball players, 10 junior basketball players, and 20 healthy men. Main Outcome Measure(s): We performed an isokinetic examination to evaluate the knee extensor (Ext) and flexor (Fl) concentric peak torque at 60°·s−1 and 240°·s−1 and (Fl only) eccentric peak torque at 30°·s−1 and 120°·s−1. Functional evaluation included countermovement jump, countermovement jump with arms, 10-m sprint, single-leg drop jump, and single-leg, 10-second continuous jumping. Variables were compared among groups using analysis of variance or a generalized linear mixed model for bilateral variables. Results: The 2 groups of basketball players demonstrated better isokinetic and functional performances than the control group did. No differences in functional or relative isokinetic variables were noted between professional and junior basketball players. Professional players with a history of knee injury failed to reach normal knee extensor strength at 60°·s−1. Knee Ext (60°·s−1) and Fl (eccentric 120°·s−1) torque values as well as 10-second continuous jumping scores were higher in those professional players without a history of knee injury than those with such a history. Compared with the group without a history of knee injury, the group with a history of knee injury maintained leg asymmetry ratios greater than 10% for almost all isokinetic variables and more than 15% for unilateral functional variables. Conclusions: The relative isokinetic and functional performances of professional basketball players were similar to those of junior

  16. Proximity to Sports Facilities and Sports Participation for Adolescents in Germany

    PubMed Central

    Reimers, Anne K.; Wagner, Matthias; Alvanides, Seraphim; Steinmayr, Andreas; Reiner, Miriam; Schmidt, Steffen; Woll, Alexander

    2014-01-01

    Objectives To assess the relationship between proximity to specific sports facilities and participation in the corresponding sports activities for adolescents in Germany. Methods A sample of 1,768 adolescents aged 11–17 years old and living in 161 German communities was examined. Distances to the nearest sports facilities were calculated as an indicator of proximity to sports facilities using Geographic Information Systems (GIS). Participation in specific leisure-time sports activities in sports clubs was assessed using a self-report questionnaire and individual-level socio-demographic variables were derived from a parent questionnaire. Community-level socio-demographics as covariates were selected from the INKAR database, in particular from indicators and maps on land development. Logistic regression analyses were conducted to examine associations between proximity to the nearest sports facilities and participation in the corresponding sports activities. Results The logisitic regression analyses showed that girls residing longer distances from the nearest gym were less likely to engage in indoor sports activities; a significant interaction between distances to gyms and level of urbanization was identified. Decomposition of the interaction term showed that for adolescent girls living in rural areas participation in indoor sports activities was positively associated with gym proximity. Proximity to tennis courts and indoor pools was not associated with participation in tennis or water sports, respectively. Conclusions Improved proximity to gyms is likely to be more important for female adolescents living in rural areas. PMID:24675689

  17. Measurements of the horizontal coefficient of restitution for a superball and a tennis ball

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2002-05-01

    When a ball is incident obliquely on a flat surface, the rebound spin, speed, and angle generally differ from the corresponding incident values. Measurements of all three quantities were made using a digital video camera to film the bounce of a tennis ball incident with zero spin at various angles on several different surfaces. The maximum spin rate of a spherical ball is determined by the condition that the ball commences to roll at the end of the impact. Under some conditions, the ball was found to spin faster than this limit. This result can be explained if the ball or the surface stores energy elastically due to deformation in a direction parallel to the surface. The latter effect was investigated by comparing the bounce of a tennis ball with that of a superball. Ideally, the coefficient of restitution (COR) of a superball is 1.0 in both the vertical and horizontal directions. The COR for the superball studied was found to be 0.76 in the horizontal direction, and the corresponding COR for a tennis ball was found to vary from -0.51 to +0.24 depending on the incident angle and the coefficient of sliding friction.

  18. Somatotype of Italian rugby players.

    PubMed

    Casagrande, G; Viviani, F

    1993-03-01

    Our aim was to collect lacking first-hand data on Italian rugby players. The Heath/Carter anthropometric somatotype method was applied to 28 "A" League performers (RP) aged 25 +/- 3.9 years of age. Their somatotypes and dimensions were compared with those found in previous studies on athletes involved in the same sporting activity, with data collected on 25 "sedentary" young Italians, and with Bailey et al.'s study on Canadians (1982). On average, the RP group resulted as being endomorphic mesomorphs (3.1 +/- 1.1 - 5.6 +/- 1.3 - 1.4 +/- 1.1), a result that is congruent with international data. They differed significantly from the balanced mesomorph CG (2.3 +/- 1.0 - 4.5 +/- 1.2 - 2.5 +/- 1.4) for all the measurements taken, apart from bi-epycondylar width. The peculiar somatotype scores found are congruent with the needs of rugby, an aerobic-anaerobic discipline which requires performers with great muscular power associated with a capacity to furnish energy, mainly through the anaerobic metabolism.

  19. Physical growth and changes in intermittent endurance run performance in young male Basque soccer players.

    PubMed

    Carvalho, Humberto M; Bidaurrazaga-Letona, Iraia; Lekue, José António; Amado, Markos; Figueiredo, António J; Gil, Susana M

    2014-01-01

    The present 4-year longitudinal study examined physical growth and development of intermittent endurance run performance in young Basque soccer players aged 10-15 years applying multilevel regression modeling. Anthropometry, predicted adult stature and Yo-Yo Intermittent Recovery level 1 test (Yo-Yo IR1) of players from the under-11 teams from the Athletic Club of Bilbao were measured at pre- and end-season (two measurements per year of study, n = 33 considered for analysis). A non-linear effect of age on intermittent endurance run was observed, with significantly higher increases in Yo-Yo IR1 between 10-11 year-old and 14-15 year-old players. The development of Yo-Yo IR1 performance in all the years of the study was influenced positively by training exposure during the seasons (P < 0.01) and independent of maturity status and body size (P > 0.05). The steady development of intermittent endurance run performance during pubertal years in adolescent Basque soccer players is partially influenced by training exposure.

  20. Soccer skill development in talented players.

    PubMed

    Huijgen, B C H; Elferink-Gemser, M T; Ali, A; Visscher, C

    2013-08-01

    The aim of the study was to gain insight into the development of soccer-specific skills and whether differences between talented players exist on the Loughborough Soccer Passing Test (LSPT). Two scores were derived from the LSPT: 1) execution time: time to complete 16 passes (speed) and 2) skill performance time: execution time including bonus and penalty time for accuracy. The study consisted of 2 parts, the first of which incorporated a quasi-longitudinal design with 270 talented players aged 10-18 years performing the LSPT (661 measurement occasions); multilevel modelling was applied. Secondly, differences between those players allowed to continue in the development program (selected, n=269) and players who were forced to leave (de-selected, n=50) were investigated using independent sample t-tests. The longitudinal data showed that the predicted execution time (i. e., speed) improved approximately 18% from age 10-18 years (P<0.05), skill performance time (i. e., combination of speed and accuracy) was predicted to improve approximately 32% (P<0.05). The second part showed that selected players outscored de-selected players only on skill performance time (P<0.05), not on execution time (P>0.05). In conclusion, in high-level youth soccer, the combination of speed and accuracy in soccer skills might be more important than speed alone.

  1. Characteristics of Smokeless Tobacco Use among High School Football Players as Related to Type of Smokeless Tobacco and Period of Use.

    ERIC Educational Resources Information Center

    Creath, Curtis J.; And Others

    1992-01-01

    Survey of high school football players (n=1,116) found that, compared to nonusers, adolescent athletes who tried smokeless tobacco were more likely to be white; to use cigarettes, alcohol, and cigars; and to have family users. Initial use was highest before age 14. Differences were found between snuff users and users of chewing tobacco. (Author/NB)

  2. Anthropometric and Physical Fitness Differences Among Brazilian Adolescents who Practise Different Team Court Sports

    PubMed Central

    Silva, Diego Augusto Santos; Petroski, Edio Luiz; Gaya, Adroaldo Cesar Araujo

    2013-01-01

    The objective of this work was to compare the anthropometric and physical fitness characteristics of Brazilian adolescents who practise team court sports and to compare specific parameters obtained for adolescents with data from the general population. This was a cross-sectional study of 1,348 male adolescents grouped as follows: basketball players (n = 287), indoor soccer players (n = 665), handball players (n = 108) and volleyball players (n = 288), all between 10 and 14 years of age. Anthropometric (body mass, body height, arm span, and body mass index) and physical fitness data (flexibility, muscular strength, explosive power, speed, aerobic fitness and agility) were collected. The Brazilian population was used as a reference and compared to the adolescent subjects using Z scores for all variables. Anthropometric characteristics and performances in physical fitness tests differed (p<0.05) among players of different sports. In addition, for each variable assessed, adolescents who practised team court sports showed similar or improved results compared to their counterparts in the general population (p<0.05). Furthermore, the anthropometric and physical fitness characteristics differed depending on the team court sport practised. These findings may elucidate which physical abilities are most impacted by the practise of a particular team sport as well as help teachers and physical education and sport professionals identify talented adolescents. PMID:23717357

  3. Concussion among Swedish elite ice hockey players.

    PubMed Central

    Tegner, Y; Lorentzon, R

    1996-01-01

    OBJECTIVE: To evaluate the frequency of concussion in Swedish ice hockey and to establish a uniform grading and treatment model for concussions of different severity. METHODS: Frequency of concussion was investigated in two studies, one retrospective and one prospective. In the retrospective study, all Swedish elite ice hockey players (n = 265) were asked to answer a questionnaire on the number and treatment of previous concussions. Only concussions diagnosed by a doctor were recorded. The questionnaire was completed by 227 players (86%). In the prospective study, all injuries including concussions occurring during game and practice in the Swedish Elite League (n = 12 teams) were recorded during four years. The causes of injury, referees judgements, diagnosis, treatment, and time absent from ice hockey were registered on special cards. RESULTS: In the retrospective study, 51 out of 227 players (22%) in the Swedish Elite League reported at least one concussion. In the prospective study, 52 concussions were reported. The incidence of a concussion is at least one concussion every year/team or a yearly risk of about 5% for a player to sustain a concussion. Most concussions occurred during league play (81%). Body contact (checking or boarding) was the most common cause of concussions. The players were absent from full training and play on a mean of 6 d. CONCLUSIONS: As this injury is potentially dangerous it must be treated seriously according to a simple treatment model presented. In cases of repeated concussions during the same season, a longer period of time away from play is suggested. In players who have sustained several concussions over the years a thorough medical examination including EEG, CT/MRI, and neuropsychological tests should be performed. If any of these is pathological the player should be advised to give up ice hockey. PMID:8889123

  4. Complex network study of Brazilian soccer players

    NASA Astrophysics Data System (ADS)

    Onody, Roberto N.; de Castro, Paulo A.

    2004-09-01

    Although being a very popular sport in many countries, soccer has not received much attention from the scientific community. In this paper, we study soccer from a complex network point of view. First, we consider a bipartite network with two kinds of vertices or nodes: the soccer players and the clubs. Real data were gathered from the 32 editions of the Brazilian soccer championship, in a total of 13411 soccer players and 127 clubs. We find a lot of interesting and perhaps unsuspected results. The probability that a Brazilian soccer player has worked at N clubs or played M games shows an exponential decay while the probability that he has scored G goals is power law. Now, if two soccer players who have worked at the same club at the same time are connected by an edge, then a new type of network arises (composed exclusively by soccer player nodes). Our analysis shows that for this network the degree distribution decays exponentially. We determine the exact values of the clustering coefficient, the assortativity coefficient and the average shortest path length and compare them with those of the Erdös-Rényi and configuration model. The time evolution of these quantities are calculated and the corresponding results discussed.

  5. Injury incidence and balance in rugby players

    PubMed Central

    M, Jaco Ras; Puckree, Threethambal

    2014-01-01

    Objective : This study determined and correlated injury incidence and balance in rugby players. Methods: A prospective survey with balance testing was conducted on first year rugby academy players (N= 114). Injury incidence, static and dynamic balance were tested pre and post-season using a Biosway portable balance system. The data was analysed using paired and independent samples t-tests at p<0.05, Odds ratios, and Spearman’s correlation coefficients. Results: 75.50% participated, 71.40% were 18 years old, and 71.40% were White. Injury was sustained by 83% of players with the knee (25%) most commonly injured. Injury incidence was 1.52 per player with an injury rate of 5.95 injuries per 1000 match playing hours. The Stability Index increased significantly (p=0.03) by 15% in the medial/lateral direction post-season compared to pre-season. Significant differences in post-test anterior posterior and overall static and front and front right dynamic stability between injured and uninjured players were noted. Risk factors for injury included the scrum-half (14.80%) playing position, injuries in the 2nd half of the match (57%), and during contact (67%). Conclusion : Injury incidence was related to static and dynamic balance in forward right direction only. PMID:25674136

  6. Game Performance Evaluation in Male Goalball Players

    PubMed Central

    Molik, Bartosz; Morgulec-Adamowicz, Natalia; Kosmol, Andrzej; Perkowski, Krzysztof; Bednarczuk, Grzegorz; Skowroński, Waldemar; Gomez, Miguel Angel; Koc, Krzysztof; Rutkowska, Izabela; Szyman, Robert J

    2015-01-01

    Goalball is a Paralympic sport exclusively for athletes who are visually impaired and blind. The aims of this study were twofold: to describe game performance of elite male goalball players based upon the degree of visual impairment, and to determine if game performance was related to anthropometric characteristics of elite male goalball players. The study sample consisted of 44 male goalball athletes. A total of 38 games were recorded during the Summer Paralympic Games in London 2012. Observations were reported using the Game Efficiency Sheet for Goalball. Additional anthropometric measurements included body mass (kg), body height (cm), the arm span (cm) and length of the body in the defensive position (cm). The results differentiating both groups showed that the players with total blindness obtained higher means than the players with visual impairment for game indicators such as the sum of defense (p = 0.03) and the sum of good defense (p = 0.04). The players with visual impairment obtained higher results than those with total blindness for attack efficiency (p = 0.04), the sum of penalty defenses (p = 0.01), and fouls (p = 0.01). The study showed that athletes with blindness demonstrated higher game performance in defence. However, athletes with visual impairment presented higher efficiency in offensive actions. The analyses confirmed that body mass, body height, the arm span and length of the body in the defensive position did not differentiate players’ performance at the elite level. PMID:26834872

  7. Does Testosterone Modulate Mood States and Physical Performance in Young Basketball Players?

    PubMed

    Miloski, Bernardo; Aoki, Marcelo S; de Freitas, Camila G; Schultz de Arruda, Ademir F; de Moraes, Helena S; Drago, Gustavo; Borges, Thiago O; Moreira, Alexandre

    2015-09-01

    This study aimed to examine and compare mood states profile and physical performance during different training phases between 2 groups of adolescent basketball players that were differentiated according to baseline testosterone concentration (T). The basketball players were submitted to an intensified training period (OVL) followed by a tapering period (TP). Twenty-three young male basketball players initiated the study. Experimental criteria data were used to stratify 16 players into high-testosterone (HTC) or low-testosterone (LTC) concentration groups. All the 16 athletes undertook 5 weeks of OVL followed by a 3-week TP. Saliva sampling, Yo-Yo intermittent recovery level 1 (Yo-Yo IRL1) test and the T-test were conducted at the beginning (T1), after OVL (T2), and after TP (T3). A similar increase in internal training load was observed during OVL when compared with TP in both groups (p < 0.05). No difference in mood states was observed between groups (p > 0.05); however, LTC displayed a higher score for fatigue (p < 0.05) and a lower score for energy index (p < 0.05) in OVL, compared with TP. A significant improvement in the Yo-Yo IRL1 test and the T-test was observed (T1 to T3) (p < 0.05), with no difference between groups (p > 0.05). In conclusion, these results suggest that LTC athletes may be more susceptible to changes in mood states during intensified training periods. In addition, data indicate that a periodized training program successfully improved the physical performance (endurance and agility) of young basketball players; however, this improvement was not affected by testosterone level.

  8. Restricted connections among distinguished players support cooperation

    NASA Astrophysics Data System (ADS)

    Perc, Matjaž; Szolnoki, Attila; Szabó, György

    2008-12-01

    We study the evolution of cooperation within the spatial prisoner’s dilemma game on a square lattice where a fraction of players μ can spread their strategy more easily than the rest due to a predetermined larger teaching capability. In addition, players characterized by the larger teaching capability are allowed to temporarily link with distant opponents of the same kind with probability p , thus introducing shortcut connections among the distinguished players. We show that these additional temporary connections are able to sustain cooperation throughout the whole range of the temptation to defect. Remarkably, we observe that, as the temptation to defect increases the optimal μ decreases, and moreover only minute values of p warrant the best promotion of cooperation. Our study thus indicates that influential individuals must be few and sparsely connected in order for cooperation to thrive in a defection-prone environment.

  9. Restricted connections among distinguished players support cooperation.

    PubMed

    Perc, Matjaz; Szolnoki, Attila; Szabó, György

    2008-12-01

    We study the evolution of cooperation within the spatial prisoner's dilemma game on a square lattice where a fraction of players mu can spread their strategy more easily than the rest due to a predetermined larger teaching capability. In addition, players characterized by the larger teaching capability are allowed to temporarily link with distant opponents of the same kind with probability p , thus introducing shortcut connections among the distinguished players. We show that these additional temporary connections are able to sustain cooperation throughout the whole range of the temptation to defect. Remarkably, we observe that, as the temptation to defect increases the optimal mu decreases, and moreover only minute values of p warrant the best promotion of cooperation. Our study thus indicates that influential individuals must be few and sparsely connected in order for cooperation to thrive in a defection-prone environment.

  10. Prevalence of Problematic Video Gaming among Ontario Adolescents

    ERIC Educational Resources Information Center

    Turner, Nigel E.; Paglia-Boak, Angela; Ballon, Bruce; Cheung, Joyce T. W.; Adlaf, Edward M.; Henderson, Joanna; Chan, Vincy; Rehm, Jurgen; Hamilton, Hayley; Mann, Robert E.

    2012-01-01

    Video game playing has become a very popular activity among adolescents. Its impact on the mental health and well-being of players is just beginning to be explored. This paper reports on the prevalence of problematic gaming in a representative sample of 2,832 Ontario students in grades 7 to 12. The survey included questions about the school grade,…

  11. Comparing spondylolysis in cricketers and soccer players

    PubMed Central

    Gregory, P; Batt, M; Kerslake, R

    2004-01-01

    Objective: To determine whether the location of spondylolysis in the lumbar spine of athletes differs with biomechanical factors. Methods: Single photon emission computerised tomography and reverse gantry computerised tomography were used to investigate 42 cricketers and 28 soccer players with activity related low back pain. Sites of increased scintigraphic uptake in the posterior elements of the lumbar spine and complete or incomplete fracture in the pars interarticularis were compared for these two sports. Results: Thirty seven (90.4%) cricketers and 23 (82.1%) soccer players studied had sites of increased uptake. In cricketers, these sites were on the left of the neural arch of 49 lumbar vertebrae and on the right of 33 vertebrae. In soccer players there was a significantly different proportion, with 17 sites on the left and 28 on the right (difference of 22.0%; 95% confidence interval (CI) 0.04 to 0.38). Lower lumbar levels showed increased scintigraphic uptake more frequently than did higher levels, although the trend was reversed at L3 and L4 in soccer. Forty spondylolyses were identified in the lumbar vertebrae of the cricketers and 35 spondylolyses in the soccer players. These comprised 26 complete and 14 incomplete fractures in the cricketers, and 25 complete and 10 incomplete fractures in the soccer players. Similar numbers of incomplete fractures were found either side of the neural arch in soccer players, but there were more incomplete fractures in the left pars (14) than in the right (2) in cricketers. The proportion of incomplete fractures either side of the neural arch was significantly different between cricket players and soccer players (difference of 37.5%; 95% CI 0.02 to 0.65). Most complete fractures were at L5 (66.7%) and more were found at L3 (15.7%) than L4 (6.9%). However, incomplete fractures were more evenly spread though the lower three lumbar levels with 41.7% at L5, 37.5% at L4, and 20.8% at L3. Conclusions: Fast bowling in cricket is

  12. Characteristics of youth soccer players aged 13–15 years classified by skill level

    PubMed Central

    Malina, Robert M; Ribeiro, Basil; Aroso, João; Cumming, Sean P

    2007-01-01

    Objective To evaluate the growth, maturity status and functional capacity of youth soccer players grouped by level of skill. Subjects The sample included 69 male players aged 13.2–15.1 years from clubs that competed in the highest division for their age group. Methods Height and body mass of players were measured and stage of pubic hair (PH) was assessed at clinical examination. Years of experience in football were obtained at interview. Three tests of functional capacity were administered: dash, vertical jump and endurance shuttle run. Performances on six soccer‐specific tests were converted to a composite score which was used to classify players into quintiles of skill. Multiple analysis of covariance, controlling for age, was used to test differences among skill groups in experience, growth status and functional capacity, whereas multiple linear regression analysis was used to estimate the relative contributions of age, years of training in soccer, stage of PH, height, body mass, the height×weight interaction and functional capacities to the composite skill score. Results The skill groups differed significantly in the intermittent endurance run (p<0.05) but not in the other variables. Only the difference between the highest and lowest skill groups in the endurance shuttle run was significant. Most players in the highest (12 of 14) and high (11 of 14) skill groups were in stages PH 4 and PH 5. Pubertal status and height accounted for 21% of the variance in the skill score; adding aerobic resistance to the regression increased the variance in skill accounted for to 29%. In both regressions, the coefficient for height was negative. Conclusion Adolescent soccer players aged 13–15 years classified by skill do not differ in age, experience, body size, speed and power, but differ in aerobic endurance, specifically at the extremes of skill. Stage of puberty and aerobic resistance (positive coefficients) and height (negative coefficient) are significant

  13. Outcome of Percutaneous Release of Tennis Elbow: A Non-Randomized Controlled Trial Study

    PubMed Central

    Khatri, Kishor; Kharel, Krishna; Byanjankar, Subin; Shrestha, Rahul; Sharma, Jay R; Vaishya, Raju; Agarwal, Amit kumar; Vijay, Vipul

    2017-01-01

    Background Tennis elbow is a common disorder of the upper extremity. It can be treated conservatively in the majority of patients, but some resistant cases eventually can be treated by percutaneous release with good functional outcome. Materials and methods This non-randomized control trial was conducted at the Department of Orthopaedics Surgery in a tertiary care hospital from July 2015 to June 2016 on 50 patients who underwent percutaneous release of the common extensor origin using an 18 gauge hypodermic needle. These patients did not respond to conservative treatment including rest, nonsteroidal anti-inflammatory drugs (NSAIDS) and local steroid injections. The outcome was graded as Excellent, Good, Fair, and Poor. Results Fifty patients (50 elbows) were included in the study. Thirty-two patients were female (64%), and 18 were male (36%). The right side was affected in 37 patients (74%) and left side in 13 (26%). The time taken to achieve a completely pain-free elbow ranged from one day to two months (average of 26.2 days). Those who did not achieve a pain-free elbow had a residual pain of 1.5 to six on the visual analogue scale (VAS) (average 2.32). Excellent outcome was noticed in 24 patients (48%); Good result in eight patients (36% ); Fair in four patients (eight percent) and Poor in four patients (eight percent). Conclusion Tennis elbow probably results from the degenerative tear of the common extensor origin, and a percutaneous tenotomy using an 18 gauge hypodermic needle is a simple, safe, patient-friendly, efficient, and easily reproducible method of treating tennis elbow in those who are resistant to conservative treatment, and it can be done as an outpatient procedure. PMID:28168130

  14. 30 Former NFL Players Pledge Their Brains for Research

    MedlinePlus

    ... 163416.html 30 Former NFL Players Pledge Their Brains for Research Donations will be used to study ... retired players who have pledged to donate their brains to research on a devastating brain disease that ...

  15. Robust Football Players Tracking Method for Soccer Scene Analysis

    NASA Astrophysics Data System (ADS)

    Kataoka, Hirokatsu; Aoki, Yoshimitsu

    For the analysis of soccer videos, positional information of players and ball is very essential. In order to obtain trajectories of the players, robust tracking for multiple players is highly required. In this paper, we propose a method to track multiple players in a soccer video which is captured by a single camera. In the case of capturing the video from a single view, there might be a lot of occluded situations of players. In order to overcome this problem, we propose a robust tracking method for multiple players by combining Particle Filter and Real AdaBoost Classifier. First, each target player is tracked by using Particle Filter. Next, an occluded situation is automatically detected by checking a distance between the target players. Then we resample the center of the gravities by classifier's detection after Particle Filter tracking. We show the experimental results and effectiveness of our proposed method.

  16. Hyperthermic-related challenges in aquatics, athletics, football, tennis and triathlon.

    PubMed

    Mountjoy, Margo; Alonso, Juan-Manuel; Bergeron, Michael F; Dvorak, Jiri; Miller, Stuart; Migliorini, Sergio; Singh, Dato' Gurcharan

    2012-09-01

    Although many elite sporting events occur in climate-controlled venues, some athletes train and compete in environments that can potentially pose a risk to the athlete's health. In particular, athletes in aquatics, track and field, tennis, football and triathlon can be exposed to extreme heat during competition or while training. The International Federations responsible for these sports are aware of these health risks and have implemented measures to help protect the health of their athletes. This review paper outlines the sport-specific environmental health risks and the safety standards implemented to safeguard athlete health.

  17. Double pendulum model for a tennis stroke including a collision process

    NASA Astrophysics Data System (ADS)

    Youn, Sun-Hyun

    2015-10-01

    By means of adding a collision process between the ball and racket in the double pendulum model, we analyzed the tennis stroke. The ball and the racket system may be accelerated during the collision time; thus, the speed of the rebound ball does not simply depend on the angular velocity of the racket. A higher angular velocity sometimes gives a lower rebound ball speed. We numerically showed that the proper time-lagged racket rotation increased the speed of the rebound ball by 20%. We also showed that the elbow should move in the proper direction in order to add the angular velocity of the racket.

  18. Visual Attentional Orienting in Developing Hockey Players.

    ERIC Educational Resources Information Center

    Enns, James T.; Richards, James C.

    1997-01-01

    Covert visual orienting was measured in 13 twelve-year-old and 11 fifteen-year-old hockey players and in 13 college students with no hockey training. Found that high-skill 15-year-olds were better able than all other groups to take advantage of the general alerting effect produced by the sudden onset of a cue. (MDM)

  19. Knee injuries in women collegiate rugby players.

    PubMed

    Levy, A S; Wetzler, M J; Lewars, M; Laughlin, W

    1997-01-01

    We evaluated the prevalence and patterns of knee injuries in 810 women collegiate rugby players. Injuries that resulted in players missing at least one game were recorded and a questionnaire was used to delineate players' rugby and knee injury history. There were 76 total knee injuries in 58,296 exposures. This resulted in a 1.3 knee injury rate per 1000 exposures. Twenty-one anterior cruciate ligament tears were reported for a 0.36 incidence per 1000 exposures. Other injuries included meniscal tears (25), medical collateral ligament sprains (23), patellar dislocations (5), and posterior cruciate ligament tears (2). Sixty-one percent of the medial collateral ligament sprains occurred in rugby forwards and 67% of anterior cruciate ligament tears occurred in rugby backs. All other injuries occurred with equal frequency in backs and forwards. This study demonstrates that knee injury rates in women's collegiate rugby are similar to those reported for other women's collegiate sports. The overall rate of anterior cruciate ligament injury in women's rugby, however, is slightly higher than that reported for women soccer and basketball players.

  20. Assessing Soccer Players and Educating Soccer Parents

    ERIC Educational Resources Information Center

    Skirka, Nicholas

    2005-01-01

    This article offers suggestions on how to assess the abilities of young soccer athletes and ways to educate parents or guardians on how to maintain an attitude that most benefits and supports the players. The abilities of young athletes on a team vary, and the expectations of both team members and parents are high, thus presenting a major…

  1. Motivational Traits of Elite Young Soccer Players

    ERIC Educational Resources Information Center

    Stewart, Craig; Meyers, Michael C.

    2004-01-01

    Among the most overlooked aspects in the development of elite young soccer players is that of specific psychological traits. Of those traits, motivation has important implications for programs whose objectives are identification and cultivation of young, skilled performers. The growth in popularity of soccer by youth and the successes experienced…

  2. Juggling key players in NMD initiation.

    PubMed

    Bono, Fulvia

    2014-08-05

    In this issue of Structure, Melero and colleagues use electron microscopy combined with biochemistry to provide structural insight into the complex between SMG1, SMG8, SMG9, UPF1, and UPF2, elucidating how key players in nonsense-mediated mRNA decay assemble at the initial steps of the process.

  3. A Player-Centered Approach to Coaching

    ERIC Educational Resources Information Center

    de Souza, Adriano; Oslin, Judy

    2008-01-01

    The purpose of this article is to describe a player-centered approach (PCA), highlighting its qualities, and then to provide examples of its application in coaching and teaching sport. Most of the examples relate to the game of volleyball, but many of the recommendations and examples can be applied to most team sports. The article will conclude…

  4. Exploring Online Game Players' Flow Experiences and Positive Affect

    ERIC Educational Resources Information Center

    Chiang, Yu-Tzu; Lin, Sunny S. J.; Cheng, Chao-Yang; Liu, Eric Zhi-Feng

    2011-01-01

    The authors conducted two studies to explore online game players' flow experiences and positive affect. Our findings indicated that online game are capable of evoking flow experiences and positive affect, and games of violent or nonviolent type may not arouse players' aggression. The players could be placed into four flow conditions: flow,…

  5. Training Patterns of Wheelchair Basketball Players in Turkey

    ERIC Educational Resources Information Center

    Tatar, Yasar

    2008-01-01

    The aim of this study was to analyze technical drills, warm-up and cool-down exercises used by wheelchair basketball players of the Turkish league in relation to training sessions. 33 male wheelchair basketball players participated in the study (mean age 26.6[plus or minus]5,95 years). All players reported that they used warm-up exercises before…

  6. Assessment of Cardiovascular Risk in Collegiate Football Players and Nonathletes

    ERIC Educational Resources Information Center

    Dobrosielski, Devon A.; Rosenbaum, Daryl; Wooster, Benjamin M.; Merrill, Michael; Swanson, John; Moore, J. Brian; Brubaker, Peter H.

    2010-01-01

    Collegiate American football players may be at risk for cardiovascular disease. Objective: To compare cardiovascular disease risk factors and cardiovascular structure and function parameters of football players, stratified by position, to a group of sedentary, nonathletes. Participants: Twenty-six collegiate football players and 13 nonathletes…

  7. Are poker players all the same? Latent class analysis.

    PubMed

    Dufour, Magali; Brunelle, Natacha; Roy, Élise

    2015-06-01

    Poker is the gambling game that is currently gaining the most in popularity. However, there is little information on poker players' characteristics and risk factors. Furthermore, the first studies described poker players, often recruited in universities, as an homogeneous group who played in only one of the modes (land based or on the Internet). This study aims to identify, through latent class analyses, poker player subgroups. A convenience sample of 258 adult poker players was recruited across Quebec during special events or through advertising in various media. Participants filled out a series of questionnaires (Canadian Problem Gambling Index, Beck Depression, Beck Anxiety, erroneous belief and alcohol/drug consumption). The latent class analysis suggests that there are three classes of poker players. Class I (recreational poker players) includes those who have the lowest probability of engaging intensively in different game modes. Participants in class II (Internet poker players) all play poker on the Internet. This class includes the highest proportion of players who consider themselves experts or professionals. They make a living in part or in whole from poker. Class III (multiform players) includes participants with the broadest variety of poker patterns. This group is complex: these players are positioned halfway between professional and recreational players. Results indicate that poker players are not an homogeneous group identified simply on the basis of the form of poker played. The specific characteristics associated with each subgroup points to vulnerabilities that could potentially be targeted for preventive interventions.

  8. Concussion Incidences and Severity in Secondary School Varsity Football Players.

    ERIC Educational Resources Information Center

    Gerberich, Susan Goodwin; And Others

    1983-01-01

    Study of Minnesota high school football players found an injury rate of 78 per 100 players; 19/100 players reported a concussion experience characterized by loss of consciousness/awareness. Of these, 69 percent returned to play the same day. Illegal blocking and tackling contributed to increased concussion. Lasting effects were prevalent. (GC)

  9. Clug; Community Land Use Game. Player's Manual with Selected Readings.

    ERIC Educational Resources Information Center

    Feldt, Allan G.

    CLUG (Community Land Use Game) is designed to provide players with an understanding of several underlying factors affecting the growth of an urban region. It has been used with players from junior high to graduate school and also with non-students. It unites concepts from sociology, economics, and geography. Players invest in land, construct…

  10. Top-level players' visual control of interceptive actions: Bootsma and van Wieringen (1990) 20 years later.

    PubMed

    Bootsma, Reinoud J; Fernandez, Laure; Morice, Antoine H P; Montagne, Gilles

    2010-08-01

    Using a two-step approach, Van Soest et al. (2010) recently questioned the pertinence of the conclusions drawn by Bootsma and Van Wieringen (1990) with respect to the visual regulation of an exemplary rapid interceptive action: the attacking forehand drive in table tennis. In the first step, they experimentally compared the movement behaviors of their participants under conditions with and without vision available during the execution of the drive. In the second step, through simulation they evaluated the extent to which a preprogrammed pattern of muscle stimulation acting on the dynamical characteristics of the musculoskeletal system could explain the patterns of movement observed, including the phenomena of kinematic convergence and compensatory variability. In this contribution, we show how methodological and conceptual shortcomings, pertaining to both parts of Van Soest et al.'s study, severely limit the impact of their findings. We argue that their conclusion-denying the possibility of visual regulation of rapid interceptive actions-cannot be upheld in the light of the existing evidence, while Bootsma and Van Wieringen's conclusion-in favor of the visual regulation of rapid interceptive actions in top-level players- still holds strong, even after 20 years. Irrespective of the trends of the moment, we suggest that both appropriate experimentation and principled theorization need to be deployed before a model-based predictive architecture can be considered as a serious alternative to a (more parsimonious) information-based control architecture.

  11. How to keep A players productive.

    PubMed

    Berglas, Steven

    2006-09-01

    After graduating from Harvard Business School with highest honors, Jane rapidly moved up the corporate ladder at a large advertising firm, racking up promotions and responsibilities along the way. By the time she became the company's creative director, she was, in everyone's estimation, an A player--one of the organization's most gifted and productive employees. But although she received an extraordinarily generous pay package and had what some people considered to be one of the most stimulating jobs in the company, Jane felt underappreciated and was talking to head-hunters. Eventually, she was lured away to a competing company that, by her own admission, offered less-challenging work. Both Jane and the advertising firm she left behind lost out. Of course, not all A players are as vulnerable as Jane. Some superstars soar to stunning heights, needing little or no special attention, and have the natural self-confidence and brilliance to stay at the top of their game with elegance and grace. But as every manager knows, megastars with manageable egos are rare. Far more common are people like Jane who are striving to satisfy an inner need for recognition that is often a sign of irrationally low self-esteem. According to the author--an executive coach, management consultant, and former faculty member of the department of psychiatry at Harvard Medical School--if you do not carefully manage the often unconscious need A players have for kudos and appreciation, they will burn out in a way that is damaging to them and unproductive for you. The key is understanding what makes your A players tick. The author suggests that you assist your stars by offering them authentic praise, helping them set boundaries, and teaching them to play nicely with subordinates. In the process, you can turn these high performers into even more effective players.

  12. Anthropometric Characteristics of Spanish Professional Basketball Players

    PubMed Central

    Alejandro, Vaquera; Santiago, Santos; Gerardo, Villa José; Carlos, Morante Juan; Vicente, García-Tormo

    2015-01-01

    The study of elite basketball players’ anthropometric characteristics alongside those of body composition contributes significantly to their profiling as professional athletes and plays an important role in the selection process, as these characteristics can have a significant impact on performance. In the current study, 110 professional basketball players from a series of Spanish professional Leagues (ACB, LEB and EBA) and youth level National Teams (U20 and U18) had their anthropometric profiles measured and compared to determine differences between them. Furthermore, all 110 players were divided into three different categories according to their playing position: guards, forwards and centres. The results obtained show no significant differences between players in different competitions in weight, height and the sum of skinfolds. Nonetheless, there were several differences related to body fat content (13.03% in ACB players and 10.52% in the lower categories and National Teams). There were also several differences found between the different playing positions amongst all playing levels in body mass (79.56 ± 2.41, 91.04 ± 1.51 and 104.56 ± 1.73 kg), height (182.28 ± 0.96, 195.65 ± 1.00 and 204.08 ± 0.67 cm), skinfold distribution and perimeters. However, there were no significant differences in body fat content between the different playing positions. The conclusions obtained from this study provide a better understanding to basketball specialists regarding the selection process of players at the elite level, especially on the transition from youth elite programs to men’s elite leagues. PMID:26240653

  13. Relative Age Effects Are a Developmental Problem in Tennis: But Not Necessarily when You're Left-Handed!

    ERIC Educational Resources Information Center

    Loffing, Florian; Schorer, Jorg; Cobley, Steve P.

    2010-01-01

    Relative Age Effects (RAEs), describing attainment inequalities as a result of interactions between biological age and age-grouping procedures, have been demonstrated across many sports contexts. This study examined whether an additional individual characteristic (i.e., handedness) mediated RAEs in tennis. Relative age and handedness distributions…

  14. Arm Care. Relief and Prevention for Shoulder Tendonitis, Tennis Elbow, Bursitis and Wrist Sprain in Athletics and Other Activities.

    ERIC Educational Resources Information Center

    Nirschl, Robert P.

    The book provides a practical and meaningful treatment program for athletes involved in sports which injure the arm or shoulder to a high degree, such as tennis, baseball, swimming, raquetball, pole vaulting, javelin throwing, and weight training. The book's chapters present information on: (1) symptoms of injury; (2) the anatomy of injury; (3)…

  15. 75 FR 65323 - The Tennis Channel, Inc. v. Comcast Cable Communications, LLC; File No. CSR-8258-P

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-22

    ... From the Federal Register Online via the Government Publishing Office FEDERAL COMMUNICATIONS COMMISSION The Tennis Channel, Inc. v. Comcast Cable Communications, LLC; File No. CSR-8258-P AGENCY: Federal Communications Commission. ACTION: Notice. SUMMARY: This document designates a program carriage complaint...

  16. Structural Analysis of Technical-Tactical Elements in Table Tennis and their Role in Different Playing Zones.

    PubMed

    Munivrana, Goran; Petrinović, Lidija Zekan; Kondrič, Miran

    2015-09-29

    For the purpose of determining the overall structure of technical-tactical elements in table tennis and evaluating their role in different playing zones around the table, a new measuring instrument (a questionnaire) was formulated that took advantage of the expert knowledge of top, world class table tennis coaches. The results of the hierarchical taxonomic (cluster) analysis showed that the overall structure of the technical-tactical elements forming the table tennis technique could be divided into three basic groups; a group of technical-tactical elements (A) used in the phase of preparing one's own and disabling the opponent's attack; a group of technical-tactical elements (B) used in the phase of attack and counterattack; and a group of technical-tactical elements (C) used in the phase of defense. The differences among the obtained groups of table tennis elements were determined by applying the Kruskal-Wallis test, while relations between the groups and their role in different playing zones around the table were analyzed by comparing the average values of the experts' scores.

  17. The coefficient of restitution for collisions of happy balls, unhappy balls, and tennis balls

    NASA Astrophysics Data System (ADS)

    Cross, Rod

    2000-11-01

    A perfectly happy ball is one that bounces to its original height when dropped on a massive, rigid surface. A completely unhappy ball does not bounce at all. In the former case, the coefficient of restitution (COR) is unity. In the latter case, the COR is zero. It is shown that when an unhappy ball collides with a happy ball, the COR increases from zero to unity as the stiffness of the happy ball decreases from infinity to zero. The COR is independent of the mass of each ball. The implication of reducing the COR of a tennis ball, as a possible means of slowing the serve in tennis, is also considered. It is shown that (a) the COR for a collision with a racket varies with the impact point and is a maximum at the vibration node near the center of the strings, and (b) the serve speed is reduced by only about 20% if the COR for a bounce on the court is reduced to zero.

  18. Mechanics and Learning Practices Associated with the Tennis Forehand: A Review

    PubMed Central

    Reid, Machar; Elliott, Bruce; Crespo, Miguel

    2013-01-01

    The forehand ranks closely behind the serve in importance in the sport of tennis. Yet, while the serve has been the focus of a litany of research reviews, the literature describing forehand stroke production has not been reviewed as extensively. The purposes of this article are therefore to review the research describing the mechanics of the forehand and then to appraise that research alongside the coach-led development of the stroke. The consensus of this research supports the importance of axial rotation of the pelvis, trunk, shoulder horizontal adduction and internal rotation as the primary contributors to the development of racket speed in the forehand. The relationship between grip style and racket velocity is similarly well established. However, it is also clear that there remains considerable scope for future research to longitudinally examine the inter-relationships between different teaching methodologies, equipment scaling and forehand mechanics. Key Points Sports biomechanics has played a key role in assisting tennis coaches to understand the mechanical characteristics of the forehand. Research has confirmed the largely positive role of modified courts and balls in increasing the technical proficiency, number and success of forehand shots of beginner children. Suggested research directions include prospective or longitudinal studies into the inter-relationships of different teaching methodologies, equipment scaling and forehand mechanics. PMID:24149800

  19. Forearm Skin Blood Flow After Kinesiology Taping in Healthy Soccer Players: An Exploratory Investigation

    PubMed Central

    Woodward, Kirsty A.; Unnithan, Vish; Hopkins, Nicola D.

    2015-01-01

    Context Kinesiology tape (KT) has become popular among athletes for both injury prevention and rehabilitation due to its reported therapeutic effects, including facilitation of lymphatic flow and enhanced peripheral blood flow. However, evidence to support such claims is insufficient. Objective To determine whether KT improves skin blood flow (SkBF) responses in young, elite soccer players. Design Randomized crossover study. Setting Research laboratory. Patients or Other Participants Thirteen healthy, elite, adolescent male soccer players (age = 14.7 ± 0.6 years). Intervention(s) Participants completed 2 experimental trials; during trial 1, the volar aspect of the dominant forearm was taped. Forearm SkBF was measured within the taped area and 3 cm lateral to the taped area. During trial 2, no tape was applied to either site. Both trials were performed within 7 days. Main Outcome Measure(s) Baseline and maximal thermally (42°C) stimulated SkBF responses were assessed using laser Doppler flowmetry. Continuously measured SkBF and derived mean arterial pressure obtained at 5-minute intervals were used to calculate cutaneous vascular conductance (CVC), the primary outcome measure. Results No differences were observed for baseline SkBF or CVC between trials or measurement sites. After local heating, no differences were evident for SkBF or CVC between trials or measurement sites. Conclusions Our findings suggest that, in healthy, trained adolescent males, KT was not associated with increased forearm SkBF. PMID:26445024

  20. A retrospective study on anthropometrical, physical fitness, and motor coordination characteristics that influence dropout, contract status, and first-team playing time in high-level soccer players aged eight to eighteen years.

    PubMed

    Deprez, Dieter N; Fransen, Job; Lenoir, Matthieu; Philippaerts, Renaat M; Vaeyens, Roel

    2015-06-01

    The goal of this article was twofold, and a 2-study approach was conducted. The first study aimed to expose the anthropometrical, physical performance, and motor coordination characteristics that influence dropout from a high-level soccer training program in players aged 8-16 years. The mixed-longitudinal sample included 388 Belgian youth soccer players who were assigned to either a "club group" or a "dropout group." In the second study, cross-sectional data of anthropometry, physical performance, and motor coordination were retrospectively explored to investigate which characteristics influence future contract status (contract vs. no contract group) and first-team playing time for 72 high-level youth soccer players (mean age = 16.2 years). Generally, club players outperformed their dropout peers for motor coordination, soccer-specific aerobic endurance, and speed. Anthropometry and estimated maturity status did not discriminate between club and dropout players. Contract players jumped further (p = 0.011) and had faster times for a 5-m sprint (p = 0.041) than no contract players. The following prediction equation explains 16.7% of the variance in future playing minutes in adolescent youth male soccer players: -2,869.3 + 14.6 × standing broad jump. Practitioners should include the evaluation of motor coordination, aerobic endurance, and speed performances to distinguish high-level soccer players further succeeding a talent development program and future dropout players, between 8 and 16 years. From the age of 16 years, measures of explosivity are supportive when selecting players into a future professional soccer career.

  1. A retrospective study on anthropometrical, physical fitness and motor coordination characteristics that influence drop out, contract status and first-team playing time in high-level soccer players, aged 8 to 18 years.

    PubMed

    Deprez, Dieter; Fransen, Job; Lenoir, Matthieu; Philippaerts, Renaat M; Vaeyens, Roel

    2014-12-02

    The goal of this manuscript was twofold and a two-study approach was conducted. The first study aimed to expose the anthropometrical, physical performance and motor coordination characteristics that influence drop out from a high-level soccer training program in players aged 8-16 years. The mixed-longitudinal sample included 388 Belgian youth soccer players who were assigned to either a 'club group' or a 'drop out group'. In the second study, cross-sectional data of anthropometry, physical performance and motor coordination were retrospectively explored to investigate which characteristics influence future contract status (contract vs. no contract group) and first-team playing time for 72 high-level youth soccer players (mean age=16.2 y).Generally, club players outperformed their drop out peers for motor coordination, soccer-specific aerobic endurance and speed. Anthropometry and estimated maturity status did not discriminate between club and drop out players. Contract players jumped further (p=0.011) and had faster times for a 5m sprint (p=0.041) than no contract players. The following prediction equation explains 16.7% of the variance in future playing minutes in adolescent youth male soccer players: -2869.3 + 14.6 * standing broad jump.Practitioners should include the evaluation of motor coordination, aerobic endurance and speed performances to distinguish high-level soccer players further succeeding a talent development program and future drop out players, between 8 and 16 years. From the age of 16 years, measures of explosivity are supportive when selecting players into a future professional soccer career.

  2. PERFORMANCE OF HIGH SCHOOL FOOTBALL PLAYERS ON CLINICAL MEASURES OF DEEP CERVICAL FLEXOR ENDURANCE AND CERVICAL ACTIVE RANGE OF MOTION: IS HISTORY OF CONCUSSION A FACTOR?

    PubMed Central

    Ruediger, Thomas; Alsalaheen, Bara; Bean, Ryan

    2016-01-01

    Background More than one million adolescent athletes participated in organized high school sanctioned football during the 2014-15 season. These athletes are at risk for sustaining concussion. Although cervical spine active range of motion (AROM) and deep neck flexor endurance may serve a preventative role in concussion, and widespread clinical use of measurements of these variables, reference values are not available for this population. Cost effective, clinically relevant methods for measuring neck endurance are also well established for adolescent athletes. Purpose The purpose of this study was to report reference values for deep cervical flexor endurance and cervical AROM in adolescent football players and examine whether differences in these measures exist in high school football players with and without a history of concussion. Methods Concussion history, cervical AROM, and deep neck flexor endurance were measured in 122 high school football players. Reference values were calculated for AROM and endurance measures; association were examined between various descriptive variables and concussion. Results No statistically significant differences were found between athletes with a history of concussion and those without. A modest inverse correlation was seen between body mass and AROM in the sagittal and transverse planes. Conclusion The results of this study indicate that the participants with larger body mass had less cervical AROM in some directions. While cervical AROM and endurance measurements may not be adequate to identify adolescents with a history of previous concussions among high school football players. However, if a concussion is sustained, these measures can offer a baseline to examine whether cervical AROM is affected as compared to healthy adolescents. Level of Evidence 2c PMID:27104049

  3. The developmental activities of elite soccer players aged under-16 years from Brazil, England, France, Ghana, Mexico, Portugal and Sweden.

    PubMed

    Ford, Paul R; Carling, Christopher; Garces, Marco; Marques, Mauricio; Miguel, Carlos; Farrant, Andrew; Stenling, Andreas; Moreno, Jansen; Le Gall, Franck; Holmström, Stefan; Salmela, John H; Williams, Mark

    2012-01-01

    The developmental activities of 328 elite soccer players aged under-16 years from Brazil, England, France, Ghana, Mexico, Portugal and Sweden were examined using retrospective recall in a cross-sectional research design. The activities were compared to the early diversification, early specialisation, and early engagement pathways. Players started their involvement in soccer at approximately 5 years of age. During childhood, they engaged in soccer practice for a mean value of 185.7, s = 124.0 h · year(-¹), in soccer play for 186.0, s = 125.3 h · year(-¹), and in soccer competition for 37.1, s = 28.9 h · year(-¹). A mean value of 2.3, s = 1.6 sports additional to soccer were engaged in by 229 players during childhood. Players started their participation in an elite training academy at 11 to 12 years of age. During adolescence, they engaged in soccer practice for a mean value of 411.9, s = 184.3 h · year(-¹), in soccer play for 159.7, s = 195.0 h · year(-¹), and in soccer competition for 66.9, s = 48.8 h · year(-¹). A mean value of 2.5, s = 1.8 sports other than soccer were engaged in by 132 players during this period. There were some relatively minor differences between countries, but generally the developmental activities of the players followed a mixture of the early engagement and specialisation pathways, rather than early diversification.

  4. Tracking soccer players based on homography among multiple views

    NASA Astrophysics Data System (ADS)

    Iwase, Sachiko; Saito, Hideo

    2003-06-01

    In this paper, we propose a method of tracking soccer players using multiple views. As many researchers have done on soccer scene analysis by using trajectories of the playser and the soccer ball, it is desirable to track soccer players robustly. Soccer player tracking enables strategy analysis, scene recovery, making scenes for broadcasting, and automatic system of the camera control. However, soccer is a sport that occlusion occurs in many cases, and tracking often fails by the occlusion of the players. It is difficult to track the players by using a single camera alone. Therefore, we use multiple view images to avoid the occlusion problem, so that we can obtain robustness in player tracking. As a first step, inner-camera operation is performed independently in each camera to track the players. In any case that player can not be tracked in the camera, inter-camera operation is performed as a second step. Tracking information of all cameras are integrated by using the geometrical relationship between cameras called homography. Inter-camera operation makes it possible to get the location of the player who is not detected in the image, who is occluded by the other player, and who is outside the angle of view. Experimental results show that robust player tracking is available by tracking advantage using multiple cameras.

  5. Reduced attentional capture in action video game players.

    PubMed

    Chisholm, Joseph D; Hickey, Clayton; Theeuwes, Jan; Kingstone, Alan

    2010-04-01

    Recent studies indicate that playing action video games improves performance on a number of attention-based tasks. However, it remains unclear whether action video game experience primarily affects endogenous or exogenous forms of spatial orienting. To examine this issue, action video game players and non-action video game players performed an attentional capture task. The results show that action video game players responded quicker than non-action video game players, both when a target appeared in isolation and when a salient, task-irrelevant distractor was present in the display. Action video game players additionally showed a smaller capture effect than did non-action video game players. When coupled with the findings of previous studies, the collective evidence indicates that extensive experience with action video games may enhance players' top-down attentional control, which, in turn, can modulate the negative effects of bottom-up attentional capture.

  6. Identification af explosive power factors as predictors of player quality in young female volleyball players.

    PubMed

    Grgantov, Zoran; Milić, Mirjana; Katić, Ratko

    2013-05-01

    With the purpose of determining the factor structure of explosive power, as well as the influence of each factor on situational efficiency, 56 young female volleyball players were tested using 14 tests for assessing nonspecific and specific explosive power. By factor analysis, 4 significant factors were isolated which explained the total of over 80% of the common variability in young female volleyball players. The first factor was defined as volleyball-specific jumping, the second factor as nonspecific jumping and sprinting, the third factor as throwing explosive power, while the fourth factor was interpreted as volleyball-specific throwing and spiking speed from the ground. Results obtained by regression analysis in the latent space of explosive power indicate that the identified factors are good predictors of player quality in young female volleyball players. The fourth factor defined as throwing and spiking speed from the ground had the largest influence on player quality, followed by volleyball-specific jumping and nonspecific jumping and sprinting, and to a much lesser extent, by throwing explosive power The results obtained in this age group bring to the fore the ability of spiking and serving a ball of high speed, which hinders the opponents from playing those balls in serve reception and field defence. This ability, combined with a high standing vertical jump reach and spike approach vertical jump reach (which is the basis of the 1st varimax factor) enables successful performance of all volleyball elements by which points are won in complex 1 (spike) and complex 2 (serve and block). Even though the 2nd factor (nonspecific jumping and sprinting) has a slightly smaller impact on situational efficiency in young players, this ability provides preconditions i.e. preparation for successful realisation of all volleyball elements, so greater attention must be paid to perfecting it in young female volleyball players.

  7. Investigation of characteristics and risk factors of sports injuries in young soccer players: a retrospective study

    PubMed Central

    2013-01-01

    Background The participation of children and adolescents in sports has become increasingly frequent, including soccer. This growing involvement gives rise to concerns regarding the risk of sports injuries. Therefore, the aim of the present study was to describe the musculoskeletal injuries in young soccer players. Methods 301 male soccer players with a mean age 14.67 ± 2.08 years were randomly recruited. The Referred Condition Inquiry was used to collect information on the mechanism of injury and anatomic site affected as well as personal data on the participants. The variables were analyzed based on the degree of association using Goodman’s test for contrasts between multinomial populations, with the p < 0.05. Results Among the 301 athletes, 24.25% reported at least one injury. With regard to height, taller individuals reported more injuries than shorter individuals (62.5% and 37.5%, respectively; p < 0.05). Injuries were more frequent among players with a training duration greater than five years (69.65%) in comparison to those who trained for a shorter duration (30.35%) (p < 0.05). The lower limbs, especially the ankle/foot and knee, were the most affected anatomic sites. Impact was the most common mechanism of injury. Conclusion The young practitioners of soccer analyzed had low rates of injury. The main causal mechanism was the impact. A taller height and longer exposure to training were the main risk factors for injury among young soccer players. PMID:23602027

  8. Volume of Physical Activity and Injury Occurrence in Young Basketball Players

    PubMed Central

    Gianoudis, Jenny; Webster, Kate E.; Cook, Jill

    2008-01-01

    Participation in organised, competitive physical activity by young athletes is increasing rapidly. This is concurrent with an increase in sporting injuries in the young population. This pilot study aimed to compare the weekly volume and types of physical activity in young basketball players injured and not injured during the season. Detailed physical activity and injury data were prospectively collected in 46 school-level basketball players aged 14 to 18 years. Participants completed physical activity logs which documented the type of physical activity undertaken, what the activity consisted of (i.e. training, competition) and the level at which it was played on a daily basis. Allied health staff completed a weekly injury form. Results showed that injured and uninjured athletes participated in a similar volume of total weekly physical activity over the season. However, injured athletes (p = 0.04) and athletes who specifically sustained overuse injuries (p = 0.01) participated in a greater amount of basketball refereeing than uninjured athletes. Based on these findings it was concluded that greater participation in running-type physical activity such as refereeing, as an addition to training and competition, may predispose the young basketball player to increased injury risk. Future research using larger sample sizes are required to further investigate the role of participation volume and type on injury occurrence in adolescent athletes. Key points Basketball players participating in larger amounts of running-type physical activity, in addition to regular training and competition, may be predisposed to overuse injury Future studies using larger sample sizes are required to investigate the precise volumes of physical activity that increase injury risk This would assist in the development of participation guidelines to decrease the current injury rates observed in the young athletic population. PMID:24150146

  9. Evolutionary game theory: molecules as players.

    PubMed

    Bohl, Katrin; Hummert, Sabine; Werner, Sarah; Basanta, David; Deutsch, Andreas; Schuster, Stefan; Theissen, Günter; Schroeter, Anja

    2014-12-01

    In this and an accompanying paper we review the use of game theoretical concepts in cell biology and molecular biology. This review focuses on the subcellular level by considering viruses, genes, and molecules as players. We discuss in which way catalytic RNA can be treated by game theory. Moreover, genes can compete for success in replication and can have different strategies in interactions with other genetic elements. Also transposable elements, or "jumping genes", can act as players because they usually bear different traits or strategies. Viruses compete in the case of co-infecting a host cell. Proteins interact in a game theoretical sense when forming heterodimers. Finally, we describe how the Shapley value can be applied to enzymes in metabolic pathways. We show that game theory can be successfully applied to describe and analyse scenarios at the molecular level resulting in counterintuitive conclusions.

  10. Telemetry and Communication IP Video Player

    NASA Technical Reports Server (NTRS)

    OFarrell, Zachary L.

    2011-01-01

    Aegis Video Player is the name of the video over IP system for the Telemetry and Communications group of the Launch Services Program. Aegis' purpose is to display video streamed over a network connection to be viewed during launches. To accomplish this task, a VLC ActiveX plug-in was used in C# to provide the basic capabilities of video streaming. The program was then customized to be used during launches. The VLC plug-in can be configured programmatically to display a single stream, but for this project multiple streams needed to be accessed. To accomplish this, an easy to use, informative menu system was added to the program to enable users to quickly switch between videos. Other features were added to make the player more useful, such as watching multiple videos and watching a video in full screen.

  11. The excluded player in coalition formation.

    PubMed

    van Beest, Ilja; Wilke, Henk; van Dijk, Eric

    2003-02-01

    Coalition research generally assumes that people strive to maximize their share of the coalition payoff and that they exclude others from joining a coalition if these others are not needed to obtain the coalition payoff. In two experiments, the authors show that this view is too narrow and that willingness to include such others is dependent on the extent to which people feel that exclusion affects the payoff of the excluded player. This finding was moderated by social value orientations. Proselfs were not affected by the consequences for the excluded players. Prosocials were less willing to exclude others the more harmful were the consequences of exclusion. Results are related to research on social exclusion, the do-no-harm principle, and social value orientations.

  12. Cervical spine injuries in football players.

    PubMed

    Thomas, B E; McCullen, G M; Yuan, H A

    1999-01-01

    Cervical spine injuries have been estimated to occur in 10% to 15% of football players, most commonly in linemen, defensive ends, and linebackers. The overwhelming majority of such injuries are self-limited, and full recovery can be expected. However, the presenting symptoms of serious cervical spine injuries may closely resemble those of minor injuries. The orthopaedic surgeon frequently must make a judgment, on the field or later in the office, about the advisability of returning the athlete to the game. These decisions can have an enormous impact on the player and his family. Most severe cervical spine injuries share the common mechanism of application of an axial load to the straightened spine. Avoiding techniques that employ head-down "spear" tackling and wearing properly fitted equipment markedly reduce the risk of serious injury.

  13. EVALUATION OF PAINFUL SHOULDER IN BASEBALL PLAYERS

    PubMed Central

    Miyazaki, Alberto Naoki; Fregoneze, Marcelo; Santos, Pedro Doneux; da Silva, Luciana Andrade; do Val Sella, Guilherme; Junior, Adriano Fernando Mendes; Soares, André Lopes; Aihara, Leandro Jun; Checchia, Sérgio Luiz

    2015-01-01

    Objective: To assess the relationship between shoulder mobility and strength and the presence of pain among baseball players. Methods: Between April and July 2009, 55 baseball players were assessed by the Shoulder and Elbow Group of the School of Medical Sciences, Santa Casa de Misericórdia, São Paulo. They were all males, aged between 15 and 33 years (mean of 21); they attended an average of three training sessions per week and had been doing this sport for a mean of 10 years. Results: 14 of the 55 players evaluated were pitchers, and 20 reported pain during the pitching motion. The mean values for lateral and medial rotation and range of motion (ROM) in the dominant shoulder were, respectively, 110 °, 61 ° and 171 °, with a statistically significant difference in relation to the non-dominant limb. Pitchers had greater gains in lateral rotation and deficits in medial rotation than did non-pitchers. Pain presented a statistically significant correlation with diminished ROM, greater length of time playing the sport and situations of “shoulder at risk”. Conclusions: Statistically significant differences in dominant shoulder mobility were found, with increased lateral rotation, diminished medial rotation and smaller ROM, in relation to the contralateral limb. There was a statistically significant relationship between the pitcher's position and greater gain in lateral rotation and diminished medial rotation. There were statistically significant correlations between pain and diminished ROM, greater length of time playing the sport and situations of “shoulder at risk”. There was a statistical tendency suggesting that players with diminished medial rotation of the dominant shoulder presented a relationship with pain. PMID:27028320

  14. Soccer injuries in female youth players.

    PubMed

    Schiff, Melissa A

    2007-04-01

    A cross-sectional survey of injuries among female youth soccer players found 44.6% (95% confidence interval 34.9%-54.8%) had ever been injured. The injury incidence rate for the current season was 2.2/1000 soccer exposure hours (95% CI 1.5-3.1). Future studies should evaluate modifiable risk factors in youth to identify injury prevention strategies.

  15. Musculoskeletal problems in soccer players: current concepts.

    PubMed

    Longo, Umile Giuseppe; Loppini, Mattia; Cavagnino, Roberta; Maffulli, Nicola; Denaro, Vincenzo

    2012-05-01

    Soccer is the most popular sport worldwide, with about 200 million players, both professionals and amateurs. Because of its popularity, it has been often proposed to be able to prevent or cure health problems around the world. Although participation in football leads to significant physical benefits such as improving well-being, extending life expectancy and reducing the likelihood of several major non-communicable diseases, the possibility to incur in soccer injuries must be considered. On average, an elite football player suffers from 1.5-7.6 injuries each 1,000 hours of training and 12-35 injuries each 1000 hours of match. Several risk factors for soccer injuries have been described. The most important of them are the level of play (the risk appears to be higher in professional than amateur players); the exercise load; and the standard of training. The injury prevention program "The 11", developed with the support of the Federation Internationale de Football Association (FIFA), aims to reduce the impact of intrinsic injury risk factors in soccer, and it has been validated in that sport. A successive modified version of "The 11" ("The 11+") has been also shown to be effective in preventing injuries in young female soccer players. The FIFA 11+ provided more than 40% of reduction of the risk of injury. Several factors can be related to the risk of injury during sport. Therefore different exercises or factors might have been responsible for efficacy of the FIFA 11+ to prevent injuries. Several improvements have been surely achieved in the last ten years, but further investigation is needed to improve the benefits of playing soccer on human health.

  16. Effects of plyometric training on soccer players

    PubMed Central

    Wang, Ying-Chun; Zhang, Na

    2016-01-01

    Plyometric training (PT) is a technique used to increase strength and explosiveness. It consists of physical exercises in which muscles exert maximum force at short intervals to increase dynamic performances. In such a training, muscles undergo a rapid elongation followed by an immediate shortening (stretch-shortening contraction), utilizing the elastic energy stored during the stretching phase. There is consensus on the fact that when used, PT contributes to improvement in vertical jump performance, acceleration, leg strength, muscular power, increase of joint awareness and overall sport-specific skills. Consequently, PT which was primarily used by martial artists, sprinters and high jumpers to improve performances has gained in popularity and has been used by athletes in all types of sports. However, although PT has been shown to increase performance variables in many sports, little scientific information is currently available to determine whether PT actually enhances skill performance in soccer players, considering that soccer is an extremely demanding sport. Soccer players require dynamic muscular performance for fighting at all levels of training status, including rapid movements such as acceleration and deceleration of the body, change of direction, vertical and horizontal jumps, endurance, speed as well as power for kicking and tackling. In this review we discussed the effects of PT on soccer players by considering gender and age categories. PMID:27446242

  17. Tibia and fibula fractures in soccer players.

    PubMed

    Boden, B P; Lohnes, J H; Nunley, J A; Garrett, W E

    1999-01-01

    We performed a retrospective review of 31 athletes who sustained a fracture of the lower leg from a direct blow while playing soccer. Fifteen fractures involved both the tibia and fibula 11 only the tibia, and 5 only the fibula. Information was collected using a standardized questionnaire. The mean follow-up from the time of injury was 30 months. Injuries typically occurred in young, competitive athletes during game situations. The mechanisms were broadly classified into several categories: contact during a slide tackle (13, 42%), a collision with the goalkeeper (8, 26%), two opposing players colliding while swinging for a loose ball (7, 23%), or a player being kicked by a standing opponent (3, 10%). The majority of fractures (26, 90%) occurred while the athletes were wearing shin guards. The point of impact was with the shin guard prior to the fracture in 16 cases (62%). Return to competitive soccer averaged 40 weeks for combined tibia and fibula fractures, 35 weeks for isolated tibia fractures, and 18 weeks for isolated fibula fractures. Injuries were associated with a high incidence of major complications (12 out of 31, 39%), especially in concurrent tibia and fibula fractures (8 out of 15, 50%). These findings suggest that lower leg fractures in soccer players are serious injuries, often necessitating a prolonged recovery time. In addition, this study questions the ability of shin guards to protect against fractures.

  18. The El Dorado of Handball? Foreign Female Players Stay, while Domestic Players Return from Abroad.

    PubMed

    Bon, Marta; Topič, Mojca Doupona; Šibila, Marko

    2016-04-01

    The main purpose of this research was to study the characteristics of migration in European women's handball based on the Slovenian example and to find the differences between the foreigners coming to Slovenia and the Slovenians transferring to foreign clubs. The research was based on 16 open face-to-face semi-structured interviews (8 Slovenians (age 29.5 ± 6.2 years) and 8 foreigners (age 35.5 ± 8.7 years)). We found out that the most powerful factor in foreigners was the financial one, while within Slovenian players it was their personal desire for progression within their sport, the club's reputation and poor conditions in their previous club. The results confirm that when making a decision on transfer, all players had the support of family and friends, while the clubs of foreign players were not as supportive. Most interviewees considered their careers successful and did not regret going abroad. The research indicates that the largest differences discovered between Slovenians and foreigners were that foreign female players chose to stay in the new country (Slovenia), while domestic players returned home after few years playing abroad. In conclusion, the results show that in top-level handball there are important differences between migration models which are based on nationality and also that the migration models change throughout time, which is largely connected with the socioeconomic events in the country of origin or transfer.

  19. The El Dorado of Handball? Foreign Female Players Stay, while Domestic Players Return from Abroad

    PubMed Central

    Topič, Mojca Doupona; Šibila, Marko

    2016-01-01

    Abstract The main purpose of this research was to study the characteristics of migration in European women’s handball based on the Slovenian example and to find the differences between the foreigners coming to Slovenia and the Slovenians transferring to foreign clubs. The research was based on 16 open face-to-face semi-structured interviews (8 Slovenians (age 29.5 ± 6.2 years) and 8 foreigners (age 35.5 ± 8.7 years)). We found out that the most powerful factor in foreigners was the financial one, while within Slovenian players it was their personal desire for progression within their sport, the club’s reputation and poor conditions in their previous club. The results confirm that when making a decision on transfer, all players had the support of family and friends, while the clubs of foreign players were not as supportive. Most interviewees considered their careers successful and did not regret going abroad. The research indicates that the largest differences discovered between Slovenians and foreigners were that foreign female players chose to stay in the new country (Slovenia), while domestic players returned home after few years playing abroad. In conclusion, the results show that in top-level handball there are important differences between migration models which are based on nationality and also that the migration models change throughout time, which is largely connected with the socioeconomic events in the country of origin or transfer. PMID:28149349

  20. Sympathetic enhancement in futsal players but not in football players after repeated sprint ability test

    PubMed Central

    Chen, Yung-Sheng; Liao, Chih-Jung; Lu, Wan-An; Kuo, Cheng-Deng

    2015-01-01

    Background Heart rate variability (HRV) can disclose the specific adaptation of sympathovagal modulation to exercise. This study investigated the change in HRV measures after anaerobic and aerobic intermittent exercises in university football and futsal players. Method 36 male university students with physically active lifestyle (n=14), football (n=12), and futsal (n=10) participated in this study. The participants completed the repeated sprint ability (RSA) test and Yo-Yo (YY) intermittent recovery test level 1 in randomised order. ECG signals of the participants were recorded in supine position 15 min before and 30 min after exercises. Before exercise, and 5 and 30 min after exercise, the blood pressures were also taken. Results In the RSA protocol, the percentage changes in normalised high-frequency power (nHFP) were significantly decreased, while the percentage changes in the very low/high frequency power ratio (VLHR) and low/high frequency power ratio (LHR) were significantly increased in futsal players after exercise, as compared with the controls. No significant changes in all HRV indices were found in the YY protocol, except the respiratory frequency. Conclusions After exercise, the percent decrease in vagal modulation in futsal players was significantly reduced, while the percentage increase in sympathetic modulation in futsal players was significantly enhanced in the RSA test, but not in the YY test, as compared with the control group. The increase in sympathetic activity and the decrease in vagal activity in the futsal players were greater than the corresponding increase and decrease in the football players in the RSA test. PMID:27900135

  1. Yo-Yo Intermittent Recovery Test Performance in Subelite Gaelic Football Players From Under Thirteen to Senior Age Groups.

    PubMed

    Roe, Mark; Malone, Shane

    2016-11-01

    Roe, M and Malone, S. Yo-Yo intermittent recovery test performance in subelite Gaelic football players from under thirteen to senior age groups. J Strength Cond Res 30 (11): 3187-3193, 2016-Gaelic football is indigenous to Ireland and has similar locomotion profiles to soccer and Australian Football. Given the increasing attention on long-term player development, investigations on age-related variation in Yo-Yo intermittent recovery test level 1 (Yo-YoIR1) performance may provide useful information in talent identification, program design, and player monitoring. Therefore, the aim of this study was to evaluate Yo-YoIR1 performance across Gaelic football age groups. Male participants (n = 355) were recruited from division one, Gaelic football teams. Participants were allocated to one of the 7 groups according to respective age groups from under 13 (U13), under 14, under 15 (U15), under 16 (U16), minor, under 21 (U21), to senior age groups. Total Yo-YoIR1 distance (m) increased progressively from U13 (885 ± 347 m) to U16 (1,595 ± 380 m) equating to a rate of change of 180.2%. In comparison to U13, total distance at minor (1,206 ± 327 m) increased by 136.4%. Subsequent increases were observed in U21 (1,585 ± 445 m) and senior players (2,365 ± 489). Minimum (800-880 m) and maximum (2,240-2,280 m) total distances were comparable for U15, U16, and U21 players. Differences in total distance (m) for all age groups were statistically significant when compared to U13 players (p < 0.002). In comparison to U13 players, the magnitude of differences between age groups for total distance was deemed to be large (effect size > 0.8). Similar trends were observed for maximum velocity and estimated V[Combining Dot Above]O2max. The evolution of Yo-YoIR1 performance in Gaelic football players from adolescents to adulthood highlights how maturation may influence sport-related running ability. Changes in Yo-YoIR1 performance should be closely monitored to optimize interventions for

  2. Experimental determination of the coefficient of drag of a tennis ball

    NASA Astrophysics Data System (ADS)

    Zayas, Joseph M.

    1986-07-01

    The standard projectile motion experiment in the general physics laboratory using a spring gun and metal projectile is not sufficiently sensitive to detect air resistance effects of the ball's motion. These effects may be successfully studied by using a commercial tennis ball pitching machine which is capable of launching balls with speeds up to about 27 m/ s with negligible spin. Assuming an air resistance force of the form f=-bv2, the coefficient b may be shown by direct solution of the equations of motion to be dependent on the muzzle velocity, the horizontal speed of the ball as it strikes the ground, and its landing angle. By measuring these quantities, b may be obtained and its value then used to compute the drag coefficient CD for the ball. Experimental values of CD compare well with similar values obtained for smooth spheres by other methods.

  3. Laser radiation in tennis elbow treatment: a new minimally invasive alternative

    NASA Astrophysics Data System (ADS)

    Paganini, Stefan; Thal, Dietmar R.; Werkmann, Klaus

    1998-01-01

    The epicondylitis humeri radialis (EHR) (tennis elbow), is a common disease in elbow joint pain syndromes. We treated patients with chronic pain for at least one year and no improvement with conservative or operative therapies with a new minimal invasive method, the EHR-Laser radiation (EHR- LR). With this method periepicondylar coagulations were applied to the trigger points of the patients. For this the previously established technique of facet joint coagulation with the Nd:Yag-laser was modified. In a follow-up study of between 6 weeks and 2 years all patients reported either a significant pain reduction or were symptom free. EHR-LR is a new method situated between conservative and surgical treatments for minimal invasive therapy of EHR. Several therapeutic rationales were discussed for the resulting pain reduction.

  4. When favourites fail: tournament trophies as reward cues in tennis finals.

    PubMed

    Bijleveld, Erik; Custers, Ruud; Aarts, Henk

    2011-10-01

    In tournaments in various sports that feature one-on-one competition, the trophy is sometimes prominently displayed near the athletes during the final. Based on recent research on subtle reward cues, we propose that such trophies have the potential to induce choking under pressure in the match favourites, who are known to be most at risk. To test this idea, we analysed real-life tennis performance data (service performance and rally performance) from professional tournaments. While favourites generally outperformed underdogs during rallies, they did not do so in finals in which (a) large amounts of money were at stake and (b) a trophy was on display near the court. These findings support the idea that tournament trophies may distract favourites by continuously reminding them of what is at stake, and via that route may severely thwart their performance.

  5. Shock-wave therapy for tennis and golfer's elbow--1 year follow-up.

    PubMed

    Krischek, O; Hopf, C; Nafe, B; Rompe, J D

    1999-01-01

    Thirty patients with chronic medial epicondylitis were treated with low-energy shock waves. They received 500 impulses of 0.08 mJ/mm2 three times at weekly intervals. At 1 year follow-up examinations were performed. According to the Verhaar criteria, only seven patients reached excellent or good results. In eight cases a fair outcome was recorded, and in 14 patients the outcome was poor. Only six patients were satisfied with the treatment. The average relief of pain was 32%. These data were significantly worse than for identically treated patients with chronic tennis elbow. Thus, the question arises as to whether extracorporal shock-wave therapy is indicated in medial epicondylitis.

  6. Kinesthetic and visual image in modeling closed motor skills: the example of the tennis serve.

    PubMed

    Féry, Y A; Morizot, P

    2000-06-01

    It was assumed that kinesthetic modeling has more beneficial effects on learning the tennis serve than visual modeling because the spatial anchor points used to reach targets within the vicinity of the body are mainly defined with respect to the body. Also, we predicted that the efficiency of modeling is also affected by the way the representations are activated mentally. Thirty two participants were assigned to kinesthetic or visual modeling with or without mental practice. Analyses showed the primacy of kinesthetic representation over visual representation in terms of speed scores and form performances but only if the learner had the opportunity to rehearse the model mentally. The results support the contention that the motor system can program closed skills more easily when one can represent efficiently the kinesthetic image of its later execution.

  7. Estimating distribution of hidden objects with drones: from tennis balls to manatees.

    PubMed

    Martin, Julien; Edwards, Holly H; Burgess, Matthew A; Percival, H Franklin; Fagan, Daniel E; Gardner, Beth E; Ortega-Ortiz, Joel G; Ifju, Pe