Baseball pitching kinematics,joint loads,and injury prevention

There is a need for the prevention of upper extremity injuries that affect a large number of competitive baseball players.Currently available evidence alludes to three possible ways to prevent these injuries:1) regulation of unsafe participation factors,2) implementation of exercise intervention to modify suboptimal physical characteristics,and 3) instructional intervention to correct improper pitching techniques.Of these three strategies,instruction of proper pitching technique is under-explored as a method of injury prevention.Therefore,the purpose of this review was to explore the utility of pitching technique instruction in prevention of pitching-related upper extremity injuries by presenting evidence linking pitching technique and pitching-related upper extremity injuries,as well as identifying considerations and potential barriers in pursuing this approach to prevent injuries.Various kinematic parameters measured using laboratory-based motion capture system have been linked to excessive joint loading,and thus pitching-related upper extremity injuries.As we gain more knowledge about the influence of pitching kinematics on joint loading and injury risk,it is important to start exploring ways to modify pitching technique through instruction and feedback while considering the specific skill components to address,mode of instruction,target population,duration of program,and ways to effectively collaborate with coaches and parents.

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

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 evidence-based evaluations and intervention programs to decrease the risk of injury in baseball players.

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

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.

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

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 base.Methods: 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 base.Results: 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 stop.Conclusion: 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.

Medial ulnar collateral ligament reconstruction of the elbow in major league baseball players:Where do we stand?

The ulnar collateral ligament(UCL) is a vital structure to the overhead athlete,especially the baseball pitcher.For reasons not completely understood,UCL injurieshave become increasingly more common in major league baseball(MLB) pitchers over the past 10 years.UCL reconstruction(UCLR) is the current gold standard of treatment for these injuries in MLB pitchers who wish to return to sport(RTS) at a high level and who have failed a course of non-operative treatment.Results following UCLR in MLB pitchers have been encouraging,with multiple RTS rates now cited at greater than 80%.Unfortunately,with the rising number of UCLR,there has also been a spike in the number of revision UCLR in MLB pitchers.Similar to primary UCLR,the etiology of the increase in revision UCLR,aside from an increase in the number of pitchers who have undergone a primary UCLR,remains elusive.The current literature has attempted to address several questions including those surrounding surgical technique(method of exposure,graft choice,management of the ulnar nerve,concomitant elbow arthroscopy,etc.),post-operative rehabilitation strategies,and timing of RTS following UCLR.While some questions have been answered,many remain unknown.The literature surrounding UCLR in MLB pitchers will be reviewed,and future directions regarding this injury in these high level athletes will be discussed.

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

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

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.

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

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 < 0.05, ES=1.35). 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.

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

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.

Baseball Becoming Popular in China

With its first introduction to China over 100 years ago, baseball is continuing to see more popularity among Chinese youth.

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

As for the massive 50 million and Santiago,their belief in baseball can be understood as an article of religious faith.With frequent references to baseball related affairs and the use of sympolism,the author hints that Santiago relies on the faith of baseball as his renewed religious hope.

Mahjong and Baseball

My television screen flicked on, and the crowd’s excitement with sports action seemed so familiar, yet momentarily strange. An announcer’s voice described the game with infectious enthusiasm. The crowd of over 70,000 in the stands was going wild, and the players were moving with precision and speed. The pitching, the batting, runners racing around the bases, and acrobatic fielding. Yes, this was baseball,

Baseball Sans Borders

If anyone needs a reminder that the word "fan" is merely the short form of "fanatic," they need only observe me watching baseball on the Internet. No, I'm not talking about a webcast with images of the game actually being played. My falsely advertised "DSL" Internet connection isn't fast enough for that. Instead, on balmy summer

Using Sports Wagering Markets to Evaluate and Compare Team Winning Streaks in Sports

Point spreads and money lines from sports wagering markets are used to evaluate the impressiveness of team streaks. Sports wagering data have previously been useful in assessing competitive balance in sports. Our approach was motivated by the amount of media scrutiny that accompanied the winning streak of the NBA’s Miami Heat and the point streak of the NHL’s Chicago Blackhawks which occurred simultaneously for the most part in 2013. The topic came to the forefront again with the 2014-2015 winning streak of the Atlanta Hawks. Three streaks are highlighted in our paper. The length of the streaks, the quality of the competition, injuries, and a variety of other factors were mentioned in the media but the discussion was limited to subjective opinions as no way of properly weighing relative influence of the factors was identified. Wagering markets provide an excellent source of information for making these judgments. Several complementary measures are described and the most impressive team streaks within and across professional baseball, basketball, football, and ice hockey are identified.

中国棒球联赛十五年进程的进退审视思考

运用统计法,文献法,对中国棒球职业联赛的形成与发展进行整理分析。该文认为:(1)职业化和商业化的运作模式是我国棒球联赛的必经之路。(2)如何协调好赛事周边运作体系,如新闻宣传,市场运作,竞赛管理等之间的整体关系,是职业联赛的保障机制。(3)以职业联赛为基础,整体提高中国棒球运动整体水平为目标。