Various Levels Of Competition Research Articles

Variability in baseball pitching biomechanics among various levels of competition

The aim of this study was to compare within-individual variability in baseball pitching among various levels of competition. It was hypothesized that variability decreases as level of competition increases. Five fastballs were analysed for 93 healthy male baseball pitchers (20 youth, 19 high school, 20 college, 20 Minor League, and 14 Major League level pitchers). Eleven kinematic, four temporal, and six kinetic parameters were quantified with a 240-Hz automated digitizing system. Three multiple analyses of variance were used to compare individual standard deviations for kinematic, temporal, and kinetic parameters among the five competition levels. There was a significant overall difference in kinematics and in six of the eleven kinematic parameters analysed: foot placement, knee flexion, pelvis angular velocity, elbow flexion, shoulder external rotation, and trunk forward tilt. Individual standard deviations tended to be greatest for youth pitchers, and decreased for higher levels of competition. Thus pitchers who advanced to higher levels exhibited less variability in their motions. Differences in temporal variation were non-significant; thus variability in pitching coordination was not improved at higher levels. Differences in kinetic variation were non-significant, implying no particular skill level has increased risk of injury due to variation in joint kinetics.

Sports Neuropsychology: Assessment and Management of Traumatic Brain InjuryEdited by Ruben J. Echemendia, Ph.D. State College, PA Published 2006, Guilford Press, New York 324 pages ISBN-10 1-57230-078-7 $49.00

Back to table of contents Previous article Next article BOOK-REVIEWFull AccessSports Neuropsychology: Assessment and Management of Traumatic Brain InjuryGary S. Solomon Ph.D.Gary S. Solomon Ph.D.Search for more papers by this authorPublished Online:1 Oct 2008https://doi.org/10.1176/jnp.2008.20.4.504AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail The past 15 years has yielded an explosion of information on the topic of concussive injuries in sports, both in the public press and in the professional literature. In 2005 the Centers for Disease Control concluded that concussion in sports was of “epidemic” proportion and estimated that 1.6 to 3.8 million cases of sports-related concussions occur annually in the United States. At least six major sports neuroscience textbooks have appeared in the past decade, including Sports Neurology by Jordan, Tsairis, and Warren (1998); Sports-Related Concussion by Bailes, Lovell, and Maroon (1998); Neurologic Athletic Head and Spine Injuries by Cantu (2000); Neurologic Sports Medicine by Bailes and Day (2001); Traumatic Brain Injury in Sports by Lovell, Echemendia, Barth, and Collins (2004); and Foundations of Sports-Related Brain Injuries by Slobounov and Sebastianelli (2006). The most recent addition to the armamentarium of sports concussion textbooks is the edited book by Dr. Ruben Echemendia, a founding member of the Penn State Cerebral Concussion Program and a recent past president of the National Academy of Neuropsychology. Sports Neuropsychology is divided into five sections. The contributing authors are primarily neuropsychologists, but also include a neurologist, a certified athletic trainer, and a sports medicine physician. Section one addresses some of the history of sports neuropsychology. Section two is devoted to the epidemiology and pathophysiology of traumatic brain injury in sports, sideline assessment of the concussed athlete, and return to play decisions. Section three discusses the nuts and bolts of neurocognitive testing programs at various levels of competition, including high school, collegiate, and professional programs. Section four is an overview of the four most frequently utilized computerized neurocognitive platforms for assessing the cognitive effects of sports concussion, and includes overviews (written in part by the developers) of CogSport, The HeadMinder Concussion Resolution Index, ImPACT, and Automated Neuropsychological Metrics (ANAM) Sports Medicine Battery. Section five concludes the text with perspectives from an athletic trainer and a sports medicine team physician. The text will likely be of greatest interest to neuropsychologists, since two of the five major sections of the book are devoted to overviews of computerized neurocognitive batteries, as well as information on sports concussion testing programs at various levels of competition. The chapters on computerized neurocognitive tests are superior in depth to the information presented in the text by Lovell et al. (2004). The text by Mark Lovell and colleagues addresses sports concussion testing by sport, whereas Sports Neuropsychology covers the subject matter by age group. Though dated, the texts by Bob Cantu (2000) and Barry Jordan and associates (1998) are likely to be of greater interest to neurologists and neurosurgeons. Sports Neuropsychology will be of interest to other sports medicine clinicians who are interested in obtaining an in-depth appreciation of the history and development of neurocognitive testing in sports, and how various cognitive functions are assessed by the different computerized neurocognitive tests. Athletic trainers and team physicians may find the chapter on sideline assessment particularly useful. Students or neuroscientists needing a review of sports concussion epidemiology and basic concussion pathophysiology will also find the book valuable. Any professional member of a sports medicine team who deals with athletic concussions and their associated issues will find the perspectives presented by Echemendia (neuropsychologist), Putukian (team physician), and Furtado (athletic trainer) particularly useful and informative. Sports Neuropsychology is well-written, does not suffer from the redundancy found in many edited texts, and should be considered a useful and authoritative review of the status of this emerging specialty. FiguresReferencesCited byDetailsCited ByRecurrent neural network-based acute concussion classifier using raw resting state EEG data11 June 2021 | Scientific Reports, Vol. 11, No. 1 Volume 20Issue 4 Fall, 2008Pages 504-504 Metrics PDF download History Published online 1 October 2008 Published in print 1 October 2008

Problems associates with the analysis of the pattern of total cross-country eventing penalty scores at advanced level of competition in the United Kingdom.

Eventing is a three phased equestrian sport. It involves the competition of a dressage test, round of show jumps and completion of a cross-country course. The cross-country phase is described by the sports governing body as the most important and influential element of the competition. Within the sport various levels of competition are run and equality of competition should be maintained at within these levels. The paper compares the relative effect of the cross-country phase of competition between 10 advanced events (sub populations) run in during 2003. Non-normality was apparent within the whole population (Kolmogorv Smirnov K statistic = 5.178 (p<0.001); Shapiro Wilks W = 0.711 (P<0.001). The use of Log (x+1) transformation was applied, positive skew (+2.853) was reduced after transformation to −0.543 (Kolmogorov K statistic = 0.754; p>0.05). The influence of extreme kurtosis was removed after transformation (+10.581 reduced to +1.288). The paper suggests that there is considerable variation observed between some sub populations. Measures of central tendency are discussed as comparative measures between events. It is apparent that arithmetic means may be misleading and the uses of other measures of central tendency are discussed including maximum likelihood estimators. Analysis of data distribution using box and whisker plots indicated outliers and extreme outliers were exerting a considerable effect on the population.

Awe and Trembling in Tournament Golf

SUMMARY Awe and trembling are investigated as they are experienced in tournament golf. Awe is offered as the experience which neutralizes frustration with the difficulty of the game as well as the spark which ignites passion for it. Included is the awe that goes with the long and straight drive and other “awesome” shots; awe and the gesture of posing at the completion of the swing; the transpersonal element in the gesture of posing; and the relation of awe to fear. The second part of this article demarcates various levels of competition and the nested levels of performance success within the main levels. A hierarchy of pressure situations is presented, followed by the identification of other variables which affect the degree of pressure felt in the tournament environment. The final section of the article presents a clinical example of how pressure affects a player in competition. Psychodynamics contributing to the situation are disclosed, along with treatment recommendations.

Effects of interspecific competition on periodic shoot elongation in oak seedlings

The effects of interspecific competition on periodic shoot elongation of Quercuspetraea (Matt.) Liebl. and Quercusrobur L. seedlings were investigated in two experiments. In the first experiment, conducted under field conditions, young oaks were grown under various levels of grass and shrub competition. The number of growth flushes produced by the seedlings was assessed on three dates during the summer. In the second experiment, conducted under controlled conditions, seedlings were grown under various levels of competition and watering regimes. Biweekly measurements of shoot elongation were made during two consecutive growing seasons. Seedlings grown with competition produced fewer growth flushes during the growing season, and those flushes were delayed. They also produced fewer growth units during each flush and those growth units were shorter. All the seedlings grown without competition flushed at the same time during the entire growing season. On the contrary, the seedlings grown with competition showed synchronous flushing in spring, but became asynchronous later in the growing season.

Interspecific competition and herbicide injury influence 10-year responses of coastal Douglas-fir and associated vegetation to release treatments

Responses of competing vegetation and planted Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco var. menziesii) were studied for 10 years after six herbicide and manual release treatments in the Washington and Oregon Coast Ranges. Research objectives were to quantify regional, long-term responses of vegetation to various levels of competition, light and soil water availability, and intensity versus importance of factors influencing Douglas-fir growth. Three treatments reduced shrub cover relative to the untreated check: triclopyr in year 1, glyphosate in years 1–5, and repeated control (via several herbicide applications) in years 1–10. Reductions in woody cover from glyphosate stimulated increases in herb cover in years 3 and 5, while repeated control reduced herb cover in years 1, 2 and 5. Through year 10, Douglas-fir survival (86–99%) varied little among treatments. Visual symptoms of herbicide injury to Douglas-fir from triclopyr (45% of trees) and glyphosate (17% of trees) were associated with 0.1 – 0.2 m reductions in first-year height. After adjusting for tree size, Douglas-fir growth in stem basal area 2 years after triclopyr was less than that of the untreated check, suggesting prolonged effects of herbicide injury. Because it sustained low levels of interspecific competition, caused minimal tree injury, and prevented overtopping cover from red alder ( Alnus rubra Bong.), repeated control was the only treatment in which Douglas-fir size (9.8 m height and 21 cm basal diameter in year 10) significantly exceeded ( P ≤ 0.02) that of the untreated check (7.8 m height and 12 cm diameter).

Year-Round Conditioning For Basketball

Year-round conditioning specifically designed for basketball has reached a high level of sophistication over the past several decades. There is growing evidence that it can contribute to improved performance and reduced injury. The major components of conditioning for basketball have been identified as anaerobic power (stages I and II), aerobic power, muscular strength/power/endurance, and flexibility. The concept of year-round conditioning uses the principles of periodization in work and rest to achieve peak performance and avoid injury. There are unique problems associated with the various levels of competition that require diligent monitoring on the part of the coach to maximize physical condition and avoid overtraining.

Impact de la compétition exercée par le framboisier (Rubusidaeus L.) et les feuillus de lumière sur la croissance du sapin (Abiesbalsamea (L.) Mill.) en régénération

This paper discusses the impact of competing vegetation on balsam fir (Abiesbalsamea (L.) Mill.) seedling growth. The study consisted of 12 permanent sample blocks of 0.5 ha. In each one, about 60 seedlings were selected to represent the various levels of competition. Ten competition indices were computed and compared for their relationship with balsam fir growth in height and diameter. Growth was slightly reduced by the competing vegetation but the relative production rate was not affected. An index using competing vegetation density and height relative to the seedling was selected for its simplicity and good correlation with the growth parameters. A simulation indicates that height growth for the next 5 years should remain correlated, although weakly, with the competing vegetation abundance. Balsam fir would be able to quickly overtop raspberry but would remain in the understory for some time when overtopped by hardwood light demanders.

Standard score assessment on physique and performance of Brazilian athletes in a six tiered competitive sports model.

The use of large cross-sectional norms on Brazilian children and youths aged 7 to 18 years within a six level competition plan helps to assess development status and monitor change. Non-athletic prototypes for comparative purposes are illustrated by the use of the lowest competitive level of 18 year olds to assess differences from internationally elite players. The purpose of this study was to establish the efficacy of this practice in male and female basketball and volleyball samples. Comparisons were made on 11 anthropometric and performance variables using percent difference (% delta) and z-score values. The z-scores were highest for height, weight, and jumping ability in both sports groups. The volleyball players were the more linear in physique and the better jumpers. Related to their prototypes the female basketball players had the highest estimated VO2 max (ml kg-1 min-1), and the best values of anaerobic power measures. It is concluded that differences in physique and performance at various levels of competition compared to non-athletic prototypes may be used to infer selective and training factors.

Survival and growth of understory trees in oak forests of the Hudson Highlands, New York

Mortality and growth rates of trees in various crown classes and size classes were analyzed from 40-year permanent plot records of slope and ravine forest dominated by chestnut oak (Quercusprinus L.) and northern red oak (Quercusrubra L.). Average 5-year mortality rates for suppressed trees ≥2.5 cm dbh of chestnut oak and red oak in the slope forest were 26 and 45%, respectively. None of the suppressed red oaks survived the 40-year period, compared with 14% of the chestnut oaks and 33% of the red maples (Acerrubrum L.). Mortality of oak trees in the intermediate crown class was less than half that of suppressed trees, but still much higher than that of maples and birches on the tracts. Survival was reasonably high for oaks as long as the top of the crown was receiving direct sunlight, but the expected 40-year survival rate of red oaks in such a position is only 20%, with an average growth rate of 1.0 mm in diameter per year. Curves and equations expressing average mortality and growth rates at various levels of competition are presented for each species.

Yield of Crested Wheatgrass following Release from Sagebrush Competition by 2,4-D

Fear of recovery by sagebrush (Artemisia tridentata) has long been one of the deterrents to undertaking reseeding projects on depleted sagebrush ranges. Various levels of competition by sagebrush have been shown to curtail production by many associated species, including crested wheatgrass (A!?-@ pyron desertorum) and native forages (Robertson, 1947; Robertson et al., 1966). Herbicides have proved to be a good tool for quick renovation of grassed ranges rendered unproductive by sagebrush competition. The rate and magnitude of increased production by crested wheatgrass after application of herbicide is the subject of this study. Methods of economic evaluation of