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 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.     

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.     

Electroplating for high aspect ratio vias in PCB manufacturing： enhancement capabilities of acoustic streaming

This paper considers the copper electrodeposit ion processes in microvias and investigates whether the quality of the electroplating process can be improved by acoustic streaming using megasonic transducers placed into a plating cell. The theoretical results show that acoustic streaming does not take place within the micro-via （either through or blind-via＇ s）, however it does help improve cupric ion transport in the area close to the mouth of a via. This replenishment of cupric ions at the mouth of micro-via leads to better quality filling of the micro-via through diffusion compared to basic conditions. Experiments showing the improved quality of the filling of vias are also presented.