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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. PMID:25111161

  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. PMID:26367081

  4. 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

  5. The prevalence of disordered eating and possible health consequences in adolescent female tennis players from Rio de Janeiro, Brazil.

    PubMed

    Coelho, Gabriela Morgado de Oliveira; de Farias, Maria Lucia Fleiuss; de Mendonça, Laura Maria Carvalho; de Mello, Danielli Braga; Lanzillotti, Haydée Serrão; Ribeiro, Beatriz Gonçalves; Soares, Eliane de Abreu

    2013-05-01

    The aim of this study was to estimate the prevalence of disordered eating and possible health consequences in adolescent female tennis players. This cross-sectional controlled study investigated the pubertal development (Tanner stages); body composition (dual energy X-ray absorptiometry-DXA); dietary intake (food record); presence of disordered eating (EAT-26, BITE and BSQ); menstrual status (questionnaire) and bone mineral density (DXA). The Female Athlete Triad (FAT) was divided into two severity stages. The study included 45 adolescents (24 athletes and 21 controls) at some pubertal developmental stage. The athletes exhibited better body composition profiles. We found that 91.7%, 33.3% and 25% of athletes and 71.4%, 9.5% and 33.3% of controls met criteria for disordered eating and/or low energy availability, menstrual irregularities and low bone mass, respectively. A greater percentage of athletes than controls presented with 1 and 2 FAT components (stage I), and 4.2% presented with the full syndrome. In conclusion, tennis players appear to present with more severe disorders than controls and should be monitored to avoid damage to their performance and health. PMID:23318655

  6. 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

  7. Advanced Tennis for Coaches, Teachers and Players.

    ERIC Educational Resources Information Center

    Tilmanis, Gundars A.

    This book is designed to help the reader attain a real understanding of the mechanics of tennis. It provides an important link between tennis theory and practice. The book covers activities that develop skills in beginners through advanced tennis and tactics applicable for seasoned players. The author draws upon scientific principles of…

  8. Impact of Fitness Characteristics on Tennis Performance in Elite Junior Tennis Players.

    PubMed

    Ulbricht, Alexander; Fernandez-Fernandez, Jaime; Mendez-Villanueva, Alberto; Ferrauti, Alexander

    2016-04-01

    The impact of fitness characteristics on tennis performance in adolescent players is not clearly understood. Therefore, the aim of the present study was to test whether physical characteristics are related to players' competitive level (i.e., national youth ranking). A secondary aim was to compare adolescent tennis players by performance level (i.e., regional selected players and the national team). A total of 902 male and female junior players (aged, 11-16 years) in Germany were evaluated using a physical testing battery: grip strength; countermovement jump; 10 and 20-m sprint; tennis-specific sprint; overhead, forehand, and backhand medicine ball throws (MBT); serve velocity and tennis-specific endurance test (hit and turn tennis test). Results showed that serve velocity (r = -0.43 to 0.64 for female subjects [♀]; r = -0.33 to 0.49 for male subjects [♂]) and upper-body power (e.g., MBT r = -0.26 to -0.49 ♀; r = -0.20 to -0.49 ♂) were the most correlated predictors of tennis performance (i.e., national youth ranking) in both female and male tennis players. Moreover, national selected players showed better performance levels than their regional counterparts, mainly in the most predictive physical characteristics (i.e., serve velocity: effect size [ES], 0.78-1.04 ♀; ES 0.92-1.02 ♂, MBT: ES, 0.66-0.88 ♀; ES, 0.67-1.04 ♂) and specific endurance (ES, 0.05-0.95 ♀; ES, 0.31-0.73 ♂). The present findings underline the importance of certain physical attributes, especially serve velocity and strength- and power-related variables (upper body), and suggest the need to include these parameters in the area of training, physical testing, and talent identification of young tennis players. PMID:26605803

  9. 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. PMID:17957025

  10. Diurnal patterns of salivary alpha-amylase and cortisol secretion in female adolescent tennis players after 16 weeks of training.

    PubMed

    Filaire, Edith; Ferreira, Jose Pedro; Oliveira, Miguel; Massart, Alain

    2013-07-01

    We examined the effects of 16 weeks of training on diurnal pattern of salivary alpha-amylase (sAA), cortisol, and the ratio of sAA over cortisol (AOC) in 12 national adolescent female tennis players. Stress and recovery were also evaluated using the Recovery-Stress-Questionnaire for Athletes-RESTQ-Sport. Data were collected after a 2-week rest (January, W0), and 4 months after W0 (W16). Subjects collected five saliva samples throughout a day. While all participants displayed the previously shown decrease after awakening in adolescents at W0, they showed a rise in the alpha-amylase awakening response and a higher alpha-amylase activity output (p<0.01) at W16 compared to W0. For the daily rhythm of cortisol we found subjects having a low overall output of salivary cortisol (p<0.01) and a blunted response to awakening at W16. Furthermore, an increase in the ratio AOC at W16, and a negative correlation between this ratio and Sport-specific recovery score. Our findings offer support for the hypothesis that increase of training load during the study period induced asymmetry activation between the two stress systems, in relation to psychological alterations and performance decrease. These results provide encouragement to continue exploring the impact of training program using a psychobiological approach among young athletes in order to prevent fatigue and preserve the health of these athletes. PMID:23200107

  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. Retired Matches Among Male Professional Tennis Players

    PubMed Central

    Breznik, Kristijan

    2012-01-01

    The aim of this study was to explore the effect of characteristics of various games and players on the proportion of retired tennis matches in the Open Era of tennis. The data included over 420,000 matches played among 17,553 tennis players in the period from 1968 to the end of 2010. The influence of the surface type was clearly confirmed, with the proportion of retired matches being higher on hard and clay courts compared to grass and carpet surfaces. Similarly, more retired matches were observed in outdoor venues than in indoor ones. The impact of other variables, tournament types, rounds at which the game was played and both players' ranks, is more ambiguous. Our interpretation of the obtained results is presented in the paper. Network analytic methods were applied to extract players with the most retired matches in their careers. Eventually, we defined a group of top tennis players and gave a more precise insight into retired matches in that group. Correspondence analysis was used to visually display the two-mode network of top players and the proportion of retired matches by surface type. Key pointsThe proportion of retired matches among professional tennis players has been increasing recently.Clay and hard courts are the most risky surfaces in relation to retired matches, particularly if the match is played at an outdoor venue.The difference in rankings of both players is proportional to the number/proportion of retired matches in professional tennis.Network analytic techniques could serve as an effective method to ascertain (a) group(s) of tennis players with the highest number of retired matches played among them. PMID:24149200

  13. Rehabilitation of the shoulder in tennis players.

    PubMed

    Plancher, K D; Litchfield, R; Hawkins, R J

    1995-01-01

    The tennis player places unique demands on the shoulder by creating a high risk for overuse and overloading of the soft tissues. Tennis requires concentric work to position and move the arm, eccentric work to stabilize the shoulder, effective depression of the humeral head to avoid impingement in the overhead position, and normal stability to prevent secondary impingement. The tennis serve produces enormous angular velocities about the shoulder joint. A comprehensive rehabilitation program has been described in which the therapist, trainer, player, and physician alike need to have an understanding of the basic biomechanics of this sport. This program can be used to treat the painful shoulder, prevent injury, and enhance performance. PMID:7712546

  14. 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)

  15. 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. PMID:20086771

  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. Mechanisms of neck and shoulder injuries in tennis players.

    PubMed

    Lee, H W

    1995-01-01

    Shoulder injuries are common among athletes involved in repetitive overhead arm movements, particularly baseball pitchers and tennis players. Due to the similarities between pitching and serving, both athletes often present with similar types of shoulder injuries. However, subtle differences in neck and shoulder movements between the pitcher and tennis player may be responsible for additional mechanisms of injuries specific to tennis players. This paper outlines the similarities and differences between the pitch and serve and discusses how these differences may relate to additional neck and/or shoulder injuries specific to tennis players. In the analyses of mechanisms of injuries sustained by tennis players, such detailed analyses of movement patterns occurring during the serve may optimize a clinician's sports-specific rehabilitation protocol. PMID:7889030

  18. [Stress fracture of the ulna in a table tennis player].

    PubMed

    Dufek, P; Ostendorf, U; Thormählen, F

    1999-06-01

    This case report describes a stress fracture of the ulna in a 26-year-old professional table-tennis player. X-ray films remained negative so that the diagnostic is based on MRT. This stress fracture is caused by changing the intensity of training and changing the table-tennis-racket. PMID:10478391

  19. 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. PMID:11829331

  20. Arthroscopic Shoulder Surgery in Female Professional Tennis Players

    PubMed Central

    Young, Simon W.; Safran, Marc R.; Dakic, Jodie; Nguyen, Michael L.; Stroia, Kathleen

    2013-01-01

    Objectives: Recent publications have highlighted the relatively poor outcome of other overhead athletes, particularly baseball players, with regard to return to sports at the same or higher level after shoulder surgery. However, true assessment of their ability when returning to sport is not as clear. Further, ability to return to other overhead sports has not been reported. Our objective was to assess outcome and time to return to previous level of function following shoulder surgery in professional tennis players. Methods: The records of all female tennis players on the Women’s Tennis Association (WTA) professional circuit between January 2008 and June 2010 were reviewed to identify players who underwent shoulder surgery on their dominant (serving) shoulder. Details of the surgery including date, procedures performed, and complications were recorded. The primary outcomes were ability and time to return to professional play, and if they were able to return to their previous level of function, as determined by singles ranking. Pre and post-operative singles rankings were used to determine rate and completeness of return to preoperative function. Their highest ranking pre-injury, post operatively, and the time to return to pre-injury ranking were evaluated. Results: During the study period eight professional women tennis players from the WTA underwent shoulder surgery on their dominant arm. All surgery was performed arthroscopically, 7 out of 8 players had more than one procedure performed during the surgery. In total, 3 players underwent debridement of a partial rotator cuff tear and 2 players underwent repair of a complete supraspinatus tear. Three players had an anterior labral repair or reconstruction for anterior instability, and one player underwent repair of a SLAP lesion. Two players underwent neurolysis of a suprascapular nerve, and three players in total underwent a subacromial decompression. All players (100%) returned to professional play. The mean

  1. Evaluation of elite table tennis players' technique effectiveness.

    PubMed

    Zhang, Hui; Liu, Wei; Hu, Jin-Ju; Liu, Rui-Zhi

    2014-01-01

    Abstract This study constructed a technique effectiveness evaluation formula for table tennis players based on the relationship between the scoring rate and usage rate of techniques and established evaluation criteria through the examination of 224 matches of the world's top 35 players. It also built a competition performance formula with the score difference theory for the exploration of the correlation between player technique effectiveness and competition performance. The results showed the three indices - the technique effectiveness of the first and third strokes (TE₁,₃), the second and fourth strokes (TE₂,₄) and the after fourth strokes (TE>₄) - could help better evaluate the technique effectiveness of elite players. The comparative analysis of Chinese elite table tennis players and players from other countries and regions revealed that Chinese players as a whole were 'excellent' in all the examined techniques except in the male's 'first and third strokes'; while players from other countries and regions were overall 'general'. The case analysis of two of the world's top players further indicated that correlation analysis of technique effectiveness and competition performance could help identify the technique indices highly correlated with player competition performance. PMID:23879820

  2. Teaching Tennis Players To Be Their Own Best Coach.

    ERIC Educational Resources Information Center

    Ward, Martin J.

    2002-01-01

    Describes how high school and college tennis coaches can prepare their athletes for competitive success, noting factors involved in performance excellence and presenting the BADGE instructional framework, which teaches players that their efforts are the greatest single influence upon future results. The paper explains the importance of positive…

  3. 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. PMID:27047841

  4. 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

  5. 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

  6. An electromyographic analysis of shoulder function in tennis players.

    PubMed

    Ryu, R K; McCormick, J; Jobe, F W; Moynes, D R; Antonelli, D J

    1988-01-01

    Shoulder injuries in tennis players are common because of the repetitive, high-magnitude forces generated around the shoulder during the various tennis strokes. An understanding of the complex sequences of muscle activity in this area may help reduce injury, enhance performance, and assist the rapid rehabilitation of the injured athlete. The supraspinatus, infraspinatus, subscapularis, middle deltoid, pectoralis major, latissimus dorsi, biceps brachii, and serratus anterior muscles were studied in six uninjured male Division II collegiate tennis players using dynamic electromyography (EMG) and synchronized high-speed photography. Each subject performed the tennis serve and the forehand and backhand groundstrokes, and each stroke was divided into stages. The tennis serve contains four stages. Three stages characterize the forehand and backhand groundstrokes. Our results indicate that the subscapularis, pectoralis major, and serratus anterior display the greatest activity during the serve and forehand. The middle deltoid, supraspinatus, and infraspinatus are most active in the acceleration and follow-through stages of the backhand. The biceps brachii increases its activity during cocking and follow-through in the serve with a similar pattern noted in the acceleration and follow-through stages of the forehand and backhand. The serratus anterior demonstrates intense activity in the serve and forehand, thus providing a stable platform for the humeral head and assisting in gleno-humeral-scapulothoracic synchrony. The tennis serve and forehand and backhand groundstrokes are accomplished by complex sequences of muscle activity that incorporate contributions from the lower extremities and trunk into smooth, coordinated patterns.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3189681

  7. 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…

  8. Differences in physical fitness among young tennis players in between 1992 and 2008.

    PubMed

    Filipčič, Aleg; Filipčič, Tjasa; Leskošek, Bojan

    2015-03-01

    The aim of this study was to find a trend of changes for selected anthropometric characteristics and motor abilities of young male and female tennis players of three different age groups. Trends were observed in the periods between 1992, 2000 and 2008. In addition, a comparison of results of tennis players and school pupils was included. The sample of subjects were selections of young tennis players and of primary and secondary schools pupils (boys and girls) divided into three age groups (12- to 13-year-olds, 14- to 15-year-olds, and 16- to 17-year-olds). Fitness tests items (backwards obstacle course, forward bend on the bench, 20-second hand-tapping, 60-second sit-ups) and three anthropometric measurements (body height, body weight, BMI) were included in this study. The analysis of trends for different periods of measurement in male and female tennis players revealed an increase in some test items and a decrease in others. In the majority of observed fitness test items, young tennis players performed better than their school peers, indicating the positive effects of training and an appropriate selection process of tennis players. Male and female tennis players were taller than the school pupils, and body height values in both groups increased from 1992 to 2008. The body weight and BMI values for male and female tennis players, and male and female pupils in all three age groups have been constantly increasing. PMID:26040081

  9. Growth and maturity status of elite British junior tennis players.

    PubMed

    Myburgh, Gillian K; Cumming, Sean P; Coelho E Silva, Manuel; Cooke, Karl; Malina, Robert M

    2016-10-01

    Growth and maturation impact the selection, development and progression of youth athletes. Individual differences in the growth and maturity may afford a performance advantage, clouding coaches and practitioners' perceptions regarding current ability and future potential. This may result in the exclusion of talented, yet less physically gifted athletes. Participants were 91 male (n = 47) and female (n = 44) elite British Junior tennis players, 8-17 years of age (12.5 ± 1.9 years). Height and body mass were measured and compared to growth charts; hand-wrist radiographs were taken. Skeletal age (SA) was estimated with the Fels method and contrasted to chronological age (CA). Mean height and body mass of individual players ranged between the 50th and 90th centiles for age and sex. Females were advanced in SA relative to CA (0.3-0.89 years.) from 8 years. Males were average to delayed in maturation from 8 to 12 years, but advanced in SA from 14 to 16 years (0.75-1.23 years). Individual differences in growth and maturation appear to contribute towards the selection of elite junior tennis players, with a bias towards males and females who are advanced in maturation and comparatively tall and heavy for their age. This has important implications for talent identification and development. PMID:26930031

  10. The Relative Age Effect and Physical Fitness Characteristics in German Male Tennis Players

    PubMed Central

    Ulbricht, Alexander; Fernandez-Fernandez, Jaime; Mendez-Villanueva, Alberto; Ferrauti, Alexander

    2015-01-01

    The aims of the study were to test: 1) whether the relative age effect (RAE) was prevalent in young (U12-U18) German male tennis players; 2) the potential influence of age and/or skill level on RAE and 3) whether maturity, anthropometric and fitness measures vary according to birth date distribution in elite youth tennis players. For the present study the following male populations were analysed: Overall German population (n = 3.216.811), all players affiliated to the German Tennis Federation (DTB) (n = 120.851), players with DTB official ranking (n = 7165), regional (n = 381) and national (n = 57) squads (11-17 years old), as well as the top 50 German senior players were analyzed. RAEs were more prevalent at higher competitive levels with more players born in the first quarter of the year compared with the reference population for ranked (29.6%), regional (38.1%) and national (42.1%) players. No systematic differences were found in any of the maturity, anthropometric and fitness characteristics of the regional squad players born across different quarters. RAEs are present in the DTB competitive system and it was more pronounced at higher competitive levels. Compared with early born, late born players who were selected into elite squads did not differ in maturation, anthropometric and fitness characteristics. Key points RAEsexist in the selection of youth tennis players in Germany, a greater percentage of players analyzed was born in the 1st quarter compared to all licensed tennis players in the country, and more pronounced with an increased competition level in youth players. Players born later in the selection year and still selected in elite squads were likely to be similar across a range of physical fitness attributes compared with those born earlier in the year. The selection process should be reevaluated and changed to reduce the impact of RAEs on tennis players. PMID:26336351

  11. 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

  12. Ultrasound of Extensor Carpi Ulnaris Tendon Subluxation in a Tennis Player.

    PubMed

    Spicer, Paul J; Romesberg, Amanda; Kamineni, Srinath; Beaman, Francesca D

    2016-06-01

    Wrist pain is common among competitive tennis players. Subluxation of the extensor carpi ulnaris (ECU) tendon has gained recognition as a cause of ulnar-side wrist pain in athletes. In tennis, the wrist is forcibly flexed, supinated, and ulnar deviated. These repetitive motions stress the ECU tendon stabilizers allowing tendon subluxation from the ulnar groove, especially in cases of anatomic variations such as a shallow groove. We present the presurgical and postsurgical imaging findings of recurrent ECU tendon subluxation in an elite tennis player. PMID:27233073

  13. 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

  14. Electromyographic analysis of elbow function in tennis players.

    PubMed

    Morris, M; Jobe, F W; Perry, J; Pink, M; Healy, B S

    1989-01-01

    Muscle activity about the elbow during tennis strokes in nine professional and collegiate level players was studied using indwelling EMG and high speed photography. Eight muscles were evaluated for the serve, forehand, and backhand strokes. The serve was divided into six stages and the ground strokes into four stages. EMG tracings were subjected to analog-to-digital conversion and a relative measure of quantity was obtained. Analysis of variance and Turkey tests were then done to assess statistical significance (P less than 0.05). The ground strokes showed low activity in all muscles tested during the preparation phase. During the acceleration phase, both the backhand and forehand showed a generalized increase in all muscle activity. Both strokes showed marked activity of the wrist extensors and, in addition, the forehand showed high activity in the brachialis and biceps. In the follow-through phase, there was a generalized decrease in muscle activity. The serve showed low activity in all muscles tested during the wind-up phase. The wrist extensors increased their activity in the cooking phase, with marked activity in late cooking. The pronator teres and the triceps showed increased activity in the acceleration phase. Follow-through phase showed low muscle activity except for the biceps, which increased in late follow-through. In conclusion, the muscles of the elbow help stabilize the elbow as a unit during the ground strokes in these high level players. Power in the serve comes from increased activity in the triceps and pronator teres. The predominant activity of the wrist extensors in all strokes may be one explanation for predisposition to injury. PMID:2757127

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

    PubMed

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

    2015-01-01

    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. PMID:26545537

  16. 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

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

    PubMed

    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

  18. Anthropometric characteristics, body composition and somatotype of elite junior tennis players

    PubMed Central

    Sánchez‐Muñoz, Cristóbal; Sanz, David; Zabala, Mikel

    2007-01-01

    Objectives The aims of this study were to describe the anthropometric characteristics, body composition and somatotype of elite male and female junior tennis players, to compare the anthropometric data, body composition and somatotype of the first 12 elite junior tennis players on the ranking with the lower ranked players, and to establish an anthropometric profile chart for elite junior tennis players. Methods A total of 123 (57 males and 66 females) elite junior tennis players participated in this study. The athletes were divided into two groups, the first 12 and the lower ranked players, according to gender. A total of 17 anthropometric variables were recorded of each subject. Results There were no significant differences in height and weight between the first 12 and the lower ranked boys, while the first 12 girls were significantly taller than the lower ranked girls (p = 0.009). Significant differences were found for humeral and femoral breadths between the first 12 and the lower ranked girls (p = 0.000; p = 0.004, respectively). The mean (SD) somatotype of elite male junior tennis players could be defined as ectomesomorphic (2.4 (0.7), 5.2 (0.8), 2.9 (0.7)) and the mean (SD) somatotype of elite female junior tennis players evaluated could be defined as endomesomorphic (3.8 (0.9), 4.6 (1.0), 2.4 (1.0)). No significant differences were found in somatotype components between the first 12 and the lower ranked players of both genders. Conclusions When comparing the first 12 and the lower ranked elite junior tennis players of both genders, no significant differences were observed in any measured item for the boys. By contrast, significant differences were observed in height and humeral and femoral breadths between the first 12 and the lower ranked girls, whereby the first 12 were taller and had wider humeral and femoral breadths than the lower ranked players. These differences could influence the playing style of junior female players. PMID:17957016

  19. Core Temperature and Sweat Responses in Professional Women's Tennis Players During Tournament Play in the Heat

    PubMed Central

    Tippet, Melissa L.; Stofan, John R.; Lacambra, Magie; Horswill, Craig A.

    2011-01-01

    Abstract Context: Tennis is often played in hot, humid environments, intensifying the thermoregulatory strain placed on the athletes. As a safety measure, some tennis organizations allow for a 10-minute break in play between the second and third sets when environmental conditions are extreme. However, the actual effect of these breaks in reducing core temperature is unknown. Objective: To determine change in core temperature after a 10-minute break in play and assess fluid balance in professional female tennis players during tournament matches in the heat. Design: Cross-sectional study. Setting: A Women's Tennis Association Tour–sanctioned outdoor tournament on hard courts under hot conditions (30.3°C ± 2.3°C). Patients or Other Participants: Seven professional tennis players. Main Outcome Measure(s): Change in core temperature after a 10-minute break in tournament play, fluid intake, and sweat losses during match play. Results: Core temperature was reduced from 38.92°C to 38.67°C (change of −0.25°C ± 0.20°C) when a break was taken (P  =  .02). Mean sweat rate during match play was 2.0 ± 0.5 L/h. During that time, mean fluid intake was 1.5 ± 0.5 L/h, resulting in a 1.2% ± 1.0% reduction in body mass. Conclusions: Female professional tennis players are subjected to high heat loads during match play in hot environments. However, a 10-minute break in play decreased core temperature in 6 of 7 players by an average of 0.25°C, indicating that the break provides practical benefits in the field. Furthermore, although mean sweat rate in this group of female tennis players was high, most athletes were still able to minimize mass loss to less than 2% of their prematch weight. PMID:21214351

  20. 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

  1. 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

  2. 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

  3. Late Stage Freiberg Infraction in a Division I Collegiate Tennis Player

    PubMed Central

    Faircloth, Johnnie; Mitchell, Jennifer J; Edwards, David S

    2015-01-01

    Introduction: Freiberg infraction is a relatively rare osteochondrosis of the metatarsal head. The etiology of Freiberg infraction is poorly understood but likely involves factors such as, repetitive trauma and vascular compromise. When discovered early, Freiberg infraction can be cured with conservative measures but late presentations require surgical intervention. We present a case of stage V Freiberg infraction in a Division I collegiate tennis player that responded to conservative treatment. Case Report: A 20 year old female tennis player presented with worsening of her chronic foot pain. She had tenderness to palpation and diminished range of motion at the second metatarsophalangeal joint. Radiographs revealed late stage Freiberg infraction of the second metatarsal. This patient’s pain was successfully treated with conservative measures; prolonging her collegiate tennis career. Conclusion: Surgical intervention is required for definitive treatment of late stage Freiberg infraction. Conservative treatment can be effective in prolonging the athlete’s career. PMID:27299057

  4. 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

  5. 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

  6. Who is the best player ever? A complex network analysis of the history of professional tennis.

    PubMed

    Radicchi, Filippo

    2011-01-01

    We considered all matches played by professional tennis players between 1968 and 2010, 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

  7. On-court endurance and performance testing in competitive male tennis players.

    PubMed

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

    2014-01-01

    The aims of this study were (a) to establish a specific endurance test procedure for competitive tennis players, combining performance, physiological and technical parameters and (b) to determine the relationship between these parameters and their competitive levels. Thirty-eight competitive male tennis players (age, 18.2 ± 1.3 years; height, 180 ± 0.08 cm; body mass, 72.7 ± 8.6 kg; mean ± SD) performed a specific endurance field test. Performance (level achieved), physiological (heart rate, maximum oxygen uptake (VO2max), and ventilatory thresholds (VT1, VT2), and technical parameters (technical effectiveness [TE]) were assessed. Bivariate and multivariate models for predicting performance level were developed. Technical effectiveness was 63.1 ± 9.1%, with 3 identified phases throughout the test (adaptation, maximum effectiveness, and steady decline). Low to moderate correlations were found between performance (final stage), physiological (VT1, VT2) and TE, and competitive performance (r = 0.35-0.61; p = 0.038-0.000). Technical effectiveness explained 37% of variability in competitive performance (r = 0.61; p = 0.001). Using TE combined with VT2 or predictability increased explaining approximately 55% (p < 0.05) of the variance in competitive performance. The present study showed the usefulness of a field test including physiological and performance elements in high-caliber tennis players, and VT2 values combined with TE were good predictors of tennis performance. PMID:23588482

  8. Osteochondritis dissecans of the lateral humeral condyle in a table tennis player.

    PubMed

    Pintore, E; Maffulli, N

    1991-08-01

    The case of a table tennis player suffering from intra-articular loose bodies of the elbow is reported. The patient developed the first signs of osteochondritis dissecans of the right lateral humeral condyle at age 16 but underwent surgery only 6 yr later. He has now resumed training and competition, despite some residual stiffness due to early osteoarthritis. This is the first case of osteochondritis dissecans of the elbow ascribed to this sport. It was probably due to repetitive valgus compressive stresses at the radiocapitellar joint during the forced movements imposed by high-level table tennis in a young athlete. PMID:1956260

  9. Relationship of Speed, Agility, Neuromuscular Power, and Selected Anthropometrical Variables and Performance Results of Male and Female Junior Tennis Players.

    PubMed

    Munivrana, Goran; Filipčić, Aleš; Filipčić, Tjaša

    2015-07-01

    The aim of the study was to analyses the relation between the selected speed, agility, and neuromuscular power test items. The sample of subjects consisted of 154 male and 152 female young tennis players. Using six motor and three anthropometrical tests we investigate differences between males and females and between two age categories. Finally, we analyzed the relation between motor and anthropometrical tests and a player's tennis performance. The correlation between the two agility test items and 5-m sprint is very large in male players, while only moderate with 20-m sprint in female category. Male tennis players have higher correlations between speed test items and neuromuscular test items. The speed test item (5-m sprint) has large correlation with a player's tennis performance. One-way analysis of variance results indicated that young male tennis players performed significantly better than females in all motor test items. Significant differences between genders have not been revealed only in the body mass index. Differences between the males aged 18& under and 16& under have been noted as significant in all test items, except the vertical jump, while differences between the females have been noted as significant in three anthropometrical tests, quarter jump, and the fan-drill test. Regression analyses have shown that the system of prediction variables explains a relatively small part of variance (46%--males and 40%--females). In both genders, it has been revealed that test items measuring speed significantly influence a player's tennis performance. PMID:26434018

  10. Male professional tennis players maintain constant serve speed and accuracy over long matches on grass courts.

    PubMed

    Maquirriain, Javier; Baglione, Roberto; Cardey, Marcelo

    2016-10-01

    The potential effect of fatigue on stroke production in tennis players is still controversial. The aim of this study was to analyse the tennis serve speed and accuracy in prolonged male professional matches played on grass courts. We analysed tennis serve statistics from five-set Wimbledon matches (n = 15; 30 players). Results showed that match duration averaged 208.3 ± 28.3 min. The overall serve speed was 177.0 ± 10.2 km/h in the first set and 176.1 ± 11.7 km/h in the fifth set (p = .34). The difference of all accuracy values of first set serves was not significantly different from those of the fifth set: percentage of valid first serves, 63.1 ± 11.1% vs. 62.3 ± 11.8%, respectively (p = .78); percentage of "aces", 11.2 ± 9.1% vs. 10.0 ± 8.9%, respectively (p = .39); percentage of "winners", 2.6 ± 7.6% vs. 1.2 ± 2.2%, respectively (p = .36); percentage of "double faults", 2.8 ± 3.0% vs. 2.8 ± 3.4% (p = .97). In conclusion, tennis players were able to maintain constant serve speed and accuracy over five-set matches played on grass courts. Professional tennis players are capable of overcoming fatigue and/or make movement adjustments to effectively perform complex technical strokes like the serve throughout matches played on grass courts lasting more than 3 h in average. PMID:26960753

  11. 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

  12. Modeling Longitudinal Changes in 5 m Sprinting Performance Among Young Male Tennis Players.

    PubMed

    Kramer, Tamara; Valente-Dos-Santos, João; Coelho-E-Silva, Manuel J; Malina, Robert M; Huijgen, Barbara C H; Smith, Joanne; Elferink-Gemser, Marije T; Visscher, Chris

    2016-02-01

    Year-to-year changes in sprinting in youth tennis players were examined in a mixed-longitudinal study (256 male players, aged 10-15 years: 993 measurements). Height (h), body mass (BM), lower limb explosive strength (LLES), and a 5-m sprint were measured over five years. During that period, players were classified as elite or sub-elite. To account for the repeated measurements within the individual nature of longitudinal data, multilevel random effects regression analyses were used. Sprint performance improved with age at each additional 1 year of age, thus predicting ∼.016 sec improvement in five-meter sprint time by all variables of the model. It was possible to predict the performance of elite tennis players in the 5-m sprint (sec) for elite players (1.1493 - (0.0159 ċ centered age) - (0.009 ċ BM) - (0.044 ċ LLES) and sub-elite players (1.1493 - (0.0159 ċ centered age) + 0.0135 - (0.009 ċ BM) - (0.044 ċ LLES) - (0.0557 ċ centered age). Sprint performance differences between elite and sub-elite players was related to longitudinal changes in body size and lower limb strength up until age 13. PMID:27420323

  13. Kinetics of the upper limb during table tennis topspin forehands in advanced and intermediate players.

    PubMed

    Iino, Yoichi; Kojima, Takeji

    2011-11-01

    The purpose of this study was to determine the significance of mechanical energy generation and transfer in the upper limb in generating the racket speed during table tennis topspin forehands. Nine advanced and eight intermediate table tennis players performed the forehand stroke at maximum effort against light and heavy backspin balls. Five high-speed video cameras operating at 200 fps were used to record the motions of the upper body of the players. The joint forces and torques of the racket arm were determined with inverse dynamics, and the amount of mechanical energy generated and transferred in the arm was determined. The shoulder internal rotation torque exerted by advanced players was significantly larger than that exerted by the intermediate players. Owing to a larger shoulder internal rotation torque, the advanced players transferred mechanical energy from the trunk of the body to the upper arm at a higher rate than the intermediate players could. Regression of the racket speed at ball impact on the energy transfer to the upper arm suggests that increase in the energy transfer may be an important factor for enabling intermediate players to generate a higher racket speed at impact in topspin forehands. PMID:22303787

  14. Tenosynovial Osteochondromatosis of the Flexor Hallucis Longus in a Division I Tennis Player.

    PubMed

    Thomsen, Timothy W; Hogrefe, Christopher P; Hall, Mederic M; Amendola, Annunziato

    2015-11-01

    Tenosynovial (extra-articular) chondromatosis (TC) is a condition characterized by the cartilaginous proliferation of synovial cells derived from the synovial lining of bursa and tendon sheaths. These lesions are often multinodular and most commonly present with complaints of swelling or pain. Treatment of TC primarily entails surgical excision. There are no known reports of TC in collegiate athletes. We present a case of TC in a Division I tennis player. PMID:25514138

  15. Physiological Responses of Young Tennis Players to Training Drills and Simulated Match Play.

    PubMed

    Gomes, Rodrigo V; Cunha, Vivian C R; Zourdos, Michael C; Aoki, Marcelo S; Moreira, Alexandre; Fernandez-Fernandez, Jaime; Capitani, Caroline D

    2016-03-01

    The aim of this study was to investigate the responses of young tennis players during 5 different training drills and to compare the responses between drills. Ten (17.0 ± 1.2 years) male tennis players participated in this study. Each athlete completed 5 total training drills. Drills 1-4 consisted of each player returning balls from a ball-serving machine and were stroke/time-controlled over 6 points. The fifth drill was a simulated match (SM) play, between 2 opposing players, and also lasted 6 points. The 4 stroke/time-controlled drills had the following strokes/time for each point: drill 1: 2 strokes/∼4 seconds, drill 2: 4 strokes/∼8 seconds, drill 3: 7 strokes/∼14 seconds, drill 4: 10 strokes/∼20 seconds. Peak heart rate (HR), blood lactate concentration (LA), and rating of perceived exertion (RPE) were measured after the first, third, and sixth point of each drill. Drills were performed in a randomized crossover design; a 2-way repeated-measures analysis of variance was used with significance set at p ≤ 0.05. All dependent variables (HR, LA, and RPE) significantly increased (p ≤ 0.05) as strokes, and time per rally increased in each drill. Furthermore, all variables were elevated to a greater magnitude (p ≤ 0.05) during the 7 and 10 stroke drills after the first, third, and sixth points when compared with the SM and the 2 and 4 stroke drills at the corresponding time points. These results suggest that the physiological responses to tennis training drills were stroke/time-dependent. Therefore, because of the intense intermittent nature of tennis, stroke/time-controlled drills, which require significant physiological demands, should be incorporated along with technically focused shorter drills to fully mimic the conditions of competitive match play. PMID:26382129

  16. The asymmetry of pectoralis muscles is greater in male prepubertal than in professional tennis players.

    PubMed

    Sanchis-Moysi, Joaquin; Dorado, Cecilia; Idoate, Fernando; González-Henríquez, Juan J; Serrano-Sanchez, Jose A; Calbet, Jose A L

    2016-10-01

    It is generally accepted that preadolescents have a limited capacity to develop muscle hypertrophy in response to exercise compared with older populations; however, studies are scarce and conflicting. The main aim of the present study was to assess if playing tennis is associated with the hypertrophy of dominant pectoralis muscles (PM) in professional (PRO) and in prepubescent tennis players (PRE). A secondary aim was to assess if the degree of asymmetry of PM is greater in PRO than PRE. The volume of PM of both sides was determined using magnetic resonance imaging in 8 male PRO (21.9 years), 6 male PRE (11 years, Tanner 1-2) and 12 male non-active controls (6 adults: 23.5 years; and 6 prepubescents: 10.7 years, Tanner 1-2). PRO and PRE had 15 and 30% greater volume, respectively, in the dominant than in the contralateral PM (P < .01). No significant side-to-side differences in PM volume were observed in the non-active controls (3%, P = .34 in adults and 5%, P = .17 in children). The degree of side-to-side asymmetry in PM volume was greater in PRE than in PRO (P < .05). In conclusion, tennis practice is associated with marked hypertrophy of dominant PM in tennis players, even at prepubertal age, whilst non-active age-matched control subjects display similar volumes in both sides. The larger asymmetry observed in PRE than in PRO may indicate a greater relative loading in the children or increased contralateral hypertrophy in the professionals. This study demonstrates that prepubertal children respond with marked hypertrophy to loading by tennis. PMID:26799312

  17. Physiological Responses to On-Court vs Running Interval Training in Competitive Tennis Players

    PubMed Central

    Fernandez-Fernandez, Jaime; Sanz-Rivas, David; Sanchez-Muñoz, Cristobal; de la Aleja Tellez, Jose Gonzalez; Buchheit, Martin; Mendez-Villanueva, Alberto

    2011-01-01

    The aim of this study was to compare heart rate (HR), blood lactate (LA) and rate of perceived exertion (RPE) responses to a tennis-specific interval training (i.e., on-court) session with that of a matched-on-time running interval training (i.e., off-court). Eight well-trained, male (n = 4) and female (n = 4) tennis players (mean ± SD; age: 16.4 ± 1.8 years) underwent an incremental test where peak treadmill speed, maximum HR (HRmax) and maximum oxygen uptake (VO2max) were determined. The two interval training protocols (i.e., off- court and on-court) consisted of 4 sets of 120 s of work, interspersed with 90 s rest. Percentage of HRmax (95.9 ± 2.4 vs. 96.1 ± 2.2%; p = 0.79), LA (6.9 ± 2.5 vs. 6.2 ± 2.4 mmol·L-1; p = 0.14) and RPE (16.7 ± 2.1 vs. 16.3 ± 1.8; p = 0.50) responses were similar for off-court and on-court, respectively. The two interval training protocols used in the present study have equivalent physiological responses. Longitudinal studies are still warranted but tennis-specific interval training sessions could represent a time-efficient alternative to off-court (running) interval training for the optimization of the specific cardiorespiratory fitness in tennis players. Key points On-court interval training protocol can be used as an alternative to running interval training Technical/tactical training should be performed under conditions that replicate the physical and technical demands of a competitive match During the competitive season tennis on-court training might be preferred to off-court training PMID:24150630

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

    PubMed

    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

  19. 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

  20. The influence of tennis court surfaces on player perceptions and biomechanical response.

    PubMed

    Starbuck, Chelsea; Damm, Loïc; Clarke, James; Carré, Matt; Capel-Davis, Jamie; Miller, Stuart; Stiles, Victoria; Dixon, Sharon

    2016-09-01

    This study aimed to examine player perceptions and biomechanical responses to tennis surfaces and to evaluate the influence of prior clay court experience. Two groups with different clay experiences (experience group, n = 5 and low-experience group, n = 5) performed a 180° turning movement. Three-dimensional ankle and knee movements (50 Hz), plantar pressure of the turning step (100 Hz) and perception data (visual analogue scale questionnaire) were collected for two tennis courts (acrylic and clay). Greater initial knee flexion (acrylic 20. 8 ± 11.2° and clay 32.5 ± 9.4°) and a more upright position were reported on the clay compared to the acrylic court (P < 0.05). This suggests adaptations to increase player stability on clay. Greater hallux pressures and lower midfoot pressures were observed on the clay court, allowing for sliding whilst providing grip at the forefoot. Players with prior clay court experience exhibited later peak knee flexion compared to those with low experience. All participants perceived the differences in surface properties between courts and thus responded appropriately to these differences. The level of previous clay court experience did not influence players' perceptions of the surfaces; however, those with greater clay court experience may reduce injury risk as a result of reduced loading through later peak knee flexion. PMID:26699792

  1. Studying the effects of self-talk on thought content with male adult tennis players.

    PubMed

    Latinjak, Alexander T; Torregrosa, Miquel; Renom, Jordi

    2010-08-01

    The current study examined the effects of self-talk on thought content during a tennis forehand crosscourt exercise. 16 adult tennis players (M age = 37.3 yr., SD = 8.31) were randomly assigned to either an experimental or a control group. After completing three baseline assessments, the players of the intervention group developed and implemented self-determined instructional cue words throughout three intervention trials. The participants' thought content was divided into three categories, and repeated-measures analyses of variance indicated a significant group by time interaction for execution-related thoughts and outcome-related thoughts, but not for circumstance-related thoughts. Follow-up comparisons showed that the experimental group players' execution-related thoughts increased and outcome-related thoughts decreased significantly, whereas thought content did not change significantly in the control group. The results of this study provided evidence for the effects of self-talk on players' thought content and supported the idea that self-talk could help athletes to focus on task relevant information. PMID:21058604

  2. 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. PMID:23916998

  3. 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

  4. A six-week neuromuscular training program for competitive junior tennis players.

    PubMed

    Barber-Westin, Sue D; Hermeto, Alex A; Noyes, Frank R

    2010-09-01

    This study evaluated the effectiveness of a tennis-specific training program on improving neuromuscular indices in competitive junior players. Tennis is a demanding sport because it requires speed, agility, explosive power, and aerobic conditioning along with the ability to react and anticipate quickly, and there are limited studies that evaluate these indices in young players after a multiweek training program. The program designed for this study implemented the essential components of a previously published neuromuscular training program and also included exercises designed to improve dynamic balance, agility, speed, and strength. Fifteen junior tennis players (10 girls, 5 boys; mean age, 13.0 +/- 1.5 years) who routinely participated in local tournaments and high-school teams participated in the 6-week supervised program. Training was conducted 3 times a week, with sessions lasting 1.5 hours that included a dynamic warm-up, plyometric and jump training, strength training (lower extremity, upper extremity, core), tennis-specific drills, and flexibility. After training, statistically significant improvements and large-to-moderate effect sizes were found in the single-leg triple crossover hop for both legs (p < 0.05), the baseline forehand (p = 0.006) and backhand (p = 0.0008) tests, the service line (p = 0.0009) test, the 1-court suicide (p < 0.0001), the 2-court suicide (p = 0.02), and the abdominal endurance test (p = 0.01). Mean improvements between pretrain and posttrain test sessions were 15% for the single-leg triple crossover hop, 10-11% for the baseline tests, 18% for the service line test, 21% for the 1-court suicide, 10% for the 2-court suicide, and 76% for the abdominal endurance test. No athlete sustained an injury or developed an overuse syndrome as a result of the training program. The results demonstrate that this program is feasible, low in cost, and appears to be effective in improving the majority of neuromuscular indices tested. We accomplished

  5. 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. PMID:25158287

  6. 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

  7. Differences among Tennis Players Aged 12, 14 And 16 Years in Certain Morphological Characteristics: A Croatian Prospective.

    PubMed

    Novak, Dario; Milanović, Dragan; Barbaros-Tudor, Petar

    2015-09-01

    A sample of young tennis players aged 12, 14 and 16 in Croatia. Sixty (60) tennis players ranked on the scale of the Croatian Tennis Association were analyzed through differences in morphological characteristics, as identified by a standard laboratory diagnostic procedure in Sports-diagnostic Centre of the Faculty of Kinesiology at the University of Zagreb. Significant differences were obtained in most of the monitored measures for the assessment of the morphological characteristics but the most significant differences were reflected in the variables for assessment of longitudinal dimensionality of the skeleton and body mass and voluminosity of the body. The statistical significance was defined at p<0.05. These differences may lead to decelerating the development of important fitness abilities (i.e., coordination), but also highlights the importance for changing the official propositions for the category of players between the ages due to the significant differences in certain morphological characteristics among all age categories. This study indicates an importance of understand grow characteristics of young players in order to effectively define tennis players playing style. PMID:26898054

  8. 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

  9. The Effects of "Grunting" on Serve and Forehand Velocity in Collegiate Tennis Players.

    PubMed

    O'Connell, Dennis G; Hinman, Martha; Hearne, Kevin F; Michael, Zach S; Nixon, Sam L

    2014-06-30

    To examine the effects of grunting on velocity and force production during dynamic and static tennis strokes in collegiate tennis players. Thirty-two (16 M and 16 F) Division II and III collegiate tennis athletes with a mean age of 20.2 ± 1.89 years participated as subjects. Demographic and survey data were obtained prior to subjects completing a 10-15 minute warm-up of serves and ground strokes while grunting and not grunting. Subjects performed randomized sets (3 grunting and 3 non-grunting trials) of serves and forehand strokes both dynamically and isometrically. Stroke velocities and isometric forces were measured with a calibrated radar gun and calibrated dynamometer, respectively. EMG data from subjects' dominant pectoralis major and contralateral external oblique muscles were recorded and averaged for data analysis. A repeated measures multivariate analysis of variance (RM-MANOVA) compared dynamic stroke velocity, isometric muscle force, and peak EMG activity during each breathing condition at the 0.05 alpha level. The RMANOVA indicated that dynamic velocity and isometric force of both serves and forehand strokes were significantly greater when subjects grunted (F=46.572, p<0.001, power=1.00). Peak muscle activity in the external oblique and pectoralis major muscles was also greater when grunting during both types of strokes (F=3.867, p=0.05, power=0.950). Grunt history, gender, perceived advantages and disadvantages of grunting, years of experience, highest level of competition, and order of testing did not significantly alter any of these results. The velocity, force, and peak muscle activity during tennis serves and forehand strokes are significantly enhanced when athletes are allowed to grunt. PMID:24983852

  10. The effects of "grunting" on serve and forehand velocities in collegiate tennis players.

    PubMed

    OʼConnell, Dennis G; Hinman, Martha R; Hearne, Kevin F; Michael, Zach S; Nixon, Sam L

    2014-12-01

    The aim of this study was to examine the effects of grunting on velocity and force production during dynamic and static tennis strokes in collegiate tennis players. Thirty-two (16 male and 16 female) division II and III collegiate tennis athletes with a mean age of 20.2 ± 1.89 years participated as subjects. Demographic and survey data were obtained before subjects completed a 10- to 15-minute warm-up of serves and ground strokes while grunting and not grunting. The subjects performed randomized sets (3 grunting and 3 nongrunting trials) of serves and forehand strokes both dynamically and isometrically. Stroke velocities and isometric forces were measured with a calibrated radar gun and calibrated dynamometer, respectively. Electromyographic (EMG) data from subjects' dominant pectoralis major and contralateral external oblique muscles were recorded and averaged for data analysis. A repeated measures multivariate analysis of variance (RM-MANOVA) compared dynamic stroke velocity, isometric muscle force, and peak EMG activity during each breathing condition at the 0.05 alpha level. The RM-MANOVA indicated that dynamic velocity and isometric force of both serves and forehand strokes were significantly greater when the subjects grunted (F = 46.572, p < 0.001, power = 1.00). Peak muscle activity in the external oblique and pectoralis major muscles was also greater when grunting during both types of strokes (F = 3.867, p = 0.05, power = 0.950). Grunt history, gender, perceived advantages, and disadvantages of grunting, years of experience, highest level of competition, and order of testing did not significantly alter any of these results. The velocity, force, and peak muscle activity during tennis serves and forehand strokes are significantly enhanced when athletes are allowed to grunt. PMID:25412161

  11. Upper limb joint muscle/tendon injury and anthropometric adaptations in French competitive tennis players.

    PubMed

    Rogowski, Isabelle; Creveaux, Thomas; Genevois, Cyril; Klouche, Shahnaz; Rahme, Michel; Hardy, Philippe

    2016-01-01

    The purpose of this study was to examine the relationship between the upper limb anthropometric dimensions and a history of dominant upper limb injury in tennis players. Dominant and non-dominant wrist, forearm, elbow and arm circumferences, along with a history of dominant upper limb injuries, were assessed in 147 male and female players, assigned to four groups based on location of injury: wrist (n = 9), elbow (n = 25), shoulder (n = 14) and healthy players (n = 99). From anthropometric dimensions, bilateral differences in circumferences and in proportions were calculated. The wrist group presented a significant bilateral difference in arm circumference, and asymmetrical bilateral proportions between wrist and forearm, as well as between elbow and arm, compared to the healthy group (6.6 ± 3.1% vs. 4.9 ± 4.0%, P < 0.01; -3.6 ± 3.0% vs. -0.9 ± 2.9%, P < 0.05; and -2.2 ± 2.2% vs. 0.1 ± 3.4%, P < 0.05, respectively). The elbow group displayed asymmetrical bilateral proportions between forearm and arm compared to the healthy group (-0.4 ± 4.3% vs. 1.5 ± 4.0%, P < 0.01). The shoulder group showed significant bilateral difference in elbow circumference, and asymmetrical bilateral proportions between forearm and elbow when compared to the healthy group (5.8 ± 4.7% vs. 3.1 ± 4.8%, P < 0.05 and -1.7 ± 4.5% vs. 1.4 ± 4.3%, P < 0.01, respectively). These findings suggest that players with a history of injury at the upper limb joint present altered dominant upper limb proportions in comparison with the non-dominant side, and such asymmetrical proportions would appear to be specific to the location of injury. Further studies are needed to confirm the link between location of tennis injury and asymmetry in upper limb proportions using high-tech measurements in symptomatic tennis players. PMID:25881663

  12. 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

  13. 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. PMID:16081176

  14. Concentric Internal and Eccentric External Fatigue Resistanc of the Shoulder Rotator Muscles in Female Tennis Players

    PubMed Central

    Niederbracht, Yvonne

    2008-01-01

    Background Shoulder muscle imbalance is a potential shoulder injury risk factor in athletes performing overhead sports. While normative functional peak strength of concentric external to concentric internal shoulder muscle fatigue data is available, comparisons of functional eccentric external to concentric internal shoulder rotator muscle fatigue resistance, which impacts muscle imbalance throughout the duration of play, have not been studied in this population. Objectives To assess fatigue resistance of the internal and external shoulder rotator muscles in female tennis players. Methods Fifteen female collegiate tennis players were tested bilaterally for shoulder concentric internal and eccentric external peak torque production throughout 20 maximal repetitions on a Kin-Com isokinetic dynamometer. Twelve t - tests were conducted to evaluate for differences in peak torque, relative fatigue ratios, and functional peak torque ratios between extremities and mode of activation during the first, as well as, last five repetitions that were conducted. Results Non-dominant concentric internal and eccentric external peak torque production significantly decreased throughout the twenty repetitions. Neither dominant concentric internal peak torque decrements and eccentric peak torque decrements were not significantly different across the twenty contractions. These changes in peak torque upon subsequent repetitions resulted in relative fatigue ratios of dominant eccentric external rotation that were significantly greater than non-dominant eccentric external rotation. Relative fatigue ratios of dominant concentric internal rotation did not differ from non-dominant concentric internal rotation. Conclusions The data suggest that eccentrically activated external shoulder rotator muscles could possibly adapt to overhead activities by becoming more fatigue resistant. PMID:21509131

  15. Automated processes in tennis: do left-handed players benefit from the tactical preferences of their opponents?

    PubMed

    Loffing, Florian; Hagemann, Norbert; Strauss, Bernd

    2010-02-01

    Previous research on laterality in sport suggests an over-representation of left-handers in interactive sports such as tennis and cricket. These findings potentially reflect left-handers' advantage over their right-handed competitors in those sports. Although considered crucial for successful performance, the tactical component of their superiority has yet to be analysed. Two studies were conducted to test for a side bias in tennis players' tactical preferences. In the first study, 108 right- and left-handed players of varying skill watched rallies on a computer screen and had to indicate where they would place the ball in the opposing half. The results showed the tactical preference of players to place more balls on a left-handed opponent's mostly stronger forehand side compared with when faced with a right-hander. In the second study, 54 professional tennis matches involving right- and left-handers were analysed with respect to ball placement frequencies on the opponent's backhand side. Significantly fewer balls were hit to the backhand side of a left-handed opponent, thus replicating the findings of Study 1 in on-court situations. Both studies indicate players' preference to place shots to their right irrespective of their opponent's handedness. Findings support the assumption that left-handers might enjoy a strategic advantage in tennis. PMID:20175013

  16. Wii Tennis Play for Low-Income African American Adolescents' Energy Expenditure.

    PubMed

    Staiano, Amanda E; Calvert, Sandra L

    2011-07-01

    Exergames, which are video games that require gross motor activity, are popular activities that produce energy expenditure. Seventy-four low-income African American 12- to 18-year-old adolescents were randomly assigned to a 30-minute condition: 1) solitary Wii tennis exergame play against virtual peers; 2) social Wii tennis exergame play against a real peer; or 3) control group with sedentary computer activity. Adolescents were tested for caloric expenditure after exposure to treatment conditions as well as on a tennis court using Actical accelerometers. Adolescents who played the social exergame against a peer expended significantly more energy than those who played alone. Both exergame groups expended more energy than the control group. Adolescents who played the social exergame also expended comparable calories to actual tennis court play during a simulated lesson. Exergames, then, could promote physical activity, thereby becoming a tool to combat the obesity crisis that is affecting many youth. PMID:24058381

  17. Five-Day Whole-Body Cryostimulation, Blood Inflammatory Markers, and Performance in High-Ranking Professional Tennis Players

    PubMed Central

    Ziemann, Ewa; Olek, Robert Antoni; Kujach, Sylwester; Grzywacz, Tomasz; Antosiewicz, Jędrzej; Garsztka, Tomasz; Laskowski, Radosław

    2012-01-01

    Context Tournament season can provoke overreaching syndrome in professional tennis players, which may lead to deteriorated performance. Thus, appropriate recovery methods are crucial for athletes in order to sustain high-level performance and avoid injuries. We hypothesized that whole-body cryostimulation could be applied to support the recovery process. Objective To assess the effects of 5 days of whole-body cryostimulation combined with moderate-intensity training on immunologic, hormonal, and hematologic responses; resting metabolic rate; and tennis performance in a posttournament season. Design Controlled laboratory study. Setting National Olympic Sport Centre. Patients or Other Participants Twelve high-ranking professional tennis players. Intervention(s) Participants followed a moderate-intensity training program. A subgroup was treated with the 5-day whole-body cryostimulation (−120°C) applied twice a day. The control subgroup participated in the training only. Main Outcome Measure(s) Pretreatment and posttreatment blood samples were collected and analyzed for tumor necrosis factor α, interleukin 6, testosterone, cortisol, and creatine kinase. Resting metabolic rate and performance of a tennis drill were also assessed. Results Proinflammatory cytokine (tumor necrosis factor α) decreased and pleiotropic cytokine (interleukin 6) and cortisol increased in the group exposed to cryostimulation. In the same group, greater stroke effectiveness during the tennis drill and faster recovery were observed. Neither the training program nor cryostimulation affected resting metabolic rate. Conclusions Professional tennis players experienced an intensified inflammatory response after the completed tournament season, which may lead to overreaching. Applying whole-body cryostimulation in conjunction with moderate-intensity training was more effective for the recovery process than the training itself. The 5-day exposure to cryostimulation twice a day ameliorated the

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

    PubMed

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

    2015-12-01

    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 pointsHIT 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 (e

  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. High-resolution ultrasound of rotator cuff and biceps reflection pulley in non-elite junior tennis players: anatomical study

    PubMed Central

    2014-01-01

    Background Tennis is believed to be potentially harmful for the shoulder, therefore the purpose of this study is to evaluate the anatomy of the rotator cuff and the coraco-humeral ligament (CHL) in a-symptomatic non-elite junior tennis players with high-resolution ultrasound (US). Methods From August 2009 to September 2010 n = 90 a-symptomatic non-elite junior tennis players (mean age ± standard deviation: 15 ± 3) and a control group of age- and sex- matched subjects were included. Shoulder assessment with a customized standardized protocol was performed. Body mass index, dominant arm, years of practice, weekly hours of training, racket weight, grip (Eastern, Western and semi-Western), kind of strings were recorded. Results Abnormalities were found at ultrasound in 14/90 (15%) players. Two players had supraspinatus tendinosis, two had subacromial impingement and ten had subacromial bursitis. CHL thickness resulted comparable in the dominant and non-dominant arms (11.3 ± 4.4 mm vs. 13 ± 4.2, p > 0.05). Multivariate analysis demonstrated that no association was present among CHL thickness and the variables evaluated. In the control group, abnormalities were found at ultrasound in 6/60 (10%) subjects (sub-acromial bursitis). No statistically significant differences between players and control group were found (p = 0.71). Conclusion In a-symptomatic non-elite junior tennis players only minor shoulder abnormalities were found. PMID:25034864

  1. Old dogs, new tricks: training the perceptual skills of senior tennis players.

    PubMed

    Caserta, Ryan J; Young, Jessica; Janelle, Christopher M

    2007-08-01

    The purpose of the study was to determine whether multidimensional perceptual-cognitive skills training, including situational awareness, anticipation, and decision making, improves on-court performance in older adults when compared with a physical training program, including stroke and footwork development. Senior tennis players (N = 27) were randomly assigned to one of three groups: perceptual-cognitive skills training, technique-footwork training, or no training. Results indicated that participants receiving perceptual-cognitive skills training had significantly faster response speeds, higher percentage of accurate responses, and higher percentage of performance decision making in posttest match situations. Findings provide clear evidence that perceptual-cognitive skills can be trained in aged individuals. Implications and suggestions for future research are offered. PMID:17968049

  2. Stress fracture of the ulna in a female table tennis tournament player.

    PubMed

    Petschnig, R; Wurnig, C; Rosen, A; Baron, R

    1997-09-01

    A stress fracture of the diaphyseal ulna occurred in a 19-year-old female competitive table tennis player with a history of secondary amenorrhea. Stress fractures are one of more common problems occurring in vigorous sports. Stress fractures of the ulna can result from any repeated forearm flexor muscle activity. In our case stress was caused by increased athletic activity by additional training twice a day six times a week starting eighth weeks before first signs of pain and by rhythmic repeated submaximal work load in a new job additional to training. Physical training is often associated with menstrual irregularity. Hormonal factors were known for six months. Spontaneous onset of pain in women and previous history of amenorrhea should include stress fractures as differential diagnosis. PMID:9407755

  3. Exercise Training-Induced Changes in Inflammatory Mediators and Heat Shock Proteins in Young Tennis Players

    PubMed Central

    Ziemann, Ewa; Zembroñ-Lacny, Agnieszka; Kasperska, Anna; Antosiewicz, Jȩdrzej; Grzywacz, Tomasz; Garsztka, Tomasz; Laskowski, Radoslaw

    2013-01-01

    Heat shock proteins (Hsp) represent proteins’ groups, whose protective function, may be induced by heat, reactive oxygen species, cytokines etc. We evaluated blood levels of Hsp27 and Hsp70, and their relation to skeletal muscle damage and inflammation in young tennis players before and after the conditioning camp. Blood samples were collected directly after tournament season, 3-day rest and 14-day conditioning camp that followed. Hydrogen peroxide (H2O2) demonstrated the highest concentration directly after tournament season, which significantly decreased at camp’s end. The pro-inflammatory cytokines IL-1β and TNFα decreased, whereas anti-inflammatory cytokines IL-6 and IL-10 increased after 3d rest and 14d camp. Hsp27 increased after 3d rest and remained so after 14d camp, while Hsp70 decreased from baseline to camp’s completion. Hsp27 and Hsp70 correlated significantly with H2O2, IL-1β and TNFα. Muscle damage, observed as creatine kinase (CK) activity changes, increased after 14d camp similarly to Hsp27 and anti-inflammatory cytokines IL-6 and IL-10. Obtained data allows to conclude that decrease of Hsp27 and increase in pro-inflammatory cytokines could be a good indicator of overreaching. Reverse tendencies in these proteins may verify accuracy of conditioning camp. Finally, this training program caused an increase in the anti-inflammatory cytokines concentrations, improving individual status of recovery. Key Points The study demonstrating low grade inflammation-induced by the tournament season in young tennis player. Three days of active rest stimulated the anti-inflammatory response via rise of Hsp27 and anti-inflammatory cytokine IL-10. Observed decrease of blood Hsp70 may support mental recovery. Thirteen-day appropriate training program led to maintaining an immunological response balance. PMID:24149807

  4. 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. PMID:25616246

  5. 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. PMID:23724603

  6. Mechanical, Hormonal and Psychological Effects of a Non-Failure Short-Term Strength Training Program in Young Tennis Players

    PubMed Central

    Sarabia, Jose Manuel; Fernandez-Fernandez, Jaime; Juan-Recio, Casto; Hernández-Davó, Hector; Urbán, Tomás; Moya, Manuel

    2015-01-01

    This study examined the effects of a 6-week non-failure strength training program in youth tennis players. Twenty tennis players (age: 15.0 ± 1 years, body height: 170.9 ± 5.1 cm, body mass: 63.3 ± 9.1 kg) were divided into experimental and control groups. Pre and post-tests included half squats, bench press, squat jumps, countermovement-jumps and side-ball throws. Salivary cortisol samples were collected, and the Profile of Mood States questionnaire was used weekly during an anatomical adaptation period, a main training period and after a tapering week. The results showed that, after the main training period, the experimental group significantly improved (p<0.05) in mean and peak power output and in the total number of repetitions during the half-squat endurance test; mean force, power and velocity in the half-squat power output test; Profile of Mood States (in total mood disturbance between the last week of the mean training period and the tapering week); and in squat-jump and countermovement-jump height. Moreover, significant differences were found between the groups at the post-tests in the total number of repetitions, mean and peak power during the half-squat endurance test, mean velocity in the half-squat power output test, salivary cortisol concentration (baselines, first and third week of the mean training period) and in the Profile of Mood States (in fatigue subscale: first and third week of the mean training period). In conclusion, a non-failure strength training protocol improved lower-limb performance levels and produced a moderate psychophysiological impact in youth elite tennis players, suggesting that it is a suitable program to improve strength. Such training protocols do not increase the total training load of tennis players and may be recommended to improve strength. PMID:25964812

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

    PubMed

    Ayala, Francisco; Moreno-Pérez, Víctor; Vera-Garcia, Francisco J; Moya, Manuel; Sanz-Rivas, David; Fernandez-Fernandez, Jaime

    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

  9. Shoulder injuries in adolescent rugby players

    PubMed Central

    Hodhody, Ghazal; Mackenzie, Tanya A

    2016-01-01

    Background Rugby is a high-intensity contact sport, frequently causing shoulder injuries. Between the ages of 12 years to 18 years, academy and county level players are being selected for professional contracts, making this is a critical stage of their career. The present study aimed to describe the patterns of injury in adolescent rugby players with shoulder injuries. Methods Academy and county level rugby players in the target age group, over a 7-year period, were included in the present study. Data collected included the mechanism of injury, position and level of play, radiology and surgical findings, and recurrence rate at a minimum of 2 years post-surgery. Results One hundred and sixty-nine cases adhered to the inclusion criteria, with most cases involving two or more pathologies in the shoulder (54%). Forwards sustained more shoulder injuries than backs, incurring more labral injuries. By contrast, backs had a higher incidence of bony pathology. The mechanism of injury frequently correlated with player positions. There was a 21% injury recurrence rate, with forwards (7%) and higher level academy players (11%) most likely to suffer a recurrence. Conclusions Shoulder injury patterns in this important group of adolescent contact athletes are complex, with recurrence rates being higher than those in older rugby players. PMID:27583014

  10. Racquet string tension directly affects force experienced at the elbow: implications for the development of lateral epicondylitis in tennis players

    PubMed Central

    Mohandhas, Badri R; Makaram, Navnit; Drew, Tim S; Wang, Weijie; Arnold, Graham P

    2016-01-01

    Background Lateral epicondylitis (LE) occurs in almost half of all tennis players. Racket-string tension is considered to be an important factor influencing the development of LE. No literature yet exists that substantiates how string-tension affects force transmission to the elbow, as implicated in LE development. We establish a quantitative relationship between string-tension and elbow loading, analyzing tennis strokes using rackets with varying string-tensions. Methods Twenty recreational tennis players simulated backhand tennis strokes using three rackets strung at tensions of 200 N, 222 N and 245 N. Accelerometers recorded accelerations at the elbow, wrist and racket handle. Average peak acceleration was determined to correlate string-tension with elbow loading. Results Statistically significant differences (p < 0.05) were observed when average peak acceleration at the elbow at 200 N string-tension (acceleration of 5.58 m/s2) was compared with that at 222 N tension (acceleration of 6.83 m/s2) and 245 N tension (acceleration of 7.45 m/s2). The 200 N racket induced the least acceleration at the elbow. Conclusions Although parameters determining force transmission to the elbow during a tennis stroke are complex, the present study was able to control these parameters, isolating the effect of string-tension. Lower string-tensions transmit less force to the elbow in backhand strokes. Reducing string-tension should be considered favourably with respect to reducing the risk of developing LE. PMID:27583017

  11. 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

  12. 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

  13. 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

  14. 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

  15. 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…

  16. 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

  17. 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.

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

    PubMed

    Lo, Kuo-Cheng; Hsieh, Yung-Chun

    2016-06-01

    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 pointsAdvanced 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

  19. 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

  20. 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

  1. Establishing percentiles for junior tennis players based on physical fitness testing results.

    PubMed

    Roetert, E P; Piorkowski, P A; Woods, R B; Brown, S W

    1995-01-01

    An important aspect of this study was the establishment of a data base. A broad data base allows for data on certain parameters to be greatly expanded and will also enhance the use and interpretation of statistical methods. A longitudinal study of these variables may also assist in monitoring the players' progress over a period of time, and can provide a useful supplement to subjective coaching appraisals. The means and standard deviation for each test were calculated according to the USTA age and gender groups, that is, 12s, 14s, and 16s for each separate gender. Additionally, the mean and standard deviations for the ages, heights, and weights of each grouping were also calculated. Once the means and standard deviations were calculated, percentile tables were developed for each of the USTA groupings (by age and gender). The percentiles for each USTA test are presented in Appendix 1. A percentile is defined as the point on the distribution below which a given percentage of the scores is found. Percentiles can provide a norm-referenced interpretation of an individual score within a distribution that often consists of scores from a comparable group of individuals. Using the USTA protocol, players and coaches now have a set of normative data by which individual player's fitness scores may be compared with participants of the USTA Area Training Centers (See appendix 1). From the test results, coaches and players can determine which fitness areas need to be improved for athletes on an individual basis. Specific training programs can then be designed based on an athlete's fitness testing results. Proper interpretation of the USTA fitness testing data base results can lead to an easy way to determine the relative position of a given fitness score in the distribution, recognizing weaker areas for the purpose of injury prevention and performance enhancement. Each player can be given a profile detailing their percentile rank relative to other area training center

  2. 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…

  3. Prediction of Impact Shock Vibrations at Tennis Player's Wrist Joint: Comparison between Conventional Weight Racket and Light Weight Racket with Super Large Head Size

    NASA Astrophysics Data System (ADS)

    Kawazoe, Yoshihiko; Takeda, Yukihiro; Nakagawa, Masamichi; Casolo, Federico; Tomosue, Ryoso; Yoshinari, Keiko

    The lightweight racket with handle-light configuration and large head size is recent tendency of high-tech tennis rackets, increasing power or post-impact ball velocity with an increasing racket swing speed. This paper investigated the performance of lightweight tennis racket with super-large head size in terms of feel or comfort. It predicted the effect of the mass and mass distribution of super-large sized rackets on the impact shock vibrations of the racket handle and the player's wrist joint when a player hits a flat forehand drive. The prediction is based on the identification of the racket characteristics, the damping of the racket-arm system, equivalent mass of the player's arm system and the approximate nonlinear impact analysis in tennis. A super-light weight balanced racket (mass: 292 g, the center of gravity LG: 363 mm from the butt end) and a conventional weight and weight balanced racket (349 g, LG: 323 mm) are selected as representatives. They are the super-large sized rackets made of carbon graphite with a head size of 120 square inches and the same geometry. The result showed that the shock vibration of the super-light weight balanced racket with super-large sized head is much larger than that of the conventional weight balanced type racket. It also showed that the sweet area of the former in terms of the shock vibration shifts from the center to the topside on the racket face compared to the latter. This is because the location of the grip on the racket handle is further from the location of the node on the handle of the first mode of super-light racket than that of the conventional weight racket.

  4. The Effects of Forced Exhalation and Inhalation, Grunting, and Valsalva Maneuver on Forehand Force in Collegiate Tennis Players.

    PubMed

    OʼConnell, Dennis G; Brewer, Jacob F; Man, Timothy H; Weldon, John S; Hinman, Martha R

    2016-02-01

    To examine the effects of forced expiration (FE), forced inspiration (FI), grunting (GR), and valsalva maneuver (VM), on air volume, maximum force production, and muscle recruitment during a simulated forehand stroke in collegiate tennis players. Superficial electrodes were placed over the anterior deltoid, pectoralis major, rectus abdominis, lumbar and thoracic erector spinae, and external and internal obliques. Subjects stood in a simulated forehand stroke stance with their dominant hand positioned on a force plate. Subjects performed 3 repetitions of maximal 2- to 3-second isometric forehands with randomly assigned breathing conditions (FE, FI, VM, and GR) and 30-seconds rest between contractions. Air volumes were also collected during each trial. A repeated-measures multivariate analysis of variance compared normalized peak electromyographic activity across the 7 muscle groups. Separate repeated measures ANOVAs compared the effect of breathing conditions on peak force production and air volume. Statistical significance was set at p ≤ 0.05 for all analyses. Overall muscle activity differed significantly by breathing condition (p = 0.031) with greater anterior deltoid activity was seen in FE and GR vs. VM. Internal oblique activity was significantly greater in GR than FI or VM, and thoracic erector spinae activity was significantly greater during FE and VM than FI. Force production did not differ significantly among breathing conditions (p = 0.74); however, GR forces were greater than FI and VM forces (p ≤ 0.05). Forced expiration air volume was significantly greater (p < 0.001) than FI, GR, or VM. These findings suggest that either GR or a more quiescent FE can be used to enhance force production. Forced expiration is a potentially safer alternative to VM and more aurally pleasing than GR. PMID:26270695

  5. 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

  6. Movement characteristics of elite tennis players on hard courts with respect to the direction of ground strokes.

    PubMed

    Martínez-Gallego, Rafael; F Guzmán, José; James, Nic; Pers, Janez; Ramón-Llin, Jesús; Vuckovic, Goran

    2013-01-01

    Previous studies of movement characteristics in tennis have considered the effect of playing surface but have assumed that playing strategies are simply determined by the surface as opposed to being under an individual's control. This study considered the selection of cross court or down the line ground strokes as being indicative of playing strategy and measured the outcome of playing these shots in terms of the opponent's movements. Matches (N = 8) at the 2011 ATP tournament 500 Valencia were recorded and analysed using SAGIT, a computer vision tracking system that allowed both players' movements to be tracked automatically, albeit with operator supervision. The data was split into (N = 188) games for analysis purposes and these lasted a median 174.24 seconds with active time (ball in play) a median proportion of 34.89% (IQR = 10.64%) of total time. During the active time losers of games tended to cover less distance (median = 80.17 m), move quicker (median = 1.38 m·s(-1)), spend more time in the defensive zones (median = 14.24 s) and less in the offensive zones (median = 44.74 s). These results suggested that game winners tended to dominate game losers, forcing them to exhibit behaviors typically associated with a defensive strategy. Defensive and offensive strategy are not well defined currently and future investigations should consider movements in relation to individual shots, in particular their velocities, at the rally level and by different individuals to better understand successful performance. Key PointsDuring the active time losers of games covered less distance, moved quicker, spend more time in the defensive zones and less in the offensive zones.These results suggested that game winners tended to dominate game losers, forcing them to exhibit behaviors typically associated with a defensive strategy.There are no differences between the proportion of cross court shots and down the line shots played by game winners and game losers.Future research should

  7. 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

  8. 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. PMID:8739719

  9. Physique and Body Composition in Soccer Players across Adolescence

    PubMed Central

    Nikolaidis, Pantelis Theodoros; Vassilios Karydis, Nikos

    2011-01-01

    Purpose Although the contribution of physique and body composition in soccer performance was recognized, these parameters of physical fitness were not well-studied in adolescent players. Aim of this study was to investigate physique and body composition across adolescence. Methods Male adolescents (N=297 aged 12.01–20.98 y), classified into nine one-year age-groups, child (control group, N=16 aged 7.34–11.97 y) and adult players (control group, N=29 aged 21.01–31.59 y), all members of competitive soccer clubs, performed a series of anthropometric measures (body mass, height, skinfolds, circumferences and girths), from which body mass index (BMI), percentage of body fat (BF%), fat mass (FM), fat free mass (FFM) and somatotype (Heath-Carter method) were calculated. Results Age had a positive association with FM (r=0.2, P<0.001) and FFM (r=0.68, P<0.001), and a negative association with BF (r=−0.12, P=0.047). Somatotype components changed across adolescence as well; age was linked to endomorphy (r=−0.17, P=0.005), mesomorphy (r=0.14, P=0.019) and ectomorphy (r=−0.17, P=0.004). Compared with age-matched general population, participants exhibited equal body mass, higher stature, lower body mass index and lower BF. Conclusion During adolescence, soccer players presented significant differences in terms of body composition and physique. Thus, these findings could be employed by coaches and fitness trainers engaged in soccer training in the context of physical fitness assessment and talent identification. PMID:22375222

  10. Hearing Threshold of Korean Adolescents Associated with the Use of Personal Music Players

    PubMed Central

    Kim, Myung Gu; Hong, Seok Min; Shim, Hyun Joon; Kim, Young Doe; Cha, Chang Il

    2009-01-01

    Purpose Hearing loss can lead to a number of disabilities and can reduce quality of life. Noise-induced hearing losses have become more common among adolescents due to increased exposure to personal music players. We, therefore, investigated the use of personal music player among Korean adolescents and the relationship between hearing threshold and usage pattern of portable music players. Materials and Methods A total of 490 adolescents were interviewed personally regarding their use of portable music players, including the time and type of player and the type of headphone used. Pure tone audiometry was performed in each subject. Results Of the 490 subjects, 462 (94.3%) used personal music players and most of them have used the personal music player for 1-3 hours per day during 1-3 years. The most common type of portable music player was the MP3 player, and the most common type of headphone was the earphone (insert type). Significant elevations of hearing threshold were observed in males, in adolescents who had used portable music players for over 5 years, for those over 15 years in cumulative period and in those who had used earphones. Conclusion Portable music players can have a deleterious effect on hearing threshold in adolescents. To preserve hearing, adolescents should avoid using portable music players for long periods of time and should avoid using earphones. PMID:20046416

  11. Comparing sports vision among three groups of soft tennis adolescent athletes: Normal vision, refractive errors with and without correction

    PubMed Central

    Chang, Shih-Tsun; Liu, Yen-Hsiu; Lee, Jiahn-Shing; See, Lai-Chu

    2015-01-01

    Background: The effect of correcting static vision on sports vision is still not clear. Aim: To examine whether sports vision (depth perception [DP], dynamic visual acuity [DVA], eye movement [EM], peripheral vision [PV], and momentary vision [MV],) were different among soft tennis adolescent athletes with normal vision (Group A), with refractive error and corrected with (Group B) and without eyeglasses (Group C). Setting and Design: A cross-section study was conducted. Soft tennis athletes aged 10–13 who played softball tennis for 2–5 years, and who were without any ocular diseases and without visual training for the past 3 months were recruited. Materials and Methods: DPs were measured in an absolute deviation (mm) between a moving rod and fixing rod (approaching at 25 mm/s, receding at 25 mm/s, approaching at 50 mm/s, receding at 50 mm/s) using electric DP tester. A smaller deviation represented better DP. DVA, EM, PV, and MV were measured on a scale from 1 (worse) to 10 (best) using ATHLEVISION software. Statistical Analysis: Chi-square test and Kruskal–Wallis test was used to compare the data among the three study groups. Results: A total of 73 athletes (37 in Group A, 8 in Group B, 28 in Group C) were enrolled in this study. All four items of DP showed significant difference among the three study groups (P = 0.0051, 0.0004, 0.0095, 0.0021). PV displayed significant difference among the three study groups (P = 0.0044). There was no significant difference in DVA, EM, and MV among the three study groups. Conclusions: Significant better DP and PV were seen among soft tennis adolescent athletes with normal vision than those with refractive error regardless whether they had eyeglasses corrected. On the other hand, DVA, EM, and MV were similar among the three study groups. PMID:26632127

  12. 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) PMID:8112273

  13. [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. PMID:23446953

  14. 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. PMID:22562745

  15. 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. PMID:8876740

  16. 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. PMID:24802802

  17. 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…

  18. Health benefits of tennis

    PubMed Central

    Pluim, Babette M; Staal, J Bart; Marks, Bonita L; Miller, Stuart; Miley, Dave

    2007-01-01

    The aim of the study was to explore the role of tennis in the promotion of health and prevention of disease. The focus was on risk factors and diseases related to a sedentary lifestyle, including low fitness levels, obesity, hyperlipidaemia, hypertension, diabetes mellitus, cardiovascular disease, and osteoporosis. A literature search was undertaken to retrieve relevant articles. Structured computer searches of PubMed, Embase, and CINAHL were undertaken, along with hand searching of key journals and reference lists to locate relevant studies published up to March 2007. These had to be cohort studies (of either cross sectional or longitudinal design), case–control studies, or experimental studies. Twenty four studies were identified that dealt with physical fitness of tennis players, including 17 on intensity of play and 16 on maximum oxygen uptake; 17 investigated the relation between tennis and (risk factors for) cardiovascular disease; and 22 examined the effect of tennis on bone health. People who choose to play tennis appear to have significant health benefits, including improved aerobic fitness, a lower body fat percentage, a more favourable lipid profile, reduced risk for developing cardiovascular disease, and improved bone health. PMID:17504788

  19. Can laboratory-based tennis profiles predict field tests of tennis performance?

    PubMed

    Perry, Arlette C; Wang, Xuewen; Feldman, Brandon B; Ruth, Tiffany; Signorile, Joseph

    2004-02-01

    The present study examined the impact of physical characteristics of adolescent competitive tennis players (13-18 years) on field tests of tennis performance. Results (n = 33) showed that boys were taller (p = 0.001), possessed greater wingspan (p = 0.030), had greater maximum oxygen consumption (p = 0.001), and performed better on isokinetic strength measurements. Multiple regression analyses controlling for age and sex showed that height (p = 0.025), maximum minute ventilation (p = 0.005), and isokinetic strength measurements significantly and positively affected ball velocity. Knee extension average power was the only variable to positively and significantly affect ball placement (p = 0.040); however, several isokinetic strength measurements negatively affected ball placement. For the nondominant side, down-the-line strokes showed reduced accuracy (p = 0.001) and ball velocity (p = 0.001) compared with cross-court strokes. Given our results, resistance training may be beneficial for the performance of on-court tennis play. PMID:14971970

  20. 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

  1. The Snapping Elbow Syndrome as a Reason for Chronic Elbow Neuralgia in a Tennis Player – MR, US and Sonoelastography Evaluation

    PubMed Central

    Łasecki, Mateusz; Olchowy, Cyprian; Pawluś, Aleksander; Zaleska-Dorobisz, Urszula

    2014-01-01

    Summary Background Ulnar neuropathy is the second most common peripheral nerve neuropathy after median neuropathy, with an incidence of 25 cases per 100 000 men and 19 cases per 100 000 women each year. Skipping (snapping) elbow syndrome is an uncommon cause of pain in the posterior-medial elbow area, sometimes complicated by injury of the ulnar nerve. One of the reason is the dislocation of the abnormal insertion of the medial triceps head over the medial epicondyle during flexion and extension movements. Others are: lack of the Osboune fascia leading to ulnar nerve instability and focal soft tissue tumors (fibromas, lipomas, etc). Recurrent subluxation of the nerve at the elbow results in a tractional and frictional neuritis with classical symptoms of peripheral neuralgia. As far as we know snapping triceps syndrome had never been evaluated in sonoelastography. Case Report A 28yo semi-professional left handed tennis player was complaining about pain in posterior-medial elbow area. Initial US examination suggest golfers elbow syndrome which occurs quite commonly and has a prevalence of 0.3–0.6% in males and 0–3–1.1% in women and may be associated (approx. 50% of cases) with ulnar neuropathy. However subsequently made MRI revealed unusual distal triceps anatomy, moderate ulnar nerve swelling and lack of medial epicondylitis symptoms. Followed (second) US examination and sonoelastography have detected slipping of the both ulnar nerve and the additional band of the medial triceps head. Discussion Snapping elbow syndrome is a poorly known medical condition, sometimes misdiagnosed as the medial epicondylitis. It describes a broad range of pathologies and anatomical abnormalities. One of the most often reasons is the slipping of the ulnar nerve as the result of the Osborne fascia/anconeus epitrochlearis muscle absence. Simultaneously presence of two or more “snapping reasons” is rare but should be always taken under consideration. Conclusions There are no

  2. 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. PMID:20647941

  3. 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…

  4. 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,…

  5. 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

    Darrall-Jones, JD, Jones, B, Roe, G, and Till, K. Reliability and usefulness of linear sprint testing in adolescent rugby union and league players. J Strength Cond Res 30(5): 1359-1364, 2016-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. PMID:26466131

  6. The Effects of Ankle Sprain on Balance Tests in Adolescent Volleyball Players with Previous History of Ankle Sprain

    PubMed Central

    Sarıal, Ceyda; Tayfur, Abdulhamıt; Kap, Beyza; Donder, Dılara; Ertuzun, Ozum Melıs; Tunay, Volga Bayrakcı

    2014-01-01

    Objectives: To investigate the impact of having previous history of inversion ankle sprain on balance tests in adolescent volleyball players. Methods: Fourty-five adolescent volleyball players with mean age of 15.26±1.03 participated in our study. Twenty-nine were uninjured (control group) and sixteen had previously experienced inversion injuries on right ankle. 9 players had the injury more than than one year ago and 7 players had it before six to twelf months. Balancing abilities were evaluated by Star Excursion Balance Test (SEBT) and Single Limb Hurdle Test (SLHT). The fact that players with history of injury had the ankle sprain at right foot led us to perform the measurements in the control group also for the right foot. We compared the results of injured and uninjured players on both tests. Results: Uninjured players' reaching distance on right foot was found out to be significantly more than in players with ankle sprain at medial and posteromedial directions of SEBT(p<.05), whereas there were no differences detected for the other directions (p>.05). For comparing athletes' performances with SLHT, finishing time was found significantly better in uninjured players (p<.05). Conclusion: Adolescent volleyball players with history of injury show lower performance on balance tests compared to uninjured players. This demonstrates that they should be given a training including balance and stabilization programs.

  7. 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

  8. Fractured diaphyseal tibiofibular synostosis in an adolescent soccer player.

    PubMed

    Santa Maria, Daniel L; Shaw, Thomas; Allen, Marque; Marin, James

    2015-01-01

    Diaphyseal tibiofibular synostosis is a rare cause of symptomatic shin pain with exertion. In this case, a 14-year-old male soccer player presented with atraumatic right shin pain made worse with running. Computed tomography revealed heterotopic ossification, or synostosis, of the tibial-fibular syndesmosis. The patient's symptoms improved with rest, without the need for operative intervention. PMID:25171880

  9. 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. PMID:23603999

  10. COMPARISON OF DYNAMIC BALANCE IN ADOLESCENT MALE SOCCER PLAYERS FROM RWANDA AND THE UNITED STATES

    PubMed Central

    Queen, Robin M.; Beckman, Brian; Kiesel, Kyle B.; Plisky, Phillip J.

    2013-01-01

    Purpose/Background: Dynamic balance is an important component of motor skill development. Poor dynamic balance has previously been associated with sport related injury. However, the vast majority of dynamic balance studies as they relate to sport injury have occurred in developed North American or European countries. Thus, the purpose of this study was to compare dynamic balance in adolescent male soccer players from Rwanda to a matched group from the United States. Methods: Twenty‐six adolescent male soccer players from Rwanda and 26 age‐ and gender‐matched control subjects from the United States were screened using the Lower Quarter Y Balance Test during their pre‐participation physical. Reach asymmetry (cm) between limbs was examined for all reach directions. In addition, reach distance in each direction (normalized to limb length, %LL) and the composite reach score (also normalized to %LL) were examined. Dependent samples t‐tests were performed with significant differences identified at p<0.05. Results: Twenty‐six male soccer players from Rwanda (R) were matched to twenty‐six male soccer players from the United States (US). The Rwandan soccer players performed better in the anterior (R: 83.9 ± 3.2 %LL; US: 76.5 ± 6.6 %LL, p<0.01), posterolateral (R: 114.4 ± 8.3 %LL ; US: 106.5 ± 8.2 %LL, p<0.01) and composite (R: 105.6 ± 1.3 %LL; US: 97.8 ± 6.2 %LL, p<0.01) reach scores. No significant differences between groups were observed for reach asymmetry. Conclusions: Adolescent soccer players from Rwanda exhibit superior performance on a standardized dynamic balance test as comparison to similar athletes from the United States. The examination of movement abilities of athletes from countries of various origins may allow for a greater understanding of the range of true normative values for dynamic balance. Levels of Evidence: 3b PMID:24377061

  11. 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

  12. Improved Tennis Racquets Have Tapered Strings

    NASA Technical Reports Server (NTRS)

    Noever, David A.

    1995-01-01

    Design concept for better performing tennis racquet. Essence of concept to taper strings in such way as to shift center of percussion (also called "sweet spot") toward the toe (outer end of racquet, farthest from player's hand). In addition to increasing power on serves, also improves player's control and feel of racquet in player's hand. Racquet less likely to twist in player's hand on off-center shots. Important element of better feel is better absorption of vibrations; especially for players having chronic arm problems. String material nylon, animal gut, or other naturally or artifically spun threads. String can be attached to conventional racquet frame.

  13. 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.

  14. 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. PMID:23539077

  15. Bilateral midshaft femoral fractures in an adolescent baseball player.

    PubMed

    Ju, D G; Mogayzel, P J; Sponseller, P D; Familiari, F; McFarland, E G

    2016-07-01

    Bone disease, specifically low bone mineral density, is a common and undertreated complication that begins during childhood in patients with cystic fibrosis (CF). This case describes a male baseball player, aged 14years, with undiagnosed CF who sustained a left midshaft femoral fracture while running toward base; 8months later, he sustained a right midshaft femoral fracture under similar conditions. After the second fracture, further evaluation revealed low bone mineral density and CF. There is no previously published report of pathologic fractures occurring in the femoral shaft in an athlete with undiagnosed CF. Patients with CF have a higher fracture rate. Low-energy fractures of major bones in athletically active individuals should be viewed with suspicion for an underlying process. PMID:26927602

  16. Juvenile tillaux fracture in an adolescent basketball player.

    PubMed

    Cassas, Kyle J; Jamison, John P

    2005-02-01

    Forced external rotation of the foot may cause a syndesmosis or high ankle sprain in an adult, but in a teenage patient, a juvenile Tillaux fracture may occur if the tibial physis has not yet closed. Diagnosis is made with plain radiographs, but CT may be necessary to determine the true articular displacement. Closed reduction with casting for 6 weeks is usually sufficient for most nondisplaced or minimally displaced fractures. Patients with more than 2 mm of displacement, as in this case of a 16-year-old basketball player, should be referred to an orthopedic surgeon. Complications include residual angular deformity and premature osteoarthritis. Most patients are able to return to full activity at 3 months postinjury. PMID:20086348

  17. 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

    Torres-Unda, J, Zarrazquin, I, Gravina, L, Zubero, J, Seco, J, Gil, SM, Gil, J, and Irazusta, J. Basketball performance is related to maturity and relative age in elite adolescent players. J Strength Cond Res 30(5): 1325-1332, 2016-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

  18. 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…

  19. Game Intensity Analysis of Elite Adolescent Ice Hockey Players

    PubMed Central

    Stanula, Arkadiusz; Roczniok, Robert

    2014-01-01

    The purpose of this study was to determine ice-hockey players’ playing intensity based on their heart rates (HRs) recorded during a game and on the outcomes of an incremental maximum oxygen uptake test. Twenty ice-hockey players, members of the Polish junior national team (U18), performed an incremental test to assess their maximal oxygen uptake (V̇O2max) in the two week’s period preceding 5 games they played at the World Championships. Players’ HRs at the first and second ventilatory thresholds obtained during the test were utilized to determine intensity zones (low, moderate, and high) that were subsequently used to classify HR values recorded during each of the games. For individual intensity zones, the following HRs expressed as mean values and as percentages of the maximal heart rate (HRmax) were obtained: forwards 148–158 b·min−1 (79.5–84.8% HRmax), 159–178 b·min−1 (85.4–95.6% HRmax), 179–186 b·min−1 (96.1–100.0% HRmax); defensemen 149–153 b·min−1 (80.0–82.1% HRmax), 154–175 b·min−1 (82.6–94.0% HRmax), 176–186 b·min−1 (94.5–100.0% HRmax). The amount of time the forwards and defensemen spent in the three intensity zones expressed as percentages of the total time of the game were: 54.91 vs. 55.62% (low), 26.40 vs. 22.38% (moderate) and 18.68 vs. 22.00% (high). The forwards spent more time in the low intensity zone than the defensemen, however, the difference was not statistically significant. The results of the study indicate that using aerobic and anaerobic metabolism variables to determine intensity zones can significantly improve the reliability of evaluation of the physiological demands of the game, and can be a useful tool for coaches in managing the training process. PMID:25713682

  20. Food habits and nutritional status assessment of adolescent soccer players. A necessary and accurate approach.

    PubMed

    Iglesias-Gutiérrez, Eduardo; García-Rovés, Pablo M; Rodríguez, Carmen; Braga, Socorro; García-Zapico, Pedro; Patterson, Angeles M

    2005-02-01

    The aim of this study was to assess the food habits and nutritional status of high level adolescent soccer players (N = 33; ages 14-16 yrs) living in their home environment. Body composition (height, mass, skinfolds), biochemical and hematological parameters, performance in soccer-specific tests (sprinting, jumping, intermittent endurance), and dietary intake (weighed food intake method) and related behaviors (nutrient supplement use, daily activity profile) were assessed. Daily energy expenditure and energy intake were 12.5 MJ and 12.6 MJ, respectively. Protein (16% of energy intake; 1.9 g/kg of body mass), lipid (38%), and cholesterol (385 mg) intake were above recommendations, while carbohydrates (45%) were below. The food intake of these adolescents was based on cereals and derivates; meat, fish, and eggs; milk and dairy products; biscuits and confectionery; and oil, butter and margarine, which provided 78% of total energy intake, 85% of proteins, 64% of carbohydrates, 90% of lipids, and 47% of fiber. Although diet provided sufficient iron, 48% of individuals showed iron deficiency without anemia. Based on these results, a well designed nutrition intervention would be advisable for optimizing performance, and especially for promoting healthy eating habits in adolescent soccer players. PMID:15855680

  1. Prevention of acute knee injuries in adolescent female football players: cluster randomised controlled trial

    PubMed Central

    Atroshi, Isam; Magnusson, Henrik; Wagner, Philippe; Hägglund, Martin

    2012-01-01

    Objective To evaluate the effectiveness of neuromuscular training in reducing the rate of acute knee injury in adolescent female football players. Design Stratified cluster randomised controlled trial with clubs as the unit of randomisation. Setting 230 Swedish football clubs (121 in the intervention group, 109 in the control group) were followed for one season (2009, seven months). Participants 4564 players aged 12-17 years (2479 in the intervention group, 2085 in the control group) completed the study. Intervention 15 minute neuromuscular warm-up programme (targeting core stability, balance, and proper knee alignment) to be carried out twice a week throughout the season. Main outcome measures The primary outcome was rate of anterior cruciate ligament injury; secondary outcomes were rates of severe knee injury (>4 weeks’ absence) and any acute knee injury. Results Seven players (0.28%) in the intervention group, and 14 (0.67%) in the control group had an anterior cruciate ligament injury. By Cox regression analysis according to intention to treat, a 64% reduction in the rate of anterior cruciate ligament injury was seen in the intervention group (rate ratio 0.36, 95% confidence interval 0.15 to 0.85). The absolute rate difference was −0.07 (95% confidence interval −0.13 to 0.001) per 1000 playing hours in favour of the intervention group. No significant rate reductions were seen for secondary outcomes. Conclusions A neuromuscular warm-up programme significantly reduced the rate of anterior cruciate ligament injury in adolescent female football players. However, the absolute rate difference did not reach statistical significance, possibly owing to the small number of events. Trial registration Clinical trials NCT00894595. PMID:22556050

  2. Quantitative assessment of the serve speed in tennis.

    PubMed

    Vaverka, Frantisek; Cernosek, Miroslav

    2016-01-01

    A method is presented for assessing the serve speeds of tennis players based on their body height. The research involved a sample of top world players (221 males and 215 females) who participated in the Grand Slam tournaments in 2008 and 2012. The method is based on the linear regression analysis of the association between the player's body height and the serve speed (fastest serve, average first-serve, and second-serve speed). The coefficient of serve speed (CSS) was calculated as the quotient of the measured and the theoretical value of the serve speed on a regression line relative to the player's body height. The CSS of >1, 1 and <1 indicate above-average, average, and below-average serve speeds, respectively, relative to the top world tennis players with the same body height. The CSS adds a new element to the already existing statistics about a tennis match, and provides additional information about the performance of tennis players. The CSS can be utilised e.g. for setting the target serve speed of a given player to achieve based on his/her body height, choosing the most appropriate match strategy against a particular player, and a long-term monitoring of the effectiveness of training focused on the serve speed. PMID:26879039

  3. 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

  4. Does carbohydrate supplementation enhance tennis match play performance?

    PubMed Central

    2013-01-01

    Background Carbohydrate (CHO) ingestion may be an interesting approach to avoid significant decrement to the tennis match performance. The aim of the present investigation was to assess the effects of CHO supplementation on tennis match play performance. Methods Twelve young tennis players (18.0 ± 1.0 years; 176 ± 3.4 cm; 68.0 ± 2.3 kg; body fat: 13.7 ± 2.4%) with national rankings among the top 50 in Brazil agreed to participate in this study, which utilized a randomized, crossover, double blind research design. The experiment was conducted over a 5-day period in which each player completed two simulated tennis matches of a 3-hour duration. The players received either a CHO or a placebo (PLA) drinking solution during simulated tennis matches. Athlete’s performance parameters were determined by filming each match with two video cameras. Each player was individually tracked for the entire duration of the match to measure the following variables: (1) games won; (2) rally duration; (3) strokes per rally; (4) effective playing time (%); (5) aces; (6) double faults; (7) first service in; (8) second service in; (9) first return in and (10) second return in. Results There were no differences between trials in any of the variables analyzed. Conclusions CHO supplementation did not improve tennis match play performance under the present experimental conditions. PMID:24148197

  5. 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 ...

  6. 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 ...

  7. Assessment of tennis elbow using the Marcy Wedge-Pro.

    PubMed Central

    Smith, R W; Mani, R; Cawley, M I; Englisch, W; Eckenberger, P

    1993-01-01

    The Marcy Wedge-Pro (MWP), a device used in training by tennis players, was employed in the assessment of tennis elbow. The MWP was used to measure the ability of patients to perform wrist extension exercises, since pain resulting from this specific activity is a prominent symptom of the condition. The MWP results were compared with clinical measures and found to identify accurately patients who responded to treatment (P < 0.05). This study illustrates the potential of the MWP to assess tennis elbow quantitatively. Images Figure 1 PMID:8130959

  8. Diurnal variation in tennis service.

    PubMed

    Atkinson, G; Speirs, L

    1998-06-01

    With informed consent, 6 competitive tennis players performed alternate 15 "first" (emphasis-speed) serves and 15 "second" (emphasis-accuracy) serves at 09:00, 14:00 and 18:00 hours. Serve velocity was measured by the digitisation of video footage of each serve. The Hewitt Tennis Achievement Test was employed to measure the accuracy of serve. The amount of spin imparted on the ball was not measured. First serves were at all times of day faster than second serves. First serves were faster but least accurate at 18:00 hours, the time of day that body temperature and grip strength were highest. At 09:00 hours, first serves were just as accurate as second serves, even though velocity of first serves was higher. No effects for time of day were found for the speed and accuracy of second serves. These results indicate that time of day does affect the performance of tennis serves in a way that suggest a nonlinear relationship between velocity and accuracy. PMID:9700810

  9. 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

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

    PubMed

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

    2015-07-01

    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 methods

  11. Analysis of Experts’ Quantitative Assessment of Adolescent Basketball Players and the Role of Anthropometric and Physiological Attributes

    PubMed Central

    Štrumbelj, Erik; Erčulj, Frane

    2014-01-01

    In this paper, we investigated two questions: (1) can measurements of anthropometric and physiological attributes substitute for expert assessment of adolescent basketball players, and (2) how much does the quantitative assessment of a player vary among experts? The first question is relevant to the potential simplification of the player selection process. The second question pertains directly to the validity of expert quantitative assessment. Our research was based on data from 148 U14 female and male basketball players. For each player, an array of anthropometric and physiological attributes was recorded, including body height, body mass, BMI, and several motor skill tests. Furthermore, each player’s current ability and potential ability were quantitatively evaluated by two different experts from a group of seven experts. Analysis of the recorded data showed that the anthropometric and physiological attributes explained between 15% and 40% of the variance in experts’ scores. The primary predictive attributes were speed and agility (for predicting current ability) and body height and growth potential (for predicting potential ability). We concluded that these attributes were not sufficiently informative to act as a substitute for expert assessment of the players’ current or potential ability. There is substantial variability in different experts’ scores of the same player’s ability. However, the differences between experts are mostly in scale, and the relationships between experts’ scores are monotonic. That is, different experts rank players on ability very similarly, but their scores are not well calibrated. PMID:25414759

  12. Injuries in racket sports among Slovenian players.

    PubMed

    Kondric, Miran; Matković, Branka R; Furjan-Mandić, Gordana; Hadzić, Vedran; Dervisević, Edvin

    2011-06-01

    On the sample of 83 top Slovenian athletes we have studied the frequency of injuries among table tennis, tennis and badminton players, types of injuries and severity of injuries--the latter based on data of players absences from training and/or competition processes. The most liable parts to injuries are shoulder girdle (17.27%), spine (16.55%) and ankle (15.83%), while foot (10.07%) and wrist (12.23%) are slightly less liable to injuries. The most frequent injuries in racket sports pertain to muscle tissues. According to this data, the majority of injuries occur halfway through a training session or a competition event, mostly during a competition season. The injuries primarily pertain to muscle tissues; these are followed by joint and tendon injuries. There are no differences between male and female players. Compared to other racket sports players, table tennis players suffer from fewer injuries. PMID:21755712

  13. The effect of music during warm-up on consecutive anaerobic performance in elite adolescent volleyball players.

    PubMed

    Eliakim, M; Meckel, Y; Nemet, D; Eliakim, A

    2007-04-01

    Music is believed to improve athletic performance. The aim of the present study was to determine the effect of arousing music during warm-up on anaerobic performance in elite national level adolescent volleyball players. Twenty-four players (12 males and 12 females) performed the Wingate Anaerobic Test following a 10-minute warm-up with and without music (two separate occasions, random order). During warm-up with music, mean heart rate was significantly higher. Following the warm-up with music, peak anaerobic power was significantly higher in all volleyball players (10.7 +/- 0.3 vs. 11.1 +/- 0.3 Watts/kg, p < 0.05, without and with music, respectively). Gender did not influence the effect of music on peak anaerobic power. Music had no significant effect on mean anaerobic output or fatigue index in both genders. Music affects warm-up and may have a transient beneficial effect on anaerobic performance. PMID:17024625

  14. Table tennis dystonia.

    PubMed

    Le Floch, Anne; Vidailhet, Marie; Flamand-Rouvière, Constance; Grabli, David; Mayer, Jean-Michel; Gonce, Michel; Broussolle, Emmanuel; Roze, Emmanuel

    2010-02-15

    Focal task-specific dystonia (FTSD) occurs exclusively during a specific activity that usually involves a highly skilled movement. Classical FTSD dystonias include writer's cramp and musician's dystonia. Few cases of sport-related dystonia have been reported. We describe the first four cases of FTSD related to table tennis (TT), two involving professional international competitors. We also systematically analyzed the literature for reports of sport-related dystonia including detailed clinical descriptions. We collected a total of 13 cases of sport-related dystonia, including our four TT players. Before onset, all the patients had trained for many years, for a large number of hours per week. Practice time had frequently increased significantly in the year preceding onset. As TT is characterized by highly skilled hand/forearm movements acquired through repetitive exercises, it may carry a higher risk of FTSD than other sports. Intensive training may result in maladaptive responses and overwhelm homeostatic mechanisms that regulate cortical plasticity in vulnerable individuals. Our findings support the importance of environmental risk factors in sport-related FTSD, as also suggested in classical FTSD, and have important implications for clinical practice. PMID:20108363

  15. 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

  16. 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

  17. Assessment of Energy Intake and Energy Expenditure of Male Adolescent Academy-Level Soccer Players during a Competitive Week.

    PubMed

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

    2015-10-01

    This study investigated the energy intake and expenditure of professional adolescent academy-level soccer players during a competitive week. Over a seven day period that included four training days, two rest days and a match day, energy intake (self-reported weighed food diary and 24-h recall) and expenditure (tri-axial accelerometry) were recorded in 10 male players from a professional English Premier League club. The mean macronutrient composition of the dietary intake was 318 ± 24 g·day(-1) (5.6 ± 0.4 g·kg(-1) BM) carbohydrate, 86 ± 10 g·day(-1) (1.5 ± 0.2 g·kg(-1) BM) protein and 70 ± 7 g·day(-1) (1.2 ± 0.1 g·kg(-1) BM) fats, representing 55% ± 3%, 16% ± 1%, and 29% ± 2% of mean daily energy intake respectively. A mean daily energy deficit of -1302 ± 1662 kJ (p = 0.035) was observed between energy intake (9395 ± 1344 kJ) and energy expenditure (10679 ± 1026 kJ). Match days (-2278 ± 2307 kJ, p = 0.012) and heavy training days (-2114 ± 2257 kJ, p = 0.016) elicited the greatest deficits between intake and expenditure. In conclusion, the mean daily energy intake of professional adolescent academy-level soccer players was lower than the energy expended during a competitive week. The magnitudes of these deficits were greatest on match and heavy training days. These findings may have both short and long term implications on the performance and physical development of adolescent soccer players. PMID:26445059

  18. Assessment of Energy Intake and Energy Expenditure of Male Adolescent Academy-Level Soccer Players during a Competitive Week

    PubMed Central

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

    2015-01-01

    This study investigated the energy intake and expenditure of professional adolescent academy-level soccer players during a competitive week. Over a seven day period that included four training days, two rest days and a match day, energy intake (self-reported weighed food diary and 24-h recall) and expenditure (tri-axial accelerometry) were recorded in 10 male players from a professional English Premier League club. The mean macronutrient composition of the dietary intake was 318 ± 24 g·day−1 (5.6 ± 0.4 g·kg−1 BM) carbohydrate, 86 ± 10 g·day−1 (1.5 ± 0.2 g·kg−1 BM) protein and 70 ± 7 g·day−1 (1.2 ± 0.1 g·kg−1 BM) fats, representing 55% ± 3%, 16% ± 1%, and 29% ± 2% of mean daily energy intake respectively. A mean daily energy deficit of −1302 ± 1662 kJ (p = 0.035) was observed between energy intake (9395 ± 1344 kJ) and energy expenditure (10679 ± 1026 kJ). Match days (−2278 ± 2307 kJ, p = 0.012) and heavy training days (−2114 ± 2257 kJ, p = 0.016) elicited the greatest deficits between intake and expenditure. In conclusion, the mean daily energy intake of professional adolescent academy-level soccer players was lower than the energy expended during a competitive week. The magnitudes of these deficits were greatest on match and heavy training days. These findings may have both short and long term implications on the performance and physical development of adolescent soccer players. PMID:26445059

  19. 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…

  20. 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…

  1. 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…

  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. PMID:27532421

  3. 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

  4. Wii Tennis Play for Low-Income African American Adolescents’ Energy Expenditure

    PubMed Central

    Staiano, Amanda E.; Calvert, Sandra L.

    2013-01-01

    Exergames, which are video games that require gross motor activity, are popular activities that produce energy expenditure. Seventy-four low-income African American 12- to 18-year-old adolescents were randomly assigned to a 30-minute condition: 1) solitary Wii tennis exergame play against virtual peers; 2) social Wii tennis exergame play against a real peer; or 3) control group with sedentary computer activity. Adolescents were tested for caloric expenditure after exposure to treatment conditions as well as on a tennis court using Actical accelerometers. Adolescents who played the social exergame against a peer expended significantly more energy than those who played alone. Both exergame groups expended more energy than the control group. Adolescents who played the social exergame also expended comparable calories to actual tennis court play during a simulated lesson. Exergames, then, could promote physical activity, thereby becoming a tool to combat the obesity crisis that is affecting many youth. PMID:24058381

  5. 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

  6. Canadian Open Tennis. Puzzle Corner.

    ERIC Educational Resources Information Center

    Andrews, Ian A.

    2000-01-01

    Describes the du Maurier Open, a women's tennis tournament. Explains that tennis becomes an elite sport at the level of the du Maurier Open. Presents a crossword puzzle that focuses on many of the female tennis stars and provides the across and down clues, a word list, and the answer key. (CMK)

  7. 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. PMID:25894070

  8. Surgical treatment of posterior interosseous nerve paralysis in a tennis player☆

    PubMed Central

    Fujioka, Hiroyuki; Tsunemi, Kenjiro; Tsukamoto, Yoshitane; Oi, Takanori; Takagi, Yohei; Tanaka, Juichi; Yoshiya, Shinichi

    2014-01-01

    We report a rare case of posterior interosseous nerve (PIN) paralysis in a tennis player. The PIN, a 2 cm section from a bifurcation point of the radial nerve, presented increased stiffness in the surgical findings and treated with free sural nerve grafting after excision of the degenerative portion of the PIN. We speculate that PIN paralysis associated with hourglass-like constriction can be caused and exacerbated by repetitive forearm pronation and supination in playing tennis. PMID:25104896

  9. Tennis injuries: epidemiology, pathophysiology, and treatment.

    PubMed

    Dines, Joshua S; Bedi, Asheesh; Williams, Phillip N; Dodson, Christopher C; Ellenbecker, Todd S; Altchek, David W; Windler, Gary; Dines, David M

    2015-03-01

    Tennis places high loads on the joints of players, with supraphysiologic forces being generated at the shoulder and elbow hundreds of times per match. Acute injuries tend to affect the lower extremity; chronic injuries usually involve the upper extremity. Commonly encountered upper extremity conditions include rotator cuff injury, internal impingement, superior labral tears, and epicondylitis of the elbow. Serving is the most strenuous stroke in tennis, with the highest peak muscle activity in the shoulder and forearm occurring during this stroke. The kinetic chain links upper extremity, lower extremity, and core muscle segments by transmitting coordinated activation and motion; in this regard, any pathologic process that disturbs the groin, hip, and abdominal musculature can further result in an increased risk of injury to the shoulder and upper extremity. Evolution in equipment and in play surfaces has also affected the type and frequency of injuries. Prevention programs that address the muscular imbalances throughout the kinetic chain may help reduce the incidence of both acute and chronic injuries experienced by tennis athletes. PMID:25667400

  10. The Effect of Grip Size on the Hitting Force During a Soft Tennis Forehand Stroke

    PubMed Central

    Ohguni, Mika; Aoki, Mitsuhiro; Sato, Hiroki; Imada, Kohdai; Funane, Sota

    2009-01-01

    Background: Grip size of a tennis racquet has been reported to influence performance, but clear evidence of a correlation has yet to be established. Hypothesis: Hitting force during a soft tennis forehand stroke correlates with grip size. Study Design: Controlled clinical study. Methods: A total of 40 healthy volunteers (20 men and 20 women) with a mean age of 21.9 years were enrolled. Of the 40 participants, 20 were experienced soft tennis players (10 men and 10 women) and 20 were nonexperienced soft tennis players (10 men and 10 women). Based on racquets with 5 different grip sizes, the hitting force during a soft tennis forehand stroke was measured with a handheld dynamometer. Correlations between 4 factors (sex, experience, grip and pinch strengths, and middle finger length) and hitting force were evaluated with each grip size. Measurements for each factor were repeated, and a 2-way analysis of variance was performed on the obtained data. Results: The hitting force was greater for male players than for female players and greater for experienced players than for nonexperienced players (P < .01). Men with large grip and pinch strengths demonstrated an increased hitting force with an increase in grip size. Men who had a long middle finger also demonstrated increased hitting force when grip size increased (P < .05). Conclusion: The hypothesis proved accurate for experienced men who had a large grip strength, a large pinch strength, and a long middle finger. Clinical Relevance: Large-grip-sized racquets may result in better forehand stroke performance when used by experienced male soft tennis players with a large grip strength, a large pinch strength, and a long middle finger. PMID:23015889

  11. The biomechanics of tennis elbow. An integrated approach.

    PubMed

    Roetert, E P; Brody, H; Dillman, C J; Groppel, J L; Schultheis, J M

    1995-01-01

    Tennis elbow afflicts 40% to 50% of the average, recreational tennis players; most of these players more than 30 years of age. Tennis elbow is thought to be the result of microtrauma, the overuse and inflammation at the origin of the ECRB as a result of repeated large impact forces created when the ball hits the racket in the backhand stroke. Several authors have found that EMG activity in the ECRB, the muscle and tendon complex afflicted in tennis elbow, is high during the acceleration and early follow-through phases of the groundstrokes and during the cocking phase of the serve. Unfortunately, none of the authors gave evidence to support the claim that muscle activity in the ECRB at ball contact is high. In the one-handed backhand, the torques at impact (17-24 nm) will be absorbed by the tendons of the elbow. Giangarra and his colleagues observed that the two-handed backhand "allows the forces at ball impact to be transmitted through the elbow rather than absorbed by the tissues at the elbow." Other authors have reported that players using a two-handed backhand will rarely develop lateral epicondylitis, because the helping arm appears to absorb more energy and changes the mechanics of the swing. As seen by Morris and colleagues, Giangarra and associates, and Leach and colleagues, players who utilize the two-handed backhand have a very low incidence of tennis elbow. These three studies conclude that the two-handed backhand stroke is probably the most effective backhand stroke to prevent lateral tennis elbow. Studies show that wrist extensors are highly involved in all strokes (serve, forehand, and both one- and two-handed backhand strokes). This relatively high involvement (40%-70% MVC) throughout play may result in overload of this muscular group. Thus, tennis elbow may be caused simply by continued use of this muscular system in all strokes, and not just because of the high forces absorbed at impact. Another theory concerning impact states that if the extensor

  12. Left-handedness in professional and amateur tennis.

    PubMed

    Loffing, Florian; Hagemann, Norbert; Strauss, Bernd

    2012-01-01

    Negative frequency-dependent effects rather than innate predispositions may provide left-handers with an advantage in one-on-one fighting situations. Support mainly comes from cross-sectional studies which found significantly enhanced left-hander frequencies among elite athletes exclusively in interactive sports such as baseball, cricket, fencing and tennis. Since professional athletes' training regimes continuously improve, however, an important unsolved question is whether the left-handers' advantage in individual sports like tennis persists over time. To this end, we longitudinally tracked left-hander frequencies in year-end world rankings (men: 1973-2011, ladies: 1975-2011) and at Grand Slam tournaments (1968-2011) in male and female tennis professionals. Here we show that the positive impact of left-handed performance on high achievement in elite tennis was moderate and decreased in male professionals over time and was almost absent in female professionals. For both sexes, left-hander frequencies among year-end top 10 players linearly decreased over the period considered. Moreover, left-handedness was, however, no longer seems associated with higher probability of attaining high year-end world ranking position in male professionals. In contrast, cross-sectional data on left-hander frequencies in male and female amateur players suggest that a left-handers' advantage may still occur on lower performance levels. Collectively, our data is in accordance with the frequency-dependent hypothesis since reduced experience with left-handers in tennis is likely to be compensated by players' professionalism. PMID:23145151

  13. Fluid and electrolyte losses during tennis in the heat.

    PubMed

    Bergeron, M F; Armstrong, L E; Maresh, C M

    1995-01-01

    A tennis player's metabolism during play in a hot environment generates an abundance of heat, which is primarily eliminated from the body by evaporation of sweat. An individual's on-court rate of fluid loss will depend on the environmental conditions, intensity of play, acclimatization, aerobic fitness, hydration status, age, and gender. Unless fluid intake closely matches sweat loss, a progressive and significant body water deficit may develop that will proportionately impair cardiovascular and thermoregulatory functions. As a result, a player can experience an increase in core temperature, premature fatigue, performance decrements, and an increased potential for heat illness. Although sweat is hypotonic compared to plasma, extended tennis play, in a hot environment, can lead to sizable Na+ and Cl- losses. Also, ad libitum drinking often leads to involuntary dehydration in these conditions. Therefore, for tennis play and training in the heat, it is important to follow a hydration plan that will minimize on-court water deficits, by optimizing fluid availability, consumption, and absorption. For tennis matches greater than 1 hour in duration, a CHO-electrolyte drink (as described earlier) is the recommended on-court beverage. PMID:7712552

  14. 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.

  15. 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

  16. 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. PMID:27014132

  17. 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

  18. Tennis Elbow (Lateral Epicondylitis)

    MedlinePlus

    ... to athletic activity. This is usually 4 to 6 months after surgery. Tennis elbow surgery is considered successful in 80% to 90% of patients. However, it is not uncommon to see a loss of strength. New Developments Platelet-rich plasma (PRP) is currently being investigated for its effectiveness ...

  19. 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…

  20. Effects of two training protocols on the forehand drive performance in tennis.

    PubMed

    Genevois, Cyril; Frican, Baptiste; Creveaux, Thomas; Hautier, Christophe; Rogowski, Isabelle

    2013-03-01

    The aim of this study was to examine the effects of 2 training modalities on the tennis forehand drive performance. Forty-four tennis players (mean ± SD: age = 26.9 ± 7.5 years; height = 178.6 ± 6.7 cm; mass = 72.5 ± 8.0 kg; International Tennis Number = 3) were randomly assigned into 3 groups. During 6 weeks, the first group performed handled medicine ball (HMB) throws included in the regular tennis practice, the second group (overweight racket-OWR) played tennis forehand drives with an overweighed racket during the regular tennis practice, and the third group (regular tennis training-RTT) practiced only tennis training as usual. Before and after the 6-week program, velocity and accuracy of tennis crosscourt forehand drives were evaluated in the 3 groups. The main results showed that after 6-week training, the maximal ball velocity was significantly increased in HMB and OWR groups in comparison with RTT (p < 0.001 and p = 0. 001, respectively). The estimated averaged increase in ball velocity was greater in HMB than in OWR (11 vs. 5%, respectively; p = 0.017), but shot accuracy tended to be deteriorated in HMB when compared with OWR and RTT (p = 0.043 and p = 0.027, respectively). The findings of this study highlighted the efficiency of both training modalities to improve tennis forehand drive performance but also suggested that the HMB throws may be incorporated into the preseason program preferably, whereas the OWR forehand drives may be included in the on-season program. PMID:22592176

  1. 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. PMID:25983591

  2. Understanding the Player: The Need for Adaption in Exergames for Adolescents.

    PubMed

    Macvean, Andrew

    2012-10-01

    Recently, exergames have become a viable aspect of physical activity interventions, with their ability to facilitate exercise within an enjoyable and motivating context. However, in order to develop optimally effective exergames suitable for a wide and diverse audience, adaptive exergames capable of adapting to suit the personality of the user are required. In this article, we discuss how an understanding of the background of players can be used to explain their in-game behavior and how this could be used to progress the exergame genre. PMID:26192004

  3. 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…

  4. The Relationships Between Simulated Tennis Performance and Biomarkers for Nitric Oxide Synthesis

    PubMed Central

    Akşit, Tolga; Turgay, Faruk; Kutlay, Emine; Z. Özkol, Mehmet; Vural, Faik

    2013-01-01

    Tennis performance requires a good aerobic endurance and recovering capacity. Nitric oxide (NO) is a gas which is not only a vasodilator and antioxidant but it also regulates the use of oxygen and glucose. The aim of this study was to examine the relationships between simulated tennis performance test (PT) and NOx (sum of nitrate+nitrite) levels and lactate elimination speed (LES). Twenty well trained male tennis players with game levels of ITN 4 (International Tennis Number) and lower (mean ± SD; age 22.9 ± 2.6 yrs; height 1.82 ± 0.06 m and mass 75.7 ± 8.0 kg) participated in the study. Participants performed three 4-min bouts and a 2-min continuous groundstroke against balls projected from a tennis ball machine at speeds of 50, 55, 62 and 70 km·h-1. After this exercise, subjects were given a 20 min passive rest. After each period and at during the recovery phase; plasma NOx, glucose (GLU) and lactate (LA) levels were determined. LES was calculated during passive recovery. GLU, LA and heart rate (HR) showed a linear increase in comparison to the values in the previous step while PT decreased significantly. Following each period NOx and glucose levels increased independently, but their decreasing rates in recovery phase were related (r = 0.470, p < 0.05). The successive increase in NOx and GLU parameters between the third and the forth periods was significant (p < 0.05). Only in the third period was there a significant relation between PT and NOx (r = 0.494; p < 0.05). In the present study, no significant relationship was found between PT and GLU, LA levels and LES. No significant correlation was found between simulated tennis performance and blood NOx levels. However the addition of loads like those in the third period in tennis trainings can be beneficial for performance in trained tennis players. It is recommended that the relationships between tennis performance with NOx and GLU are studied during a real tennis match. Key Points In a sport like tennis

  5. 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

  6. 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)…

  7. 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…

  8. 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.

  9. 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…

  10. 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. PMID:24599611

  11. 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

  12. 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. PMID:24756167

  13. Sequential avulsions of the tibial tubercle in an adolescent basketball player.

    PubMed

    Huang, Ying Chieh; Chao, Ying-Hao; Lien, Fang-Chieh

    2010-05-01

    Tibial tubercle avulsion is an uncommon fracture in physically active adolescents. Sequential avulsion of tibial tubercles is extremely rare. We reported a healthy, active 15-year-old boy who suffered from left tibial tubercle avulsion fracture during a basketball game. He received open reduction and internal fixation with two smooth Kirschner wires and a cannulated screw, with every effort to reduce the plate injury. Long-leg splint was used for protection followed by programmed rehabilitation. He recovered uneventfully and returned to his previous level of activity soon. Another avulsion fracture happened at the right tibial tubercle 3.5 months later when he was playing the basketball. From the encouragement of previous successful treatment, we provided him open reduction and fixation with two small-caliber screws. He recovered uneventfully and returned to his previous level of activity soon. No genu recurvatum or other deformity was happening in our case at the end of 2-year follow-up. No evidence of Osgood-Schlatter disease or osteogenesis imperfecta was found. Sequential avulsion fractures of tibial tubercles are rare. Good functional recovery can often be obtained like our case if we treat it well. To a physically active adolescent, we should never overstate the risk of sequential avulsion of the other leg to postpone the return to an active, functional life. PMID:20093955

  14. Effects of the Tennis Tournament on Players’ Physical Performance, Hormonal Responses, Muscle Damage and Recovery

    PubMed Central

    Ojala, Tuomo; Häkkinen, Keijo

    2013-01-01

    The purpose of this study was to examine changes in selected physiological and performance variables of male tennis players (n=8) during a 3-day tennis tournament and the following 2-day recovery period. Each player played three two-hour tennis matches. The following measurements were taken: blood samples for serum testosterone T, cortisol C, creatinekinase CK, performance tests of maximal isometric leg press MVC and maximal rate of force development RFD, 5m run 5m, 5-leap 5l, counter movement jump CMJ and serve velocity S and DOMS questionnaire. During the games at 40 and 80 minutes the following tests were made: blood sample, MVC, 5m, CMJ and S. Both MVC and RFD were before the 2nd and 3rd match significantly lower than before the 1st match (p < 0.02) and remained reduced after 1 to 2 days of recovery. Serum C was significantly higher than the baseline value before each match (p < 0.05) and after 40 minutes of playing (p < 0.03). Serum T elevated from the baseline during every match at T40 (p < 0.02). CK elevated during the whole tournament peaking after the 3rd match. After one rest day CK was still significantly higher than the baseline value. Upper and lower body DOMS were elevated significantly but remained above the baseline after one rest day. The tennis tournament leads to reduced MVC and RFD, increased muscle damage and soreness and reduced recovery. It seems that a tennis tournament causes such a heavy speed strength load for the legs in addition to muscle damage that the recovery of explosive attributes of leg extensor muscles is impaired after two days of rest after the tournament. Serum cortisol and testosterone concentration elevated before and during the tennis match, but the outcome of the tennis match is difficult to predict using C or/and T levels before, during or after the match. Key Points The tennis tournament impairs player’s MVC and RFD, increases muscle damage and soreness and reduces recovery. One day of rest after the tennis tournament

  15. 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

  16. Indicators of throwing arm fatigue in elite adolescent male baseball players: a randomized crossover trial.

    PubMed

    Freeston, Jonathan; Adams, Roger; Ferdinands, René E D; Rooney, Kieron

    2014-08-01

    Throwing carries an inherent risk of injury that worsens in the presence of arm fatigue. The purpose of this study was to identify markers that could facilitate the early detection of this type of fatigue, by comparing the response to bouts of throwing-specific and running-based exercise. Thirteen elite junior male baseball players were tested twice, 7 days apart with a randomized crossover design. They were assessed for shoulder proprioception, maximal throwing velocity, and throwing accuracy before and after a 10-minute bout of either throwing-specific (THROW) or general (RUN) exercise. Maximal throwing velocity was reduced similarly after both THROW and RUN bouts (-1.0 ± 0.4 vs. -0.6 ± 0.2 m·s-1, respectively; p ≤ 0.05); however, accuracy was only reduced after THROW (7.6 ± 3.4 cm; p ≤ 0.05). Arm soreness increased significantly more after THROW than RUN (3.5 ± 0.7 vs. 1.4 ± 0.5 km·h-1, respectively; p ≤ 0.05). Shoulder proprioception did not change after either exercise bout. The results suggest that throwing velocity is an indicator of general fatigue, whereas throwing accuracy and arm soreness are markers of arm fatigue. Shoulder proprioception does not seem to be a sensitive marker of either type of fatigue. Throwing velocity should be monitored to gauge overall fatigue levels, whereas accuracy and arm soreness should be closely monitored to gauge arm fatigue and throwing-induced injury risk. PMID:24513620

  17. Biomechanical Analysis of Abdominal Injury in Tennis Serves. A Case Report

    PubMed Central

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

    2015-01-01

    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 points In 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. PMID:25983591

  18. Hydration and thermal strain during tennis in the heat

    PubMed Central

    Bergeron, Michael F

    2014-01-01

    Competitive tennis in the heat can prompt substantial sweat losses and extensive consequent body water and electrolyte deficits, as well as a level of thermal strain that considerably challenges a player's physiology, perception of effort, and on-court well-being and performance. Adequate hydration and optimal performance can be notably difficult to maintain when multiple same-day matches are played on successive days in hot weather. Despite the recognised effects of the heat, much more research needs to be carried out to better appreciate the broader scope and full extent of the physiological demands and hydration and thermal strain challenges facing junior and adult players in various environments, venues and competition scenarios. However, certain recommendations of best practices should be emphasised to minimise exertional heat illness risk and improve player safety, well-being and on-court performance. PMID:24668373

  19. Sport Nutrition and Doping in Tennis: An Analysis of Athletes’ Attitudes and Knowledge

    PubMed Central

    Kondric, Miran; Sekulic, Damir; Uljevic, Ognjen; Gabrilo, Goran; Zvan, Milan

    2013-01-01

    Nutrition and doping issues are rarely studied in the sport of tennis. The aims of this investigation were to determine knowledge on doping (KD) and knowledge on sport nutrition (KSN), and corresponding socio-demographic-, sport-, and sport-nutrition- and doping-factors among an international sample of high-level tennis players of both sexes (43 females; 22 years old on average). In the first phase of the investigation, the KSN and KD questionnaires were studied for their reliability and validity. The consumption of NS is found to be very high, with almost of all the females and 80% of the males using NS at least occasionally. The athletes showed a low tendency regarding future doping usage, although most of them are convinced that doping does exist in tennis. Since athletes declared that their coaches are their main source of information about NS and doping, future studies should investigate what coaches actually know about such problems. KSN has been found to be protective against potential doping behavior in the future. Males are found to be more prone to doping than females. Therefore, in order to prevent doping behavior in tennis we strongly suggest intensive educational programs on sports nutrition and doping-related problems. Key Points The incidence of nutritional supplementation use among the tennis players is found to be very high, especially among the females. Although most of the subjects are of the opinion that the doping behavior is present in tennis circuit, we have found a low tendency regarding future doping usage, and high levels of athletes’ trust in their coaches with regard to nutritional supplementation and doping. There are indices that the knowledge about nutrition is protective factor against potential doping behavior. It clearly reinforces the need to include a wide educational program on sports nutrition in tennis, but also in other sports. PMID:24149808

  20. Effects of 8-week in-season plyometric training on upper and lower limb performance of elite adolescent handball players.

    PubMed

    Chelly, Mohamed Souhaiel; Hermassi, Souhail; Aouadi, Ridha; Shephard, Roy J

    2014-05-01

    We hypothesized that replacement of a part of the normal in-season regimen of top-level adolescent handball players by an 8-week biweekly course of lower and upper limb plyometric training would enhance characteristics important to competition, including peak power output (Wpeak), jump performance, muscle volume, and ball throwing velocity. Study participants (23 men, age: 17.4 ± 0.5 years, body mass: 79.9 ± 11.5 kg, height: 1.79 ± 6.19 m, body fat: 13.8 ± 2.1%) were randomly assigned between controls (C; n = 11) and an experimental group (E, n = 12). Measures preintervention and postintervention included force-velocity ergometer tests for upper (Wupper peak) and lower limbs (Wlower peak), force platform determinations of squat jump (SJ) and countermovement jump (CMJ) characteristics (jump height, maximal force, initial velocity, and average power), video filming of sprint velocities (first step [V1S], first 5 m [V5m], and 25-30 m [Vmax]), and anthropometric estimates of leg muscle volume. E showed gains relative to C in Wupper peak and Wlower peak (p < 0.01 and p < 0.001), SJ (height p < 0.01; force p ≤ 0.05), CMJ (height p < 0.01; force p < 0.01 and relative power p ≤ 0.05), and sprint velocities (p < 0.001 for V1S, V5m, and Vmax). E also showed increases in leg and thigh muscle volumes (p < 0.001), but arm muscle volumes did not differ from control. We conclude that introduction of biweekly plyometric training into the standard regimen improved components important to handball performance, particularly explosive actions, such as sprinting, jumping, and ball throwing velocity. PMID:24149768

  1. 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.)

  2. A one-season prospective study of injuries and illness in elite junior tennis.

    PubMed

    Pluim, B M; Loeffen, F G J; Clarsen, B; Bahr, R; Verhagen, E A L M

    2016-05-01

    The objective of this study was to estimate the incidence and prevalence of injury and illness among elite junior tennis players. A cohort of 73 players (11-14 years) in the 2012-2013 Dutch national high-performance program was followed for 32 weeks; all participants completed the study. The OSTRC Questionnaire on Health Problems was used to record self-reported injuries and illnesses and to record training and match exposure. Main outcome measures were average prevalence of overuse injury and illness and incidence density of acute injury. On average, players practiced 9.1 h/week (SD 0.6; range 2.3-12.0) and had 2.2 h of match play (SD 0.6; range 2.3-12.0). During the course of the study, 67 players reported a total of 187 health problems. The average weekly prevalence of all health problems was 21.3% (95% CI: 19.2-22.9), of which 12.1% (95% CI: 10.9-13.3) constituted overuse injuries and 5.8% (95% CI: 4.6-6.9) illnesses. The incidence of acute injuries was 1.2/1000 h of tennis play (95% CI: 0.7-1.7). The high occurrence of overuse injuries among elite junior tennis players suggests that an early focus on preventative measures is warranted, with a particular focus on the monitoring and management of workload. PMID:25944058

  3. 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. PMID:25675134

  4. Movement-production strategy in tennis: a case study.

    PubMed

    Gillet, Eric; Leroy, David; Thouvarecq, Régis; Mégrot, Fabrice; Stein, Jean-François

    2010-07-01

    The present case study fell within the framework of the "absolute approach of expertise" because it assesses a "truly exceptional individual" (Chi, MTH, Cambridge Handbook of Expertise and Expert Performance, London, United Kingdom: Cambridge University Press, 2006, pp. 121-130). This technique analysis examined the movement-production strategy used by a professional tennis player performing serve-return strokes. This research enabled us to establish the relation between tennis serve-return technique and successful performance. An optoelectronic system was used to capture and analyze the expert player's stroke production in a live situation to determine the temporal trajectory of the serve-return initiation movement. Some differences between the serve-return shots were observed concerning the occurrence time of the lateral racquet displacement, the amplitude of the racquet movement, and the average latency time. No difference was observed for the gravity center (GC) movements. Backhand, forehand, and reprogramming strokes were executed with a general constancy of occurrence and average times of the GC and racquet movements. This expert player used a predictive movement-production strategy specified by a high level of reproducibility of the movement with nevertheless adaptive skills during reprogramming strokes. This adaptation supported either the development of highly consistent motor programs or the use of a more flexible strategy based on the perception-action coupling. PMID:20555282

  5. 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

  6. Acute Effects of Static Stretching, Dynamic Exercises, and High Volume Upper Extremity Plyometric Activity on Tennis Serve Performance

    PubMed Central

    Gelen, Ertugrul; Dede, Muhittin; Bingul, Bergun Meric; Bulgan, Cigdem; Aydin, Mensure

    2012-01-01

    The purpose of this study was to compare the acute effects of static stretching; dynamic exercises and high volume upper extremity plyometric activity on tennis serve performance. Twenty-six elite young tennis players (15.1 ± 4.2 years, 167.9 ± 5.8 cm and 61.6 ± 8.1 kg) performed 4 different warm-up (WU) routines in a random order on non-consecutive days. The WU methods consisted of traditional WU (jogging, rally and serve practice) (TRAD); traditional WU and static stretching (TRSS); traditional WU and dynamic exercise (TRDE); and traditional WU and high volume upper extremity plyometric activity (TRPLYP). Following each WU session, subjects were tested on a tennis serve ball speed test. TRAD, TRSS, TRDE and TRPLYO were compared by repeated measurement analyses of variance and post-hoc comparisons. In this study a 1 to 3 percent increase in tennis serve ball speed was recorded in TRDE and TRPLYO when compared to TRAD (p< 0.05). However, no significant change in ball speed performance between TRSS and TRAD. (p> 0.05). ICCs for ball speed showed strong reliability (0.82 to 0.93) for the ball speed measurements.The results of this study indicate that dynamic and high volume upper extremity plyometric WU activities are likely beneficial to serve speed of elite junior tennis players. Key points After the traditional warm up in tennis, static stretching has no effect on serve speed. Tennis players should perform dynamic exercises and/or high volume upper extremity plyometric activities to improve their athletic performance. PMID:24150068

  7. Plantar pressures in the tennis serve.

    PubMed

    Girard, Olivier; Eicher, Frank; Micallef, Jean-Paul; Millet, Grégoire

    2010-06-01

    In-shoe loading patterns were examined in each foot (back and front) separately during two types of tennis serve [first (or flat) and second (or twist) serve] and two service stance styles [foot-up (back foot is moved forward next to front foot for push-off) and foot-back (feet remain at the same relative level)]. Ten competitive tennis players completed five trials for each type of serve and service stance style in random order. Plantar pressure distribution was recorded using Pedar insoles divided into nine areas for analysis. Mean and peak pressures (+15.2%, P < 0.01 and +12.8%, P < 0.05) as well as maximal forces (+20.2%, P < 0.01) were higher under the lateral forefoot of the front foot in first than in second serves, while mean forces were higher (+17.2%, P < 0.05) under the lesser toes. Relative load was higher on the lateral forefoot (+20.4%, P < 0.05) but lower (-32.5%, P < 0.05) on the medial heel of the front foot with foot-up compared with foot-back stance. Using a foot-up stance, loading of the back foot was higher (+31.8%, P < 0.01) under the lateral mid-foot but lower (-29.9%, P < 0.01) under the medial forefoot. The type of serve and the stance style adopted have a significant effect on foot loading. Such findings might help improve mechanical efficiency of the serve. PMID:20496222

  8. Effect of type 3 (oversize) tennis ball on serve performance and upper extremity muscle activity.

    PubMed

    Blackwell, John; Knudson, Duane

    2002-07-01

    This study investigated the effect of the larger diameter (Type 3) tennis ball on performance and muscle activation in the serve. Sixteen male advanced tennis players performed serves using regular size and Type 3 tennis balls. Ball speed, surface electromyography, and serve accuracy were measured. There were no significant differences in mean initial serve speeds between balls, but accuracy was significantly greater (19.3%) with the Type 3 ball than with the regular ball. A consistent temporal sequence of muscle activation and significant differences in mean activation of different muscles were observed. However, ball type had no effect on mean arm muscle activation. These data, combined with a previous study, suggest that play with the larger ball is not likely to increase the risk of overuse injury, but serving accuracy may increase compared to play with the regular ball. PMID:14658375

  9. Competitive Performance Correlates of Mental Toughness in Tennis: A Preliminary Analysis.

    PubMed

    Cowden, Richard G

    2016-08-01

    This study investigated relationships between mental toughness and measures of competitive performance in tennis. Forty-three male (N = 25) and female (N = 18) players (M age = 13.6 years, SD = 2.4) completed the mental toughness inventory, and the point-by-point outcomes recorded during a competitive tennis match (singles) were used to generate performance indices for each athlete. The results indicated that mental toughness was associated with several, but not all, macro, micro, and critical moment performance indices. The findings suggest mental toughness may contribute to successful performance during tennis competition, although the importance of the construct appears to depend depend on specific match situations. Future mental toughness research should consider a range of factors related to sport performance, including athletes' and opponents' physical, technical, and tactical abilities. PMID:27502244

  10. 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

  11. Effects of Body Mass Index and Full Body Kinematics on Tennis Serve Speed

    PubMed Central

    Wong, Francis KH; Keung, Jackie HK; Lau, Newman ML; Ng, Douglas KS; Chung, Joanne WY; Chow, Daniel HK

    2014-01-01

    Effective training to improve serve speed is important for competitive tennis players. The purposes of this study were to investigate the effects of anthropometric factors and whole body kinematics of elite players on ball speed and to propose possible training strategies for improving the quality of tennis serves. Body and racket kinematics of tennis serves of 12 male elite Hong Kong players were investigated. The tennis serve was divided into four phases: I) Back-Swing Phase, II) Lead-Leg-Drive Phase, III) Forward-Swing Phase, and IV) Follow-Through Phase. It was shown that racket-side knee range of motion during phases II and III (r=0.705; p<0.05), racket-side knee peak extension velocity during phase II (r=0.751; p<0.01), racket-side hip peak extension velocity during phase II (r=0.657; p<0.05), racket-side shoulder range of motion in the coronal plane during phase III (r=0.616; p<0.05), racket-side elbow peak extension velocity during phase III (r=0.708; p<0.01) and body mass index (r=0.577; p<0.05) were significantly correlated with ball speed. Body mass index and the identified kinematic parameters that were significantly correlated with ball speed could be used as training guidelines for coaches and players to improve serve speed. Players should pay particular attention in training to increasing the extension velocity and range of motion of the identified joints. PMID:25031669

  12. 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

  13. Viewers & Players

    MedlinePlus

    ... Player View applications, content, and videos developed with Flash on any platform or browser. swf flv Windows Media Player Play video and audio files on PC operating systems. mp3 wav wmz Microsoft Excel Viewer Open, view ...

  14. Deliberate practice predicts performance over time in adolescent chess players and drop-outs: a linear mixed models analysis.

    PubMed

    de Bruin, Anique B H; Smits, Niels; Rikers, Remy M J P; Schmidt, Henk G

    2008-11-01

    In this study, the longitudinal relation between deliberate practice and performance in chess was examined using a linear mixed models analysis. The practice activities and performance ratings of young elite chess players, who were either in, or had dropped out of the Dutch national chess training, were analysed since they had started playing chess seriously. The results revealed that deliberate practice (i.e. serious chess study alone and serious chess play) strongly contributed to chess performance. The influence of deliberate practice was not only observable in current performance, but also over chess players' careers. Moreover, although the drop-outs' chess ratings developed more slowly over time, both the persistent and drop-out chess players benefited to the same extent from investments in deliberate practice. Finally, the effect of gender on chess performance proved to be much smaller than the effect of deliberate practice. This study provides longitudinal support for the monotonic benefits assumption of deliberate practice, by showing that over chess players' careers, deliberate practice has a significant effect on performance, and to the same extent for chess players of different ultimate performance levels. The results of this study are not in line with critique raised against the deliberate practice theory that the factors deliberate practice and talent could be confounded. PMID:18433518

  15. 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. PMID:24465638

  16. 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. PMID:25816346

  17. Effect of low-compression balls on wheelchair tennis match-play.

    PubMed

    Sindall, P; Lenton, J P; Malone, L; Douglas, S; Cooper, R A; Hiremath, S; Tolfrey, K; Goosey-Tolfrey, V

    2014-05-01

    The purpose of this study was to compare court-movement variables and physiological responses to wheelchair tennis match-play when using low vs. standard compression tennis balls. Eleven wheelchair basketball players were monitored during repeated bouts of tennis (20 min) using both ball types. Graded and peak exercise tests were completed. For match-play, a data logger was used to record distance and speed. Individual linear heart rate oxygen consumption relationships were used to estimate match-play oxygen uptake. Significant main effects for ball type revealed that total distance (P<0.05), forward distance (P<0.05), and average speed (P<0.05) were higher for play using a low-compression ball. A lower percentage of total time was spent stationary (P<0.001), with significantly more time spent at speeds of 1-1.49 (P<0.05), 1.5-1.99 (P<0.05) and 2.0-2.49 (P<0.05) m ∙ sec(-1) when using the low-compression ball. Main effects for physiological variables were not significant. Greater total and forward distance, and higher average speeds are achieved using a low-compression ball. The absence of any difference in measured HR and estimated physiological responses would indicate that players move further and faster at no additional mean physiological cost. This type of ball will be useful for novice players in the early phases of skill development. PMID:24081621

  18. 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

  19. 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

  20. Designing for Insight: A Case Study from Tennis Player Analysis.

    PubMed

    Albrecht, Kim; Yucesoy, Burcu

    2016-01-01

    Visualization is an important tool, necessary for making sense of vast amounts of data. Many data science projects make use of visualization techniques to illustrate and explain their results. But complex interactive visualizations can also be excellent exploration tools to help guide the analysis, detect early signs of problems and irregularities, suggest new discoveries, and test the effectiveness and efficiency of scientific models. This article describes a combinatory design process that uses a method of incremental addition to create increasingly complex arrangements and thus create new ways to see data and discover new insights. PMID:27514032

  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. Oxygen uptake and heart rate response of 6 standardized tennis drills.

    PubMed

    Bekraoui, Nabyl; Fargeas-Gluck, Marie-Agnès; Léger, Luc

    2012-10-01

    The purpose of this study was to compare the oxygen uptake of various on-court tennis drills. Eleven tennis players were monitored with a portable metabolic device to measure oxygen uptake of 6 different tennis drills at low and high speeds. The 6 drills were done with or without striking the ball, over half or full-width of the court, in attack or defense mode, using forehand or backhand strokes. Oxygen uptake values (mean ± SD) ranged from 33.8 ± 4.2 to 42.3 ± 5.1 mL·kg⁻¹·min⁻¹ when running at low speed on the full-width court in defense mode without striking the ball and when running at high speed on the full-width court in attack mode while striking the ball, respectively. Specific differences were observed. Attacking mode requires 6.5% more energy than defensive playing mode. Backhand strokes demand 7% more energy at low speed than forehand ones. Running and striking the ball costs 10% more energy than running without striking the ball. While striking the ball, shuttle running on half-width court costs 14% more energy than running on full-width courts. The specificity of the oxygen uptake responses obtained for these various tennis drills gives an improved representation of their energy cost and could be used to optimize training loads. PMID:22871149

  3. 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. PMID:25117871

  4. 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

  5. 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).…

  6. The effect of HMB supplementation on body composition, fitness, hormonal and inflammatory mediators in elite adolescent volleyball players: a prospective randomized, double-blind, placebo-controlled study.

    PubMed

    Portal, Shawn; Zadik, Zvi; Rabinowitz, Jonathan; Pilz-Burstein, Ruty; Adler-Portal, Dana; Meckel, Yoav; Cooper, Dan M; Eliakim, Alon; Nemet, Dan

    2011-09-01

    The use of ergogenic nutritional supplements is becoming inseparable from competitive sports. β-Hydroxy-β-Methylbutyric acid (HMB) has recently been suggested to promote fat-free mass (FFM) and strength gains during resistance training in adults. In this prospective randomized, double-blind, placebo-controlled study, we studied the effect of HMB (3 g/day) supplementation on body composition, muscle strength, anaerobic and aerobic capacity, anabolic/catabolic hormones and inflammatory mediators in elite, national team level adolescent volleyball players (13.5-18 years, 14 males, 14 females, Tanner stage 4-5) during the first 7 weeks of the training season. HMB led to a significant greater increase in FFM by skinfold thickness (56.4 ± 10.2 to 56.3 ± 8.6 vs. 59.3 ± 11.3 to 61.6 ± 11.3 kg in the control and HMB group, respectively, p < 0.001). HMB led to a significant greater increase in both dominant and non-dominant knee flexion isokinetic force/FFM, measured at fast (180°/sec) and slow (60°/sec) angle speeds, but had no significant effect on knee extension and elbow flexion and extension. HMB led to a significant greater increase in peak and mean anaerobic power determined by the Wingate anaerobic test (peak power: 15.5 ± 1.6 to 16.2 ± 1.2 vs. 15.4 ± 1.6 to 17.2 ± 1.2 watts/FFM, mean power: 10.6 ± 0.9 to 10.8 ± 1.1 vs. 10.7 ± 0.8 to 11.8 ± 1.0 watts/FFM in control and HMB group, respectively, p < 0.01), with no effect on fatigue index. HMB had no significant effect on aerobic fitness or on anabolic (growth hormone, IGF-I, testosterone), catabolic (cortisol) and inflammatory mediators (IL-6 and IL-1 receptor antagonist). HMB supplementation was associated with greater increases in muscle mass, muscle strength and anaerobic properties with no effect on aerobic capacity suggesting some advantage for its use in elite adolescent volleyball players during the initial phases of the training season. These effects were not accompanied by hormonal and

  7. 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. PMID:26177373

  8. 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.

  9. 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. PMID:27111711

  10. Shoulder Rotator Muscle Dynamometry Characteristics: Side Asymmetry and Correlations with Ball-Throwing Speed in Adolescent Handball Players

    PubMed Central

    Pontaga, Inese; Zidens, Janis

    2014-01-01

    The aim of the investigation was to: 1) compare shoulder external/internal rotator muscles’ peak torques and average power values and their ratios in the dominant and non-dominant arm; 2) determine correlations between shoulder rotator muscles’ peak torques, average power and ball-throwing speed in handball players. Fourteen 14 to 15-year-old male athletes with injury-free shoulders participated in the study (body height: 176 ± 7 cm, body mass 63 ± 9 kg). The tests were carried out by an isokinetic dynamometer system in the shoulder internal and external rotation movements at angular velocities of 60°/s, 90°/s and 240°/s during concentric contractions. The eccentric external– concentric internal rotator muscle contractions were performed at the velocity of 90°/s. The player threw a ball at maximal speed keeping both feet on the floor. The speed was recorded with reflected light rays. Training in handball does not cause significant side asymmetry in shoulder external/internal rotator muscle peak torques or the average power ratio. Positive correlations between isokinetic characteristics of the shoulder internal and external rotator muscles and ball-throwing speed were determined. The power produced by internal rotator muscles during concentric contractions after eccentric contractions of external rotator muscles was significantly greater in the dominant than in the non-dominant arm. Thus, it may be concluded that the shoulder eccentric external/concentric internal rotator muscle power ratio is significantly greater than this ratio in the concentric contractions of these muscles. PMID:25414738

  11. Upper limb joint kinetic analysis during tennis serve: Assessment of competitive level on efficiency and injury risks.

    PubMed

    Martin, C; Bideau, B; Ropars, M; Delamarche, P; Kulpa, R

    2014-08-01

    The aim of this work was to compare the joint kinetics and stroke production efficiency for the shoulder, elbow, and wrist during the serve between professionals and advanced tennis players and to discuss their potential relationship with given overuse injuries. Eleven professional and seven advanced tennis players were studied with an optoelectronic motion analysis system while performing serves. Normalized peak kinetic values of the shoulder, elbow, and wrist joints were calculated using inverse dynamics. To measure serve efficiency, all normalized peak kinetic values were divided by ball velocity. t-tests were used to determine significant differences between the resultant joint kinetics and efficiency values in both groups (advanced vs professional). Shoulder inferior force, shoulder anterior force, shoulder horizontal abduction torque, and elbow medial force were significantly higher in advanced players. Professional players were more efficient than advanced players, as they maximize ball velocity with lower joint kinetics. Since advanced players are subjected to higher joint kinetics, the results suggest that they appeared more susceptible to high risk of shoulder and elbow injuries than professionals, especially during the cocking and deceleration phases of the serve. PMID:23293868

  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. PMID:26434017

  13. 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

  14. How to know and choose online games: differences between current and potential players.

    PubMed

    Teng, Ching-I; Lo, Shao-Kang; Wang, Pe-Cheng

    2007-12-01

    This study investigated how different adolescent players acquire game information and the criteria they use in choosing online games and found that (1) current players generally use comprehensive information sources more than potential players do; (2) current players rely on free trials and smooth display of motion graphics as choice criteria more than potential players do; (3) potential players rely on the look of advertisements more than current players do; (4) both current and potential players most likely use word-of-mouth and gaming programs on TV as information sources; and (5) endorser attractiveness is ranked the least important among six choice criteria by both current and potential players. PMID:18085974

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

    PubMed

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

    2012-12-01

    There is a need to investigate the effect of specific movement strategies in reducing biomechanical risk factors for anterior cruciate ligament injury in young female athletes. The purpose of this study was (a) to determine the feasibility of implementing a novel movement strategy (Core-PAC) into a team warm-up before soccer training based on subject compliance and integration of the Core-PAC into the warm-up and (b) 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) before kicking a soccer ball, and a side hop (SH) task after immediate instruction and after a 4-week training program. A convenience sample of ten 14- to 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, 2 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 N·m·kg(-1) during the SC (p < 0.03), 0.17 N·m·kg(-1) during the USC (p = 0.05), and 0.27 N·m·kg(-1) 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 1 method of modifying high-risk movements for ACL injury such as side cutting and single-leg landing. PMID:22210470

  16. 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

  17. Performance Prediction of Active Piezo Fiber Rackets in Terms of Tennis Power

    NASA Astrophysics Data System (ADS)

    Kawazoe, Yoshihiko; Takeda, Yukihiro; Nakagawa, Masamichi

    Several former top players sent a letter to the International Tennis Federation (ITF) encouraging the governing body to revisit the question of rackets. In the letter, the players wrote that racket technology has led to major changes in how the game is played at the top level. This paper investigated the physical properties of a new type of racket with active piezoelectric fibers appeared recently in the market, and predicted the various factors associated with the frontal impact, such as impact force, contact time, deformation of ball and strings, and also estimated the racket performance such as the coefficient of restitution, the rebound power coefficient, the post-impact ball velocity and the sweet areas relevant to the power in tennis. It is based on the experimental identification of the dynamics of the ball-racket-arm system and the approximate nonlinear impact analysis with a simple swing model. The predicted results with forehand stroke model can explain the difference in mechanism of performance between the new type racket with active piezoelectric fibers and the conventional passive representative rackets. It showed that this new type racket provides higher coefficient of restitution on the whole area of string face and also gives larger rebound power coefficients particularly at the topside and bigger powers on the whole area of string face but the difference was not so large. It seems that the racket-related improvements in play are relatively small and the players themselves continue to improve, accordingly there is a gap between a perception and reality.

  18. Gender differences in myocardial function and arterio-ventricular coupling in response to maximal exercise in adolescent floor-ball players

    PubMed Central

    2014-01-01

    Background The hemodynamic and cardiac responses to exercise have been widely investigated in adults. However, little is known regarding myocardial performance in response to a short bout of maximal exercise in adolescents. We therefore sought to study alterations in myocardial function and investigate sex-influences in young athletes after maximal cardiopulmonary testing. Methods 51 adolescent (13-19 years old) floor-ball players (24 females) were recruited. All subjects underwent a maximal exercise test to determine maximal oxygen uptake (VO2max) and cardiac output. Cardiac performance was investigated using conventional and tissue velocity imaging, as well as 2D strain echocardiography before and 30 minutes following exercise. Arterio-ventricular coupling was evaluated by means of single beat ventricular elastance and arterial elastance. Results Compared to baseline the early diastolic myocardial velocity (E′LV) at the basal left ventricular (LV) segments declined significantly (females: E′LV: 14.7 +/- 2.6 to 13.6 +/- 2.9 cm/s; males: 15.2 +/- 2.2 to 13.9 +/- 2.3 cm/s, p < 0.001 for both). Similarly, 2D strain decreased significantly following exercise (2D strain LV: from 21.5 +/- 2.4 to 20.2 +/- 2.7% in females, and from 20 +/- 1 to 17.9 +/- 1.5% in males, p < 0.05 for both). However, there were no significant changes in LV contractility estimated by elastance in either sex following exercise (p > 0.05). Arterial elastance) Ea) at baseline was identified as the only predictor of VO2max in males (r = 0.76, p < 0.001) but not in females (p > 0.05). Conclusions The present study demonstrates that vigorous exercise of short duration results in a significant decrease of longitudinal myocardial motion in both sexes. However, in view of unaltered end systolic LV elastance (Ees), these reductions most probably reflect changes in the loading conditions and not an attenuation of myocardial function per se. Importantly, we show that arterial

  19. VIEW OF BUILDING 221 (TENNIS COURTS) FROM NORTHWEST CORNER WITH ...

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

    VIEW OF BUILDING 221 (TENNIS COURTS) FROM NORTHWEST CORNER WITH BUILDING 23 IN BACKGROUND, FACING SOUTHEAST - Roosevelt Base, Tennis Courts, Corner of Reeves Avenue & Pennsylvania Street, Long Beach, Los Angeles County, CA

  20. VIEW OF BUILDING 221 (TENNIS COURTS) FROM NORTHEAST CORNER, BUILDING ...

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

    VIEW OF BUILDING 221 (TENNIS COURTS) FROM NORTHEAST CORNER, BUILDING 24 IN BACKGROUND, FACING SOUTHWEST - Roosevelt Base, Tennis Courts, Corner of Reeves Avenue & Pennsylvania Street, Long Beach, Los Angeles County, CA

  1. General view, Belair Bath and Tennis Club, Belair at Bowie, ...

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

    General view, Belair Bath and Tennis Club, Belair at Bowie, Maryland, looking west. - Belair Bath and Tennis Club, Southwest corner of Belair Drive and Tulip Grove Drive, Bowie, Prince George's County, MD

  2. 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

  3. 1. FACILITY 26, TENNIS AND BASKETBALL COURTS. VIEW LOOKING NORTHWEST ...

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

    1. FACILITY 26, TENNIS AND BASKETBALL COURTS. VIEW LOOKING NORTHWEST TOWARD QUARTERS F. - Chollas Heights Naval Radio Transmitting Facility, Tennis Courts, 6410 Zero Road, San Diego, San Diego County, CA

  4. Squash ball to eye ball: the likelihood of squash players incurring an eye injury.

    PubMed

    Barrell, G V; Cooper, P J; Elkington, A R; Macfadyen, J M; Powell, R G; Tormey, P

    1981-10-01

    The records of the 118 patients treated as Southampton Eye Hospital during 1978-9 for injuries incurred while playing squash, badminton, tennis, table tennis, cricket, and football show that for squash the main cause of eye injury was the player being hit by the ball. Severe eye injuries--those requiring treatment as an inpatient--were rare but much more frequent than such injuries in other sports. Less serious injuries--those requiring treatment as an outpatient--were also rare, with a frequency comparable with that of similar injuries in football and badminton. Squash players are most unlikely to incur an eye injury, but should this occur it has far-reaching consequences both in the short and the long term. Each individual player must weigh these chances and consequences against the possible inconvenience of using some form of eye protection. PMID:6793167

  5. Does an Eye-Hand Coordination Test Have Added Value as Part of Talent Identification in Table Tennis? A Validity and Reproducibility Study

    PubMed Central

    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. PMID:24465638

  6. 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. PMID:25162649

  7. Evaluation of a real world intervention using professional football players to promote a healthy diet and physical activity in children and adolescents from a lower socio-economic background: a controlled pretest-posttest design

    PubMed Central

    2014-01-01

    Background The increasing rates of obesity among children and adolescents, especially in those from lower socio-economic backgrounds, emphasise the need for interventions promoting a healthy diet and physical activity. The present study aimed to examine the effectiveness of the ‘Health Scores!’ program, which combined professional football player role models with a school-based program to promote a healthy diet and physical activity to socially vulnerable children and adolescents. Methods The intervention was implemented in two settings: professional football clubs and schools. Socially vulnerable children and adolescents (n = 165 intervention group, n = 440 control group, aged 10-14 year) provided self-reported data on dietary habits and physical activity before and after the four-month intervention. Intervention effects were evaluated using repeated measures analysis of variance. In addition, a process evaluation was conducted. Results No intervention effects were found for several dietary behaviours, including consumption of breakfast, fruit, soft drinks or sweet and savoury snacks. Positive intervention effects were found for self-efficacy for having a daily breakfast (p < 0.01), positive attitude towards vegetables consumption (p < 0.01) and towards lower soft drink consumption (p < 0.001). A trend towards significance (p < 0.10) was found for self-efficacy for reaching the physical activity guidelines. For sports participation no significant intervention effect was found. In total, 92 pupils completed the process evaluation, the feedback was largely positive. Conclusions The ‘Health Scores!’ intervention was successful in increasing psychosocial correlates of a healthy diet and PA. The use of professional football players as a credible source for health promotion was appealing to socially vulnerable children and adolescents. PMID:24886227

  8. 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. PMID:25482916

  9. 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

  10. Match activity and physiological responses during a junior female singles tennis tournament

    PubMed Central

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

    2007-01-01

    Objective To assess physiological load in conjunction with individual patterns of match‐play activity in junior female tennis players during actual singles tennis competition. Methods Eight elite junior female tennis players (n = 8; mean (SD) age, 17.3 (1.9) years) took part in a 2 day invitational tournament. Activity pattern analysis was performed during competitive matches. Heart rate and blood lactate concentrations were measured during selected changeovers breaks in play. Results The activity profile of junior female players were: rally duration, (mean (SD)) 8.2 (5.2) s; rest time between rallies, 17.7 (6.5) s; effective playing time, 21.9 (3.8)%; strokes per rally, 2.7 (1.7); changes of direction per rally, 2.3 (1.4). The mean (SD) heart rate and blood lactate concentration recorded during the matches were 161 (5) beats/min and 2.0 (0.8) mmol/litre. Heart rate and blood lactate concentration values were influenced by the characteristics of the match and mean (SD) heart rate was significantly higher (p = 0.004) during service games (166 (15.4) beats/min) than in return games (156 (19.6) beats/min), while blood lactate concentrations were not significantly different (p = 0.83) between service (2.3 (0.6) mmol/litre) and return games (2.3 (0.9) mmol/litre). We found a significant (p<0.05) positive relationship between rally duration, strokes per rally, changes of direction and blood lactate and heart rate responses, with stronger correlations when the players were serving. Conclusions The physiological (ie, blood lactate and heart rate) responses associated with match play were influenced by the characteristics of the match (rally duration, strokes per rally and changes of direction), with higher heart rate on service position. Training programs should reflect these demands placed on female players during competitive match play. PMID:17562743

  11. Vibration modeling and supression in tennis racquets.

    SciTech Connect

    Farrar, C. R.; Buechler, M. A.; Espino, Luis; Thompson, G. A.

    2003-01-01

    The size of the 'sweet spot' is one measure of tennis racquet performance. In terms of vibration, the sweet spot is determined by the placement of nodal lines across the racquet head. In this studx the vibrational characteristics of a tennis racquet are explorod to discover the size and location of the sweet spot. A numerical model of the racquet is developed using finite element analysis and the model is verified using the results from an experimental modal analysis. The affects of string tension on the racquet's sweet spot and mode shapes are then quantified. An investigation is also carried out to determine how add-on vibrational datnpers affect the sweet spot.

  12. 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

  13. 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. PMID:21904239

  14. 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

  15. 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. PMID:22091787

  16. Tennis Rackets and the Parallel Axis Theorem

    NASA Astrophysics Data System (ADS)

    Christie, Derek

    2014-04-01

    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.

  17. Buyer's Guide for Tennis Court Construction.

    ERIC Educational Resources Information Center

    United States Tennis Court & Track Builders Association.

    This booklet examines seven planning and decision-making tips for investing in and building tennis courts that can prolong court life and get the most from the investment. It examines defining needs, developing a budget, considering the use of a consultant, choosing a site, choosing a surface and developing working specifications, making specific…

  18. 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.

  19. 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…

  20. Little League Baseball and Players' Self-Esteem.

    ERIC Educational Resources Information Center

    Hawkins, Donna B.; Gruber, Joseph J.

    1982-01-01

    The effect of a season of little league baseball on the self-esteem of 94 pre-adolescent players was investigated. The Coopersmith Self-esteem Inventory and a newly devised Baseball-Self scale were administered. Significant improvements in players' total Self-esteem, Home-Parents and School-Academic scores were found. (Author/PN)

  1. Lower trunk kinematics and muscle activity during different types of tennis serves

    PubMed Central

    Chow, John W; Park, Soo-An; Tillman, Mark D

    2009-01-01

    Background To better understand the underlying mechanisms involved in trunk motion during a tennis serve, this study aimed to examine the (1) relative motion of the middle and lower trunk and (2) lower trunk muscle activity during three different types of tennis serves - flat, topspin, and slice. Methods Tennis serves performed by 11 advanced (AV) and 8 advanced intermediate (AI) male tennis players were videorecorded with markers placed on the back of the subject used to estimate the anatomical joint (AJ) angles between the middle and lower trunk for four trunk motions (extension, left lateral flexion, and left and right twisting). Surface electromyographic (EMG) techniques were used to monitor the left and right rectus abdominis (LRA and RRA), external oblique (LEO and REO), internal oblique (LIO and RIO), and erector spinae (LES and RES). The maximal AJ angles for different trunk motions during a serve and the average EMG levels for different muscles during different phases (ascending and descending windup, acceleration, and follow-through) of a tennis serve were evaluated. Results The repeated measures Skill × Serve Type × Trunk Motion ANOVA for maximal AJ angle indicated no significant main effects for serve type or skill level. However, the AV group had significantly smaller extension (p = 0.018) and greater left lateral flexion (p = 0.038) angles than the AI group. The repeated measures Skill × Serve Type × Phase MANOVA revealed significant phase main effects in all muscles (p < 0.001) and the average EMG of the AV group for LRA was significantly higher than that of the AI group (p = 0.008). All muscles showed their highest EMG values during the acceleration phase. LRA and LEO muscles also exhibited high activations during the descending windup phase, and RES muscle was very active during the follow-through phase. Conclusion Subjects in the AI group may be more susceptible to back injury than the AV group because of the significantly greater trunk

  2. Field-Based Pre-Cooling for On-Court Tennis Conditioning Training in the Heat

    PubMed Central

    Duffield, Rob; Bird, Stephen P.; Ballard, Robert J.

    2011-01-01

    The present study investigated the effects of pre-cooling for on- court, tennis-specific conditioning training in the heat. Eight highly-trained tennis players performed two on-court conditioning sessions in 35°C, 55% Relative Humidity. Sessions were randomised, involved either a pre-cooling or control session, and consisted of 30-min of court- based, tennis movement drills. Pre-cooling involved 20-min of an ice-vest and cold towels to the head/neck and legs, followed by warm-up in a cold compression garment. On-court movement distance was recorded by 1Hz Global Positioning Satellite (GPS) devices, while core temperature, heart rate and perceptual exertion and thermal stress were also recorded throughout the session. Additionally, mass and lower-body peak power during repeated counter-movement jumps were measured before and after each session. No significant performance differences were evident between conditions, although a moderate-large effect (d = 0.7-1.0; p > 0.05) was evident for total (2989 ± 256 v 2870 ± 159m) and high-intensity (805 ± 340 v 629 ± 265m) distance covered following pre-cooling. Further, no significant differences were evident between conditions for rise in core temperature (1.9 ± 0.4 v 2. 2 ± 0.4°C; d > 0.9; p > 0.05), although a significantly smaller change in mass (0.9 ± 0.3 v 1. 3 ± 0.3kg; p < 0.05) was present following pre-cooling. Perceived thermal stress and exertion were significantly lower (d > 1.0; p < 0.05) during the cooling session. Finally, lower-body peak power did not differ between conditions before or after training (d < 0.3; p > 0.05). Conclusions: Despite trends for lowered physiological load and increased distances covered following cooling, the observed responses were not significantly different or as explicit as previously reported laboratory-based pre-cooling research. Key points Pre-cooling did not significantly enhance training performance or reduce physiological load for tennis training in the heat

  3. Biochemical assessments of retinol, alpha-tocopherol, pyridoxal--5-phosphate oxidative stress index and total antioxidant status in adolescent professional basketball players and sedentary controls.

    PubMed

    Yilmaz, Necat; Erel, Ozcan; Hazer, Muhsin; Bağci, Cahit; Namiduru, Emine; Gül, Ece

    2007-01-01

    Physical training is known to increase the antioxidant defence system and reduce exercise-induced oxidative stress. However, intense physical aerobic and anaerobic training with competition, such as those imposed on young professional basketball players can induce an increase of oxidative stress, which can be implicated with overtraining. The aim of this study was to test the effect of training and competition load on oxidative stress, antioxidant status, and vitamin levels in basketball players. Oxidative Stres Index (OSI 1), Total Peroxide (TPx) antioxidant (vitamin E, A and The total antioxidant status (TAC 1)), biochemical lipid parameters, as well as training results were measured. Results showed that all plasma vitamin levels were significantly higher in basketball players (vitamin A: 1.61 +/- 0.05 mmol/l, vitamin E: 26.45 +/- 0.72 mmol/l, vitamin B6: 10.58 +/- 0.7 mgr/l) than sedentary controls (vitamin A: 1.22 +/- 0.04 mmol /l, vitamin E: 19.24 +/- 0.73 mmol/l, vitamin B6: 6.0 +/- 0.35 mgr/l) (p < 0.01). In addition TAC 1 was 2.06 +/- 0.02 and 1.89 +/- 0.01 mmol Trolox eq/L in basketball players and controls, respectively (p < 0.01). Conversely OSI was 0.89 +/- 0.09 arbitrary unit and 0.88 +/- 0.071 arbitrary unit in basketball players and controls, respectively (p > 0.05). However, total plasma peroxide level (TPx) of basketball players and controls was not statistically different (18.55 +/- 2.07 and 17.18 +/- 1.61 micromol H2O2/L, respectively; p > 0.05). We conclude that physical exercise increase antioxidant levels and cause balance of the homeostasis. Training can not have positive or negative effects on oxidative stress depending on training load. The results suggested that oxidative stress and antioxidant measurement are significant in the biological follow-up of young basketball players. PMID:17593769

  4. 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.

  5. 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.

  6. Viscoelastic modelling of tennis ball properties

    NASA Astrophysics Data System (ADS)

    Sissler, L.; Jones, R.; Leaney, P. G.; Harland, A.

    2010-06-01

    An explicit finite element (FE) tennis ball model which illustrates the effects of the viscoelastic materials of a tennis ball on ball deformation and bounce during normal impacts is presented. A tennis ball is composed of a rubber core and a fabric cover comprised of a wool-nylon mix which exhibit non-linear strain rate properties during high velocity impacts. The rubber core model was developed and validated using low strain rate tensile tests on rubber samples as well as high velocity normal impacts of pressurised cores at velocities ranging from 15 m/s to 50 m/s. The impacts were recorded using a high speed video (HSV) camera to determine deformation, impact time and coefficient of restitution (COR). The material properties of the core model were tuned to match the HSV results. A two component anisotropic fabric model was created which included artificial Rayleigh damping to account for hysteresis effects, and the core model 'tuning' process was used to refine the cloth layer. The ball model's parameters were in good agreement with experimental data at all velocities for both cores and complete balls, and a time sequenced comparison of HSV ball motion and FE model confirmed the validity of the model.

  7. Thermal, physiological and perceptual strain mediate alterations in match-play tennis under heat stress

    PubMed Central

    Périard, Julien D; Racinais, Sébastien; Knez, Wade L; Herrera, Christopher P; Christian, Ryan J; Girard, Olivier

    2014-01-01

    Objectives This study compared the thermal, physiological and perceptual responses associated with match-play tennis in HOT (∼34°C wet-bulb-globe temperature (WBGT)) and COOL (∼19°C WBGT) conditions, along with the accompanying alterations in match characteristics. Methods 12 male tennis players undertook two matches for an effective playing time (ie, ball in play) of 20 min, corresponding to ∼119 and ∼102 min of play in HOT and COOL conditions, respectively. Rectal and skin temperatures, heart rate, subjective ratings of thermal comfort, thermal sensation and perceived exertion were recorded, along with match characteristics. Results End-match rectal temperature increased to a greater extent in the HOT (∼39.4°C) compared with the COOL (∼38.7°C) condition (p<0.05). Thigh skin temperature was higher throughout the HOT match (p<0.001). Heart rate, thermal comfort, thermal sensation and perceived exertion were also higher during the HOT match (p<0.001). Total playing time was longer in the HOT compared with the COOL match (p<0.05). Point duration (∼7.1 s) was similar between conditions, while the time between points was ∼10 s longer in the HOT relative to the COOL match (p<0.05). This led to a ∼3.4% lower effective playing percentage in the heat (p<0.05). Although several thermal, physiological and perceptual variables were individually correlated to the adjustments in time between points and effective playing percentage, thermal sensation was the only predictor variable associated with both adjustments (p<0.005). Conclusions These adjustments in match-play tennis characteristics under severe heat stress appear to represent a behavioural strategy adopted to minimise or offset the sensation of environmental conditions being rated as difficult. PMID:24668377

  8. "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…

  9. Tennis Enhances Well-being in University Students.

    PubMed

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

    2016-05-18

    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

  10. 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

  11. 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…

  12. 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…

  13. 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…

  14. 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…

  15. Scapular Resting Position and Gleno-Humeral Movement Dysfunction in Asymptomatic Racquet Players: A Case-Control Study

    PubMed Central

    Shimpi, Apurv P.; Bhakti, Shah; Roshni, Karnik; Rairikar, Savita A.; Shyam, Ashok; Sancheti, Parag K.

    2015-01-01

    Background: Racquet sports, especially lawn tennis and badminton have been gaining popularity in Asian countries like India. With this increase in popularity, the injury rate in the sport has also increased. Objectives: The study will help detect the presence of gleno-humeral movement dysfunction and scapular resting position abnormality in asymptomatic racquet players, thus providing basis for screening the players and allow the clinician to determine if the asymmetry is a normal adaptation in the player or an abnormal change associated with injury. Materials and Methods: 46 asymptomatic professional players were divided into a study group of 23 players (16 tennis and 7 badminton) and control group of 23 football players. Assessment of passive gleno-humeral range of motion and distance of spine and inferior angle of scapula from corresponding spinous process were measured bilaterally and between groups. Results: There was statistically significant reduction in range of internal rotation (62.17 ± 8.09), extension (39.78 ± 4.12) and an increase in the external rotation (106.95 ± 7.49) of dominant compared to non-dominant arm of racquet players and a statistically significant decrease in internal rotation (78.69 ± 10.24), extension (44.78 ± 3.19), adduction (37.39 ± 6.54) and an increase in external rotation (102.6 ± 5.19) of dominant arm of racquet players compared to football players. Study also showed statistically significant increase in the spino-scapular distance at the level of inferior angle of scapula (10.23 ± 1.43) on dominant side compared to non-dominant. Conclusions: The dominant side scapula of asymptomatic racquet players showed increased external rotation and elevation as compared to the non-dominant side. Also, reduced shoulder internal rotation, extension and adduction and gain in shoulder external rotation was observed on the dominant side of racquet players when compared to the control group. PMID:26715968

  16. 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

  17. 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

  18. An Exploration of Exertion in Mixed Reality Systems via the ``Table Tennis for Three'' Game

    NASA Astrophysics Data System (ADS)

    Mueller, Florian ‘Floyd'; Gibbs, Martin R.; Vetere, Frank

    Humans experience their physical and social environment through their bodies and their associated movement actions. However, most mixed reality systems approach the integration of the real with a virtual world from a computational perspective, often neglecting the body’s capabilities by offering only limited interaction possibilities with a few augmented tangible objects. We propose a view on mixed reality systems that focuses on the human body and its movements, because we believe such an approach has the potential to support novel interaction experiences, as explored by a prototypal gaming system that was inspired by exertion actions exhibited in table tennis. “Table Tennis for Three” enables augmented bodily experiences while offering new opportunities for interaction, such as supporting three players simultaneously across geographical distances. This case study offers an exploration of the role of the human body and its associated movement actions in mixed reality systems, aiming to contribute toward an understanding of the use of exertion in such systems. Such an understanding can support leveraging the many benefits of exertion through mixed reality systems and therefore guide future advances in this research field.

  19. Upper-body kinematics in team-handball throw, tennis serve, and volleyball spike.

    PubMed

    Wagner, H; Pfusterschmied, J; Tilp, M; Landlinger, J; von Duvillard, S P; Müller, E

    2014-04-01

    Overarm movements are essential skills in many different sport games; however, the adaptations to different sports are not well understood. The aim of the study was to analyze upper-body kinematics in the team-handball throw, tennis serve, and volleyball spike, and to calculate differences in the proximal-to-distal sequencing and joint movements. Three-dimensional kinematic data were analyzed via the Vicon motion capturing system. The subjects (elite players) were instructed to perform a team-handball jump throw, tennis serve, and volleyball spike with a maximal ball velocity and to hit a specific target. Significant differences (P < 0.05) between the three overarm movements were found in 17 of 24 variables. The order of the proximal-to-distal sequencing was equal in the three analyzed overarm movements. Equal order of the proximal-to-distal sequencing and similar angles in the acceleration phase suggest there is a general motor pattern in overarm movements. However, overarm movements appear to be modifiable in situations such as for throwing or hitting a ball with or without a racket, and due to differences at takeoff (with one or two legs). PMID:22813080

  20. The Teachers' Guide to Urban Tennis Instruction. The New York City Schoolyard Tennis Program. Pilot Program, Spring 1984.

    ERIC Educational Resources Information Center

    New York City Board of Education, Brooklyn, NY. Div. of Curriculum and Instruction.

    This guide is designed for New York City school teachers who will conduct tennis classes for about 50 students while using limited tennis facilities. The insides of school buildings and school playgrounds will constitute the "courts" for these lessons. This type of introduction to the sport is intended to give students a sense of the game and its…

  1. When Less Is More: Reduced Usefulness Training for the Learning of Anticipation Skill in Tennis

    PubMed Central

    Smeeton, Nicholas J.; Huys, Raoul; Jacobs, David M.

    2013-01-01

    Participants in this study practiced with feedback to anticipate the left-right direction of forehand tennis shots played by stick-figure players. A technique based on principal component analysis was used to remove dynamical differences that are associated with shots to different directions. Different body regions of the stick-figure players were neutralized with this procedure in the pretests and posttests, and in the practice phases. Experiment 1 showed that training is effective if during practice information is consistently present in the whole body of the player, but not if the information is neutralized in the whole body in half of the practice trials. Experiment 2 showed that training is effective if the variance associated with the direction of the shots is consistently present in one body region but neutralized in others, and that transfer occurs from practice with information in one body region to performance in conditions with information preserved only in other regions. Experiment 3 showed that occlusion has a much larger detrimental effect on learning than the applied neutralization technique, and that transfer between body regions occurs also with occlusion. Discussed are theoretical implications for understanding how biological motion is perceived and possible applications in a type of training referred to as reduced usefulness training. PMID:24244564

  2. Another day, another tennis coaching intervention, but does this one do what coaches purport?

    PubMed

    Reid, Machar; Giblin, Georgia

    2015-06-01

    A proficient serve is critical to successful tennis performance, and consequently coaches and players devote considerable time refining this stroke. In so doing, a wide variety of interventions are used or trialled, generally with very little empirical support. This study examined the efficacy of a commonly used service intervention, where players focus on exaggerating their finish (arabesque) position to promote specific changes in lower limb and trunk kinematics. The kinematics of eight high-performance junior players hitting flat serves were compared to the acute changes in kinematics elicited by the arabesque follow through position on serves using a 10-camera VICON MX motion analysis system. The significantly greater front (landing leg) hip flexion (p < 0.05) and forward trunk flexion (p < 0.05) confirmed the more exaggerated arabesque landing position following the arabesque instruction. The arabesque instruction resulted in increased frontal plane trunk range of motion and peak angular velocity in the forward swing, and increased leg drive during the drive phase. Practically, the results support the use of the arabesque instruction, effectively promoting the desired acute changes in trunk kinematics (i.e. increased frontal plane trunk rotation angular velocity) and leg drive (i.e. increased back knee extension angular velocity and front/back vertical hip velocity). PMID:26102205

  3. The impact of match-play tennis in a hot environment on indirect markers of oxidative stress and antioxidant status

    PubMed Central

    Knez, Wade L; Périard, JP

    2014-01-01

    Objectives The purpose of this study was to determine the impact of changes in oxidative stress and antioxidant status in response to playing tennis in HOT (∼36°C and 35% relative humidity (RH)) and COOL (∼22°C and 70% RH) conditions. Methods 10 male tennis players undertook two matches for an effective playing time (ie, ball in play) of 20 min, corresponding to ∼122 and ∼107 min of total play in HOT and COOL conditions, respectively. Core body temperature, body mass and indirect markers of oxidative stress (diacrons reactive oxygen metabolic test) and antioxidant status (biological antioxidant potential test) were assessed immediately prematch, midmatch and postmatch, and 24 and 48 h into recovery. Results Regardless of the condition, oxidative stress remained similar throughout play and into recovery. Likewise, match-play tennis in the COOL had no impact on antioxidant status. However, antioxidants status increased significantly in the HOT compared with COOL environment (p<0.05). Body mass losses (∼0.5 kg) were similar between conditions. Rectal temperature increased during both matches (p<0.05), but with a greater magnitude in the HOT (39.3±0.5°C) versus COOL (38.7±0.2°C) environment (p<0.05). Conclusions Match-play tennis in the heat does not exacerbate the development of oxidative stress, but significantly increases antioxidant status. These data suggest that the heat stress observed in the HOT environment may provide a necessary signal for the upregulation of antioxidant defence, dampening cellular damage. PMID:24668382

  4. Biomechanics of the serve in tennis. A biomedical perspective.

    PubMed

    Elliott, B C

    1988-11-01

    Epidemiological studies have indicated that the serve, arguably the most important facet of the game of tennis, is also the most likely stroke to cause injury, particularly to the elbow and back. A review of the kinematic and kinetic studies on the service action fails to clearly identify the reason(s) for these injuries. Data from these studies does, however, allow possible causes of injury to be postulated. Electromyographic data from the prime mover muscles involved in the serve have shown that muscle action was greater for beginners, whose muscles were active for longer periods than those of advanced players. Ground reaction forces associated with different serving techniques were small compared to those recorded from activities involving running or jumping. The potential to cause injury seems to be related to high internal forces (combination of muscle and joint reaction forces), particularly where these forces are associated with poor technique and high segment accelerations. These situations occur when the racket moves behind the body and the vertebral column is laterally flexed and hyperextended. The pronation of the forearm and the forces associated with the swing to the ball, the impact and the early follow through are also factors that have the potential to cause injury. The action of serving induces strains and pressures upon the body. A sensible approach to the number of serves, particularly when practising (overuse), appropriate physical preparation and a technique that does not introduce excessive forces to selected body parts (misuse) will greatly reduce the potential for injury from this activity. PMID:3064237

  5. 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…

  6. Separating chokers from nonchokers: predicting real-life tennis performance under pressure from behavioral tasks that tap into working memory functioning.

    PubMed

    Bijleveld, Erik; Veling, Harm

    2014-08-01

    To better understand the characteristics of athletes who tend to underperform under pressure, we investigated how (a) working memory (WM) capacity and (b) responsiveness of the dopamine system shape real-life performance under pressure. We expected that athletes with smaller WM capacity or a more responsive dopamine system (as operationalized with a risk-taking measure) are especially prone to fail during decisive moments. In a sample of competitive tennis players, WM capacity was measured with the Automated Operation Span task (AOSPAN); responsiveness of the dopamine system was measured with a risk-taking measure, the Balloon Analogue Risk Task (BART). As expected, higher AOSPAN scores predicted better performance during decisive sets; higher BART scores predicted worse performance during decisive sets. These findings indicate that real-life tennis performance can be predicted from behavioral tasks that tap into WM functioning and risk taking, and suggest that the ability to effectively use WM despite pressure separates chokers from nonchokers. PMID:25226603

  7. 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

  8. Visual- spatial capacity: gender and sport differences in young volleyball and tennis athletes and non-athletes

    PubMed Central

    2014-01-01

    Background In the general population visual-spatial ability is better in males, due to the influence of biological and socio-cultural factors. We know that sport activity improves motor skills. The aim of this work is to determine if these gender differences exist in young athletes. The orientation test described by Terzi and standardized by Cesaroni, used to measure spatial ability, was carried out on 60 volleyball or 60 tennis athletes as well as on 60 non-sporting subjects. Results The data analysis revealed a worse performance for non-athletes in comparison with athletes in both components of test (p < 0.0001; p = 0.04), with no differences between the volleyball and tennis groups. As far as gender comparison is concerned, as expected in the non- sport group the males presented better values (p < 0.001; p = 0.006). However in both sports groups there weren’t any gender differences in either part of the test (p = 0.18; p = 0.056). Conclusions These results confirm that during athletic preparation in volleyball and tennis the specific training is able to develop spatial ability. Besides, boys and girls have similar performance demands and training experience. It appears that this specific training could be responsible for modifying gender differences in performance of spatial ability during adolescence. PMID:24447526

  9. 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

  10. 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

  11. GENERAL VIEW OF MAIN HOUSE, TENNIS COURTS, SWIMMING POOL, JOE'S ...

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

    GENERAL VIEW OF MAIN HOUSE, TENNIS COURTS, SWIMMING POOL, JOE'S CABIN AND BUNKHOUSE (LEFT TO RIGHT); CAMERA FACING SOUTH - Harry Carey Ranch, 28515 San Francisquito Canyon Road, Saugus, Los Angeles County, CA

  12. 21. VIEW OF TENNIS COURTS LOOKING NORTHEAST FROM ROOF OF ...

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

    21. VIEW OF TENNIS COURTS LOOKING NORTHEAST FROM ROOF OF BUILDING 8970 (CREW READINESS BUILDING). - Loring Air Force Base, Alert Area, Southeastern portion of base, east of southern end of runway, Limestone, Aroostook County, ME

  13. Circular stair from Parking Overlook to Clay Tennis Courts, Riverside ...

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

    Circular stair from Parking Overlook to Clay Tennis Courts, Riverside Park at 96th Street, looking southwest. - Henry Hudson Parkway, Extending 11.2 miles from West 72nd Street to Bronx-Westchester border, New York County, NY

  14. 20. VIEW OF TENNIS COURTS LOOKING SOUTH, WITH CONVERTED BASKETBALL ...

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

    20. VIEW OF TENNIS COURTS LOOKING SOUTH, WITH CONVERTED BASKETBALL COURT IN FOREGROUND. - Loring Air Force Base, Alert Area, Southeastern portion of base, east of southern end of runway, Limestone, Aroostook County, ME

  15. Matchplay characteristics of Grand Slam tennis: implications for training and conditioning.

    PubMed

    Reid, Machar; Morgan, Stuart; Whiteside, David

    2016-10-01

    The purpose of this study was to probe the sex-based differences in the stroke and movement dynamics of Grand Slam hard-court tennis. Player and ball tracking data were collated for 102 male and 95 female players during the 2012-2014 Australian Open tournaments. Serve, serve return, groundstroke and movement data were compared between sexes. Serve statistics were the subject of the largest differences, with males achieving significantly faster speeds, aces and unreturned serves while also winning a greater percentage of service points. When returning serve, women contacted the ball closer to the net, lower to the ground and achieved flatter ball trajectories than males. Groundstroke frequencies were similar between sexes, although males hit with greater speed, flatter trajectories and impacted more shots inside the baseline. Distance covered per set or during points won or lost was not sex dependent, yet men exhibited faster average movement speeds. These findings highlight the need for sex-specific training and practice designs that cater to the different stroke dynamics, particularly in relation to the first serve and serve-return, as well as movement speeds. PMID:27009823

  16. Posture in basketball players.

    PubMed

    Perrin, P; Perrin, C; Courant, P; Béné, M C; Durupt, D

    1991-01-01

    Static and dynamic posturography was recorded in eleven professional national basketball players (complete team). This sport requires balance and skill and is practiced by tall subjects (average height: 197 cm) with a history of 10 to 15 tibio-tarsal sprains. In static tests, with eyes open or closed, the way was similar between controls and players, while the area was increased for the latter. Area increment could be related to the history of ankle trauma reported by these subjects. In toes up dynamic tests, the latency of the first response (short latency response-myotatic reflex) was shorter in players. Data provided by national charts were used to compare posturography performance and player's skill. The best player who also ranks high in the national chart, has distinctive results in static posturography, with almost no difference when the test is performed with closed eyes. PMID:1950556

  17. 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

  18. 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. PMID:26109450

  19. 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

  20. Performance factors related to the different tennis backhand groundstrokes: a review.

    PubMed

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

    2015-03-01

    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 pointsOne-and two-handed backhands require different motor coordinationTwo-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 limbPlayers using a two-handed backhand should learn early a slice one-handed backhand because of the different co-ordination pattern involvedEquipment scaling is a great tool for coaches to learn early proper one-handed backhand strokesFuture research related to the interaction between backhand technique, gender and skill level is needed. PMID:25729308

  1. Neuromuscular adjustments of the knee extensors and plantar flexors following match-play tennis in the heat

    PubMed Central

    Périard, Julien D; Girard, Olivier; Racinais, Sébastien

    2014-01-01

    Objectives This study tested the hypothesis that impairments in lower limb maximal strength and voluntary activation (VA) are exacerbated following match-play tennis in hot compared with cool conditions. Methods Torque and VA were evaluated during brief (5 s) and sustained (20 s) maximal voluntary isometric contractions of the knee extensors (KE) and plantar flexors (PF) in 12 male tennis players before (pre) and after (post, 24 h and 48 h) ∼115 min of play in hot (∼37°C) and cool (∼22°C) conditions. Results Rectal temperature was higher following play in hot than in cool (∼39.2 vs ∼38.5°C; p<0.05). Torque production decreased from prematch to postmatch during the brief and sustained contractions in hot (KE: ∼22%; PF: ∼13%) and cool (KE: ∼9%, PF: ∼7%) (p<0.05). KE strength losses in hot were greater than in cool (p<0.05) and persisted for 24 h (p<0.05). Postmatch brief and sustained KE VA was lower in hot than in cool (p<0.05), in which VA was maintained. PF VA was maintained throughout the protocol. Peak twitch torque and maximum rates of torque development and relaxation in the KE and PF were equally reduced postmatch relative to prematch in hot and cool conditions (p<0.05), and were restored near baseline within 24 h. Conclusions Neuromuscular system integrity of the lower limbs is compromised immediately following match-play tennis in hot and cool conditions due to the development of peripheral fatigue. The larger and persistent KE strength losses observed under heat stress are associated with greater levels of central fatigue especially during sustained contractions. PMID:24668379

  2. 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

  3. Bone marrow injection: A novel treatment for tennis elbow

    PubMed Central

    Singh, Ajit; Gangwar, Devendra Singh; Singh, Shekhar

    2014-01-01

    Objective: The objective of this prospective study was assessment of efficacy of bone marrow aspirate (BMA) (containing plasma rich in growth factors and mesenchymal stem cells) injection in treatment of tennis elbow. Materials and Methods: A total of 30 adult patients of previously untreated tennis elbow were administered single injection of BMA. This concentrate was made by centrifugation of iliac BMA at 2000 rpm for 20-30 min and only upper layer containing platelet rich plasma and mononuclear cells was injected. Assessment was performed at baseline, 2 weeks, 6 weeks and 12 weeks using Patient-rated Tennis Elbow Evaluation (PRTEE) score. Results: Baseline pre-injection mean PRTEE score was 72.8 ± 6.97 which decreased to a mean PRTEE score of 40.93 ± 5.94 after 2 weeks of injection which was highly significant (P < 0.0001). The mean PRTEE score at 6 week and 12 week follow-up was 24.46 ± 4.58 and 14.86 ± 3.48 respectively showing a highly significant decrease from baseline scores (P < 0.0001). Conclusion: Treatment of tennis elbow patients with single injection of BMA showed a significant improvement in short to medium term follow-up. In future, such growth factors and/or stem cells based injection therapy can be developed as an alternative conservative treatment for patients of tennis elbow, especially who have failed non-operative treatment before surgical intervention is taken. PMID:25097421

  4. Effect of the racket mass and the rate of strokes on kinematics and kinetics in the table tennis topspin backhand.

    PubMed

    Iino, Yoichi; Kojima, Takeji

    2016-01-01

    The purpose of this study was to investigate the effect of the racket mass and the rate of strokes on the kinematics and kinetics of the trunk and the racket arm in the table tennis topspin backhand. Eight male Division I collegiate table tennis players hit topspin backhands against topspin balls projected at 75 balls · min(-1) and 35 balls · min(-1) using three rackets varying in mass of 153.5, 176 and 201.5 g. A motion capture system was used to obtain trunk and racket arm motion data. The joint torques of the racket arm were determined using inverse dynamics. The racket mass did not significantly affect all the trunk and racket arm kinematics and kinetics examined except for the wrist dorsiflexion torque, which was significantly larger for the large mass racket than for the small mass racket. The racket speed at impact was significantly lower for the high ball frequency than for the low ball frequency. This was probably because pelvis and upper trunk axial rotations tended to be more restricted for the high ball frequency. The result highlights one of the advantages of playing close to the table and making the rally speed fast. PMID:26208598

  5. Video Player Keyboard Shortcuts

    MedlinePlus

    ... https://www.nlm.nih.gov/medlineplus/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 ...

  6. 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

  7. 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…

  8. Influence of repeated bouts of table tennis training on cardiac biomarkers in children.

    PubMed

    Ma, Guodong; Liu, Yanhuan; Liu, Kemin

    2014-04-01

    It is documented that exercise can increase serum cardiac troponins in adults and adolescents; however, there is a lack of related studies concerning the release of cardiac troponins in children. This study investigated the influence of table tennis training on cardiac biomarkers in children. Twenty-eight male children performed six 10-min forehand exercise sessions with 5-min recovery intervals. Serum cardiac troponin T (cTnT) and I (cTnI), and creatinine kinase isoenzyme MB (CK-MB) were assessed before exercise, immediately after the last 10 min of exercise (PEI), 4 h post-exercise (PE4), 24 h post-exercise (PE24), and 48 h post-exercise (PE48). Cardiac function was measured using an ultrasound system (GE Vivid7 Dimension) at rest state. Serum cTnT, cTnI, and CK-MB were significantly elevated from the PEI sample point, and returned to baseline at the PE48 sample point in children. Serum cTnT in four (14.29%), nine (32.14%), and two (7.14%) subjects at the PEI, PE4, and PE24 sample points, respectively, exceeded the cutoff for myocardial injury. At the PE4 sample point, cTnT in five subjects (17.86%) exceeded the cutoff for acute myocardial infarction. Serum cTnI in two (14.29%), seven (25%), and two (7.14 %) subjects at the PEI, PE4, and PE24 timepoints, respectively, exceeded the cutoff for myocardial injury. cTnI in two subjects (7.14%) exceeded the cutoff for acute myocardial infarction at the PE4 timepoint in children. Repeated bouts of table tennis forehand training can significantly increase the release of serum cardiac troponins in some children. PMID:24272170

  9. Open Versus Arthroscopic Tennis Elbow Release

    PubMed Central

    Leiter, Jeff; Clark, Tod; McRae, Sheila; Dubberley, James; MacDonald, Peter B.

    2016-01-01

    Objectives: The primary objective of this study was to determine if quality of life and function are different following arthroscopic versus open tennis elbow release surgery. Based on retrospective studies, both approaches have been found to be beneficial, but no prospective randomized comparison has been conducted to date. Methods: Following a minimum six-months of conservative treatment, seventy-one patients (>16 yrs old) were randomized intraoperatively to undergo either arthroscopic or open lateral release. Outcome measures were the Disabilities of the Arm, Shoulder and Hand questionnaire (DASH), a 5-question VAS Pain Scale, and grip strength. Study assessments took place pre-, and 6-week, 3-, 6-, and 12-months post-surgery. Comparisons between groups and within groups over time were conducted using repeated measures ANOVA. A minimal clinically significant difference for the DASH had been previously identified as 15 points, and was used to compare groups as well at 12-months post-operative (Beaton et al. 2001). Results: Fifteen women and 19 men underwent the open procedure with a mean age of 47.1 years (6.7) and 13 women and 21 men were in the arthroscopic group with a mean age of 45.0 (6.9). No pre-surgery differences were found between groups based on age, sex, DASH or VAS scores. Both groups demonstrated a significant improvement in subjective measures and grip strength by 12-months post-surgery, and no significant differences were found between groups at any time point. The DASH, our primary outcome, decreased from a mean (SD) of 47.5 (14.5) pre-surgery to 21.9 (21.8) at 12-months post-surgery in the Open group and from 52.7 (16.0) to 22.6 (21.1) in the Arthroscopic group. VAS-pain scores (%) decreased in the Open group from 62.5 (17.2) pre-operatively to 30.0 (26.5) at 12-months. In the arthroscopic group, scores decreased from 63.7 (15.9) to 26.2 (24.6). Grip strength (kg) increased on the affected side from 23.6 (14.9) to 29.3 (16.3) and 21.4 (15.4) to

  10. Concussion Study Shows Player-To-Player Hits Most Damaging

    MedlinePlus

    ... Study Shows Player-to-Player Hits Most Damaging Running longer before the contact happens also spells more ... the University of Georgia. "We also found that running a long distance before colliding with an opponent ...

  11. 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…

  12. Tennis-Badminton-Squash Guide. June 1974-June 1976.

    ERIC Educational Resources Information Center

    Sherman, Patricia, Ed.; And Others

    This guide is a collection of essays by various authors on tennis, badminton, and squash. The document is divided into three sections, one for each sport. The topics covered include general teaching methods, methods to employ for teaching specific skills such as the lob or the backhand, the use of visual aids, conditioning drills, study questions,…

  13. Tectonic Tennis Balls: The STRATegy COLUMN for Precollege Science Teachers.

    ERIC Educational Resources Information Center

    Metzger, Ellen Pletcher

    1994-01-01

    Contains instructions and two patterns for making a terrestrial globe and a tectonic globe. The pattern is designed to be glued onto a tennis ball. By constructing the globes, students obtain a greater understanding of the locations of the edges of continents and the earth's plates. (AIM)

  14. 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…

  15. 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…

  16. Physical Education: Tennis, Physical Fitness, Body-Building.

    ERIC Educational Resources Information Center

    Veilleux, Dave

    This unit plan for introducing high school students to the game of tennis is divided into objectives and suggested activities. A listing of resource outlets and retail prices for equipment and audiovisual materials is included. Student evaluation procedures are outlined, and a sample evaluation checklist is provided. (LH)

  17. 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

  18. 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 ...

  19. Shoulder joint loading in the high performance flat and kick tennis serves

    PubMed Central

    Reid, Machar; Elliott, Bruce; Alderson, Jacque

    2007-01-01

    Objective To quantify and compare the full body kinematics and shoulder joint kinetics during the high‐performance tennis flat (FS) and kick serves (KS). Methods A 12‐camera 250 Hz, Vicon motion analysis system recorded the three‐dimensional FS and KS of 12 high‐performance male players. A total of 22 paired Student's t tests, with an accompanying partial Bonferroni correction (p<0.01), determined statistically significant differences between the variables of interest in both serves. Results Higher peak horizontal, vertical and absolute racquet velocities were developed during the FS, while higher lateral velocities characterised the KS. Similar shoulder joint kinematics and kinetics punctuated both serves, but with some variation in trunk and lower limb mechanics. Conclusions Similar shoulder joint kinetics assisted the development of varying three‐dimensional racquet velocities in the FS and KS. The comparable shoulder joint loading conditions point to the repetitive, long‐term performance of either serve as relevant in shoulder joint injury pathologies. PMID:17513331

  20. 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

  1. 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)

  2. The Role of Knee Positioning and Range-of-Motion on the Closed-Stance Forehand Tennis Swing

    PubMed Central

    Nesbit, Steven M.; Serrano, Monika; Elzinga, Mike

    2008-01-01

    This paper discusses the role of knee positioning and range-of- motion on the closed-stance forehand tennis swing. The analyses of tennis swing mechanics were performed using a computer model comprised of a full-body model of a human and an inertial model of a racket. The model was driven by subject forehand swings (16 female college-level subjects) recorded with a high-speed digital motion analysis system. The study discovered that both initial knee positioning and range-of-motion were positively related to racket velocity and characteristic of more skilled players. The direct effects of knee positioning and range-of-motion on racket movement are minimal, however there are several indirect biomechanical effects on the forehand motion such as movement of the body mass center, work of the knee, hip and back joints, and the angular range-of-motion of the hips and torso. Some of these indirect effects were related to racket velocity and characteristic of more skilled players. Factors that influenced knee positioning and range-of-motion include years of playing, amount of coaching, and body style. Efforts to both increase and restrict the knee movements of the subjects resulted in substantially lower racket velocities (and other detrimental biomechanical effects) implying that there may be optimal knee positions and range-of-motion for a given subject. The most skilled subject exhibited a high degree of consistency of knee positioning and range-of-motion. This subject adjusted for varying ball height through modified initial knee positioning while maintaining fairly constant ranges-of-motion. Key pointsInitial knee positioning and range-of-motion were positively related to racket velocity and characteristic of more skilled players for the closed stance forehand motion.Knee positioning and range-of-motion had several indirect biomechanical effects on the forehand motion such as movement of the body mass center, work of the knee, hip and back joints, and the angular

  3. Pictorial essay: Ultrasonography in ‘tennis leg’

    PubMed Central

    Shah, Jeshil R; Shah, Bipin R; Shah, Ankit B

    2010-01-01

    Tennis leg is caused by a rupture of the medial head of the gastrocnemius muscle, usually at its distal musculotendinous junction region. However, tears in this muscle and its tendon are also included under the term ‘tennis leg’. It is seen regularly in practice and is an important cause of a painful calf. The common USG findings include: disruption of the pinnate pattern of the distal medial gastrocnemius, usually near the junction of the triceps surae (which is the echogenic line between the gastrocnemius, the soleus, and the plantaris muscles), fluid tracking along the fascia, adjacent hematoma, and intramuscular tears as well as hematomas. USG is useful for confirming the diagnosis, excluding other causes of a painful calf, for assessing the severity of the disease, and in follow-up. PMID:21577246

  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. PMID:23238089

  5. Tennis in hot and cool conditions decreases the rapid muscle torque production capacity of the knee extensors but not of the plantar flexors

    PubMed Central

    Girard, Olivier; Racinais, Sébastien; Périard, Julien D

    2014-01-01

    Objectives To assess the time course of changes in rapid muscle force/torque production capacity and neuromuscular activity of lower limb muscles in response to prolonged (∼2 h) match-play tennis under heat stress. Methods The rates of torque development (RTD) and electromyographic activity (EMG; ie, root mean square) rise were recorded from 0 to 30, –50, –100 and –200 ms during brief (3–5 s) explosive maximal isometric voluntary contractions (MVC) of the knee extensors (KE) and plantar flexors (PF), along with the peak RTD within the entirety of the torque-time curve. These values were recorded in 12 male tennis players before (prematch) and after (postmatch, 24 and 48 h) match-play in HOT (∼37°C) and COOL (∼22°C) conditions. Results The postmatch core temperature was greater in the HOT (∼39.4°C) vs COOL (∼38.7°C) condition (p<0.05). Reductions in KE RTD occurred within the 0–200 ms epoch after contraction onset postmatch and at 24 h, compared with prematch, independent of environmental conditions (p<0.05). A similar reduction in the KE peak RTD was also observed postmatch relative to prematch (p<0.05). No differences in KE RTD values were observed after normalisation to MVC torque. Furthermore, the rate of KE EMG activity rise remained unchanged. Conversely, the PF contractile RTD and rate of EMG activity rise were unaffected by the exercise or environmental conditions. Conclusions In the KE, a reduction in maximal torque production capacity following prolonged match-play tennis appears to account for the decrease in the rate of torque development, independent of environmental conditions, while remaining unchanged in the PF. PMID:24668381

  6. Tennis-Badminton-Squash Guide with Official Rules. June 1972 - June 1974.

    ERIC Educational Resources Information Center

    Knight, Martha, Ed.; And Others

    Rules in tennis, badminton, and squash for girls and women from June 1972 - June 1974 are discussed. Standards in the sports are detailed along with the Division for Girls and Women's Sports (DGWS) statement of beliefs. Specific articles dealing with teaching techniques, officiating techniques, and rules for tennis and badminton are presented.…

  7. 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.

  8. 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

  9. SteroMoviePlayer

    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 moviemore » 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

  10. Eating and nutrition habits in young competitive athletes: a comparison between soccer players and cyclists.

    PubMed Central

    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. PMID:25674549

  11. 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

  12. Ankle injuries in basketball players.

    PubMed

    Leanderson, J; Nemeth, G; Eriksson, E

    1993-01-01

    We carried out a retrospective study of the frequency of ankle sprains in basketball players. A questionnaire about previous ankle injuries, time off after such injuries, current ankle problems, personal data, number of practice hours and the use of prophylactic measures was sent out to 102 basketball players in a second division league in Sweden. Ninety-six players answered. 92% of them had suffered an ankle sprain while playing basketball, and of these 83% reported repeated sprains of one ankle. In the last two seasons, 78% of the players had injured at least one ankle. The injury frequency in the investigation was 5.5 ankle injuries per 1000 activity hours. 22% of the players used some kind of prophylactic support of their ankle joints. Because of the great number of ankle sprains and the disability in terms of time away from sports that they cause, prevention of these injuries is essential. PMID:8536029

  13. Elite collegiate tennis athletes have lower 2D: 4D ratios than those of nonathlete controls.

    PubMed

    Hsu, Cheng-Chen; Su, Borcherng; Kan, Nai-Wen; Lai, Su-Ling; Fong, Tsorng-Harn; Chi, Chung-Pu; Chang, Ching-Chyuan; Hsu, Mei-Chich

    2015-03-01

    The ratio of the length of the second finger (index finger) to the fourth finger (ring finger) (2D:4D ratio) is a putative marker for prenatal hormones. Physiological research has suggested a low 2D:4D ratio correlates with high athletic ability. Athletes of specific sports (e.g., American football) have lower 2D:4D ratios than those of nonathletes, whereas athletes of some sports (e.g., rowing, gymnastics, and soccer) do not. This study investigated the 2D:4D ratios among collegiate tennis athletes, elite collegiate tennis athletes, and nonelite collegiate tennis athletes and compared them with nonathletes of both sexes. The participants included 43 elite collegiate tennis athletes (Level I intercollegiate athletes in Taiwan; 27 males and 16 females), 107 nonelite collegiate tennis athletes (Level II athletes; 55 males and 52 females), and 166 nonathlete college students (80 males and 86 females). The principle findings suggest that (a) regardless of sex, collegiate tennis athletes have lower 2D:4D values than those of nonathletes; (b) elite collegiate tennis athletes have lower 2D:4D values than those of nonathletes; (c) among females but not males, athletes and nonelite athletes have lower 2D:4D values than those of nonathletes; and (d) males have lower 2D:4D values than those of females. PMID:25226321

  14. Rotation sequence is an important factor in shoulder kinematics. Application to the elite players' flat serves.

    PubMed

    Bonnefoy-Mazure, A; Slawinski, J; Riquet, A; Lévèque, J-M; Miller, C; Chèze, L

    2010-07-20

    The aim of this study was to test three different rotation sequences (YXY, ZXY, and XZY) on the shoulder kinematics (rotations of the humerus relative to the thorax) during an original movement such as the tennis flat serve (FS). Nine elite male and female players performed a minimum of five flat serves. An optoelectronic motion analysis system was used to record the movements. Segment kinematics during each FS was reconstructed from the spatial trajectories of the markers according to ISB recommendations. For each rotation sequence, three angles were reported for the shoulder joint, each corresponding to a rotation component around a defined axis. The occurrence of gimbal lock (GL) and angle amplitude coherences were examined. From these three rotation sequences tested, it appears that the XZY sequence was the only decomposition not to suffer from GL. Moreover, the rotation sequence XZY was found to be coherent for all rotation components. Thus, these results show that the best rotation sequence, from both GL and amplitude coherence points of view, is XZY to describe the shoulder kinematics during the tennis serve. PMID:20382388

  15. The Effects of Scaling Tennis Equipment on the Forehand Groundstroke Performance of Children

    PubMed Central

    Larson, Emma J.; Guggenheimer, Joshua D.

    2013-01-01

    The modifications that have taken place within youth sports have made games, such as basketball, soccer, or tennis, easier for children to play. The purpose of this study was to determine the effects low compression (LC) tennis balls and scaled tennis courts had on the forehand groundstroke performance of children. The forehand groundstroke performances of eight subjects’ (8.10 ± 0.74 yrs) using LC tennis balls were measured on a scaled tennis court and standard compression balls (SC) on a standard court. Forehand groundstroke performance was assessed by the ForeGround test which measures Velocity Precision Success Index (VPS) and Velocity Precision Index (VP). Participants attempted three different forehand rally patterns on two successive days, using LC balls on the 18.3m court one day and SC balls on the 23.8m court the other. When using LC balls, participants’ recorded higher overall VPS performance scores (p < 0.001) for each non-error stroke as well as higher VP scores (p = 0.01). The results of this study confirmed that the use of modified balls and modified court size may increase the control, velocity and overall success rate of the tennis forehand groundstroke of children. Key Points This study observed the effects of modified tennis balls and court had on the forehand groundstroke performance in children. Modified ball compression and modified court size can increase control, velocity and overall success of tennis performance. Children will have more success learning the game of tennis using modified equipment than using standard equipment. PMID:24149812

  16. 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.

  17. 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

  18. 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

    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

  19. 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…

  20. Tennis core strings of polyamide-6 modified by surface-capped nano-silica

    NASA Astrophysics Data System (ADS)

    Liu, Juan; Yi, Hongling; Lin, Heng; Zheng, Baicun

    2013-01-01

    A new method that modified silica nanoparticles were infused into PA6 is to produce tennis core string through a melt-extrusion process. The idea was to produce a highly strong and elastic tennis core string of PA6, utilizing the interactions between modified silica and polymer. The effects of surface-capped nano-silica on the strength and elongation of tennis core string were studied. It has been observed that with the infusion of silica nanoparticles modified by γ-glycidoxypropyltrimethoxysilane (GPS), the stress at breaking and E-modulus of tennis core string is enhanced by 46.24% and 15.17% comparing with neat PA6 with changeless elongation at breaking at a critical concentration. The source of this improvement has been traced to the produced strong covalent bond and hydrogen bond between epoxy groups and-COOH and-NH2 in polyamide. Besides, compared with kinds of others strings of previous research results, tennis core string added nano-silica modified by γ-glycidoxypropyltrimethoxysilane (GPS) has a strength at breaking at 352.43 MPa exceeding the natural gut string, the polyvinylidene fluoride (PVDF), Monofil string and integrated nylon string by 42.05%, 4.49% and 9.38%, respectively. Meanwhile, tennis core string of polyamide modified by surface-capped nanosilica (PGMNS) has a higher elastic ratio at 0.15 than the other four strings.

  1. 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…

  2. 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

  3. 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. PMID:25568727

  4. Acute Compartment Syndrome After Gastrocnemius Rupture (Tennis Leg) in a Nonathlete Without Trauma.

    PubMed

    Tao, Li; Jun, Huang; Muliang, Ding; Deye, Song; Jiangdong, Ni

    2016-01-01

    Acute compartment syndrome is a serious emergency that warrants urgent decompression, and tennis leg (i.e., rupture of the medial head of the gastrocnemius) is a known clinical condition that is usually treated symptomatically, with good results overall. In rare cases, acute compartment syndrome is associated with tennis leg after severe direct muscle trauma or severe exercise in athletes or physically active individuals. We present an unusual case of acute compartment syndrome secondary to tennis leg after the patient, a nonathlete, had disembarked from a truck without any trauma. Clinicians should have a high index of suspicion for atraumatic compartment syndrome, and timely surgical fasciotomy must be undertaken to avoid complications resulting from delayed diagnosis and treatment. PMID:25435006

  5. 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

  6. A numerical and experimental study of the kinematics of a tennis ball

    NASA Astrophysics Data System (ADS)

    Navarro Sorroche, Juan

    A numerical and experimental study of the kinematics of a tennis ball. An experimental apparatus to collect data of the tennis ball in motion is designed and constructed. Data collected by the experimental apparatus is corrected by the intrinsic and extrinsic camera distortions before numeric calculation predictions of the ball's point of impact with the court are made. The experimental apparatus constructed together with comprehensive numeric computations including atmospheric conditions and spin decay, allowed making predictions of the ball's point of impact with the court with and errors <0.029%

  7. 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.

  8. 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

  9. Longitudinal study of repeated sprint performance in youth soccer players of contrasting skeletal maturity status.

    PubMed

    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, CA(2), 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 CA(2) - 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 of youth

  10. 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

  11. Management of Tennis Elbow with sodium hyaluronate periarticular injections

    PubMed Central

    2010-01-01

    Objectives To determine the efficacy and safety of peri-articular hyaluronic acid injections in chronic lateral epicondylosis (tennis elbow). Design Prospective randomized clinical trial in primary care sport medicine. Patients Three hundred and thirty one consecutive competitive racquette sport athletes with chronic (>3 months) lateral epicondylosis were administered 2 injections (first injection at baseline) into the subcutaneous tissue and muscle 1 cm. from the lateral epicondyle toward the primary point of pain using a two-dimensional fanning technique. A second injection was administered 1 week later. Outcomes measures Assessments were done at baseline, days 7, 14, 30, 90 and 356. Efficacy measures included patient's visual analogue scale (VAS) of pain at rest (0-100 mm) and following assessment of grip strength (0-100 mm). Grip strength was determined using a jamar hydraulic hand dynamometer. Other assessments included patients' global assessment of elbow injury (5 point categorical scale; 1 = no disability, 5 = maximal disability), patients' assessment of normal function/activity (5 point categorical scale), patients/physician satisfaction assessment (10 point categorical scale), time to return to pain-free and disability-free sport and adverse events as per WHO definition. Differences between groups were determined using an intent-to-treat ANOVA. Results Average age of the study population was 49 years (± 12 years). One hundred and sixty-five patients were randomized to the HA and 166 were randomized to the control groups. The change in VAS pain was -6.7 (± 2.0) for HA vs -1.3 (± 1.5) for control (p < 0.001). The VAS post handgrip was -7.8 (± 1.3) vs +0.3 (± 2.0) (p < 0.001) which corresponded to a significant improvement in grip of 2.6 kg in the HA vs control groups (p < 0.01). Statistically significant improvement in patients' global assessment of elbow injury (p < 0.02), patients' assessment of normal function/activity (p < 0.05) and patients

  12. Effects of Taping on Pain, Grip Strength and Wrist Extension Force in Patients with Tennis Elbow

    PubMed Central

    Shamsoddini, Alireza; Hollisaz, Mohammad Taghi

    2013-01-01

    Background Tennis elbow (TE) is a common musculotendinous degenerative disorder of the extensor origin at the lateral humeral epicondyle. Different modes of treatment are used for management of tennis elbow. Objectives This study investigated the effect of the taping technique (TT) on pain, grip strength and wrist extension force in treatment of tennis elbow. Patients and Methods Thirty patients (16 men /14 women with a mean age of 32.2 years) with tennis elbow of their dominant arm participated in this study. Outcome measures were assessment of pain at the lateral aspect of the elbow, grip strength and wrist extension force before and five to ten minutes after application of elbow tape on the affected and unaffected arms. A Visual Analog Scale was used to assess pain. A dynamometer and a hand-held dynamometer were used for evaluation of grip strength and wrist extension force, respectively. Results Among the variables, significant differences were found in wrist extension forces between effected and unaffected arms (P = 0.02). Changes in grip strength showed statically significant improvements in the affected arm compared to the unaffected arm (P = 0.03). Also, in assessment of pain at the lateral epicondyle, the mean change between affected and unaffected arms was significant, with P = 0.001. Conclusions The taping technique, as applied in this study demonstrates an impressive effect on wrist extension force and grip strength of patients with TE. Elbow taping also reduces pain at the lateral aspect of the elbow in these patients. PMID:24350156

  13. 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

  14. 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 the safety…

  15. [Physiological changes in middle-aged persons and old people before and after tennis competition].

    PubMed

    Chai, Z; Long, Y; Zhan, C; Wu, Z; Wang, R; Tang, C; Zhou, L

    1992-09-01

    An examination of medical and physiological changes before and after tennis competition was performed on 71 middle-aged persons and old people in order to know whether they were adapted to this intense match or not. The result was that in the male group 1 (50-59 yrs), the heart rate, respiration rate and blood pressure before and after the tennis game had no significant differences (P > 0.05), indicating that this group was fit for the tennis competition, in the male group 2 (60-69 yrs) and male group 3 (70-79 yrs), as age advances, the number of unfitness to this game was increased gradually; in the female group (50-59 yrs), 28.5% of them showed a marked increase in the heart rate after the competition. We think that when persons have an electrocardiogram showing a significant undue changes of the ST segment and T wave after the contest, they are not suitable to this violent competition. So the medical surveillance is very important for the old people to play violent games such as tennis. The periodical health examination should be done before any exercise event with emphasis on the cardiovascular system so that the old sportsman can choose the proper exercise item and take self-control during the exercise. PMID:1304549

  16. 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…

  17. 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…

  18. 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 ...

  19. Adolescent development

    MedlinePlus

    Development - adolescent; Growth and development - adolescent ... rights and privileges. Establish and maintain satisfying relationships. Adolescents will learn to share intimacy without feeling worried ...

  20. Meniscal injuries in basketball players.

    PubMed

    Zedde, Pietro; Mela, Federico; Del Prete, Fabio; Masia, Francesco; Manunta, Andrea F

    2014-01-01

    Basketball is a highly competitive sport in which the knee joint is constantly subject to physical stresses. Basketball-related traumatic injuries are the result of specific technical movements. Even though basketball is not considered a contact sport, injuries in basketball players are due both to athletes' handling of the ball and to their intense physical interaction during games. Nowadays, traumatic meniscal injuries are constantly on the increase, especially in young athletes, and they are generally the result of compressive forces together with knee flexion rotation. Recognition of the great importance of meniscal biomechanics and of the functional role of the meniscus has resulted in the adoption of an increasingly preserving approach, also in the light of the effects, in terms of articular degeneration, of removing meniscal tissue. Even though recent decades have seen considerable developments in arthroscopic meniscectomy techniques, geared at preserving as much meniscal tissue as possible, basketball players undergoing this treatment often present, in the long run, clinical symptomatology severe enough to compromise their participation in competitive sport. Hence the treatment of meniscal injuries in athletes has become more and more preserving in recent years, through recourse to surgical techniques such as meniscal repair, biological replacement implantation and donor meniscus implantation, which allow pain relief, return to competitive activities and stable long-term results, slowing down arthritic progression. Therefore, considering the increasing number of meniscal injuries in basketball players, which can jeopardize their sporting careers, great importance is now attached to early diagnosis and to the correct choice of meniscal injury treatment in these athletes. PMID:25750909

  1. Auditory memory function in expert chess players

    PubMed Central

    Fattahi, Fariba; Geshani, Ahmad; Jafari, Zahra; Jalaie, Shohreh; Salman Mahini, Mona

    2015-01-01

    Background: Chess is a game that involves many aspects of high level cognition such as memory, attention, focus and problem solving. Long term practice of chess can improve cognition performances and behavioral skills. Auditory memory, as a kind of memory, can be influenced by strengthening processes following long term chess playing like other behavioral skills because of common processing pathways in the brain. The purpose of this study was to evaluate the auditory memory function of expert chess players using the Persian version of dichotic auditory-verbal memory test. Methods: The Persian version of dichotic auditory-verbal memory test was performed for 30 expert chess players aged 20-35 years and 30 non chess players who were matched by different conditions; the participants in both groups were randomly selected. The performance of the two groups was compared by independent samples t-test using SPSS version 21. Results: The mean score of dichotic auditory-verbal memory test between the two groups, expert chess players and non-chess players, revealed a significant difference (p≤ 0.001). The difference between the ears scores for expert chess players (p= 0.023) and non-chess players (p= 0.013) was significant. Gender had no effect on the test results. Conclusion: Auditory memory function in expert chess players was significantly better compared to non-chess players. It seems that increased auditory memory function is related to strengthening cognitive performances due to playing chess for a long time. PMID:26793666

  2. 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…

  3. 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…

  4. 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

  5. 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. PMID:23866239

  6. 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

  7. 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 ideas/concepts, examination of current policies, awareness of history…

  8. 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.

  9. [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. PMID:24214593

  10. Energy Cost of Common Activities in Children and Adolescents

    PubMed Central

    Lyden, Kate; Keadle, Sarah Kozey; Staudenmayer, John; Freedson, Patty; Alhassan, Sofiya

    2014-01-01

    Background The Compendium of Energy Expenditures for Youth assigns MET values to a wide range of activities. However, only 35% of activity MET values were derived from energy cost data measured in youth; the remaining activities were estimated from adult values. Purpose To determine the energy cost of common activities performed by children and adolescents and compare these data to similar activities reported in the compendium. Methods Thirty-two children (8–11 years old) and 28 adolescents (12–16 years) completed 4 locomotion activities on a treadmill (TRD) and 5 age-specific activities of daily living (ADL). Oxygen consumption was measured using a portable metabolic analyzer. Results In children, measured METs were significantly lower than compendium METs for 3 activities [basketball, bike riding, and Wii tennis (1.1–3.5 METs lower)]. In adolescents, measured METs were significantly lower than compendium METs for 4 ADLs [basketball, bike riding, board games, and Wii tennis (0.3–2.5 METs lower)] and 3 TRDs [2.24 m·s−1, 1.56 m·s−1, and 1.34 m·s−1 (0.4–0.8 METs lower)]. Conclusion The Compendium of Energy Expenditures for Youth is an invaluable resource to applied researchers. Inclusion of empirically derived data would improve the validity of the Compendium of Energy Expenditures for Youth. PMID:22398418

  11. MRI of the wrist is not recommended for age determination in female football players of U-16/U-17 competitions.

    PubMed

    Tscholl, P M; Junge, A; Dvorak, J; Zubler, V

    2016-03-01

    Age determination on magnetic resonance imaging (MRI) of the wrist is a reliable method in male football players to evaluate their eligibility to participate in Under 17 tournaments. MRI of the wrist was performed in 487 female volunteers aged 13-19 years from Brazil, Germany, Malaysia, and Tanzania, and in 139 female football players participating in Under-16 and Under-17 football tournaments. A previously validated method for grading fusion of the distal radial epiphysis in male adolescent was used. Moderate correlation of chronological age and epiphyseal fusion was found in the normative control group (r = .59) and weak correlation in female football players (r = .27). Complete fusion of the distal radial epiphysis was observed in two 15-year-old volunteers of the control group (1.7%) and in 17.6% (3 of 17) of 14-year-old football players. Up to 10.8% (47 of 437) in the control group and 14.4% (20 of 139) of the football players 17 years or younger had complete fused epiphysis. Because of earlier osseous maturity in female adolescents, the grade of fusion of the distal radial epiphysis on MRI is not recommended for pretournament age determination for the age of 17 and younger in female. PMID:25880786

  12. 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

  13. 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. PMID:24632735

  14. Let's hear it for B players.

    PubMed

    DeLong, Thomas J; Vijayaraghavan, Vineeta

    2003-06-01

    In the much-heralded war for talent, it's hardly surprising that companies have invested a lot of time, money, and energy in hiring and retaining star performers. For most CEOs, recruiting stars is simply more fun; for one thing, the young A players they interview often remind them of themselves at the same age. For another, A players' brilliance and drive is infectious; you simply want to be in their company. Besides, in these troubled times, when businesses are so vulnerable, people who seem to have what it takes to turn around a company's performance are almost irresistible. But our understandable fascination with star performers can lure us into the dangerous trap of underestimating the vital importance of the supporting actors. It's true that A players can make enormous contributions to performance. Yet, as the authors have found, companies' long-term performance--even survival--depends far more on the unsung commitment and contributions of their B players. These capable, steady performers are the best supporting actors of the corporate world. Companies are routinely blinded to the important role B players serve in saving organizations from themselves. They counter-balance the ambitions of the company's high-performing visionaries, whose much-esteemed strengths, when carried to an extreme, can lead to reckless or volatile behavior. In this sense, B players act as a stabilizing force for charismatic A players who might otherwise destabilize the organization. Unfortunately, organizations rarely learn to value their B players in ways that are gratifying for either the company or these employees. As a result, they see their profits sinking without understanding why. This article will help you to rethink the role of your organization's B players. The authors show how you can mentor and nurture B players to ensure their continued participation in the company. PMID:12800720

  15. Examining Player Anger in World of Warcraft

    NASA Astrophysics Data System (ADS)

    Barnett, Jane; Coulson, Mark; Foreman, Nigel

    This questionnaire study of the sources of anger in World of Warcraft applies classical quantitative measurement scale construction to a new problem, generating a host of questionnaire items that could find use in future studies, and identifying four major categories of events that cause negative effect among players. First, 33 players provided examples of in-game scenarios that had made them angry, and their responses were culled to create a 93-item battery rated by hundreds of player respondents in terms of anger intensity and anger frequency. An iterative process of factor analysis and scale reliability assessment led to a 28-item instrument measuring four anger-provoking factors: Raids/Instances, Griefers, Perceived Time Wasting, and Anti-social Players. These anger-causing scenarios were then illustrated by concrete examples from player and researcher experiences in World of Warcraft. One striking finding is that players become angry at other players' negative behavior, regardless of whether that behavior was intended to harm.

  16. Physiological characteristics of international female soccer players.

    PubMed

    Manson, Sarah A; Brughelli, Matt; Harris, Nigel K

    2014-02-01

    The purpose of this study was to investigate the physiological characteristics of Fédération Internationale de Football Association (FIFA) eligible international female soccer players aged 14-36 years and to determine if measures were significantly different for players selected (i.e., starters) to the starting line up for an FIFA tournament as compared with those not selected (i.e., nonstarters). Fifty-one (N = 18 Under 17; N = 18 Under 20; N = 15 Senior) international female soccer players participated in this study. The subjects underwent measurements of anthropometry (height and body mass), lower body strength (isokinetic testing), sprint kinetics and kinematics (nonmotorized treadmill), leg power (unilateral jumping), and maximal aerobic velocity (30:15 intermittent fitness test) during the final preparatory stage for an FIFA event. Outcomes of the age group data indicate that differences in physiological capacities are evident for the Under 17 players as compared with those for the Under 20 and Senior capped international players, suggesting a plateau in the acquisition of physical qualities as players mature. Starters tended to be faster (effect size [ES] = 0.55-1.0, p < 0.05) and have a higher maximal aerobic velocity (ES = 0.78-2.45, p < 0.05), along with greater eccentric leg strength (ES = 0.33-1.67, p < 0.05). Significant differences were detected between starters and nonstarters for isokinetic leg strength (ES = 0.54-1.24, p < 0.05) and maximal aerobic velocity (ES = 0.87, p < 0.05) for Under 17 players, where maximal aerobic velocity was the primary difference between starters and nonstarters (ES = 0.83-2.45, p < 0.05) for the Under 20 and Senior players. Coaches should emphasize the development of speed, maximal aerobic velocity, and leg strength in developing female soccer players. PMID:24476742

  17. 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

  18. 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. PMID:25734780

  19. Trajectory-based ball detection and tracking with aid of homography in broadcast tennis video

    NASA Astrophysics Data System (ADS)

    Yu, Xinguo; Jiang, Nianjuan; Ang, Ee Luang

    2007-01-01

    Ball-detection-and-tracking in broadcast tennis video (BTV) is a crucial but challenging task in tennis video semantics analysis. Informally, the challenges are due to camera motion and the other causes such as the presence of many ball-like objects and the small size of the tennis ball. The trajectory-based approach proposed by us in our previous papers mainly counteracted the challenges imposed by causes other than camera motion and achieves a good performance. This paper proposes an improved trajectory-based ball detection and tracking algorithm in BTV with the aid of homography, which counteracts the challenges caused by camera motion and bring us multiple new merits. Firstly, it acquires an accurate homography, which transforms each frame into the "standard" frame. Secondly, it achieved higher accuracy of ball identification. Thirdly, it obtains the ball projection position in the real world, instead of ball location in the image. Lastly, it also identifies landing frames and positions of the ball. The experimental results show that the improved algorithm can obtain not only higher accuracy in ball identification and in ball position alike, but also ball landing frames and positions. With the intent of using homography to improve the video-based event detection for smart home we also do some experiments on acquiring the homography for home surveillance video.

  20. Temporal structure analysis of broadcast tennis video using hidden Markov models

    NASA Astrophysics Data System (ADS)

    Kijak, Ewa; Oisel, Lionel; Gros, Patrick

    2003-01-01

    This work aims at recovering the temporal structure of a broadcast tennis video from an analysis of the raw footage. Our method relies on a statistical model of the interleaving of shots, in order to group shots into predefined classes representing structural elements of a tennis video. This stochastic modeling is performed in the global framework of Hidden Markov Models (HMMs). The fundamental units are shots and transitions. In a first step, colors and motion attributes of segmented shots are used to map shots into 2 classes: game (view of the full tennis court) and not game (medium, close up views, and commercials). In a second step, a trained HMM is used to analyze the temporal interleaving of shots. This analysis results in the identification of more complex structures, such as first missed services, short rallies that could be aces or services, long rallies, breaks that are significant of the end of a game and replays that highlight interesting points. These higher-level unit structures can be used either to create summaries, or to allow non-linear browsing of the video.

  1. 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. PMID:25958943

  2. 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. PMID:17927534

  3. Considering maturation status and relative age in the longitudinal evaluation of junior rugby league players.

    PubMed

    Till, K; Cobley, S; O' Hara, J; Cooke, C; Chapman, C

    2014-06-01

    This study longitudinally evaluated whether maturation and relative age interact with time during adolescence to differentially affect the development of anthropometric and fitness characteristics in junior rugby league players. Anthropometric and fitness characteristics of 81 junior players selected into the UK Rugby Football League's talent identification and development process were assessed over three consecutive occasions (i.e., under-13s, -14s, -15s). Players were grouped and compared in relation to maturational status (i.e., early, average, late) and relative age quartile (i.e., quartile 1). Repeated measures multivariate analysis of variance identified significant (P < 0.001) overall main effects for maturation group, relative age quartile and importantly a maturation group by time interaction. Findings showed that the early-maturing group had the greatest anthropometric characteristics and medicine ball throw across the three occasions. However, the late-maturing group increased their height (early = 5.0 cm, late = 10.3 cm), medicine ball throw and 60-m sprint (early = -0.46 s, late = -0.85 s) the most throughout the 2-year period. Early (de)selection policies currently applied in talent identification and development programs are questionable when performance-related variables are tracked longitudinally. During adolescence, maturation status alongside relative age should be considered and controlled for when assessing athlete potential for future progression. PMID:23289942

  4. 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…

  5. The Cheerleader and the Football Player.

    ERIC Educational Resources Information Center

    Patil, Malati

    2001-01-01

    Describes an activity in physics using a narrative about a bet between a cheerleader who claims she can lift a 300-pound football player off the ground. Includes questions, teaching notes, and solutions. (MM)

  6. Major League Baseball Players' Life Expectancies.

    PubMed

    Saint Onge, Jarron M; Rogers, Richard G; Krueger, Patrick M

    2008-07-17

    OBJECTIVE: We examine the importance of anthropometric and performance measures, and age, period, and cohort effects in explaining life expectancies among major league baseball (MLB) players over the past century. METHODS: We use discrete time hazard models to calculate life tables with covariates with data from Total Baseball, a rich source of information on all players who played in the major league. RESULTS: Compared to 20-year-old U.S. males, MLB players can expect almost five additional years of life. Height, weight, handedness, and player ratings are unassociated with the risk of death in this population of highly active and successful adults. Career length is inversely associated with the risk of death, likely because those who play longer gain additional incomes, physical fitness, and training. CONCLUSIONS: Our results indicate improvements in life expectancies with time for all age groups and indicate possible improvements in longevity in the general U.S. population. PMID:19756205

  7. 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.

  8. Decomposition of Multi-player Games

    NASA Astrophysics Data System (ADS)

    Zhao, Dengji; Schiffel, Stephan; Thielscher, Michael

    Research in General Game Playing aims at building systems that learn to play unknown games without human intervention. We contribute to this endeavour by generalising the established technique of decomposition from AI Planning to multi-player games. To this end, we present a method for the automatic decomposition of previously unknown games into independent subgames, and we show how a general game player can exploit a successful decomposition for game tree search.

  9. 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. PMID:24270458

  10. Game Performance Evaluation in Male Goalball Players.

    PubMed

    Molik, Bartosz; Morgulec-Adamowicz, Natalia; Kosmol, Andrzej; Perkowski, Krzysztof; Bednarczuk, Grzegorz; Skowroński, Waldemar; Gomez, Miguel Angel; Koc, Krzysztof; Rutkowska, Izabela; Szyman, Robert J

    2015-11-22

    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

  11. Bridging Media with the Help of Players

    NASA Astrophysics Data System (ADS)

    Nitsche, Michael; Drake, Matthew; Murray, Janet

    We suggest harvesting the power of multiplayer design to bridge content across different media platforms and develop player-driven cross-media experiences. This paper first argues to partially replace complex AI systems with multiplayer design strategies to provide the necessary level of flexibility in the content generation for cross-media applications. The second part describes one example project - the Next Generation Play (NGP) project - that illustrates one practical approach of such a player-driven cross-media content generation. NGP allows players to collect virtual items while watching a TV show. These items are re-used in a multiplayer casual game that automatically generates new game worlds based on the various collections of active players joining a game session. While the TV experience is designed for the single big screen, the game executes on multiple mobile phones. Design and technical implementation of the prototype are explained in more detail to clarify how players carry elements of television narratives into a non-linear handheld gaming experience. The system describes a practical way to create casual game adaptations based on players' personal preferences in a multi-user environment.

  12. Cortical thinning in former professional soccer players.

    PubMed

    Koerte, Inga K; Mayinger, Michael; Muehlmann, Marc; Kaufmann, David; Lin, Alexander P; Steffinger, Denise; Fisch, Barbara; Rauchmann, Boris-Stephan; Immler, Stefanie; Karch, Susanne; Heinen, Florian R; Ertl-Wagner, Birgit; Reiser, Maximilian; Stern, Robert A; Zafonte, Ross; Shenton, Martha E

    2016-09-01

    Soccer is the most popular sport in the world. Soccer players are at high risk for repetitive subconcussive head impact when heading the ball. Whether this leads to long-term alterations of the brain's structure associated with cognitive decline remains unknown. The aim of this study was to evaluate cortical thickness in former professional soccer players using high-resolution structural MR imaging. Fifteen former male professional soccer players (mean age 49.3 [SD 5.1] years) underwent high-resolution structural 3 T MR imaging, as well as cognitive testing. Fifteen male, age-matched former professional non-contact sport athletes (mean age 49.6 [SD 6.4] years) served as controls. Group analyses of cortical thickness were performed using voxel-based statistics. Soccer players demonstrated greater cortical thinning with increasing age compared to controls in the right inferolateral-parietal, temporal, and occipital cortex. Cortical thinning was associated with lower cognitive performance as well as with estimated exposure to repetitive subconcussive head impact. Neurocognitive evaluation revealed decreased memory performance in the soccer players compared to controls. The association of cortical thinning and decreased cognitive performance, as well as exposure to repetitive subconcussive head impact, further supports the hypothesis that repetitive subconcussive head impact may play a role in early cognitive decline in soccer players. Future studies are needed to elucidate the time course of changes in cortical thickness as well as their association with impaired cognitive function and possible underlying neurodegenerative process. PMID:26286826

  13. 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)

  14. 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

  15. [Physiological adolescence, pathological adolescence].

    PubMed

    Olié, Jean-Pierre; Gourion, David; Canceil, Olivier; Lôo, Henri

    2006-11-01

    The uncertainties of looming adulthood, nostalgia for childhood, and a general malaise explain the crisis of adolescence. Rebellion, conflict, occasional failure at school or in society, and at-risk behaviors are not always signs of future psychiatric illness. In contrast, the physician must be in a position to identify tell-tale signs such as dysmorphophobia, existential anxiety, a feeling of emptiness, and school or social breakdown. Most psychiatric disorders that begin in adolescence are only diagnosed several years after onset. Yet early diagnosis is of utmost importance, as treatment becomes less effective and the long-term prognosis worsens with time. Suicide is the second cause of death during adolescence. All signs of suicidal behavior require hospitalization and evaluation in a psychiatric unit. Antidepressants may be necessary in adolescence. The recent controversy concerning a possible increase in the suicidal risk during antidepressant treatment should not mask the fact that the real public health issue is depression, and not antidepressants. Eating disorders are especially frequent among adolescent girls; it is important to identify psychiatric comorbidities such as schizophrenia, depression and obsessive-compulsive disorders, and to assess the vital risk. Illicit drug and alcohol consumption are frequent during adolescence; for example, close to half of all French adolescents have tried cannabis at least once. Once again, it is important to detect psychiatric comorbidities in substance-abusing adolescents. Phobia is an underdiagnosed anxiety disorder among adolescents; it may become chronic if proper treatment is not implemented, leading to suffering and disability. Finally, two major psychiatric disorders--schizophrenia and bipolar disorder--generally begin in adolescence. Treatment efficacy and the long-term prognosis both depend on early diagnosis. Treatment must be tailored to the individual patient. "Borderline" states are over

  16. The Structure of Morpho-Functional Conditions Determining the Level of Sports Performance of Young Badminton Players

    PubMed Central

    Jaworski, Janusz; Żak, Michał

    2015-01-01

    The aim of the study was to determine the structure of morpho-functional models that determine the level of sports performance in three consecutive stages of training of young badminton players. In the course of the study, 3 groups of young badminton players were examined: 40 preadolescents aged 11–13, 32 adolescents aged 14–16, and 24 adolescents aged 17–19. The scope of the study involved basic anthropometric measurements, computer tests analysing motor coordination abilities, motor skills encompassing speed, muscular power and strength, and cardiorespiratory endurance. Results of the study indicate that the structure of morpho-functional models varies at different stages of sports training. Sets of variables determining sports performance create characteristic complexes of variables that do not constitute permanent models. The dominance of somatic features and coordination abilities in the early stages of badminton training changes for the benefit of speed and strength abilities. PMID:26557205

  17. The Structure of Morpho-Functional Conditions Determining the Level of Sports Performance of Young Badminton Players.

    PubMed

    Jaworski, Janusz; Żak, Michał

    2015-09-29

    The aim of the study was to determine the structure of morpho-functional models that determine the level of sports performance in three consecutive stages of training of young badminton players. In the course of the study, 3 groups of young badminton players were examined: 40 preadolescents aged 11-13, 32 adolescents aged 14-16, and 24 adolescents aged 17-19. The scope of the study involved basic anthropometric measurements, computer tests analysing motor coordination abilities, motor skills encompassing speed, muscular power and strength, and cardiorespiratory endurance. Results of the study indicate that the structure of morpho-functional models varies at different stages of sports training. Sets of variables determining sports performance create characteristic complexes of variables that do not constitute permanent models. The dominance of somatic features and coordination abilities in the early stages of badminton training changes for the benefit of speed and strength abilities. PMID:26557205

  18. Changes in Muscle Strength in U19 Soccer Players During an Annual Training Cycle

    PubMed Central

    Lehnert, Michal; Xaverová, Zuzana; De Ste Croix, Mark

    2014-01-01

    The aim of the study was to investigate the seasonal variation in isokinetic strength of the knee flexors and extensors, and conventional (H/QCONV) and functional (H/QFUNC) hamstring to quadriceps strength ratios in highly trained adolescent soccer players. The players (n=11; age 17.8±0.3) were measured at the end of the competitive season (autumn), at the beginning and the end of pre-season (winter) and during the sixth week of a new competitive season. Isokinetic peak torque (concentric and eccentric) was measured at 60°·s-1 in a sitting position with the hip flexed at 100°. The testing range of motion was set from 10 – 90° of knee flexion. The players performed a set of five maximum repetitions for both the dominant and non-dominant leg. Statistically significant differences (p<0.001) between the four seasonal measurements were noted for peak torque of the dominant leg knee flexors in concentric muscle action only. A post hoc analysis revealed a statistically significant increase in peak torque from the 1st to the 4th measurement (p<0.001; d=0.692) and from the 2nd to the 4th (p<0.01; d=0.564). The differences in the changes of peak torque of the knee flexors and extensors depending on type of muscle action and tendencies found in the H/Q ratios throughout the annual training cycle indicate that strength assessment of the knee flexors and extensors and their balance throughout the annual training cycle could be beneficial for elite male adolescent soccer players both in terms of performance and risk of injury. PMID:25414751

  19. The polygenic profile of Russian football players.

    PubMed

    Egorova, Emiliya S; Borisova, Alyona V; Mustafina, Leysan J; Arkhipova, Alina A; Gabbasov, Rashid T; Druzhevskaya, Anastasiya M; Astratenkova, Irina V; Ahmetov, Ildus I

    2014-01-01

    Research concerned with predictors of talent in football has highlighted a number of potentially important and partially inherited measures such as body size, anaerobic power, aerobic capacity, agility, psychological profile, game intelligence and susceptibility to injuries. Genotyping for performance-associated DNA polymorphisms at an early age could be useful in predicting later success in football. The aim of the study was to investigate individually and in combination the association of common gene polymorphisms with football player's status. A total of 246 Russian football players and 872 controls were genotyped for 8 gene polymorphisms, which were previously reported to be associated with athlete status. Four alleles (ACE D, ACTN3 Arg577, PPARA rs4253778 C and UCP2 55Val) were first identified, showing discrete associations with football player's status. Next, we determined the total genotype score (TGS, from the accumulated combination of the 4 polymorphisms, with a maximum value of 100 for the theoretically optimal polygenic score) in athletes and controls. The mean TGS was significantly higher in football players (52.0 (17.6) vs. 41.3 (15.5); P < 0.0001) than in controls. These data suggest that the likelihood of becoming a football player depends on the carriage of a high number of "favourable" gene variants. PMID:24784145

  20. 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

  1. 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

  2. Practice and play in the development of German top-level professional football players.

    PubMed

    Hornig, Manuel; Aust, Friedhelm; Güllich, Arne

    2016-01-01

    This study examined the developmental sporting activities of 52 German football first Bundesliga professionals (including 18 senior national team members) and 50 fourth to sixth league amateur players. They reported their volumes of organised football practice/training, including its "microstructure" (proportions of physical conditioning, skill exercises and playing forms), non-organised leisure football play and engagement in other sports through their career, respectively. Analyses revealed that the Bundesliga professionals performed moderate amounts of organised football practice/training throughout their career. They accumulated 4264 (mean value) hours over ~16 years before debuting in 1st Bundesliga; senior National Team debut was preceded by 4532 hours (mean) over ~17 years. Within the "microstructure" of organised practice/training, the proportion of playing forms developed from ~52% (childhood) to ~45% (adolescence) and ~40% (adulthood) and physical conditioning from ~13% to ~14% and ~23%. Outside organised involvement, these players engaged in extensive non-organised leisure football play making ~68%, ~54% and ~9% of all football involvement. Subsuming organised and non-organised football, ~86% (childhood), ~73% (adolescence) and ~43% (adulthood) of all activity was game play (exclusive matchplay). National Team differed from amateurs in more non-organised leisure football in childhood, more engagement in other sports in adolescence, later specialisation, and in more organised football only at age 22+ years. Relative to numerous other studies, these players performed less organised practice, particularly less physical conditioning, but greater proportions of playing activities. The findings are discussed relative to the significance of playing forms and variable involvements and are reflected against the deliberate practice and Developmental Model of Sport Participation (DMSP) frameworks. PMID:25440296

  3. The Effects of Individualized Resistance Strength Programs on Knee Muscular Imbalances in Junior Elite Soccer Players

    PubMed Central

    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. PMID:26630271

  4. 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. PMID:25734781

  5. Individual recovery profiles in basketball players.

    PubMed

    Moreno, Jordi; Ramos-Castro, Juan; Rodas, Gil; Tarragó, Joan R; Capdevila, Lluís

    2015-01-01

    In the sport context, recovery has been characterized as a multifactor process (physiological, psychological, behavioral, social, etc.). This study takes a multidisciplinary approach to find psychophysiological markers of the stress-recovery process. It aims to determine how athletes' specific recovery actions relate to their perceptions of recovery, and Heart Rate Variability (HRV). A total of 196 assessments were analyzed from 6 players on a men's professional basketball team within the Liga LEB Oro basketball federation (2012/2013 season). Perceptions of recovery, recovery strategies, and HRV were recorded. The results show a pattern of individual differences in behavior related to athletes' recovery actions and HRV profiles throughout the season (p < .05). Moreover, we observed that each player had different recovery needs. In light of these results, we suggest an individualistic approach to evaluating and monitoring recovery to attend more accurately to each player's recovery needs. PMID:25908013

  6. Musicians' Medicine: Musculoskeletal Problems in String Players

    PubMed Central

    Lee, Han-Sung; Park, Ho Youn; Yoon, Jun O; Kim, Jin Sam; Chun, Jae Myeung; Aminata, Iman W.; Cho, Won-Joon

    2013-01-01

    There is increasing attention to medical problems of musicians. Many studies find a high prevalence of work-related musculoskeletal disorders in musicians, ranging from 73.4% to 87.7%, and string players have the highest prevalence of musculoskeletal problems. This paper examines the various positions and movements of the upper extremities in string players: 1) basic postures for holding instruments, 2) movements of left upper extremity: fingering, forearm posture, high position and vibrato, 3) movements of right upper extremity: bowing, bow angles, pizzicato and other bowing techniques. These isotonic and isometric movements can lead to musculoskeletal problems in musicians. We reviewed orthopedic disorders that are specific to string players: overuse syndrome, muscle-tendon syndrome, focal dystonia, hypermobility syndrome, and compressive neuropathy. Symptoms, interrelationships with musical performances, diagnosis and treatment of these problems were then discussed. PMID:24009899

  7. Anthropometric Characteristics of Spanish Professional Basketball Players.

    PubMed

    Alejandro, Vaquera; Santiago, Santos; Gerardo, Villa José; Carlos, Morante Juan; Vicente, García-Tormo

    2015-06-27

    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

  8. The Boyd–McLeod procedure for tennis elbow: mid- to long-term results

    PubMed Central

    Jeavons, Richard; Richards, Ian; Bayliss, Neil

    2014-01-01

    Background Tennis elbow is a common condition that usually responds to conservative measures. In refractory cases, surgical intervention is indicated. A plethora of surgical techniques have been described. We report the mid- to long-term outcomes of the Boyd–McLeod procedure for refractory tennis elbow. Methods A retrospective analysis and current review of patients that had undergone the Boyd–McLeod procedure over a 12-year period was undertaken. Demographics, time to discharge, length of follow-up and outcome scores were collected. Results Seventy patients underwent surgery. Mean time to discharge was 15.35 weeks, with 88% successful outcomes. Fifty-four patients were available for current follow-up at mean of 5.52 years (range 1.17 years to 11.49 years). Range of motion in all patients was unchanged. There were no revision procedures. Mean (SD) Mayo Elbow Performance Score was 90.85 (13.11), with 75.5% returning a good or excellent score and 24.5% a fair outcome. The mean (SD) Oxford Elbow Score was 44.04 (6.92); mean (SD) pain score was 89.5 (17.58); mean (SD) function score was 95.34 (9.59) and mean (SD) socio-psychological score was 91.50 (17.01). Overall, 83% of patients had an Oxford Elbow Score of 43 or greater, suggesting excellent outcome. Conclusions We show that the Boyd–McLeod procedure is an excellent option over both the short- and long-term for refractory tennis elbow.

  9. Behavioral coaching in the development of skills in football, gymnastics, and tennis

    PubMed Central

    Allison, Mary Ghesquiere; Ayllon, Teodoro

    1980-01-01

    A review of the literature indicates that methods of skill acquisition based on the operant paradigm have been scientifically validated with many motor behaviors. However, these procedures have been limited to the use of positive reinforcement for correct performance when applied to the acquisition of complex sports skills in natural settings. To find complementary procedures to enhance skill acquisition, a coaching method involving several behavioral techniques was developed that focused on remediation of errors. This coaching method combined the following components: (1) systematic use of verbal instructions and feedback, (2) positive and negative reinforcement, (3) positive practice, and (4) time out. Three sports, football, gymnastics, and tennis, were selected to determine the effectiveness and generality of this behavioral coaching method. A total of 23 male and female subjects, ranging in age from 11 to 35, was included in this study. Baseline data were first collected for each sport under standard coaching conditions. Next, the behavioral coaching method was evaluated depending on the sport in either a multiple baseline or a reversal design. The behavioral dimensions selected were blocking in football; backward walkovers, front hand springs, and reverse kips in gymnastics; and the forehand, backhand, and serve in tennis. Behavioral coaching was immediately effective in increasing the correct execution of complex skills in all three sports. Gains of up to 10 times the baseline performance were achieved in each sport. In football, behavioral coaching resulted in an increase in correct blocking performance from a baseline average of 5% to 51.3%. Gymnasts' performances increased from baseline averages of 2.7% to 52.6% across the three skills. In tennis, standard coaching produced an average of 6% correct performance which increased dramatically under behavioral coaching to 57% across the three strokes. The success of the behavioral coaching package used here

  10. Anthropometric characteristics of Columbia, South Carolina, youth baseball players and Dixie Youth World Series players.

    PubMed

    French, Karen E; Spurgeon, John H; Nevett, Michael E

    2007-06-01

    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 of the twelve teams participating in the 1995 Dixie Youth World Series. Normative data for the United States (NCHS) were used as comparative data. Two trained anthropometrists measured standing height, sitting height, lower limb height, upper limb length, arm girth, calf girth, tricep skinfold, and abdomen skinfold on all participants. In both samples, pitchers, short stops, and first basemen were a more highly skilled group and exhibited larger body size (greater standing height, sitting height, lower limb height, upper limb length) than children who played at other positions. The standing height of local little league players was similar to the median of reference data at ages 7, 8, and 9 years. The standing height and weight of skilled players in both samples approximated the 75th percentile for standing height and weight at ages 10, 11, 12, and 13 years. The results suggest that baseball players exhibit larger body size than the normal population at young ages. Body size may be an important criterion used by coaches to select and assign young players to certain positions. PMID:17679491

  11. Effects of new sports tennis type exercise on aerobic capacity, follicle stimulating hormone and N-terminal telopeptide in the postmenopausal women

    PubMed Central

    Shin, Hyun-Jae; Lee, Ha-Yan; Cho, Hye-Young; Park, Yun-Jin; Moon, Hyung-Hoon; Lee, Sung-Hwan; Lee, Sung-Ki; Kim, Myung-Ki

    2014-01-01

    Menopause is characterized by rapid decreases in bone mineral density, aerobic fitness, muscle strength, and balance. In the present study, we investigated the effects of new sports tennis type exercise on aerobic capacity, follicle stimulating hormone (FSH) and N-terminal telopeptide (NTX) in the postmenopausal women. Subjects were consisted of 20 postmenopausal women, who had not menstruated for at least 1 yr and had follicle-stimulating hormone levels > 35 mIU/L, estradiol levels< 40 pg/mL. The subjects were randomly divided into two groups: control group (n= 10), new sports tennis type exercise group (n= 10). New sports tennis type exercise was consisted of warm up (10 min), new sports tennis type exercise (40 min), cool down (10 min) 3 days a per week for 12 weeks. The aerobic capacities were increased by 12 weeks new sports tennis type exercise. New sports tennis type exercise significantly increased FSH and NTx levels, indicating biochemical markers of bone formation and resorption. These findings indicate that 12 weeks of new sports tennis type exercise can be effective in prevention of bone loss and enhancement of aerobic capacity in postmenopausal women. PMID:24877043

  12. Tennis-ball state of a self-avoiding wormlike polymer on a spherical surface

    NASA Astrophysics Data System (ADS)

    Zhang, Wu-Yang; Chen, Jeff Z. Y.

    2011-05-01

    Using Monte Carlo simulations of a wormlike chain that contains the excluded-volume interaction, we demonstrate that a directionally anisotropic state exists at high surface coverage, when the chain is confined to a spherical surface. The isotropic-anisotropic transition has first-order characteristics and can be compared with the isotropic-nematic transition observed in lyotropic polymer systems, both driven by the excluded-volume interaction. Unlike a nematic state, the anisotropic state observed here displays the so-called tennis-ball conformation, coupling the polymer-segment orientation preference with positional order.

  13. 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.

  14. The Influence of Ball Velocity and Court Illumination on Reaction Time for Tennis Volley

    PubMed Central

    Tu, Jui-hung; Lin, Yaw-feng; Chin, Shu-chen

    2010-01-01

    The he purpose of this study is to examine the effects of ball velocity, court illumination, and volley type on the reaction time (RT) of a tennis athlete for a volley stroke. Eights cases with two different ball velocities (high and low), two volley types (forehand and backhand ) and two court illumination levels (dark and bright) were studied. The 30 participating subjects consisted of 18 male and 12 female college tennis athletes (age: 24 ± 3.2 yr), with a United States Tennis Association (USTA) ranking above 2.5. In order to ensure the validity of real-world correlations, the experiments were designed to simulate real competition situations. Reaction times were measured for volley strokes in response to different approaching ball velocities (high: 25.05 ± 0.37 m/s and low: 17.56 ± 0.92 m·s-1) for several volley types (forehand and backhand) and court illumination levels (55649 ± 4292 lux and 363.24 ± 6.53 lux on the court). During the tests, the signals from an electromyogram sensor and a 3-axis accelerometer (± 50 g) were recorded using an NI DAQ card (NI PXI-6251) and then analyzed to determine reaction time (RT), premotor reaction time (PRT), and motor reaction time (MRT) through the LabVIEW system. Subsequent 3-way ANOVA analysis indicated no RT, PRT, or MRT interaction between ball velocity, volley type and illumination. The ball velocity and illumination parameters did affect RT and PRT values significantly with p < 0.05, no significant variation in MRT was observed across any implemented experimental conditions. All experimental results indicate that ball velocity and illumination levels strongly affect the value of PRT, but have no significant effect on the value of MRT, the changes in RT were dominated by PRT. Key points RT can generally be divided into two components with the help of the electromyogram (EMG) signal - the premotor reaction time (PRT) and the motor reaction time (MRT). The purpose of this study is to examine the effects of ball

  15. Effect of age on anthropometric and physical performance measures in professional baseball players.

    PubMed

    Mangine, Gerald T; Hoffman, Jay R; Fragala, Maren S; Vazquez, Jose; Krause, Matthew C; Gillett, Javair; Pichardo, Napoleon

    2013-02-01

    The purpose of this study was to investigate age-related changes in anthropometric and performance variables in professional baseball players. Baseball players (n = 1,157) from several professional baseball organizations were categorized into 7 cohorts based upon age. All adolescent athletes were categorized as age group 1 (AG1), whereas the next 5 groups (AG2-AG6) consisted of players 20-22, 23-25, 26-28, 29-31, and 31-34 years, respectively. The final group (AG7) comprised athletes ≥35 years. All performance assessments were part of the athlete's normal preseason training camp testing routine. Field assessments were used to analyze lower-body power, speed, agility, grip strength, and body composition. The players were heaviest between the ages of 29 and 31 (AG5), and their body mass in that age group was 10.1% (p = 0.004) greater than that of AG1. A 7.0% increase (p = 0.000) in lean body mass occurred between AG1 and AG5. No differences in 10-yd sprint times or agility were seen across any age group or position. A 2.0 seconds (p = 0.001) slower run time for the 300-yd shuttle was seen between AG4 and AG5 for all positions combined. Elevations in grip strength were seen at AG4 compared with AG1 (p = 0.001) and AG2 (p = 0.007) for all positions combined. No other differences were noted. Lower-body power was increased for all positions combined from AG1 to AG3 (p = 0.007). This pattern was similar to that observed in position players, but a 12.4% decrease (p = 0.024) in VJMP was seen between AG7 and AG5 in pitchers. Results of this study indicate that lower-body power is maintained in baseball players until the age of 29-31, whereas speed, agility, and grip strength are maintained in players able to play past the age of 35 years. Age-related differences observed in this study suggest that athletes focus on their strength and conditioning programs to extend the length of their professional careers. PMID:22505124

  16. 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

  17. High School Football Players Suffer More Symptoms After Concussion

    MedlinePlus

    ... gov/medlineplus/news/fullstory_158603.html High School Football Players Suffer More Symptoms After Concussion: Study Meanwhile, ... MONDAY, May 2, 2016 (HealthDay News) -- High school football players are more likely to suffer more symptoms ...

  18. 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,…

  19. Video Player Keyboard Shortcuts: MedlinePlus

    MedlinePlus

    ... mode. Keyboard shortcuts are also not supported in Internet Explorer 8. About MedlinePlus Site Map FAQs Contact Us Get email updates Subscribe to RSS Follow us Disclaimers Copyright Privacy Accessibility Quality Guidelines Viewers & Players MedlinePlus Connect for EHRs For Developers ...

  20. 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)

  1. 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…

  2. 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…

  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. Review of tennis serve motion analysis and the biomechanics of three serve types with implications for injury.

    PubMed

    Abrams, Geoffrey D; Sheets, Alison L; Andriacchi, Thomas P; Safran, Marc R

    2011-11-01

    The tennis serve has the potential for musculoskeletal injury as it is an overhead motion and is performed repetitively during play. Early studies evaluating the biomechanics and injury potential of the tennis serve utilized skin-based marker technologies; however, markerless motion measurement systems have recently become available and have obviated some of the problems associated with the marker-based technology. The late cocking and early acceleration phases of the kinetic chain of the service motion produce the highest internal forces and pose the greatest risk of injury during the service motion. Previous biomechanical data on the tennis serve have primarily focused on the flat serve, with some data on the kick serve, and very little published data elucidating the biomechanics of the slice serve. This review discusses the injury potential of the tennis serve with respect to the four phases of the service motion, the history, and early findings of service motion evaluation, as well as biomechanical data detailing the differences between the three types of serves and how this may relate to injury prevention, rehabilitation, and return to play. PMID:22303788

  5. 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…

  6. Tennis Elbow Diagnosis Using Equivalent Uniform Voltage to Fit the Logistic and the Probit Diseased Probability Models

    PubMed Central

    Lee, Tsair-Fwu; Lin, Wei-Chun; Wang, Hung-Yu; Lin, Shu-Yuan; Wu, Li-Fu; Guo, Shih-Sian; Huang, Hsiang-Jui; Ting, Hui-Min; Chao, Pei-Ju

    2015-01-01

    To develop the logistic and the probit models to analyse electromyographic (EMG) equivalent uniform voltage- (EUV-) response for the tenderness of tennis elbow. In total, 78 hands from 39 subjects were enrolled. In this study, surface EMG (sEMG) signal is obtained by an innovative device with electrodes over forearm region. The analytical endpoint was defined as Visual Analog Score (VAS) 3+ tenderness of tennis elbow. The logistic and the probit diseased probability (DP) models were established for the VAS score and EMG absolute voltage-time histograms (AVTH). TV50 is the threshold equivalent uniform voltage predicting a 50% risk of disease. Twenty-one out of 78 samples (27%) developed VAS 3+ tenderness of tennis elbow reported by the subject and confirmed by the physician. The fitted DP parameters were TV50 = 153.0 mV (CI: 136.3–169.7 mV), γ50 = 0.84 (CI: 0.78–0.90) and TV50 = 155.6 mV (CI: 138.9–172.4 mV), m = 0.54 (CI: 0.49–0.59) for logistic and probit models, respectively. When the EUV ≥ 153 mV, the DP of the patient is greater than 50% and vice versa. The logistic and the probit models are valuable tools to predict the DP of VAS 3+ tenderness of tennis elbow. PMID:26380281

  7. Structural Analysis of Technical-Tactical Elements in Table Tennis and their Role in Different Playing Zones

    PubMed Central

    Munivrana, Goran; Petrinović, Lidija Zekan; Kondrič, Miran

    2015-01-01

    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. PMID:26557204

  8. 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. PMID:26557204

  9. 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)…

  10. 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. PMID:24317705

  11. 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…

  12. 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…

  13. High School Rugby Players' Perception of Coaching Effectiveness

    ERIC Educational Resources Information Center

    Broodryk, Retief; van den Berg, Pieter Hendrick

    2011-01-01

    The aims of this study were firstly to determine the players' perceptions of their respective coaches' coaching effectiveness and secondly, determine the difference between big and small schools of the players' perceptions of their respective coaches' coaching effectiveness. Four hundred and seventy six players from 22 schools were asked to fill…

  14. 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…

  15. 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)

  16. 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,…

  17. The architecture of the chess player's brain.

    PubMed

    Hänggi, Jürgen; Brütsch, Karin; Siegel, Adrian M; Jäncke, Lutz

    2014-09-01

    The game of chess can be seen as a typical example for an expertise task requiring domain-specific training and experience. Despite intensive behavioural studies the neural underpinnings of chess performance and expertise are not entirely understood. A few functional neuroimaging studies have shown that expert chess players recruit different psychological functions and activate different brain areas while they are engaged in chess-related activities. Based on this functional literature, we predicted to find morphological differences in a network comprised by parietal and frontal areas and especially the occipito-temporal junction (OTJ), fusiform gyrus, and caudate nucleus. Twenty expert chess players and 20 control subjects were investigated using voxel-based and surface-based morphometry as well as diffusion tensor imaging. Grey matter volume and cortical thickness were reduced in chess players compared with those of control men in the OTJ and precunei. The volumes of both caudate nuclei were not different between groups, but correlated inversely with the years of chess playing experience. Mean diffusivity was increased in chess players compared with that of controls in the left superior longitudinal fasciculus and the Elo score (a chess tournament ranking) was inversely related to mean diffusivity within the right superior longitudinal fasciculus. To the best of our knowledge we showed for the first time that there are specific differences in grey and white matter morphology between chess players and control subjects in brain regions associated with cognitive functions important for playing chess. Whether these anatomical alterations are the cause or consequence of the intensive and long-term chess training and practice remains to be shown in future studies. PMID:25065494

  18. Hamstring Injuries in Professional Football Players

    PubMed Central

    Cohen, Steven B.; Towers, Jeffrey D.; Zoga, Adam; Irrgang, Jay J.; Makda, Junaid; Deluca, Peter F.; Bradley, James P.

    2011-01-01

    Background: Magnetic resonance imaging (MRI) allows for detailed evaluation of hamstring injuries; however, there is no classification that allows prediction of return to play. Purpose: To correlate time for return to play in professional football players with MRI findings after acute hamstring strains and to create an MRI scoring scale predictive of return to sports. Study Design: Descriptive epidemiologic study. Methods: Thirty-eight professional football players (43 cases) sustained acute hamstring strains with MRI evaluation. Records were retrospectively reviewed, and MRIs were evaluated by 2 musculoskeletal radiologists, graded with a traditional radiologic grade, and scored with a new MRI score. Results were correlated with games missed. Results: Players missed 2.6 ± 3.1 games. Based on MRI, the hamstring injury involved the biceps femoris long head in 34 cases and the proximal and distal hamstrings in 25 and 22 cases, respectively. When < 50% of the muscle was involved, the average number of games missed was 1.8; if > 75%, then 3.2. Ten players had retraction, missing 5.5 games. By MRI, grade I injuries yielded an average of 1.1 missed games; grade II, 1.7; and grade III, 6.4. Players who missed 0 or 1 game had an MRI score of 8.2; 2 or 3 games, 11.1; and 4 or more games, 13.9. Conclusions: Rapid return to play (< 1 week) occurred with isolated long head of biceps femoris injures with < 50% of involvement and minimal perimuscular edema, correlating to grade I radiologic strain (MRI score < 10). Prolonged recovery (missing > 2 or 3 games) occurs with multiple muscle injury, injuries distal to musculotendinous junction, short head of biceps injury, > 75% involvement, retraction, circumferential edema, and grade III radiologic strain (MRI score > 15). Clinical Relevance: MRI grade and this new MRI score are useful in determining severity of injury and games missed—and, ideally, predicting time missed from sports. PMID:23016038

  19. 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

  20. 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

  1. A comparison of muscle activations during traditional and abbreviated tennis serves.

    PubMed

    Seeley, Matthew K; Uhl, Tim L; McCrory, Jean; McGinn, Patricia; Kibler, W Ben; Shapiro, Robert

    2008-05-01

    The abbreviated tennis serve is a relatively novel modification of the traditional serve that has been reported to provide performance advantages over the traditional technique. However, there are limited objective data regarding the benefits and biomechanics of the abbreviated serve; no data exist that describe shoulder muscle activations during the abbreviated serve. The purpose of this study was to compare muscle activations between the traditional and abbreviated serves. Electromyographic data were collected for the anterior and posterior deltoid, infraspinatus, middle trapezius, latissimus dorsi, serratus anterior, and pectoralis major. When muscle activations were compared during each serve phase, no significant differences were observed between the traditional and abbreviated tennis serve techniques, indicating that the traditional and abbreviated serves are similar regarding shoulder muscle activations. These results could have implications for performance of and injury related to the abbreviated versus traditional serve technique. Although the abbreviated serve has anecdotally been described as advantageous, the present data do not indicate any significant advantages or disadvantages in performing the abbreviated serve technique versus the traditional serve. PMID:18610776

  2. 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. PMID:20695718

  3. Ankle sprain and postural sway in basketball players.

    PubMed

    Leanderson, J; Wykman, A; Eriksson, E

    1993-01-01

    The present study compares postural ankle stability between previously injured basketball players, uninjured players and a control/group. Postural sway was recorded and analysed by stabilometry using a specially designed computer-assisted forceplate. Recordings were obtained for 60 s on each foot. The stabilometric results in the players with no previous injuries did not differ from those in the controls. Players with a previously injured ankle differed significantly from the control group. These players had a larger mean postural sway and used a larger sway area. PMID:8536030

  4. 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

    2014-12-01

    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. PMID:25474335

  5. 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. PMID:26010800

  6. 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

  7. Exploring design features for enhancing players' challenge in strategy games.

    PubMed

    Hsu, Shang Hwa; Wen, Ming-Hui; Wu, Muh-Cherng

    2007-06-01

    This paper examines how to make a player feel more challenged in a strategic computer game. It is hypothesized that information availability and resource advantage affect play difficulty, which in turn affects the challenge experienced. The difficulty of play can be defined in terms of the mental workload that players experience and the physical effort that players exert. Forty-five male college and graduate students participated in a 3 x 3 (information availability x resource advantage) between-subjects factorial design experiment. This experiment measured player mental workload, physical effort, and challenge. The results indicate that information availability affects player mental workload, and resource advantage affects levels of player physical effort, respectively. Moreover, the relationship between mental workload and challenge was found to be an inverted U-shaped curve; in other words, too much or too little mental workload may decrease player challenge. The relationship between physical effort and challenge exhibited similar characteristics. PMID:17594263

  8. 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. PMID:22788752

  9. Protective Equipment and Player Characteristics Associated With the Incidence of Sport-Related Concussion in High School Football Players

    PubMed Central

    McGuine, Timothy A.; Hetzel, Scott; McCrea, Michael; Brooks, M. Alison

    2015-01-01

    Background The incidence of sport-related concussion (SRC) in high school football is well documented. However, limited prospective data are available regarding how player characteristics and protective equipment affect the incidence of SRC. Purpose To determine whether the type of protective equipment (helmet and mouth guard) and player characteristics affect the incidence of SRC in high school football players. Design Cohort study; Level of evidence, 2. Methods Certified athletic trainers (ATs) at each high school recorded the type of helmet worn (brand, model, purchase year, and recondition status) by each player as well as information regarding players’ demographics, type of mouth guard used, and history of SRC. The ATs also recorded the incidence and days lost from participation for each SRC. Incidence of SRC was compared for various helmets, type of mouth guard, history of SRC, and player demographics. Results A total of 2081 players (grades 9–12) enrolled during the 2012 and/or 2013 football seasons (2287 player-seasons) and participated in 134,437 football (practice or competition) exposures. Of these players, 206 (9%) sustained a total of 211 SRCs (1.56/1000 exposures). There was no difference in the incidence of SRC (number of helmets, % SRC [95% CI]) for players wearing Riddell (1171, 9.1% [7.6%–11.0%]), Schutt (680, 8.7% [6.7%–11.1%]), or Xenith (436, 9.2% [6.7%–12.4%]) helmets. Helmet age and recondition status did not affect the incidence of SRC. The rate of SRC (hazard ratio [HR]) was higher in players who wore a custom mouth guard (HR = 1.69 [95% CI, 1.20–2.37], P <.001) than in players who wore a generic mouth guard. The rate of SRC was also higher (HR = 1.96 [95% CI, 1.40–2.73], P <.001) in players who had sustained an SRC within the previous 12 months (15.1% of the 259 players [95% CI, 11.0%–20.1%]) than in players without a previous SRC (8.2% of the 2028 players [95% CI, 7.1%–9.5%]). Conclusion Incidence of SRC was similar

  10. 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

  11. 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.

  12. Reinforcement learning in professional basketball players.

    PubMed

    Neiman, Tal; Loewenstein, Yonatan

    2011-01-01

    Reinforcement learning in complex natural environments is a challenging task because the agent should generalize from the outcomes of actions taken in one state of the world to future actions in different states of the world. The extent to which human experts find the proper level of generalization is unclear. Here we show, using the sequences of field goal attempts made by professional basketball players, that the outcome of even a single field goal attempt has a considerable effect on the rate of subsequent 3 point shot attempts, in line with standard models of reinforcement learning. However, this change in behaviour is associated with negative correlations between the outcomes of successive field goal attempts. These results indicate that despite years of experience and high motivation, professional players overgeneralize from the outcomes of their most recent actions, which leads to decreased performance. PMID:22146388

  13. Design and implementation of a SMIL player

    NASA Astrophysics Data System (ADS)

    Xia, Jue; Shim, Simon; Wang, Ying; Lee, Yen-Jen

    1998-12-01

    Synchronized Multimedia Integration Language (SMIL) is a recommendation developed by the Synchronized Multimedia Working Group in the World Wide Web Consortium. SMIL is a simple and standard way to specify a timeline based synchronized multimedia presentation over the Internet. It is a declarative authoring language based on a Extensible Markup Language to define language-specific data types and tags. A SMIL player schedules presentation in a SMIL file, and retrieves media objects on the Web using URLs described in the field. The SMIL file is a plain text file and can be edited using a simple text editor. We present the approaches of implementing a SMIL player within the desktop system constraints. The reference implementation is a Java applet, which follows a platform-neutral programming paradigm and makes use of Java Media Framework. The applet can run in any main stream web browser.

  14. Pure Java-based streaming MPEG player

    NASA Astrophysics Data System (ADS)

    Tolba, Osama; Briceno, Hector; McMillan, Leonard

    1999-01-01

    We present a pure Java-based streaming MPEG-1 video player. By implementing the player entirely in Java, we guarantee its functionality across platforms within any Java-enabled web browsers, without the need for native libraries. This allows greater sue of MPEG video sequences, because the users will no longer need to pre-install any software to display video, beyond Java compatibility. This player features a novel forward-mapping IDCT algorithm that allows it to play locally stored, CIF-sized video sequences at 11 frames per second, when run on a personal computer with Java 'just-in-time' compiler. The IDCT algorithm can run with greater speed when the sequence is viewed at reduced size; e.g., performing approximately 1/4 the amount of computation when the user resizes the sequence to 1/2 its original width and height. We are able to play video streams stored anywhere on the Internet with acceptable performance using a proxy server, eliminating the need for large-capacity auxiliary storage. Thus, the player is well suited to small devices, such as digital TV set-top decoders, requiring little more memory than is required for three video frames. Because of our modular design, it is possible to assemble multiple video streams from remote sources and present them simultaneously to the viewers, subject to network and local performance limitations. The same modular system can further provide viewers with their own customized view of each sessions; e.g., moving and resizing the video display window dynamically, and selecting their preferred set of video controls.

  15. Seasonal Mood Disturbances in Collegiate Hockey Players

    PubMed Central

    Rosen, Lionel W.; Shafer, Christine L.; Smokler, Carol; Carrier, David; McKeag, Douglas B.

    1996-01-01

    Objective: The purpose of this paper is to: 1) describe the seasonal affective disorder syndrome using a case illustration, 2) provide a simple and reliable method for identifying seasonal affective disorder, and 3) provide data as to the prevalence of the syndrome in a subset of collegiate hockey players. Design and Setting: Collegiate hockey players were selected, because their practices begin in the fall and play is completed in the spring. The teams selected for participation were from the far Northwest and the upper Midwest regions. Subjects: Sixty-eight Division I hockey players volunteered for the study. The three teams from which the subjects were chosen were located above latitude 42°/45' north. Subjects were from the northern latitudes. Measurements: The Seasonal Pattern Assessment Questionnaire was used to screen for seasonality. A sample of the athletes was also examined using the Hamilton Rating Scale for Depression together with the Diagnostic and Statistical Manual of Mental Disorders (4th ed) criteria for Seasonal Pattern Specifier. Results: Thirty-three (51%) were asymptomatic, 7 (11%) met the criteria for seasonal affective disorder, and 25 (39%) hockey players scored in the range that could classify them as candidates for subsyndromal seasonal affective disorder. Conclusions: The prevalence of seasonal affective disorder among our sample approximated the national norm for the northern latitudes. However, the prevalence of subsyndromal seasonal affective disorder in our population was 25% compared to 13% reported nationally. Light therapy has been shown to reverse the effects of the disorders; however, further research needs to be conducted to determine its acceptance and effectiveness by the athletic population. PMID:16558403

  16. 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

  17. 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

  18. Friendship Quality in Youth Sport: Relationship to Age, Gender, and Motivation Variables.

    ERIC Educational Resources Information Center

    Weiss, Maureen R.; Smith, Alan L.

    2002-01-01

    Examined age and gender differences in the quality of sport friendship, noting relationships between friendship quality and motivation-related variables and reexamining the validity of the Sport Friendship Quality Scale (SFQS). Adolescent tennis players completed the SFQS and other measures. Age and gender differences in friendship emerged.…

  19. Slow motion replay detection of tennis video based on color auto-correlogram

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaoli; Zhi, Min

    2012-04-01

    In this paper, an effective slow motion replay detection method for tennis videos which contains logo transition is proposed. This method is based on the theory of color auto-correlogram and achieved by fowllowing steps: First,detect the candidate logo transition areas from the video frame sequence. Second, generate logo template. Then use color auto-correlogram for similarity matching between video frames and logo template in the candidate logo transition areas. Finally, select logo frames according to the matching results and locate the borders of slow motion accurately by using the brightness change during logo transition process. Experiment shows that, unlike previous approaches, this method has a great improvement in border locating accuracy rate, and can be used for other sports videos which have logo transition, too. In addition, as the algorithm only calculate the contents in the central area of the video frames, speed of the algorithm has been improved greatly.

  20. 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.

  1. Cortical topography of event-related potentials to winning and losing in a video tennis game.

    PubMed

    Ivanitsky, A M; Kurnitskaya, I V; Sobotka, S

    1986-07-01

    The event-related potentials (ERP) in frontal and posterior associative cortex in right and left hemispheres were studied in two different outcomes of a television tennis game. These outcomes were 'win' and 'loss' of the ball, the first serving as a model of positive, the second as a model of negative emotional reactions. The ERPs consisted of 4 waves: P300, N600, P800, N1000. The most characteristic interhemispheric difference for 'win' was an increase of N600 in the left posterior associative cortex, and for 'loss', a decrease of P800 in the right frontal area. Thus, the positive and negative emotional reactions have specific spatio-temporal cortical organizations. The topography of ERP related to positive and negative emotions was disturbed in depressive patients. The patients revealed a larger negativity of the right posterior associative cortex and the left frontal cortex waves both at winning and losing the ball. PMID:3733492

  2. Iontophoresis Versus Cyriax-Type exercises in Chronic Tennis Elbow among industrial workers

    PubMed Central

    Fathy, Abdelhamid Akram

    2015-01-01

    Introduction: Tennis elbow (TE) is one of the most commonly encountered upper limb conditions. It mainly affects people who use the hand grip against resistance frequently, resulting in microtrauma to the wrist extensors tendon, causing pain. This study was conducted to compare the application of iontophoresis of 0.4% dexamethasone and Cyriax-type exercises in the treatment of chronic tennis elbow (CTE). Methods: Twenty-two industrial worker diagnosed as having CTE participated in this study, and their ages ranged from 25 to 52. They were assigned randomly to two groups, i.e., “group A” in which the workers were treated by iontophoresis of 0.4% Dexamethasone and “group B” in which the workers were treated by conducting Cyriax-type exercises on the affected tendon. Both groups received stretching exercises for the common extensors tendon for 10 minutes in addition to five minutes of pulsed US 1.1 W/cm2 six times over two weeks. The outcome of the treatment was assessed one week after the last session by the visual analog scale (VAS) to assess pain, by the Oxford elbow score (OES) to measure the patient’s satisfaction, and by a handgrip dynamometer to measure the strength of the handgrip. Results: The application of 0.4% dexamethasone iontophoresis and the use of Cyriax-type exercises both provided significant improvement in the pain, patient’s satisfaction, and the power of the handgrip, and there were no significant difference (p > 0.001) in any of the three measures after the first week’s treatment. Conclusions: Both iontophoresis of 0.4% dexamethasone and Cyriax-type exercises were successful as treatment modalities for patients with CTE, and there were no significant differences between both of them in the treatment of those cases. PMID:26435828

  3. The effect of haptic guidance and visual feedback on learning a complex tennis task.

    PubMed

    Marchal-Crespo, Laura; van Raai, Mark; Rauter, Georg; Wolf, Peter; Riener, Robert

    2013-11-01

    While haptic guidance can improve ongoing performance of a motor task, several studies have found that it ultimately impairs motor learning. However, some recent studies suggest that the haptic demonstration of optimal timing, rather than movement magnitude, enhances learning in subjects trained with haptic guidance. Timing of an action plays a crucial role in the proper accomplishment of many motor skills, such as hitting a moving object (discrete timing task) or learning a velocity profile (time-critical tracking task). The aim of the present study is to evaluate which feedback conditions-visual or haptic guidance-optimize learning of the discrete and continuous elements of a timing task. The experiment consisted in performing a fast tennis forehand stroke in a virtual environment. A tendon-based parallel robot connected to the end of a racket was used to apply haptic guidance during training. In two different experiments, we evaluated which feedback condition was more adequate for learning: (1) a time-dependent discrete task-learning to start a tennis stroke and (2) a tracking task-learning to follow a velocity profile. The effect that the task difficulty and subject's initial skill level have on the selection of the optimal training condition was further evaluated. Results showed that the training condition that maximizes learning of the discrete time-dependent motor task depends on the subjects' initial skill level. Haptic guidance was especially suitable for less-skilled subjects and in especially difficult discrete tasks, while visual feedback seems to benefit more skilled subjects. Additionally, haptic guidance seemed to promote learning in a time-critical tracking task, while visual feedback tended to deteriorate the performance independently of the task difficulty and subjects' initial skill level. Haptic guidance outperformed visual feedback, although additional studies are needed to further analyze the effect of other types of feedback visualization on

  4. 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, Peter G; Evers, Brandon S; Rambo, Thomas J

    2012-01-01

    Unmanned aerial vehicles (UAV), or drones, have been used widely in military applications, but more recently civilian applications have emerged (e.g., wildlife population monitoring, traffic monitoring, law enforcement, oil and gas pipeline threat detection). UAV can have several advantages over manned aircraft for wildlife surveys, including reduced ecological footprint, increased safety, and the ability to collect high-resolution geo-referenced imagery that can document the presence of species without the use of a human observer. We illustrate how geo-referenced data collected with UAV technology in combination with recently developed statistical models can improve our ability to estimate the distribution of organisms. To demonstrate the efficacy of this methodology, we conducted an experiment in which tennis balls were used as surrogates of organisms to be surveyed. We used a UAV to collect images of an experimental field with a known number of tennis balls, each of which had a certain probability of being hidden. We then applied spatially explicit occupancy models to estimate the number of balls and created precise distribution maps. We conducted three consecutive surveys over the experimental field and estimated the total number of balls to be 328 (95%CI: 312, 348). The true number was 329 balls, but simple counts based on the UAV pictures would have led to a total maximum count of 284. The distribution of the balls in the field followed a simulated environmental gradient. We also were able to accurately estimate the relationship between the gradient and the distribution of balls. Our experiment demonstrates how this technology can be used to create precise distribution maps in which discrete regions of the study area are assigned a probability of presence of an object. Finally, we discuss the applicability and relevance of this experimental study to the case study of Florida manatee distribution at power plants. PMID:22761712

  5. Estimating Distribution of Hidden Objects with Drones: From Tennis Balls to Manatees

    PubMed Central

    Martin, Julien; Edwards, Holly H.; Burgess, Matthew A.; Percival, H. Franklin; Fagan, Daniel E.; Gardner, Beth E.; Ortega-Ortiz, Joel G.; Ifju, Peter G.; Evers, Brandon S.; Rambo, Thomas J.

    2012-01-01

    Unmanned aerial vehicles (UAV), or drones, have been used widely in military applications, but more recently civilian applications have emerged (e.g., wildlife population monitoring, traffic monitoring, law enforcement, oil and gas pipeline threat detection). UAV can have several advantages over manned aircraft for wildlife surveys, including reduced ecological footprint, increased safety, and the ability to collect high-resolution geo-referenced imagery that can document the presence of species without the use of a human observer. We illustrate how geo-referenced data collected with UAV technology in combination with recently developed statistical models can improve our ability to estimate the distribution of organisms. To demonstrate the efficacy of this methodology, we conducted an experiment in which tennis balls were used as surrogates of organisms to be surveyed. We used a UAV to collect images of an experimental field with a known number of tennis balls, each of which had a certain probability of being hidden. We then applied spatially explicit occupancy models to estimate the number of balls and created precise distribution maps. We conducted three consecutive surveys over the experimental field and estimated the total number of balls to be 328 (95%CI: 312, 348). The true number was 329 balls, but simple counts based on the UAV pictures would have led to a total maximum count of 284. The distribution of the balls in the field followed a simulated environmental gradient. We also were able to accurately estimate the relationship between the gradient and the distribution of balls. Our experiment demonstrates how this technology can be used to create precise distribution maps in which discrete regions of the study area are assigned a probability of presence of an object. Finally, we discuss the applicability and relevance of this experimental study to the case study of Florida manatee distribution at power plants. PMID:22761712

  6. Vascular Health in American Football Players: Cardiovascular Risk Increased in Division III Players

    PubMed Central

    Feairheller, Deborah L.; Aichele, Kristin R.; Oakman, Joyann E.; Neal, Michael P.; Cromwell, Christina M.; Lenzo, Jessica M.; Perez, Avery N.; Bye, Naomi L.; Santaniello, Erica L.; Hill, Jessica A.; Evans, Rachel C.; Thiele, Karla A.; Chavis, Lauren N.; Getty, Allyson K.; Wisdo, Tia R.; McClelland, JoAnna M.; Sturgeon, Kathleen; Chlad, Pam

    2016-01-01

    Studies report that football players have high blood pressure (BP) and increased cardiovascular risk. There are over 70,000 NCAA football players and 450 Division III schools sponsor football programs, yet limited research exists on vascular health of athletes. This study aimed to compare vascular and cardiovascular health measures between football players and nonathlete controls. Twenty-three athletes and 19 nonathletes participated. Vascular health measures included flow-mediated dilation (FMD) and carotid artery intima-media thickness (IMT). Cardiovascular measures included clinic and 24 hr BP levels, body composition, VO2 max, and fasting glucose/cholesterol levels. Compared to controls, football players had a worse vascular and cardiovascular profile. Football players had thicker carotid artery IMT (0.49 ± 0.06 mm versus 0.46 ± 0.07 mm) and larger brachial artery diameter during FMD (4.3 ± 0.5 mm versus 3.7 ± 0.6 mm), but no difference in percent FMD. Systolic BP was significantly higher in football players at all measurements: resting (128.2 ± 6.4 mmHg versus 122.4 ± 6.8 mmHg), submaximal exercise (150.4 ± 18.8 mmHg versus 137.3 ± 9.5 mmHg), maximal exercise (211.3 ± 25.9 mmHg versus 191.4 ± 19.2 mmHg), and 24-hour BP (124.9 ± 6.3 mmHg versus 109.8 ± 3.7 mmHg). Football players also had higher fasting glucose (91.6 ± 6.5 mg/dL versus 86.6 ± 5.8 mg/dL), lower HDL (36.5 ± 11.2 mg/dL versus 47.1 ± 14.8 mg/dL), and higher body fat percentage (29.2 ± 7.9% versus 23.2 ± 7.0%). Division III collegiate football players remain an understudied population and may be at increased cardiovascular risk. PMID:26904291

  7. Talented football players' development of achievement motives, volitional components, and self-referential cognitions: A longitudinal study.

    PubMed

    Feichtinger, Philip; Höner, Oliver

    2015-01-01

    Adolescence is regarded as a key developmental phase in the course of talented football players' careers. The present study focuses on early adolescent players' development of achievement motives, volitional components, and self-referential cognitions. Based on the multidimensional and dynamic nature of talent, the development of multifaceted personality characteristics is an important issue in the context of sports talent research. According to previous findings in psychology, personality characteristics' development is defined by both stability and change, and the current study analyses four different types: differential stability (I), mean-level change (II), individual-level change (III), and structural stability (IV). The sample consists of 151 male players in the talent development programme of the German Football Association. Psychological diagnostics of the personality characteristics are implemented across longitudinal sections over a time period of three seasons, from the U12 to U14 age classes. The results reveal that the personality characteristics show (I) moderate test-retest correlations over one-year intervals (.43 ≤ rtt ≤ .62), and lower coefficients for a two-year period (.26 ≤ rtt ≤ .53). (II) Most of the personality characteristics' mean values differ significantly across the age classes with small effect sizes (.01 ≤ [Formula: see text] ≤ .03). (III) Only minor individual-level changes in the football players' development are found. (IV) The personality characteristics' associations within a two-factor structure do not stay invariant over time. From the results of the present study, conclusions are drawn regarding the talent identification and development process. PMID:26313875

  8. Player preferences among new and old violins

    PubMed Central

    Fritz, Claudia; Curtin, Joseph; Poitevineau, Jacques; Morrel-Samuels, Palmer; Tao, Fan-Chia

    2012-01-01

    Most violinists believe that instruments by Stradivari and Guarneri “del Gesu” are tonally superior to other violins—and to new violins in particular. Many mechanical and acoustical factors have been proposed to account for this superiority; however, the fundamental premise of tonal superiority has not yet been properly investigated. Player's judgments about a Stradivari's sound may be biased by the violin's extraordinary monetary value and historical importance, but no studies designed to preclude such biasing factors have yet been published. We asked 21 experienced violinists to compare violins by Stradivari and Guarneri del Gesu with high-quality new instruments. The resulting preferences were based on the violinists’ individual experiences of playing the instruments under double-blind conditions in a room with relatively dry acoustics. We found that (i) the most-preferred violin was new; (ii) the least-preferred was by Stradivari; (iii) there was scant correlation between an instrument's age and monetary value and its perceived quality; and (iv) most players seemed unable to tell whether their most-preferred instrument was new or old. These results present a striking challenge to conventional wisdom. Differences in taste among individual players, along with differences in playing qualities among individual instruments, appear more important than any general differences between new and old violins. Rather than searching for the “secret” of Stradivari, future research might best focused on how violinists evaluate instruments, on which specific playing qualities are most important to them, and on how these qualities relate to measurable attributes of the instruments, whether old or new. PMID:22215592

  9. Making star teams out of star players.

    PubMed

    Mankins, Michael; Bird, Alan; Root, James

    2013-01-01

    Top talent is an invaluable asset: In highly specialized or creative work, for instance, "A" players are likely to be six times as productive as "B" players. So when your company has a crucial strategic project, why not multiply all that firepower and have a team of your best performers tackle it? Yet many companies hesitate to do this, believing that all-star teams don't work: Big egos will get in the way. The stars won't be able to work with one another. They'll drive the team Leader crazy. Mankins, Bird, and Root of Bain & Company believe it's time to set aside that thinking. They have seen all-star teams do extraordinary work. But there is a right way and a wrong way to organize them. Before you can even begin to assemble such a team, you need to have the right talent management practices, so you hire and develop the best people and know what they're capable of. You have to give the team appropriate incentives and leaders and support staffers who are stars in their own right. And projects that are ill-defined or small scale are not for all-star teams. Use them only for critical missions, and make sure their objectives are clear. Even with the right setup, things can still go wrong. The wise executive will take steps to manage egos, prune non-team-players, and prevent average coworkers from feeling completely undervalued. She will also invest a lot of time in choosing the right team Leader and will ask members for lots of feedback to monitor how that leader is doing. PMID:23390743

  10. [Adolescent pregnancy].

    PubMed

    Fatichi, B

    1991-10-01

    This exploration of adolescent pregnancy focuses on adolescents whose pregnancies are undesired. The physical and psychic transformations of puberty and adolescence may be experienced differently in different social contexts. The prolongation of school attendance in Western societies means that most adolescents remain financially dependent on their parents. But greater sexual freedom in the society at large has been reflected in an increase in early sexual activity among adolescents. Wider use of contraception has not completely eliminated prenatal pregnancy among adolescents. Adolescent pregnancies have actually declined in France as a proportion of all pregnancies carried to term, from 4% to 1.5-2% in the past 10 or 15 years. But in 1986, 42.5% of all induced abortions were performed on adolescents. Among causes of unwanted pregnancy in adolescents are their frequent inability to believe that they may be at risk of pregnancy, or that pregnancy can result from the 1st sexual intercourse. The episodic nature of sexual relations, the lack of ready availability of contraception, and specific shortcomings of different methods are factors in the frequent failure of adolescents to protect themselves against undesired pregnancy. Adolescents may become pregnant out of loneliness or to prove that they are women, or as a result of incest or prostitution. Adolescents who seek abortions are those who have discovered and acknowledged their pregnancies before the 12th week and had the courage to inform their parents and obtain legal permission for the abortion. Pregnancy terminations are more frequent in more advantaged societal sectors with more structured family life. The moral shock and sense of failure associated with abortion are often deeply felt by adolescents. Their experience is greatly influenced by the attitudes of those around them. Adolescents who carry their pregnancies to term are those who have not sought abortion in the 1st 12 weeks. Often they refuse to admit

  11. Enhancements for Multi-Player Monte-Carlo Tree Search

    NASA Astrophysics Data System (ADS)

    Nijssen, J. (Pim) A. M.; Winands, Mark H. M.

    Monte-Carlo Tree Search (MCTS) is becoming increasingly popular for playing multi-player games. In this paper we propose two enhancements for MCTS in multi-player games: (1) Progressive History and (2) Multi-Player Monte-Carlo Tree Search Solver (MP-MCTS-Solver). We analyze the performance of these enhancements in two different multi-player games: Focus and Chinese Checkers. Based on the experimental results we conclude that Progressive History is a considerable improvement in both games and MP-MCTS-Solver, using the standard update rule, is a genuine improvement in Focus.

  12. Elbow and Shoulder Lesions of Baseball Players*

    PubMed Central

    2008-01-01

    George Eli Bennett was born in Claryville, NY, in the Catskill Mountains, in 1885 [3]. His parents both died by the time he was 11, leaving him the need to work while going to school, but he excelled in school and sports. He played semipro baseball at the age of 16. After high school he work in various jobs in the Midwest before he could afford to attend the University of Maryland Medical School, from which he graduated in 1908. At the age of 25 in 1910, he joined the staff at the Johns Hopkins Hospital, where he remained until his resignation in 1947. Dr. Bennett was one of a few men who served as President of both the American Orthopaedic Association and the American Academy of Orthopaedic Surgeons. While Dr. Bennett made many contributions to orthopaedic surgery, including children’s and nonoperative orthopaedics, he was best known for his work in sports medicine (undoubtedly related to his being a gifted athlete). His fame extended well beyond the orthopaedic community, for he treated many famous athletes. Sports Illustrated recognized him upon his death in an article entitled, “Mender of Immortals” [4]. His intimate knowledge of sports undoubtedly contributed to his sage judgments. At an emotional dinner in 1958 many famous athletes sometimes tearfully paid tribute to Dr. Bennett. Joe Garagiola commented on the occasion, “After listening to that all-star team of players Dr. Bennett has mended, I’m sorry I didn’t break my leg” [4]. Among Dr. Bennett’s many publications, including those related to sports, we have chosen one [2] of two articles [1,2] he wrote on elbow and shoulder problems in baseball players. He described the now well-known degenerative changes and periarticular calcific deposits that occur in the elbows and shoulders of pitchers. Some of these, he suggested, were not symptomatic and he advised against treatment. Dr. Bennett commented, however, “Since professional athletes are human beings, not supermen, general health often

  13. Fibular Fracture in a Female Rugby Player.

    PubMed

    Mendola, Jonathan A; Johnson, Michael; Goss, Don

    2016-07-01

    A 20-year-old female rugby player was injured when an opponent landed on her leg during a match. Twelve days after injury, the team's certified athletic trainer referred the patient to a physical therapist due to continued pain. Following fluoroscopic imaging, which was utilized by the physical therapist because standard radiographs were unavailable in close proximity, she was referred for radiographs, which demonstrated a midfibular diaphyseal fracture. J Orthop Sports Phys Ther 2016;46(7):608. doi:10.2519/jospt.2016.0411. PMID:27363575

  14. Cervical spine injuries in rugby players.

    PubMed

    Sovio, O M; Van Peteghem, P K; Schweigel, J F

    1984-03-15

    Nine patients with serious cervical spine injuries that occurred while they were playing rugby were seen in a British Columbia acute spinal cord injury unit during the period 1975-82. All the injuries had occurred during the "scrum" or the "tackle". Two of the patients were rendered permanently quadriplegic, and one patient died. There is a need for a central registry that would record all cervical spine injuries in rugby players as well as for changes in the rules of the game. PMID:6697282

  15. Focused and Radial Shock Wave Therapy in the Treatment of Tennis Elbow: A Pilot Randomised Controlled Study

    PubMed Central

    Król, Piotr; Franek, Andrzej; Durmała, Jacek; Błaszczak, Edward; Ficek, Krzysztof; Król, Barbara; Detko, Ewa; Wnuk, Bartosz; Białek, Lidia; Taradaj, Jakub

    2015-01-01

    The purpose of this article was to evaluate and compare the efficacy of radial and focused shock wave therapies applied to treat tennis elbow. Patients with tennis elbow were randomized into two comparative groups: focused shock wave therapy (FSWT; n=25) and radial shock wave therapy (RSWT; n=25). Subjects in the FSWT and RSWT groups were applied with a focused shock wave (3 sessions, 2000 shocks, 4 Hz, 0.2 mJ/mm2) and a radial shock wave (3 sessions, 2000 + 2000 shocks, 8 Hz, 2.5 bar), respectively. The primary study endpoints were pain relief and functional improvement (muscle strength) one week after therapy. The secondary endpoint consisted of the results of the follow-up observation (3, 6 and 12 weeks after the study). Successive measurements showed that the amount of pain patients felt decreased in both groups. At the same time grip strength as well as strength of wrist extensors and flexors of the affected extremity improved significantly. Both focused and radial shock wave therapies can comparably and gradually reduce pain in subjects with tennis elbow. This process is accompanied by steadily improved strength of the affected extremity. PMID:26557197

  16. Counseling adolescents.

    PubMed

    Yamuna, Srinivasan

    2013-11-01

    Skills for counseling adolescents are acquired over a period of time by all practitioners of adolescent health. Though the principles of counseling remain the same the process of counseling an adolescent differs considerably from that of a child or an adult. Adolescents are in their transition between childhood and adulthood with physical, emotional and social challenges to face. The maturity level of each adolescent differs and that decides the pace and contents of each session. The counselor sets the context in a non judgmental manner so that the adolescent feels the ease and eagerness to self disclose. Privacy and confidentiality are two key issues that have to be taken care of during counseling. PMID:23888379

  17. What Differentiates Professional Poker Players from Recreational Poker Players? A Qualitative Interview Study

    ERIC Educational Resources Information Center

    McCormack, Abby; Griffiths, Mark D.

    2012-01-01

    The popularity of poker (and in particular online poker) has increasingly grown worldwide in recent years. This increase in the popularity of poker has led to the increased incidence of the "professional poker player". However, very little empirical research has been carried out into this relatively new group of gamblers. The aim was to determine…

  18. Tennis elbow

    MedlinePlus

    ... Jr., Miller MD, eds. DeLee and Drez's Orthopaedic Sports Medicine . 3rd ed. Philadelphia, PA: Elsevier Saunders; 2009:chap ... by: C. Benjamin Ma, MD, Assistant Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, ...

  19. Scapula Kinematics of Youth Baseball Players

    PubMed Central

    Oliver, Gretchen; Weimar, Wendi

    2015-01-01

    Literature has revealed the importance of quantifying resting scapular posture in overhead athletes as well as quantifying scapular kinematics during dynamic movement. Prior to this project much of the attention in throwing research had been focused on the position of the humerus without description of the positioning of the scapula. Therefore, it was the purpose of this study to present scapular kinematics during pitching in youth baseball players. Twenty-five youth baseball players (age 11.3 + 1.0 years; body height 152.4 + 9.0 cm; body mass 47.5 + 11.3 kg), with no history of injury, participated in the study. Scapular kinematics at the events of maximum humeral external rotation (MER) and maximum humeral internal rotation (MIR) during the pitching motion were assessed three-dimensionally while pitching fastballs for strikes. Results revealed that at the event of MER, the scapula was in a position of retraction, upward rotation and a posterior tilt. While at the event of MIR, the scapula was protracted, upward rotated and tilted anteriorly. PMID:26839605

  20. Scapula Kinematics of Youth Baseball Players.

    PubMed

    Oliver, Gretchen; Weimar, Wendi

    2015-12-22

    Literature has revealed the importance of quantifying resting scapular posture in overhead athletes as well as quantifying scapular kinematics during dynamic movement. Prior to this project much of the attention in throwing research had been focused on the position of the humerus without description of the positioning of the scapula. Therefore, it was the purpose of this study to present scapular kinematics during pitching in youth baseball players. Twenty-five youth baseball players (age 11.3 + 1.0 years; body height 152.4 + 9.0 cm; body mass 47.5 + 11.3 kg), with no history of injury, participated in the study. Scapular kinematics at the events of maximum humeral external rotation (MER) and maximum humeral internal rotation (MIR) during the pitching motion were assessed three-dimensionally while pitching fastballs for strikes. Results revealed that at the event of MER, the scapula was in a position of retraction, upward rotation and a posterior tilt. While at the event of MIR, the scapula was protracted, upward rotated and tilted anteriorly. PMID:26839605

  1. GADD45 proteins: central players in tumorigenesis

    PubMed Central

    Tamura, Rodrigo Esaki; de Vasconcellos, Jaíra Ferreira; Sarkar, Devanand; Libermann, Towia A; Fisher, Paul B; Zerbini, Luiz Fernando

    2013-01-01

    The Growth Arrest and DNA Damage-inducible 45 (GADD45) proteins have been implicated in regulation of many cellular functions including DNA repair, cell cycle control, senescence and genotoxic stress. However, the pro-apoptotic activities have also positioned GADD45 as an essential player in oncogenesis. Emerging functional evidence implies that GADD45 proteins serve as tumor suppressors in response to diverse stimuli, connecting multiple cell signaling modules. Defects in the GADD45 pathway can be related to the initiation and progression of malignancies. Moreover, induction of GADD45 expression is an essential step for mediating anti-cancer activity of multiple chemotherapeutic drugs and the absence of GADD45 might abrogate their effects in cancer cells. In this review, we present a comprehensive discussion of the functions of GADD45 proteins, linking their regulation to effectors of cell cycle arrest, DNA repair and apoptosis. The ramifications regarding their roles as essential and central players in tumor growth suppression are also examined. We also extensively review recent literature to clarify how different chemotherapeutic drugs induce GADD45 gene expression and how its up-regulation and interaction with different molecular partners may benefit cancer chemotherapy and facilitate novel drug discovery. PMID:22515981

  2. Strength Asymmetry of the Shoulders in Elite Volleyball Players

    PubMed Central

    Hadzic, Vedran; Sattler, Tine; Veselko, Matjaž; Markovic, Goran; Dervisevic, Edvin

    2014-01-01

    Context: Volleyball players are reported to have shoulder strength imbalances. Previous authors have primarily investigated small samples of male players at a single skill level, without considering playing position, and with inconsistent findings. Objective: To evaluate shoulder strength asymmetry and a history of shoulder injury in a large sample of professional volleyball players of both sexes across different playing positions and skill levels. Design: Descriptive laboratory study. Patients or Other Participants: A sample of 183 volleyball players (99 men, 84 women). Main Outcome Measure(s): We assessed shoulder internal-rotator and external-rotator concentric strength at 60°/s using an isokinetic dynamometer and dominant-nondominant differences in shoulder strength and strength ratios using repeated-measures analyses of variance. Peak torque was normalized for body mass and external-rotation/internal-rotation concentric strength. Results: Internal-rotation strength was asymmetric in favor of the dominant side in both sexes, regardless of previous shoulder injury status. Male volleyball players had a lower shoulder strength ratio on the dominant side, regardless of previous shoulder injury status. However, this finding was valid only when hand dominance was taken into account. Female volleyball players playing at a higher level (ie, first versus second division) were 3.43 times more likely to have an abnormal strength ratio. Playing position was not associated with an abnormal shoulder strength ratio or strength asymmetry. Conclusions: In male volleyball players, the external-rotation/internal-rotation strength ratio of the dominant shoulder was lower, regardless of playing position, skill level, or a previous shoulder injury. In female players, the ratio was less only in those at a higher skill level. Although speculative, these findings generally suggest that female volleyball players could have a lower risk of developing shoulder-related problems than male

  3. Sex-specific differences in injury types among basketball players

    PubMed Central

    Ito, Eri; Iwamoto, Jun; Azuma, Koichiro; Matsumoto, Hideo

    2015-01-01

    The purpose of the present study was to investigate sex-specific differences in injury types among basketball players. According to our database, during the 20-year period between October 1991 and June 2011, 1,219 basketball players (640 males and 579 females) consulted our sports medicine clinic; in total, 1,414 injuries in basketball players (729 injuries in males and 685 injuries in females) were recorded. The mean age of patients was 19.6 years. The most common injury site was the knee, followed by the foot and ankle, lower back, and upper extremities. There was a higher proportion of female players presenting with a knee injury, compared with male players (50.4% vs 41.7%), and a lower proportion of female players presenting with an upper extremity injury (5.1% vs 9.7%). The proportion of anterior cruciate ligament injury in the 10–19-year-old age group was higher among female players than among male players (45.9% vs 22.1%), while the proportions of Osgood–Schlatter disease in the 10–19-year-old age group and jumper’s knee (patellar and femoral tendinopathy) in the 20–29-year-old age group were higher among male players than among female players (12.5% vs 1.8% and 14.6% vs 3.7%, respectively). However, the proportions of other injuries did not differ significantly between male and female players. The present observational study, which was performed using a retrospective case-series design, showed the existence of sex-specific differences in knee injuries sustained while participating in basketball. PMID:25565908

  4. Match analysis and player characteristics in rugby sevens.

    PubMed

    Ross, Alex; Gill, Nicholas; Cronin, John

    2014-03-01

    Rugby sevens is a contact sport contested by two teams of seven players who compete over two 7-min halves, most frequently played in a tournament style. The IRB Sevens World Series is thought of as the preeminent rugby sevens competition in the world and has grown in competitiveness from its inception in 2000. The decision to include rugby sevens in the 2016 Olympics is likely to increase the global profile and participation in the game. Many rugby sevens players concurrently compete in 15-a-side rugby union as backs and loose forwards; however, a continued increase in the popularity of rugby sevens will likely see the emergence of the specialist rugby sevens player. Often thought of as the abbreviated version of rugby union, rugby sevens is played under nearly identical laws and on the same field dimensions as the 15-man code. However, research has shown the movement demands of rugby sevens and rugby union are dissimilar, with rugby sevens players spending a larger proportion of the game running at high intensity (≥ 5 m s(-1)). Given the dissimilarity in match demands in conjunction with differences in the competition structure between the codes, it appears the considerable depth of literature specific to performance in rugby union may be of little value for the preparation of rugby sevens players. Investigations of the physical characteristics of rugby sevens players show backs are lighter and shorter than forwards, while players across all positions possess a lean body composition. International rugby sevens players have similar speed characteristics to rugby union backs across distances of 10-30 m; however, rugby sevens players appear to have superior intermittent aerobic endurance. Despite being of likely importance, little is known of the strength and power characteristics of rugby sevens players. Research into the speed and aerobic endurance characteristics of rugby sevens players has not distinguished between backs and forwards and, as such, it is unclear

  5. Labor Market Structure and Salary Determination among Professional Basketball Players.

    ERIC Educational Resources Information Center

    Wallace, Michael

    1988-01-01

    The author investigates the labor market structure and determinants of salaries for professional basketball players. An expanded version of the resource perspective is used. A three-tiered model of labor market segmentation is revealed for professional basketball players, but other variables also are important in salary determination. (Author/CH)

  6. Comparison of Academic Success between CTC Basketball Players and Nonplayers.

    ERIC Educational Resources Information Center

    Marcotte, James

    A study was conducted at Cincinnati Technical College (CTC) to discover whether college athletes, particularly basketball players, performed as well as their non-athlete counterparts in terms of grade point average (GPA), credit hours completed, and graduation. A sample of 51 CTC basketball players was matched against a sample of 51 non-players…

  7. The Mental Skills Training of University Soccer Players

    ERIC Educational Resources Information Center

    Sadeghi, Hassan; Omar-Fauzee, Mohd-Sofian; Jamalis, Marjohan; Ab-Latif, Rozita; Cheric, Majid Chahrdah

    2010-01-01

    The purpose of this study is to identify the kind of mental skills training needed most by the university soccer players. Eight male university football players (aged 25 to 36) from one large university in Kuala Lumpur agreed to participate in this study. On average, they have 10 years of playing experience. All of them have signed the informed…

  8. Differences in Soccer Kick Kinematics between Blind Players and Controls

    ERIC Educational Resources Information Center

    Giagazoglou, Paraskevi; Katis, Athanasios; Kellis, Eleftherios; Natsikas, Christos

    2011-01-01

    The purpose of the current study was to examine the kinematic differences during instep soccer kicks between players who were blind and sighted controls. Eleven male soccer players who were blind and nine male sighted performed instep kicks under static and dynamic conditions. The results indicated significantly higher (p less than 0.05) ball…

  9. Decision-Making and Thought Processes among Poker Players

    ERIC Educational Resources Information Center

    St. Germain, Joseph; Tenenbaum, Gershon

    2011-01-01

    This study was aimed at delineating decision-making and thought processing among poker players who vary in skill-level. Forty-five participants, 15 in each group, comprised expert, intermediate, and novice poker players. They completed the Computer Poker Simulation Task (CPST) comprised of 60 hands of No-Limit Texas Hold 'Em. During the CPST, they…

  10. Kibbutz Adolescents.

    ERIC Educational Resources Information Center

    Mazor, Aviva, Ed.

    1993-01-01

    This special issue on adolescence in the Israeli kibbutz contains a series of seven papers that seek to advance thought and research regarding the relationship between a communal way of life and individual developmental processes in adolescence and early adulthood. The articles represent a transitional era as the kibbutz evolves. (SLD)

  11. Adolescent Literacy

    ERIC Educational Resources Information Center

    Ippolito, Jacy, Ed.; Steele, Jennifer L., Ed.; Samson, Jennifer F., Ed.

    2012-01-01

    "Adolescent Literacy" initially appeared as a special issue of the "Harvard Educational Review". It explores key issues and debates in the adolescent literacy crisis, the popular use of cognitive strategies, and disciplinary and content-area literacy. Also examined are alternative forms of literacy, afterschool interventions, new instruction…

  12. Adolescent Neurodevelopment

    PubMed Central

    Spear, Linda Patia

    2012-01-01

    Purpose The purpose of this paper is to outline notable alterations occurring in the adolescent brain, and consider potential ramifications of these developmental transformations for public policy and programs involving adolescents. Methods Developmental changes in the adolescent brain obtained from human imaging work are reviewed, along with results of basic science studies. Results Adolescent brain transformations include both progressive and regressive changes that are regionally specific and serve to refine brain functional connectivity. Along with still maturing inhibitory control systems that can be overcome under emotional circumstances, the adolescent brain is associated with sometimes elevated activation of reward-relevant brain regions, whereas sensitivity to aversive stimuli may be attenuated. At this time, the developmental shift from greater brain plasticity early in life to the relative stability of the mature brain is still tilted more towards plasticity than seen in adulthood, perhaps providing an opportunity for some experience-influenced sculpting of the adolescent brain. Conclusions Normal developmental transformations in brain reward/aversive systems, areas critical for inhibitory control, and regions activated by emotional, exciting and stressful stimuli may promote some normative degree of adolescent risk-taking. These findings have a number of potential implications for public policies and programs focused on adolescent health and well-being. PMID:23332574

  13. Stress fracture of the radial styloid process in a judo player: a case report.

    PubMed

    Hashiguchi, Hiroshi; Iwashita, Satoshi; Ohkubo, Atsushi; Sawaizumi, Takuya; Takai, Shinro

    2015-01-01

    Stress fractures of the upper limbs are uncommon, and are most often reported as individual cases or small series. In particularly, stress fractures around the wrist are even less common. A stress fracture of the radial styloid process in a judo player was surgically treated, and a favorable treatment outcome was obtained. A 16-year-old adolescent boy experienced pain in the right wrist, with no apparent trigger, while playing judo. Stress fracture of the radial styloid process was diagnosed with plain radiographs and was treated conservatively with cast immobilization. Although bone union was achieved, the fracture recurred after he resumed paying judo. Thus, surgical treatment was performed. The procedure was resection of the distal bone fragment. He resumed practicing 2 months postoperatively and returned to judo matches after 1 more month. As of 1 year after distal bone fragment resection, he was able to participate in judo without pain, limited range of motion, or instability of the wrist. PMID:25959203

  14. Sleep Position Trainer versus Tennis Ball Technique in Positional Obstructive Sleep Apnea Syndrome

    PubMed Central

    Eijsvogel, Michiel M.; Ubbink, Rinse; Dekker, Janita; Oppersma, Eline; de Jongh, Frans H.; van der Palen, Job; Brusse-Keizer, Marjolein G.

    2015-01-01

    Study Objective: Positional therapy (PT) is an effective therapy in positional obstructive sleep apnea syndrome (POSAS) when used, but the compliance of PT is low. The objective of this study was to investigate whether a new kind of PT is effective and can improve compliance. Methods: 29 patients were treated with the sleep position trainer (SPT), 26 patients with the tennis ball technique (TBT). At baseline and 1 month polysomnography, Epworth Sleepiness Scale (ESS) and the Quebec Sleep Questionnaire (QSQ) were taken. Daily compliance was objectively measured in both groups. Results: Both therapies prevent supine sleep position to a median of 0% (min-max: SPT 0.0% to 67%, TBT 0.0% to 38.9%), resulting in a treatment success (AHI < 5) in 68.0% of the SPT and 42.9% of the TBT patients. The ESS at baseline was < 10 in both groups. Sleep quality parameters, such as wake after sleep onset (WASO; p = 0.001) and awakenings (p = 0.006), improved more in the SPT group. Total QSQ scores (0.4 ± 0.2, p = 0.03), the QSQ domains nocturnal symptoms (0.7 ± 0.2, p = 0.01), and social interactions (0.8 ± 0.3, p = 0.02) changed in favor of the SPT group. Effective compliance (≥ 4 h/night + ≥ 5 days/week) was 75.9% for the SPT and 42.3% for the TBT users (p = 0.01). Conclusion: In mild POSAS with normal EES the new SPT device and the standard TBT are equally effective in reducing respiratory indices. However, compared to the TBT, sleep quality, quality of life, and compliance improved significantly more in the SPT group. Citation: Eijsvogel MM, Ubbink R, Dekker J, Oppersma E, de Jongh FH, van der Palen J, Brusse-Keizer MG. Sleep position trainer versus tennis ball technique in positional obstructive sleep apnea syndrome. J Clin Sleep Med 2015;11(2):139–147. PMID:25515276

  15. Evaluating and treating neurobehavioral symptoms in professional American football players

    PubMed Central

    Possin, Katherine L.; Hess, Christopher P.; Huang, Eric J.; Grinberg, Lea T.; Nolan, Amber L.; Cohn-Sheehy, Brendan I.; Ghosh, Pia M.; Lanata, Serggio; Merrilees, Jennifer; Kramer, Joel H.; Berger, Mitchel S.; Miller, Bruce L.; Yaffe, Kristine; Rabinovici, Gil D.

    2015-01-01

    Summary In the aftermath of multiple high-profile cases of chronic traumatic encephalopathy (CTE) in professional American football players, physicians in clinical practice are likely to face an increasing number of retired football players seeking evaluation for chronic neurobehavioral symptoms. Guidelines for the evaluation and treatment of these patients are sparse. Clinical criteria for a diagnosis of CTE are under development. The contribution of CTE vs other neuropathologies to neurobehavioral symptoms in these players remains unclear. Here we describe the experience of our academic memory clinic in evaluating and treating a series of 14 self-referred symptomatic players. Our aim is to raise awareness in the neurology community regarding the different clinical phenotypes, idiosyncratic but potentially treatable symptoms, and the spectrum of underlying neuropathologies in these players. PMID:26336629

  16. Adolescent suicide.

    PubMed

    1996-01-01

    In the introduction to this report our committee, with its focus on adolescent development, expressed its concern that adolescent suicidal behavior represented a grave crisis in the adolescent, a crisis not only in the development of the adolescent but one that endangers the existence of the adolescent. The possibility of a fatal outcome is abhorrent to us as physicians and psychiatrists, as it is to all those entrusted with the care and development of our fellow human beings. Consequently, we explored the ways in which developmental and other forces lead to adolescent suicide and the measures that can be taken to prevent it. We first considered the historical and cross-cultural aspects of suicidal behaviors. Societal and cultural stresses arise from parental attitudes, beliefs, expectations, and childrearing practices that evolve from the social and economic needs in each culture. If unbalanced by growth-sustaining supports, they may compromise or constrict the existential adaptive ability of the developing adolescent and place the adolescent at risk for suicide. Research into vulnerability in adolescence has revealed gender, ethnic, and geographic differences in the dimension of the problem and has indicated the social, psychological, and biological conditions that increase the likelihood that adolescents will resort to suicidal behaviors. Research is still needed to distinguish those adolescents who commit suicide from those adolescents with similar conditions who do not. Research has only begun to explore the ways in which the interaction of specific individual dynamics, precipitating events, and personal characteristics result in an adolescent's attempt of suicide. We discussed the strengths that adolescents acquire, but we emphasized the weaknesses that ensue as adolescents are faced with the impact of the thrust of their own biological, psychological, and social development with the forces inherent in their cultures. Adolescents progress through this period

  17. Anthropometric and performance comparisons in professional baseball players.

    PubMed

    Hoffman, Jay R; Vazquez, Jose; Pichardo, Napoleon; Tenenbaum, Gershon

    2009-11-01

    This study compared anthropometric and performance variables in professional baseball players and examined the relationship between these variables and baseball-specific performance (i.e., home runs, total bases, slugging percentage, and stolen bases). During a 2-year period, 343 professional baseball players were assessed for height, weight, body composition, grip strength, vertical jump power, 10-yard sprint speed, and agility. Subject population consisted of players on the rosters of one of the minor league affiliates (Rookie, A, AA, AAA) or major league team (MLB). All testing occurred at the beginning of spring training. Players in Rookie and A were significantly (p < 0.05) leaner than players in MLB and AAA. These same players had significantly lower lean body mass than seen in MLB, AAA, and AA players. Greater grip strength (p < 0.05) was seen in MLB and AAA than in Rookie and A. Players in MLB were also faster (p < 0.05) than players in AA, A, and Rookie. Vertical jump power measures were greater (p < 0.05) in MLB than AA, A, and Rookie. Regression analysis revealed that performance measures accounted for 25-31% of the variance in baseball-specific power performance. Anthropometric measures failed to add any additional explanation to the variance in these baseball-specific performance variables. Results indicated that both anthropometric and performance variables differed between players of different levels of competition in professional baseball. Agility, speed, and lower-body power appeared to provide the greatest predictive power of baseball-specific performance. PMID:19826310

  18. Influence of players' physique on rugby football injuries.

    PubMed Central

    Lee, A J; Myers, J L; Garraway, W M

    1997-01-01

    OBJECTIVES: To determine whether there is an association between a player's physique and injuries incurred while playing rugby football. METHODS: A cohort study was carried out involving all senior rugby clubs in the Scottish Borders during the 1993-1994 rugby season. Somatotype estimates were determined for 1152 (95%) of the 1216 eligible players. Body mass index (BMI), chest to waist ratio, and the ponderal index (PI) were used to classify players' physique as endomorphic (obese), mesomorphic (muscular), and ectomorphic (linear). RESULTS: A strong association was found between physique and age (chi 2 test: chi 2 = 317.2, df = 10, P < 0.0001). More younger players were ectomorphs. Older players were more often endomorphic. The physiques of forwards and backs were significantly different (chi 2 test: chi 2 = 58.6, df = 2, P < 0.0001), with forwards being of a heavier build than three-quarters, even after adjustment for age. Endomorphic players were more likely than ectomorphs to be injured in a match after adjustment for age (age-adjusted mean BMI for players who were injured in a match was 25.4 compared with 24.6 for players who were not injured in a match, P < 0.0001; adjusted chest to waist ratio means were 1.136 and 1.125 respectively, P = 0.0307; adjusted PI means were 0.414 and 0.417 respectively, P = 0.0056). Increased risk of injury may occur when players play out of position, since one fifth of all injuries occurred in this circumstance. CONCLUSIONS: Further research needs to be conducted using a more objective method of measuring somatotype on a further cohort of players so that the risk of injury for different body types can be examined more closely and related to other potential confounding factors. The level of increased risk for individuals playing out of their usual playing position needs to be established with a greater degree of certainty. PMID:9192128

  19. A Method for Using Player Tracking Data in Basketball to Learn Player Skills and Predict Team Performance.

    PubMed

    Skinner, Brian; Guy, Stephen J

    2015-01-01

    Player tracking data represents a revolutionary new data source for basketball analysis, in which essentially every aspect of a player's performance is tracked and can be analyzed numerically. We suggest a way by which this data set, when coupled with a network-style model of the offense that relates players' skills to the team's success at running different plays, can be used to automatically learn players' skills and predict the performance of untested 5-man lineups in a way that accounts for the interaction between players' respective skill sets. After developing a general analysis procedure, we present as an example a specific implementation of our method using a simplified network model. While player tracking data is not yet available in the public domain, we evaluate our model using simulated data and show that player skills can be accurately inferred by a simple statistical inference scheme. Finally, we use the model to analyze games from the 2011 playoff series between the Memphis Grizzlies and the Oklahoma City Thunder and we show that, even with a very limited data set, the model can consistently describe a player's interactions with a given lineup based only on his performance with a different lineup. PMID:26351846

  20. Histone variants: emerging players in cancer biology

    PubMed Central

    Vardabasso, Chiara; Hasson, Dan; Ratnakumar, Kajan; Chung, Chi-Yeh; Duarte, Luis F.

    2014-01-01

    Histone variants are key players in shaping chromatin structure, and, thus, in regulating fundamental cellular processes such as chromosome segregation and gene expression. Emerging evidence points towards a role for histone variants in contributing to tumor progression, and, recently, the first cancer-associated mutation in a histone variant-encoding gene was reported. In addition, genetic alterations of the histone chaperones that specifically regulate chromatin incorporation of histone variants are rapidly being uncovered in numerous cancers. Collectively, these findings implicate histone variants as potential drivers of cancer initiation and/or progression, and, therefore, targeting histone deposition or the chromatin remodeling machinery may be of therapeutic value. Here, we review the mammalian histone variants of the H2A and H3 families in their respective cellular functions, and their involvement in tumor biology. PMID:23652611