Influence of pelvis rotation styles on baseball pitching mechanics

Efficient, sequential timing is essential for upper level pitching. Interestingly, pitchers vary considerably in timing related elements of pitching style including pelvis rotation, arm cocking, stride leg behaviour, and pitch delivery time. The purpose of this study was to determine whether relationships exist among these elements by examining the overall style of pitchers exhibiting different pelvis rotation patterns. Pitching styles were defined by pelvis orientation at the instant of stride foot contact. Pitchers demonstrating a pelvis orientation greater than 30 degrees were designated as 'early rotators', while pitchers demonstrating a pelvis orientation less than 30 degrees were designated as 'late rotators'. Kinematic and temporal differences were associated with the two styles. During the arm cocking phase, early rotators showed significantly greater shoulder external rotation at the instant of stride foot contact, earlier occurrence of maximum pelvis rotation angular velocity, and shorter time taken to complete the phase. However, by the instant of maximum shoulder external rotation, early and late rotators appeared remarkably similar as no significant difference occurred in pelvis and arm orientations. Therefore, it appears that early and late rotators used different methods to achieve similar results, including throwing velocity. Significant differences in throwing arm kinetics were also found for 10 of the 11 measures in the study. As the pelvis assumed a more open position at stride foot contact, maximum kinetic values were found to both decrease in magnitude and occur at an earlier time within the pitch.     

Development and evaluation of a biomechanics concept inventory

To help instructors in evaluating innovations in biomechanics instruction, a standardised test of the key concepts taught in the introductory biomechanics course was developed. The Biomechanics Concept Inventory (BCI) consists of 24 questions that test four prerequisite competencies and eight biomechanics competencies. Three hundred and sixty seven students from ten universities throughout the United States took the test at the beginning and the end of the introductory biomechanics course. Analysis of a sub-sample of the students showed that the BCI was reliable with typical errors in internal consistency and test-retest conditions of 1.4 and 2.0 questions, respectively. Mean pre-test scores (8.5 +/- 2.0) significantly (p < 0.0001) improved to 10.5 +/- 3.2 in the posttest (n = 305). Typical biomechanics students could correctly answer half of the prerequisite questions on the pre-test. Instruction resulted in a mean normalised gain (g) of 13.0% of maximum possible improvement that was consistent with research on traditional instruction in introductory physics courses. It was concluded that the BCI could be an effective tool to evaluate the overall effect of pedagogical strategies on student learning of key biomechanical concepts in the introductory biomechanics course.     

The influence of communal vs. individual learning context on the academic performance in social studies of grade 4–5 African-Americans

Empirical research utilizing the communal learning construct suggests that culturally-informed pedagogy enhances academic performance for African-American children. The present investigation examined the effect of culturally-informed learning contexts on recall performance in geography lessons. The sample consisted of 69 African-American Grade 4–5 public school students. Weeks 1 and 2 consisted of both learning and testing phases. Week 3 consisted only of a testing phase. Analyses of variance techniques revealed that, overall, subjects in the communal learning context performed significantly better on each of the two weekly quizzes and on the comprehensive examination than those in the individual learning context. Limitations of the findings and future research directions are discussed.     

The Development of an Instrument for the Evaluation of Some Aspects of the Taught Component of an Advanced Courses Module for Teachers in International Schools

A scheme of professional development for teachers, leading to the award of Advanced Certificate, Advanced Diploma or degree of Master of Education, has been in operation at the University of Bath School of Education for some years. Recently this modular scheme has been extended to become more accessible to teachers in international and overseas schools around the world, with modules taught in a range of locations internationally including a Summer School held annually in July at the University of Bath. The Methods of Educational Enquiry (MEE) module provides an introduction to aspects of educational research and is recommended to participants as an early module for study: between 1992 and 1993 this module has thus been taught on more occasions than any other, in a number of different locations and by a number of different tutors. This paper considers issues arising from the implementation of an instrument for the evaluation of some aspects of the taught component of the MEE module in a wide range of contexts, and describes the development of two related measures of participants' satisfaction with respect to this component. A further paper will consider a wider range of issues across a number of different modules in a range of locations.     

The Talent Development Model of Schooling: Placing Students at Promise for Academic Success

The work at the Center for Research on the Education of Students Placed At Risk (CRESPAR) has been guided by the Talent Development model, a comprehensive paradigm for school reform. The Talent Development model asserts that all students can learn in demanding, high-expectation academic settings. This goal is reachable if schools are committed to implementing multiple, evidence-based activities to "overdetermine success," and if all relevant stakeholders are genuinely involved, supportive, and held accountable. First, however, the traditional function of schooling must be redirected from that of classifying, sorting, and weeding out students to maximizing every child's potential for academic development. The model is itself a work in progress. Research done at CRESPAR is presented to demonstrate how we are building and evaluating it, with the ultimate aim to contribute to preparing our nation's children for productive participation in their communities and society at large.     

Technology,Learning Communities and Young People: The Future Something Project

The Future Something Project (FSP), a two‐year action research project, was devised to nurture the creative and technological talent of small groups of young people at risk by creating a structured network, mentored and driven by creative professionals exploring innovative ways for the two distinct target groups to work together. The project practice is located within the new field of interaction design and takes a social and critical approach to art and design pedagogy. The external research team found that one valuable way of looking at the FSP enterprise was through the social theory of communities of practice (CoPs) developed in the 1990s by Lave and Wenger. The creation of a learning community as a pedagogical strategy is central to the conception and practice of this project. This article, therefore, sets out to apply an existing theory to a new art and design context together with more general thoughts on learning communities. It explores the potential of new technologies and different settings to effect learning within structured networks and local and virtual communities of practice.     

去美丽的加州旅行吧!

正说起美国加州,优胜美地(Yosemite)、棕榈泉(Palm Springs)、迪士尼乐园(Disneyland)也许是人们较为熟知的名字。本期,旅居中国的Jeff Gerdes将带领我们感受一个美国人眼中的加州:除了在好莱坞大片中经常出现的金门大桥(Golden