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51.
The prevalence of ischaemia-related symptoms is remarkably high among elite indoor volleyball players. Since the exposure to sport-specific demands may be higher in beach volleyball compared to indoor volleyball, the aim of this study was to assess the prevalence of ischaemia-related symptoms and associated risk factors among world-class beach volleyball players. Therefore, a questionnaire survey was performed among beach volleyball players active during the 2013 Grand Slam Beach Volleyball in the Netherlands. In total, 60 of the 128 beach volleyball players (47%) participated: 26 males and 34 females from 17 countries. The self-reported prevalence of cold or blue or pale digits in the dominant hand during or immediately after practice or competition was 38% (n = 23). Two risk factors were independently associated with symptoms of blue or pale digits: more than 14 years playing volleyball (odds ratio (OR) 4.42, 90% confidence interval (90% CI) 1.30–15.07) and sex (female) (OR 4.62, 90% CI 1.15–18.57). In conclusion, the prevalence of symptoms associated with digital ischaemia is high among international world-class beach volleyball players. Female sex and the length of the volleyball career were independently associated with an increased risk of ischaemia-related symptoms. The high prevalence of these seemingly innocuous symptoms and possible associated risk factors warrant regular monitoring since early detection can potentially prevent thromboembolic complications and irreversible tissue damage.  相似文献   
52.
This study investigated the evolution of physical and technical performances in the English Premier League (EPL), with special reference to league ranking. Match performance observations (= 14,700) were collected using a multiple-camera computerised tracking system across seven consecutive EPL seasons (2006–07 to 2012–13). Final league rankings were classified into Tiers: (A) 1st–4th ranking (= 2519), (B) 5th–8th ranking (= 2965), (C) 9th–14th ranking (= 4448) and (D) 15th–20th ranking (= 4768). Teams in Tier B demonstrated moderate increases in high-intensity running distance while in ball possession from the 2006–07 to 2012–13 season (< 0.001; effect size [ES]: 0.68), with Tiers A, C and D producing less pronounced increases across the same period (< 0.005; ES: 0.26, 0.41 and 0.33, respectively). Large increases in sprint distance were observed from the 2006–07 to 2012–13 season for Tier B (< 0.001; ES: 1.21), while only moderate increases were evident for Tiers A, C and D (< 0.001; ES: 0.75, 0.97 and 0.84, respectively). Tier B demonstrated large increases in the number of passes performed and received in 2012–13 compared to 2006–07 (< 0.001; ES: 1.32–1.53) with small-to-moderate increases in Tier A (< 0.001; ES: 0.30–0.38), Tier C (< 0.001; ES: 0.46–0.54) and Tier D (< 0.001; ES: 0.69–0.87). The demarcation line between 4th (bottom of Tier A) and 5th ranking (top of Tier B) in the 2006–07 season was 8 points, but this decreased to just a single point in the 2012–13 season. The data demonstrate that physical and technical performances have evolved more in Tier B than any other Tier in the EPL and could indicate a narrowing of the performance gap between the top two Tiers.  相似文献   
53.
This paper examines the video-based pedagogical practices of Terry (pseudonym), a head coach of a professional junior academy squad. Data were collected through 6 in-depth, semi-structured interviews and 10 field observations of Terry’s video-based coaching in situ. Three embracing categories were generated from the data. These demonstrated that Terry’s video-based coaching was far from apolitical. Rather, Terry strategically used performance analysis technologies to help fulfil various objectives and outcomes that he understood to be expected of him within the club environment. Kelchtermans’ micropolitical perspective, Callero’s work addressing role and Groom et al.’s grounded theory were primarily utilised to make sense of Terry’s perceptions and actions. The findings point to the value of developing contextually grounded understandings of coaches’ uses of video-based performance analysis technology. Doing so could better prepare coaches for this aspect of their coaching practice.  相似文献   
54.
The aim of this study was to quantify the type of offensive sequences that result in goals in elite futsal. Thirty competitive games in the Spanish Primera Division de Sala were analysed using computerised notation analysis for patterns of play that resulted in goals. More goals were scored in positional attack (42%) and from set pieces (27%) compared to other activities. The number of defence to offense “transitions” (= 45) and the start of offensive plays due to the rules of the game (= 45) were the most common type of sequences that resulted in goals compared to other patterns of play. The central offensive zonal areas were the most common for shots on goal, with 73% of all goals scored from these areas of the pitch compared to defensive and wide zones. The foot was the main part of the body involved in scoring (= 114). T-pattern analysis of offensive sequences revealed regular patterns of play, which are common in goal scoring opportunities in futsal and are typical movement patterns in this sport. The data demonstrate common offensive sequences and movement patterns related to goals in elite futsal and this could provide important information for the development of physical and technical training drills that replicate important game situations.  相似文献   
55.
Limited recommendations of wheelchair configurations for court sports have been identified in the published literature. To accommodate the wide range of impairments in wheelchair rugby, players are given a point score that reflects their impairment. Players have regularly been grouped as high-, mid-, or low-point players in research, with high-point players having greater levels of muscle function compared with other classifications. This research documented the wheelchair configurations of elite Australian wheelchair rugby players across classification groups. Significant differences (p < 0.05) were found for increased seat height and decreased seat depth for high-point players compared with low- and mid-point groups, respectively. Low-point players displayed reduced wheelchair mass compared with high- and mid-point players, as well as increased frame length. Camber angles showed no significant differences across the classification groups. The incorporation of anthropometric measures, such as the elbow angle at the top dead center, was also investigated. While elbow angle showed no significant differences, seat height-to-total arm length ratio was higher for high-point players. Participants also completed surveys detailing their perception of the effect of altering wheelchair configurations. It is suggested that wheelchair configurations should consider an individual’s anthropometrics, impairment, training history, and court role to promote optimal performance, with predictive modeling having the potential to reduce the associated time and cost.  相似文献   
56.
While scholars have increasingly engaged with the (micro)political and emotional experiences of coaches in professional and semi-professional football, little attention has been given to grass-roots coaches’ understandings of these issues. The aim of this paper is to outline one possible research agenda that could contribute to the development of a rich and increasingly nuanced understanding of the everyday realities of being a grass-roots football coach. In particular, we consider (volunteer) coaches’ participation in grass-roots football to be an inherently relational endeavour. Following the presentation of a creative fiction that is based upon our shared experiences of being grass-roots football coaches, we then illustrate how relational thinking might be productively applied to exploring the social, (micro)political and emotional features of grass-roots football coaching.  相似文献   
57.
This investigation examined the oxidative stress (F2-Isoprostane; F2-IsoP) and inflammatory (interleukin-6; IL-6) responses to repeat-sprint training in hypoxia (RSH). Ten trained male team sport athletes performed 3(sets)*9(repetitions)*5?s cycling sprints in simulated altitude (3000?m) and sea-level conditions. Mean and peak sprint power output (MPO and PPO) were recorded, and blood samples were collected pre-exercise, and again at 8 and 60?min post-exercise. Both MPO and PPO were significantly reduced in hypoxia (compared to sea-level) in the second (MPO: 855?±?89 vs. 739?±?95?W, p?=?.006; PPO: 1024?±?114 vs. 895?±?112?W, p?=?.010) and third (MPO: 819?±?105 vs. 686?±?83?W, p?=?.008; PPO: 985?±?125 vs. 834?±?99?W, p?=?.008) sets, respectively. IL-6 was significantly increased from pre- to 1?h post-exercise in both hypoxia (0.7?±?0.2 vs. 2.4?±?1.4?pg/mL, p?=?.004) and sea-level conditions (0.7?±?0.2 vs. 1.6?±?0.3?pg/mL, p?d?=?0.80) suggesting higher IL-6 levels of post-hypoxia. F2-IsoP was significantly lower 1?h post-exercise in both the hypoxic (p?=?.005) and sea-level (p?=?.002) conditions, with no differences between trials. While hypoxia can impact on exercise intensity and may result in greater post-exercise inflammation, it appears to have little effect on oxidative stress. These results indicate that team sport organisations with ready access to hypoxic training facilities could confidently administer RSH without significantly increasing the post-exercise inflammatory or oxidative stress response.  相似文献   
58.
We identified the perceptual–cognitive skills and player history variables that differentiate players selected or not selected into an elite youth football (i.e. soccer) programme in Australia. A sample of elite youth male football players (n?=?127) completed an adapted participation history questionnaire and video-based assessments of perceptual–cognitive skills. Following data collection, 22 of these players were offered a full-time scholarship for enrolment at an elite player residential programme. Participants selected for the scholarship programme recorded superior performance on the combined perceptual–cognitive skills tests compared to the non-selected group. There were no significant between group differences on the player history variables. Stepwise discriminant function analysis identified four predictor variables that resulted in the best categorization of selected and non-selected players (i.e. recent match-play performance, region, number of other sports participated, combined perceptual–cognitive performance). The effectiveness of the discriminant function is reflected by 93.7% of players being correctly classified, with the four variables accounting for 57.6% of the variance. Our discriminating model for selection may provide a greater understanding of the factors that influence elite youth talent selection and identification.  相似文献   
59.
The aim of this study was to determine whether, as a result of collaborative-online reading of a chapter from a book of an academic nature, the quality of the collaborative summary that the readers would write would be higher than that written by readers who would both read the same chapter and write a summary in a face-to-face setting. In this study we examined the difference between the summaries written by participants from two groups, each group was divided into subgroups of 3 participants who had read collaboratively a chapter of a book, and collaborated on writing a summary. The participants of the experimental group read the chapter as it appeared in a website for collaborative reading built especially for this study and the participants were asked to summarize the chapter on a shared online digital document. The participants of the control group were asked to read the chapter face-to-face and to collaboratively summarize it in hand writing. The quality of the summaries was evaluated with a tool developed by Rivard (2001). This tool was developed to measure the quality of the summaries. In our study the main and secondary ideas that were supposed to be included in the participants’ summaries were identified by three literature teachers using ten different criteria and the summaries were analyzed by two other judges based on these criteria. The findings indicated that there were significant differences in the majority of the writing indicators being measured with the tool. The findings indicated that collaborative-online reading and writing produce a summary of a higher quality than one read and hand written collaboratively face-to-face.  相似文献   
60.
This investigation presents a framework for understanding and also to test the efficacy of Social Work intervention on the well being of the white collared employee (industrial employee) and his/her family. A comprehensive and intensive personal- family exploration was done to uncover the relatedness of seemingly disparate areas of the clients lives. A total of 80 executives (industrial employees) served as subjects. A baseline assessment was done using structured, standardized interview-schedules/questionnaires. The results of the study can be enumerated as follows: After the Social Work intervention, the executives in occupational profile, there were significant changes in Role perception, overload, role conflict, low status and poor peer relations. In coping strategies there was significant improvement in sub-scales like problem solving and unproductive coping. Significant reduction was noticed in their proneness to heart disease, depression, inadequate mental mastery, and perceived ill health. There was significant improvement in their family group support, and in their expressiveness, achievement, orientation, active-recreational and organizational characteristics.  相似文献   
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