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David Whiteside Bruce Clifford Elliott Brendan Lay Machar Reid 《Journal of sports sciences》2015,33(7):675-686
Enhancing the understanding of coordination and variability in the tennis serve may be of interest to coaches as they work with players to improve performance. The current study examined coordinated joint rotations and variability in the lower limbs, trunk, serving arm and ball location in the elite female tennis serve. Pre-pubescent, pubescent and adult players performed maximal effort flat serves while a 22-camera 500 Hz motion analysis system captured three-dimensional body kinematics. Coordinated joint rotations in the lower limbs and trunk appeared most consistent at the time players left the ground, suggesting that they coordinate the proximal elements of the kinematic chain to ensure that they leave the ground at a consistent time, in a consistent posture. Variability in the two degrees of freedom at the elbow became significantly greater closer to impact in adults, possibly illustrating the mechanical adjustments (compensation) these players employed to manage the changing impact location from serve to serve. Despite the variable ball toss, the temporal composition of the serve was highly consistent and supports previous assertions that players use the location of the ball to regulate their movement. Future work should consider these associations in other populations, while coaches may use the current findings to improve female serve performance. 相似文献
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Serving to different locations: set-up, toss, and racket kinematics of the professional tennis serve
Reid M Whiteside D Elliott B 《Sports biomechanics / International Society of Biomechanics in Sports》2011,10(4):407-414
The serve, as the most important stroke in tennis, has attracted considerable biomechanical interest. Of its component parts, the swing has received disproportionate research attention and consequently, little is known regarding toss kinematics. Indeed, the age-old question of whether players serve to different parts of the court from the same toss remains unanswered. Six right-handed professionally ranked players hit first serves (FSs) and second serves (SSs) to three 2 x 1 m target areas reflecting the landing locations of T, body and wide serves, respectively, on the deuce court. A 22 camera, 250 Hz VICON MX motion analysis system captured racket, ball, foot, and h and kinematics. Repeated measures ANOVAs assessed within-player differences in foot, racket, and ball kinematics within the FS and SS as a function of landing location. The positions of the front foot, ball zenith, and ball impact were significantly different in the FS, while kinematics across all SS were consistent. Front foot position was closer to the centre mark in the T FS and players impacted the ball further left in the wide FS compared to the T FS. This study discusses the findings in the context of the development of the serve as well as potential implications for the return. 相似文献
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Robert H. Bradley Leanne Whiteside Daniel J. Mundfrom Patrick H. Casey Kelly J. Kelleher Sandra K. Pope 《Child development》1994,65(2):346-360
The caregiving environment experienced by 243 premature, low birthweight (LBW) children living in poverty was examined to determine whether the quality of care such children receive affords them some measure of protection from the generally deleterious consequences of poverty and prematurity. Only 26 children were identified as functioning in the normal range for cognitive, social/adaptive, health, and growth parameters at age 3. These children, who showed early signs of resiliency, differed from nonresilient children in that they were receiving more responsive, accepting, stimulating, and organized care. They were also living in safer, less crowded homes. 6 "protective" aspects of caregiving were identified and used as part of a cumulative protection index. Children with less than 3 protective aspects of caregiving present at age 1 had only a 2% probability of being resilient, and only a 6% probability if fewer than 3 were present at age 3. Overall, premature LBW children born into conditions of poverty have a very poor prognosis of functioning within normal ranges across all the dimensions of health and development assessed. However, those raised in a setting with 3 or more protective factors were more likely to show early signs of resiliency. 相似文献
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Marie Hardin Scott Simpson Erin Whiteside Kim Garris 《Mass Communication and Society》2013,16(2):211-233
Title IX, the 1972 federal law that guarantees girls and young women access to scholastic sporting opportunities, has been the catalyst for explosive growth in female athletics. Despite evidence that Title IX has opened doors for female athletes without closing them to boys, the law continues to be a source of controversy. This research explores the ways stories in U.S. regional and national newspapers framed Title IX issues between 2002 and 2005, critical years for the civil-rights legislation because of political and legal activity at the national level. Content analysis found that although most stories avoided negative framing devices, stories about the Title IX Commission during 2002 and 2003 more often used negative framing that could perpetuate misunderstanding about the law. Further, paper size, placement of stories and reporter gender were factors in the way stories framed and sourced Title IX coverage. This study points to the need of journalists for a better understanding of the law and its impact on high school and collegiate athletics. Journalists also need to better understand Title IX's relationship with the fiscal hierarchy of collegiate athletics in U.S. universities so “blame the victim” mythology is not reinforced. Journalists should reject patriarchal frames and report about Title IX in ways that benefit public discourse. 相似文献
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Nicola A. Conners‐Burrow Danya L. Johnson Leanne Whiteside‐Mansell Lorraine McKelvey Regina A. Gargus 《Psychology in the schools》2009,46(7):593-604
This study examines the degree to which support from parents and teachers buffers the level of depression for four groups of children involved in bullying (victim, bully, bully‐victims, or not involved children). Nine hundred and seventy‐seven 5th‐, 9th‐, and 11th‐grade students in the rural South completed questionnaires on bullying, social support, and depression. Children who were not involved in bullying reported less depression and more social support than children involved in bullying, and bully‐victims were the most at‐risk group. Furthermore, results indicate that in all four bully status groups, children reported fewer symptoms of depression when support from parents was high compared to when it was low. For all groups except victims, when parental support was low, support from teachers was associated with fewer symptoms of depression. When parental support was high, the impact of support from the teacher was not significant. © 2009 Wiley Periodicals, Inc. 相似文献
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Bañales Josefina Pech Alexandria Pinetta Bernardette J. Pinedo Andres Whiteside Maiya Diemer Matthew A. Romero Andrea J. 《Research in higher education》2022,63(4):589-609
Research in Higher Education - Guided by Critical Consciousness Theory and the Multicontextual Model for Diverse Learning Environments, this research explored whether a critical reflection of... 相似文献
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Globally, universities are increasingly seeking to equip their graduates with specific “soft” skills to complement traditional “hard” skills so they can function in a rapidly changing and dynamic world. While hard skills are relatively straightforward to define and foster the same cannot be said for soft skills, despite the latter being increasingly acknowledged as equally, if not more, important. This paper assesses the feasibility of an Australian wellbeing course in the context of explicit soft skills training at one Chinese university in a pilot with 29 second-year students. Using an exploratory mixed-methods design, quantitative impact measures were collected before and after the intervention to complement qualitative workshop evaluations. Results clearly show that participants found both the content of the training as well as the participatory social learning approach relevant and acceptable. The training had a statistically significant positive impact on the assessed human qualities soft skills outcomes. Implications of the findings for the current interest in training Chinese university students in the spirit of innovation and enterprise are highlighted. 相似文献