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A comparison of base running and sliding techniques in collegiate baseball with implications for sliding into first base

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Journal of Sport and Health Science 2016年第3期5卷 361-367页

作者： Travis Ficklin Jesus Dapena Alexander Brunfeldt Biomechanics Laboratory University of Northern Iowa Department of Kinesiology Indiana University Biomedical Engineering University of Michigan

Purpose: The purpose of this study was to compare 4 techniques for arrival at a base after sprinting maximally to reach it: sliding head-first, sliding feet-first, running through the base without slowing, and stopping on the base. A secondary purpose of the study was to determine any advantage there may be to diving into first base to arrive sooner than running through the ***: Two high-definition video cameras were used to capture 3-dimensional kinematics of sliding techniques of 9 intercollegiate baseball players. Another video camera was used to time runs from first base to second in 4 counterbalanced conditions: running through the base, sliding head-first, sliding feet-first, and running to a stop. Mathematical modeling was used to simulate diving to first base such that the slide would begin when the hand touches the ***: Based upon overall results, the quickest way to the base is by running through it, followed by head-first, feet-first, and running to a ***: There was a non-significant trend toward an advantage for diving into first base over running through it, but more research is needed,and even if the advantage is real, the risks of executing this technique probably outweigh the miniscule gain.

关键词： baseball Biomechanics First base Running Sliding

A biomechanical study of fast throwing movements of the shoulder in baseball pitching

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Chinese Medical Journal 1997年第3期 60-64页

作者：薛庆云

Objective To define the biomechanic function of the shoulder in fast throwing movements in baseball pitching. Methods Using NAC high speed video and PIAS LA 555 computer system, overhand pitching movements carried out by 12 healthy Japanese professional baseball pitchers were analyzed in three dimensions. The pitching motion was displayed as stick to stick figures dynamically. Results Pitching motion was a combination of translational and rotational movements. Acceleration and deceleration, being two typical motion patterns, worked sequentially through the anatomic link system from the pivot leg to the pitching hand. During the acceleration phase, the shoulder joint acted as a junction point and a fulcrum, supporting the rotational acceleration motion, shoulder forward flexion and elbow extension. According to the changing glenohumeral angles of the pitching shoulder, shearing force turned into tension force which worked on the anterior shoulder structures and then shifted to the posterior part of the joint. Conclusions In fast throwing motion, the shoulder functions as an important fulcrum to support the pitching arm during the acceleration phase. Avoiding excessive stress and shearing force on the joint components and enhancing coordination of muscle action are important to a successful throwing motion and the prevention of shoulder injury. Familial occurrence of hemangioblastoma of central nervous system $$$$ Zhou Fanmin , Zhang Rong, Ji Yaodong , Xu Qiwu Zhou Liangfu and Shi Yuquan Objective To study the familial occurrence of hemangioblastoma of the central nervous system and to search for an effective way to diagnose and manage the disease. Methods From 1974 to 1993, six patients with hemangioblastoma with family history underwent surgical treatment at our hospital. Computerized tomography (CT) or magnetic resonance imaging (MRI) technique was used for the diagnoses before operation. Results Each patient had more than two relative

关键词：薛庆 pitching movements throwing study fast shoulder the biomechanical baseball

baseball as the Man's Religious Faith in The Old Man and the Sea

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海外英语 2010年第9X期 8-9页

作者：赵喆 Beijing Normal University

As for the massive 50 million and Santiago,their belief in baseball can be understood as an article of religious *** frequent references to baseball related affairs and the use of sympolism,the author hints that Santi... 详细信息

关键词： The Old Man and the Sea baseball civil religion Santiago

Physical contributors to glenohumeral internal rotation deficit in high school baseball players

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Journal of Sport and Health Science 2015年第3期4卷 299-306页

作者： Elizabeth E. Hibberd Casey E. Shutt Sakiko Oyama J. Troy Blackburn Joseph B. Myers Department of Health Science The University of Alabama Tuscaloosa AL 35487-0311 USA U.S. Army-Baylor University San Antonio TX 78234-6100 USA Department of Health and Kinesiology University of Texas at San Antonio San Antonio TX 78249 USA Department of Exercise and Sport Science Neuromuscular Research Laboratory University of North Carolina at Chapel Hill Chapel Hill NC 27599-8700 USA Department of Exercise and Sport Science Sports Medicine Research Laboratories University of North Carolina at Chapel Hill Chapel Hill NC 27599-8700 USA

Background： Glenohumeral internal rotation deficit （GIRD） is a risk factor for shoulder and elbow injury in baseball players. Although this evidence forms a basis for recommending stretching, clinical measures of internal rotation range of motion （ROM） do not differentiate if GIRD is due to muscular, capsuloligamentous, or osseous factors. Understanding the contributions of these structures to GIRD is important for the development of targeted interventions. We hypothesize that the osseous component will have the greatest relative contribution to GIRD, followed by muscle stiffness and posterior capsule thickness. Methods： Internal rotation ROM, muscle stiffness （teres minor, infraspinatus, and posterior deltoid）, posterior capsule thickness, and humeral retrotorsion were evaluated on 156 baseball players. A side-to-side difference was calculated for each variable. Variables were entered into a multivariable linear regression to determine the significant predictors of GIRD. Results： The regression model was statistically significant （R2 = 0.134, F（1, 156） = 24.0, p 〈 0.01） with only humeral retrotorsion difference remaining as a significant predictor （β = -0.243, t156 = -4.9, p 〈 0.01）. A greater humeral retrotorsion side-to-side difference was associated with more GIRD. Conclusion： Humeral retrotorsion accounted for 13.3% of the variance in GIRD. The stiffness of the superficial shoulder muscles and capsular thickness, as measured in this study, were not predictors of GIRD. Factors not assessed in this study, such as deeper muscle stiffness, capsule/ ligament laxity, and neuromuscular regulation of muscle stiffness may also contribute to GIRD. Since it is the largest contributor to GIRD, causes of changes in humeral retrotorsion need to be identified. The osseous component only accounted for 13.3% of the variance in GIRD, indicating a large contribution from soft tissues factors that were not addressed in this study. These factors need to be identified to develop evi

关键词： baseball GIRD Humeral retrotorsion Muscle stiffness Posterior capsule thickness

Impact of the Drag Force and the Magnus Effect on the Trajectory of a baseball

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World Journal of Mechanics 2015年第4期5卷 49-58页

作者： Haiduke Sarafian The Pennsylvania State University University College York PA USA

We consider the impact of drag force and the Magnus effect on the motion of a baseball. Quantitatively we show how the speed-dependent drag coefficient alters the trajectory of the ball. For the Magnus effect we envision a scenario where the rotation of the ball confines the Magnus force to the vertical plane;gravity, drag force and the Magnus force make a trio-planar system. We investigate the interplay of these forces on the trajectories.

关键词： Drag Force Magnus Effect Spinning Ball baseball Nonlinear Physics Mathematica

Dynamical Model with Application to the Analysis of the Sweet Spot on a baseball Bat

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American Journal of Computational Mathematics 2015年第4期5卷 458-467页

作者： Li Cheng Zaiqiang Ku College of Mathematics and Physics Huanggang Normal University Huanggang China

In this paper, we analyze the effect on the ball-bat model of corking the bat, and investigate the relationship between the sweet spot and different materials. First and foremost, we develop a simple but effective theoretical model to give a rough estimate for the sweet spot of the bat. Second, we give a simplified abstract form of bat which facilitates the description and modeling study. Last but not least, according to different material caused rotary inertia and different recovery coefficient, researches on the different material hitting effect were made.

关键词： baseball Bat Sweet Spot Dynamical Model Finite Element

Comparison of base running in baseball players and track-and-field athletes

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Health 2011年第1期3卷 26-31页

作者： Kazuyoshi Miyaguchi Shinich Demura Kazuya Nagai Yu Uchida 不详

This study aimed to examine the relationship be-tween sprint ability and base running of baseball players and track-and- field (T&F) athletes, and to identify the association between sprint ability and running skill on base running. The subjects were 25 male university baseball players and 15 male T&F athletes without baseball experience. The straight sprint time of 54.8 m and 109.6 m (corresponding to the distance to second and home) was measured. In the home run test, the times to reach each base were measured. In the second base run test, the actual running distance and 3 m section time around the first base were measured. Base running efficiency was obtained by dividing the base running time by the straight sprint time. T&F athletes showed higher values than baseball players only in the 109.6 m straight sprint time (P baseball players were significantly superior to T&F athletes in terms of base running efficiency. As for 3 m section times, baseball players showed significant and higher values. The straight sprint time showed significant and high correlations (r = 0.87, 0.90) between the 109.6 m run and the run home and be-tween the 54.8 m run and the second base run in baseball players, but not in T&F athletes. It was found that superior sprint ability does not always lead to good base running. In base running, it is important to run outward to some extent. In particular, the skill acquisition of base running in 3 m sections around the base will contribute to shortening base running time.

关键词： Sprint Ability Running Skill Efficiency baseball

The Prevalence and Characteristics of Thoracic Outlet Syndrome in High School baseball Players

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Health 2017年第8期9卷 1223-1234页

作者： Kenichi Otoshi Shinichi Kikuchi Kinshi Kato Ryohei Sato Takahiro Igari Takahiro Kaga Hiroaki Shishido Shinichi Konno Ryuji Koga Kozo Furushima Yoshiyasu Itoh Department of Sports Medicine Fukushima Medical University School of Medicine Fukushima Japan Department of Orthopaedic Surgery Fukushima Medical University School of Medicine Fukushima Japan Keiyu Orthopaedic Hospital Tatebayashi Japan

Thoracic outlet syndrome (TOS) is one of the common neurovascular disorders of the upper extremities, and the compression or traction of the brachial plexus is the main pathology. We hypothesized that baseball players are more likely to be affected by TOS compared with other overhead-throwing athletes because of strenuous use of their throwing arm. The purpose of this study was to investigate the prevalence and clinical characteristics of TOS in high school baseball players. One thousand two hundred eighty-eight high school baseball players were included in this study. The prevalence of symptomatic TOS and its association to disorders of the upper extremities were investigated. The prevalence of symptomatic TOS was 32.8%. Age- and position-adjusted logistic regression analysis revealed that subjects with symptomatic TOS were at significantly higher risk of shoulder and/or elbow pain (odds ratio [OR]: 1.96, 95% confidence interval [CI]: 1.50 - 2.58) and a higher recurrence rate of shoulder and/or elbow pain during the previous season (OR: 2.38, 95% CI: 1.87 - 3.04). As for physical findings, subjects with symptomatic TOS were also at significantly higher risk of MUCL tenderness (OR: 2.53, 95% CI: 1.83 - 3.50), positive milking maneuver, (OR: 2.63, 95% CI: 1.78 - 3.91), positive subacromial impingement sign (OR: 1.92, 95% CI: 1.20 - 3.07), and positive posterior impingement sign (OR: 2.34, 95% CI: 1.67 - 3.28) compared to the subjects without symptomatic TOS. It is necessary to recognize that TOS is not a rare pathology in overhead-throwing athletes, especially baseball players, and that players with symptomatic TOS are at significantly higher risk of shoulder/elbow pain.

关键词： Thoracic Outlet Syndrome baseball Players Prevalence

What factors are associated with premature death among professional baseball players in Japan?

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Health 2013年第4期5卷 757-760页

作者： Hideyuki Kanda Satoshi Tsuboi Masayoshi Tsuji Takeyasu Kakamu Yayoi Mori Takehito Hayakawa Tetsuhito Fukushima Department of Epidemiology and Public Health School of Medicine Yokohama City University Yokohama Japan Department of Hygiene and Preventive Medicine Fukushima Medical University Fukushima Japan

The aim of this study is to clarify factors related to premature death among Japanese professional baseball players by a case-control analysis. The subjects are two matching groups of 622 Japan Professional baseball (JPB) league players, those deceased and those surviving. Cases and controls are matched by birth year. All players debuted on the first string between 1934 and 2003, and are listed in The Official baseball Encyclopedia of Japan. To compare means and frequencies of characteristics between deceased and surviving groups, t-tests and chi-square tests were used. A logistic regression analysis was assessed contributions of each independent variable on death. Significant differences between deceased and surviving players were observed in this study;deceased players had higher body mass indexes and longer careers. Furthermore, logistic regression analysis confirmed that body mass index and career length were statistically significant determinants of death for baseball players. This is the first report to examine factors of death for professional baseball players except employing data attained from Major League baseball.

关键词： Factors of Death Professional baseball Player Body Mass Index Career Length