Ball launch conditions for skilled golfers using drivers of different lengths in an indoor testing facility

The displacement of the golf ball struck by a driving club is affected by several player characteristics and equipment parameters and their interrelationships. Some modelling and simulation studies have shown a relationship between shaft length and clubhead speed, supported by a few experimental studies. The aim of the present study was to examine the relationship between driver length and ball launch conditions in an indoor test facility using a ball launch monitor. Nine males considered to be skilled golfers participated in the study. Four driving clubs of total length 117, 119, 124, and 132 cm were assembled from commercially available components and were used to strike golf shots while initial ball velocity, backspin rate, and launch angles were measured. Statistical analysis identified a significant difference in initial launch speed due to club length, a significant difference between participants, but no difference between the trials for a given golfer. A positive trend was noted between backspin and launch angle for all four clubs, and significant inverse associations between initial launch speed and backspin rate and launch angle. However, the combined launch conditions associated with increasing length were not considered optimal, with uncontrolled swingweight and moment of inertia effects considered to be limiting factors.     

Body composition of English Premier League soccer players: Influence of playing position,international status,and ethnicity

Abstract

Body composition is a key consideration in the physical make-up of professional soccer players. The aims of the present study were to determine whether the body composition of professional soccer players varied according to playing position, international status or ethnicity, and to establish which variables best distinguished the soccer players from a reference group. Body composition was assessed using dual-energy X-ray absorptiometry in 64 male professional soccer players. Measured variables included bone mineral density and the relative amounts of lean and fat mass. Data were analysed using analysis of variance and stepwise discriminant function. The soccer players recorded better values than a reference group (n = 24) for all body composition compartments. Percent lean mass and bone mineral density were the variables best able to identify the soccer players (95.5% correctly classified). Differences in body composition were evident between goalkeepers and outfield players, but not between outfield playing positions. No differences were found on the basis of international status. The non-Caucasian players demonstrated significantly lower percent body fat (9.2 ± 2.0%) than the Caucasian players (10.7 ± 1.8%). It was concluded that body composition is important for elite soccer players, but that homogeneity between players at top professional clubs results in little variation between individuals.     

Determination of the swing technique characteristics and performance outcome relationship in golf driving for low handicap female golfers

Abstract

Previous studies on the kinematics of the golf swing have mainly focused on group analysis of male golfers of a wide ability range. In the present study, we investigated gross body kinematics using a novel method of analysis for golf research for a group of low handicap female golfers to provide an understanding of their swing mechanics in relation to performance. Data were collected for the drive swings of 16 golfers using a 12-camera three-dimensional motion capture system and a stereoscopic launch monitor. Analysis of covariance identified three covariates (increased pelvis–thorax differential at the top of the backswing, increased pelvis translation during the backswing, and a decrease in absolute backswing time) as determinants of the variance in clubhead speed (adjusted r ² = 0.965, P < 0.05). A significant correlation was found between left-hand grip strength and clubhead speed (r = 0.54, P < 0.05) and between handicap and clubhead speed (r = ?0.612, P < 0.05). Flexibility measures showed some correlation with clubhead speed; both sitting flexibility tests gave positive correlations (clockwise: r = 0.522, P < 0.05; counterclockwise: r = 0.711, P < 0.01). The results suggest that there is no common driver swing technique for optimal performance in low handicap female golfers, and therefore consideration should be given to individual swing characteristics in future studies.     

Texts

Made in America: Immigrant Students in Our Public Schools. Laurie Olsen, New York: The New Press, 1997, 276 pages, $25.00 (hardcover), ISBN 1–5658–4400–9, and $14.95 (softcover), ISBN 1–5658–4471–8.

The Power of Their Ideas: Lessons for America From a Small School in Harlem. Deborah Meier, Boston: Beacon Press, 1995, 190 pages, $12.00 (softcover). ISBN 0–8070–3111–9.

Yesterday, Today & Tomorrow: Meeting the Challenge of Our Multicultural America & Beyond. Paul D. Christiansen and Michelle Young, San Francisco: Gaddo Gap Press, 1996, 376 pages, $29.95 (softcover). ISBN 1–8801–9218–7.     

Viewing restorative approaches to addressing challenging behaviour of minority ethnic students through a community of practice lens

The disproportionately high rates of school exclusion and lower levels of academic achievement of students from particular minority ethnic groups have been a focus of investigation in educational research across the world for some time. This articles uses a communities of practice framework to examine how restorative practice can draw on family and community values to support students whose behaviour is unacceptable in schools to recognize their own agency in behaving for good or ill and reintegrate them into the school community. At the same time, it acknowledges hurt that may be done to victims of wrong-doing and emphasizes putting things right between all those affected. The examples here are from Aotearoa New Zealand. They relate to practices influenced by traditional Māori cultural values. However, the principles and process associated with restorative practices that aim to restore harmony between the individual, the victim and the collective rather than to punish and exclude may be relevant within other student groups where high rates of exclusion from school are problematic.     

Institutional shaping of research priorities: A case study on avian influenza

Since outbreaks in 2003, avian influenza has received a considerable amount of funding and become a controversial science policy issue in various respects. Like in many other global and multidisciplinary societal problems fraught with high levels of uncertainty, a variety of perspectives have emerged over how to “tackle” avian influenza and public voices have expressed concern over how research funds are being allocated. In this article, we document if and how research agendas are being informed by public policy debates. We use qualitative and quantitative approaches to examine the relations between expectations of outcomes of public science and the existing research landscape. Interviews with a cross-section of stakeholders reveal a wide range of perspectives and values associated with the nature and objectives of existing research avenues. We find that the landscape of public avian influenza research is not directly driven by expectations of societal outcomes. Instead, it is shaped by three institutional drivers: pharmaceutical industry priorities, publishing and public research funding pressures, and the mandates of science-based policy or public health organizations. These insights suggest that, in research prioritization, funding agencies should embrace a broad perspective of research governance that explicitly considers underlying institutional drivers. Deliberative approaches in public priority setting might help to make agendas more plural and diverse and thus more responsive to the contested and uncertain nature of avian influenza research.     

Kinecting Physics: Conceptualization of Motion Through Visualization and Embodiment

The purpose of this work was to share our findings in using the Kinect technology to facilitate the understanding of basic kinematics with middle school science classrooms. This study marks the first three iterations of this design-based research that examines the pedagogical potential of using the Kinect technology. To this end, we explored the impact of using the Kinect in conjunction with an SDK Physical Virtual Graphing program on students’ understanding of displacement, velocity and acceleration compared to students who conducted more traditional inquiry of the same concepts. Results of this study show that, while there may be some affordances to be gained from integrating this technology, there is a need for a scaffolded approach that helps students to understand the “messiness” of the data collected. Further, meta-cognitive activities, such as reflective opportunities, should be integrated into the inquiry experiences in order to scaffold student learning and reinforce concepts being presented. While the Kinect did work to generate large-scale visualization and embodied interactions that served as a mechanism for student understanding, this study also suggests that a complementary approach that includes both the use of hands-on inquiry and the use of the Kinect sensor, with each activity informing the other, could be a powerful technique for supporting students’ learning of kinematics.     

Joining the goblins: fictional narratives and the development of student‐teachers’ reflection on practice in the further education sector

This paper explores ways in which student‐teachers in the Lifelong Learning sector are able to draw on fictionalised accounts of their own teaching practice experiences in order to gain a clearer understanding of their models and expectations of professionalism, and of how they, as individuals, locate their current position within the profession as a community of practice. It argues that the translation of experience into fiction – in this case specifically in the form of fairy tales – can be usefully applied in order to enhance and encourage reflection on practice as part of an action research cycle. Drawing on the evidence gathered, the paper goes on to suggest that student teachers’ main preoccupation at this stage of their development is not so much with meeting ‘standards’ of professionalism as with questions of behaviours and practices that will lead to a sense of belonging and acceptance; and with the need to transform their status, in relation to the profession, from that of outsider to insider.     

Choice of Reading Comprehension Test Influences the Outcomes of Genetic Analyses

Vowel representations are particularly difficult for children to learn because most vowel phonemes can be spelled in several different ways. Children in Grades 1, 2, and 3 spelled nonwords with an ambiguous vowel and reported their spelling strategies. Analysis of the children's spellings and strategy reports revealed a shift in relying solely on phonological information to considering orthographic information for making vowel letter choices. Implications for vowel spelling development are discussed.