The kinematic differences between accurate and inaccurate squash forehand drives for athletes of different skill levels     

Benjamin K. Williams  Ross H. Sanders  Joong Hyun Ryu  Philip Graham-Smith  Peter J. Sinclair 《Journal of sports sciences》2020,38(10):1115-1123

ABSTRACT

To maintain the accuracy of squash shots under varying conditions, such as the oncoming ball’s velocity and trajectory, players must adjust their technique. Although differences in technique between skilled and less-skilled players have been studied, it is not yet understood how players vary their technique in a functional manner to maintain accuracy under varying conditions. This study compared 3-dimensional joint and racket kinematics and their variability between accurate and inaccurate squash forehand drives of 9 highly skilled and 9 less-skilled male athletes. During inaccurate shots, less-skilled players hit the ball with a more open racket, demonstrating a difference in this task-relevant parameter. No joint kinematic differences were found for accuracy for either group. Coordinated joint rotations at the elbow and wrist both displayed a “zeroing-in” effect, whereby movement variability was reduced from the initiation of propulsive joint rotation to a higher consistency at ball-impact; potentially highlighting the “functionality” of the variability prior to the impact that enabled consistent task-relevant parameters (racket orientation and velocity) under varying conditions. Further, highly skilled players demonstrated greater consistency of task-relevant parameters at impact than less-skilled players. These findings highlight the superior ability of highly skilled players to adjust their technique to achieve consistent task-relevant parameters and a successful shot.  相似文献   

Static and dynamic accuracy of a magnetic-inertial measurement unit used to provide racket swing kinematics     

Benjamin Kane Williams  Ross H. Sanders  Joong Hyun Ryu  Pitre C. Bourdon  Philip Graham-Smith  Peter J. Sinclair 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(2):202-214

Magnetic-inertial measurement units (MIMUs) are becoming more prevalent in sports biomechanics and may be a viable tool to evaluate kinematic parameters. This study examined the accuracy of a MIMU to estimate orientation angles under static conditions and dynamically from a squash racket during a forehand drive shot. A MIMU was mounted onto a goniometer and moved through 0–90°, with static data collected at 10° increments during 10 repetitions of all three axes. Typical error analyses showed the MIMU to be very reliable (TE ≤ 0.03°). MIMU accuracy was determined via intraclass correlation coefficients (ICC) (r > 0.999, p < 0.001). An ordinary least products regression showed no proportional bias and minimal fixed bias for all axes. Dynamic accuracy was assessed by comparing MIMU and optical motion capture data of squash racket swing kinematics. A MIMU was fixed onto a racket and 10 participants each hit 10 forehand shots. Mean orientation angle error at ball impact was <0.50° and ICC showed very high correlations (r ≥ 0.988, p < 0.001) for all orientations. Swing phase root mean squared errors were ≤2.20°. These results indicate that a MIMU could be used to accurately and reliably estimate selected racket swing kinematics.  相似文献   

Promoting schoolchildren’s self-esteem in physical education: testing the effectiveness of a five-month teacher training     

Benjamin Rubeli  Esther Oswald  Achim Conzelmann  Jürg Schmid  Stefan Valkanover 《Physical Education & Sport Pedagogy》2020,25(4):346-360

ABSTRACT

Background: Schoolchildren’s personality development is considered a central goal of physical education (PE). With regard to the relationship between psychological well-being and global self-esteem over the life course, the promotion of positive self-esteem is an issue of particular significance. Past research revealed that PE taught with an individualized teacher frame of reference (iTFR) and a reflexive teaching style is associated with positive effects on facets of children’s perceived sports competence. However, it remains an open question whether this teaching styles has the potential to promote positive self-esteem.

Purpose: The present study investigated whether a five-month teacher training, aimed to enhance the teachers’ iTFR and their reflexive teaching style in PE, has a positive effect on students’ perceived sports competence and their global self-esteem. To analyse the implementation quality, changes in students’ perceived iTFR and perceived reflexive teaching style were investigated.

Method: A total of 21 teachers were assigned to either an intervention group (n?=?13), receiving the five-month teacher training, or a control group (n?=?8) consisting of regular teaching without teacher training. The teacher training encompassed five three-hour consecutive sessions during which the teachers acquired theoretical and practical knowledge about the promotion of competence perceptions in PE with a reflexive teaching style and an iTFR. Between the sessions, the teachers were instructed to implement an iTFR and a reflexive teaching style into their own PE classes. To evaluate the effects of the teacher training, their students’ (N?=?315, 53.7% girls, M_age?=?13.2 y, SD_age?=?1.3 y) perceived teaching style (iTFR and reflexive teaching), perceived sports competence and global self-esteem were measured with paper-pencil questionnaires at three measurement points (pre, post and follow-up).

Findings: Linear mixed effect models showed that students of the intervention group reported an increase in their teachers’ reflexive teaching style, but there were no changes with regard to iTFR. With regard to students’ perceived sports competence and global self-esteem, there were significant interaction effects between time and group over a period of eight months (from pre-test to follow-up), indicating positive effects on these self-concept dimensions due to the teacher training.

Conclusion: The present study indicates that a long-term teacher training supports PE teachers to implement teaching styles with the aim to promote students’ self-concept. Furthermore, the findings lead to the assumption that a more pronounced iTFR in combination with an enhanced reflexive teaching style has the potential to positively influence schoolchildren’s perceived sports competence and global self-esteem.  相似文献   

Prenatal Maternal Stress,Child Cortical Thickness,and Adolescent Depressive Symptoms     

Elysia Poggi Davis  Benjamin L. Hankin  Laura M. Glynn  Kevin Head  Dae Jin Kim  Curt A. Sandman 《Child development》2020,91(2):e432-e450

Prenatal maternal stress predicts subsequent elevations in youth depressive symptoms, but the neural processes associated with these links are unclear. This study evaluated whether prenatal maternal stress is associated with child brain development, and adolescent depressive symptoms using a prospective design with 74 mother child pairs (40 boys). Maternal stress was assessed during pregnancy, child cortical thickness at age 7, and depressive symptoms at age 12. Prenatal maternal stress was associated with less cortical thickness primarily in frontal and temporal regions and with elevated depressive symptoms; child cortical thickness additionally correlated with adolescent depressive symptoms. The observed associations are consistent with the possibility that cortical thickness in superior frontal regions links associations between prenatal maternal stress and adolescent depressive symptoms.  相似文献   

Libraries and Spatial Literacy: Toward Next-Generation Education     

Benjamin D. Branch 《College & Undergraduate Libraries》2014,21(1):109-114

The role of the library is to assist citizens in skills development critical to national interest and empowerment as literacy ambassadors, in general. Specifically, the work by the Federal Geographic Data Committee (1994) indicates that spatial literacy is for every citizen and not just a set of workforce specialists. Hence, the use of maps in decision making and problem solving will become fundamental to all professions, including library professionals. Thus, a spatial literacy awareness and rationale for such as standard job ability is discussed as a future librarian workforce proficiency and knowledge transfer medium.  相似文献   

Relationship of reading fluency assessment data with state accountability test scores: A longitudinal comparison of grade levels     

Benjamin Silberglitt  Matthew K. Burns  Na'im H. Madyun  Kathryn E. Lail 《Psychology in the schools》2006,43(5):527-535

The No Child Left Behind Act of 2001 mandated statewide accountability testing and focused the accountability conversation on reading. Therefore, the current study examined the relationship between curriculum‐based measurement for reading (R‐CBM) and state accountability test scores, potential grade differences in relationship magnitude, and differences in relationship magnitude among R‐CBM and Maze as they compare to state test scores. Data for 5,472 students in Grades 3, 5, 7, and 8 were correlated and resulted in corrected coefficients that ranged from .51 (eighth graders) to .71 (third graders) for R‐CBM and .49 (eighth graders) to .54 (seventh graders) for Maze. The coefficients between R‐CBM and state test scores were significantly larger for third and fifth graders than those for eighth graders. No significant differences in magnitude were found between the correlation coefficients for state test scores to R‐CBM and to Maze among seventh or eighth graders. Potential implications and suggestions for future research are included. © 2006 Wiley Periodicals, Inc. Psychol Schs 43: 527–535, 2006.  相似文献   

Explaining outsourcing in health,sport and physical education     

Benjamin J. Williams  Doune Macdonald 《Sport, Education and Society》2015,20(1):57-72

Outsourcing is a complex, controversial and pervasive practice that is increasingly becoming a matter of concern for educational researchers. This article contributes to this literature by examining outsourcing practices related to health, sport and physical education (HSPE). Specifically, it reports data on specialist health and physical education (HPE) teachers', principals' and external providers' reasons for participating in outsourcing arrangements. These data were obtained from a collective case study of six schools and the external providers that they outsourced HSPE to over a 12-month period, using semi-structured interviews and overt participant observations. The findings illustrate the ways in which the informants explained their outsourcing practices using a variety of educationally and organisationally oriented reasons. Educational value, human resources (e.g. expertise), physical resources (e.g. facilities) and symbolic resources (e.g. status) were reasons for outsourcing HSPE that were commonly cited by principals and specialist HPE teachers. Among external providers, educational value, income generation and promotion/advertising were frequently cited to explain their work with and for schools. These findings illustrate the ways in which outsourcing practices in HSPE articulate with, and are implicated in, broader educational privatisations. They also highlight the boundaries that outsourcing practices trouble or reinforce, such as those marking the purview of markets, membership of the HPE profession and the constitution of expertise.  相似文献   

Sporting Entertainments,Discarded Possibilities and the Case of Football as a Variety Sport, 1905–1906     

Benjamin Litherland 《Sport in History》2015,35(3):391-418

During the winter of 1905/6, Olympia held a series of spectacular indoor, electrically lit football matches. Organised by the showman Edwin Cleary, the purpose of these matches was to provide entertaining shows to large audiences. Using Pierre Bourdieu's theory of fields, this article argues that such an organisation was a continuation of a longer interaction between sport and the stage that was restricted during the coalescence of the sporting and exercise field in the late nineteenth century. The ultimate failure of the venture, moreover, is attributed to the power of the Football Association in the sub-field of football. The article uses the football games as a case study to demonstrate the usefulness of this theory to the study of sport more broadly.  相似文献   

JournalGuide: bringing authors and journals together          下载免费PDF全文

Benjamin MUDRAK 《Learned Publishing》2015,28(2):147-149

• As a result of the considerable (and growing) number of scholarly journals, it is difficult for authors to find the best place for their research, even as many journals face challenges in finding new submissions.
• JournalGuide ( www.journalguide.com ) is a free tool that matches user‐inputted keywords or text to article metadata and returns journals that have recently published similar work.
• Users can then compare information about these journals and make an informed decision about where to submit.

  相似文献   

Gay On-Screen: The Relationship Between Exposure to Gay Characters on Television and Heterosexual Audiences' Endorsement of Gay Equality     

Bradley J. Bond  Benjamin L. Compton 《广播与电子媒介杂志》2015,59(4):717-732

The current study, grounded in the parasocial contact hypothesis, employed a survey of emerging adults to investigate the relationship between exposure to gay characters on television and heterosexuals' endorsement of gay equality. A positive relationship existed between exposure to on-screen gay characters and gay equality endorsement. The relationship was stronger for racial minority participants than for White participants, and for participants who had no or few interpersonal relationships with openly gay individuals than for participants who had more than three respective relationships. Results are discussed in terms of the parasocial contact hypothesis and television as an agent of social change.  相似文献