Kinematics and kinetics of youth baseball pitching with standard and lightweight balls

Because youth athletes are smaller and weaker than their adult counterparts, smaller equipment and fields are often used in youth sports. Previous research has shown that youth baseball pitchers use similar motions to older pitchers, but generate lower kinetics and angular velocities at the shoulder and elbow. The purpose of this study was to determine potential biomechanical benefits for youth pitchers to use lighter baseballs. Thirty-four youth (11.1 ± 0.7 years) pitchers pitched both standard [5 ounce (142 g)] and lightweight [4 ounce(113 g)] baseballs in a laboratory setting. Kinematic and kinetic parameters were measured with a six-camera high-speed motion analysis system. Three repeated measures MANOVAs were used to compare (p > 0.05) position, velocity, and kinetic parameters between the standard and lightweight baseballs. Subjective data were also collected. Pitching the lightweight ball produced no difference in arm position, but greater shoulder, elbow, and ball velocities. With the lightweight ball, pitchers produced decreased kinetics.Post-hoc analysis of the kinetic data revealed significant decreases in elbow varus torque and shoulder internal rotation torque. The data suggest that playing with lightweight baseballs may reduce the risk of overuse injury in the youth pitcher and also help develop arm speed. However, before introducing lightweight baseballs into the youth game, the effect of lighter, faster pitched balls for the batters and fielders should also be considered.     

“I'm A Teacher Not A Social Worker”—A case study in consultation and in‐set coursie design

Pastoral care of teachers is concerned with their personal, individual recognition, needs and welfare. The concept dates back to the 1970s and has been elaborated in the literature in succeeding decades. This article attempts to draw together various outlines on the subject, focusing on what they suggest about how pastoral care of teachers can be implemented. The resulting model is presented in the form of tables summarizing authors’ suggestions in five key areas of support: Induction, Curriculum, Procedural, Professional and Personal.     

Learning About Tool Categories via Eavesdropping

Prior research has found that toddlers will form enduring artifact categories after direct exposure to an adult using a novel tool. Four studies explored whether 2‐ (N = 48) and 3‐year‐olds (N = 32) demonstrate this same capacity when learning by eavesdropping. After surreptitiously observing an adult use 1 of 2 artifacts to operate a bell via a monitor, 3‐year‐olds returned to the demonstrated kind of tool as “for” the task and avoided it for an alternative task over 2 days. Two‐year‐olds performed similarly after eavesdropping on someone with more discriminable artifacts via the method of a window rather than a monitor. These results demonstrate that toddlers can acquire enduring artifact categories after less than 40 s of surreptitious observation.     

For Young Jumpers,Differences are in the Movement's Control,Not its Coordination

Abstract

Previous research on the development of jumping has indicated that the coordination of the jump is stable from its inception, but that individual differences lie in the control of the task. The purpose of this study was to examine control in the vertical jump as performed by novice jumpers. Two groups of children who varied in their ability to regulate the takeoff angle were compared on measures of coordination and control. The children's groups were also compared to a group of skilled adults. Both children's groups demonstrated temporal coordination patterns comparable to the adult pattern, though the children were distinguished from the adults on selected spatial (control) measures. The results indicate that a mature pattern of coordination for the jump exists at the earliest stages of the behavior's appearance in the movement repertoire. The novice, however, lacks the ability to precisely control, or tune, the movement to task demands.     

Topics and Features of Academic Medical Library Tutorials

ABSTRACT

In a 2007 study, librarians at the University of South Carolina School of Medicine Library examined freely available online tutorials on academic medical library Web sites. The team identified tutorial topics, determined common design features, and assessed elements of active learning in library-created tutorials; the team also generated a list of third-party tutorials to which medical libraries link. This article updates the earlier study, describing changes and trends in tutorial content and design on medical libraries' Web sites; the project team plans to continue to track trends in tutorial development by repeating this study annually.     

Common Core State Standards: Challenge and Collaboration

The Common Core State Standards provide a framework of internationally benchmarked standards that outline what students should know, understand, and be able to do in order to be college and career ready. This essay explores the untapped potential in the sharing of resources across the nation, especially during times of economic challenges.