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901.
Primary objective: Teacher evaluation is being revamped by policy-makers. The marginalized status of physical education has protected this subject area from reform for many decades, but in our current era of system-wide, data-based decision-making, physical education is no longer immune. Standardized and local testing, together with structured observation measures, are swiftly being mandated in the USA as required elements of teacher evaluation systems in an effort to improve school programs and student achievement. The purpose of this investigation was to document how this reform was initiated and the experiences of teachers, students and administrators, from three high school physical education programs, during initiation of this reform. Documenting how physical education programs respond to such reforms develops our understanding of top-down reform efforts and helps to identify conditions under which such reforms have the intended effect on physical education teachers and student learning in physical education.

Theoretical framework: Fullan’s three phases of school change has been used to analyze and guide school change efforts in several subject areas including physical education. The phases are initiation, implementation and institutionalization. This study is situated primarily within the first phase of school change, the initiation phase.

Methods and procedures: This study took place over a 21-month period in 3 suburban school districts in a northeast metropolitan area of the USA. Interviews with district physical education administrators, high school physical education teachers and students were conducted. Field notes of physical education classes, informal interviews and related artifacts including pre- and post-physical education assessments were collected. To ensure trustworthiness, several steps were taken including member checks, triangulation and peer review. The data were analyzed to find common themes and patterns using the constant comparative method.

Results: Several themes emerged: (1) changes in curriculum and assessment; (2) effect on administrators; (3) stakeholder apathy and (4) department collaboration.

Conclusion: Changes, although minor, did take place in the wake of this top-down teacher reform; however, additional research needs to be completed to determine whether or not these changes are meaningful or long lasting.  相似文献   

902.
903.
Abstract

Quiet eye training (QET) may be a more effective method for teaching children to catch than traditional training (TT) methods, but it is unclear if the benefits accrued persist in the long term. Thirty children were randomly allocated into a QET or TT group and, while wearing a mobile eye tracker, underwent baseline testing, training and two retention tests over a period of eight weeks, using a validated throw and catch task. During training, movement-related information was provided to both groups, while the QET group received additional instruction to increase the duration of their targeting fixation (QE1) on the wall prior to the throw, and pursuit tracking (QE2) period on the ball prior to catching. In both immediate (R1) and delayed (R2, six weeks later) retention tests, the QET group had a significantly longer QE1 duration and an earlier and longer QE2 duration, compared to the TT group, who revealed no improvements. A performance advantage was also found for the QET compared to the TT group at both R1 and R2, revealing the relatively robust nature of the visuomotor alterations. Regression analyses suggested that only the duration of QE1 predicted variance in catch success post-training, pointing to the importance of a pre-programming visuomotor strategy for successful throw and catch performance.  相似文献   
904.
Introduction: Many factors may contribute to running-related injury. These include fatigue and footwear, the combination of which has rarely been studied, in particular with reference to barefoot running, recently advocated as a method to reduce injury risk. Methods: Twenty-two runners (12 well-trained and 10 trained) participated in a 10?km fatiguing trial. Knee and ankle joint kinematics and kinetics and electromyography were assessed during overground running in the barefoot and shod condition. This was performed pre- and post-fatigue using a motion capture system and force platforms. Results: Initial loading rate increased in the trained runners when barefoot but not shod. Shod knee stiffness increased in both groups after fatigue, whereas barefoot knee stiffness decreased only in the trained group. A reduction in barefoot bicep femoris pre-activation was found in both groups. During stance, a reduction in vastus lateralis and biceps femoris and an increase in tibialis anterior activity were found over time in both groups and conditions. Trained runners decreased gluteus medius and increased lateral gastrocnemius median frequency for both conditions after fatigue. Conclusion: When fatigued, gait adjustments in habitually shod runners may increase injury risk when running barefoot. Training status may be a risk factor for injury, as less-trained runners experience muscular fatigue changes that may compromise ground reaction force attenuation. Caution is recommended when transitioning to pure barefoot running.  相似文献   
905.
Abstract

The aim of the study was to explore the significance of the ‘timing’ of the quiet eye (QE), and the relative importance of late (online control) or early (pre-programming) visual information for accuracy. Twenty-seven skilled golfers completed a putting task using an occlusion paradigm with three conditions: early (prior to backswing), late (during putter stroke), and no (control) occlusion of vision. Performance, QE, and kinematic variables relating to the swing were measured. Results revealed that providing only early visual information (occluding late visual information) had a significant detrimental effect on performance and kinematic measures, compared to the control condition (no occlusion), despite QE durations being maintained. Conversely, providing only late visual information (occluding early visual information) was not significantly detrimental to performance or kinematics, with results similar to those in the control condition. These findings imply that the visual information extracted during movement execution – the late proportion of the QE – is critical when golf putting. The results challenge the predominant view that the QE serves only a pre-programming function. We propose that the different proportions of the QE (before and during movement) may serve different functions in supporting accuracy in golf putting.  相似文献   
906.
The aim of this study was to determine whether gait cycle characteristics are associated with running economy in elite Kenyan runners. Fifteen elite Kenyan male runners completed two constant-speed running sets on a treadmill (12 km ·h?1 and 20 km ·h?1). VO2 and respiratory exchange ratio values were measured to calculate steady-state oxygen and energy cost of running. Gait cycle characteristics and ground contact forces were measured at each speed. Oxygen cost of running at different velocities was 192.2 ± 14.7 ml· kg?1· km?1 at 12 km· h?1 and 184.8 ± 9.9 ml· kg?1· km?1 at 20 km· h?1, which corresponded to a caloric cost of running of 0.94 ± 0.07 kcal ·kg?1·km?1 and 0.93 ± 0.07 kcal· kg?1· km?1. We found no significant correlations between oxygen and energy cost of running and biomechanical variables and ground reaction forces at either 12 or 20 km· h?1. However, ground contact times were ~10.0% shorter (very large effect) than in previously published literature in elite runners at similar speeds, alongside an 8.9% lower oxygen cost (very large effect). These results provide evidence to hypothesise that the short ground contact times may contribute to the exceptional running economy of Kenyan runners.  相似文献   
907.
The purpose of this study was to investigate the accuracy of fat-free mass (FFM) estimates from two-compartment (2C) models including air displacement plethysmography (ADP), ultrasound (US), near-infrared interactance (NIR), and the Jackson and Pollock skinfold equation (SKF) against a criterion four-compartment (4C) model in elite male rowers. METHODS: Twenty-three elite-level male rowers (mean± SD; age 24.6 ± 2.2 years; stature: 191.4 ± 7.2 cm; mass: 87.2 ± 11.2 kg) participated in this investigation. All body composition assessments were performed on the same day in random order, except for hydrostatic weighing (HW), which was measured last. FFM was evaluated using a 4C model, which included total body water from bioimpedance spectroscopy, body volume from HW, and total body bone mineral via dual-energy X-ray absorptiometry. The major findings of the study were that the 2C models evaluated overestimated FFM and should be considered with caution for the assessment of FFM in elite male rowers. Future studies should use multiple-compartment models, with measurement of TBW and bone mineral content, for the estimation of FFM.  相似文献   
908.
The present study aimed to extend research that has focused on the identification of stressors associated with coaching practice by systematically evaluating how such stressors effect athletes, and more broadly, the coach–athlete relationship. A total of 13 professional- and national-level athletes were interviewed to address the three study aims: how they detect when a coach is encountering stressors, how coach experiences of stress effects them as an athlete, and how effective the coach is when experiencing stress. Following content analysis, the data suggested athletes were able to detect when a coach was experiencing stress and this was typically via a variety of verbal and behavioural cues. Despite some positive effects of the coach experiencing stress, the majority were negative and varied across a range of personal influences on the athlete, and effects on the general coaching environment. It was also the broad view of the athletes that coaches were less effective when stressed, and this was reflected in performance expectations, perceptions of competence, and lack of awareness. The findings are discussed in relation to the existing theory and with reference to their implications for applied practice, future research, and development of the coach–athlete relationship.  相似文献   
909.
This study examined the separate and combined effects of heat acclimation and hand cooling on post-exercise cooling rates following bouts of exercise in the heat. Seventeen non-heat acclimated (NHA) males (mean ± SE; age, 23 ± 1 y; mass, 75.30 ± 2.27 kg; maximal oxygen consumption [VO2 max], 54.1 ± 1.3 ml·kg?1·min?1) completed 2 heat stress tests (HST) when NHA, then 10 days of heat acclimation, then 2 HST once heat acclimated (HA) in an environmental chamber (40°C; 40%RH). HSTs were 2 60-min bouts of treadmill exercise (45% VO2 max; 2% grade) each followed by 10 min of hand cooling (C) or no cooling (NC). Heat acclimation sessions were 90–240 min of treadmill or stationary bike exercise (60–80% VO2 max). Repeated measures ANOVA with Fishers LSD post hoc (α < 0.05) identified differences. When NHA, C (0.020 ± 0.003°C·min?1) had a greater cooling rate than NC (0.013 ± 0.003°C·min?1) (mean difference [95%CI]; 0.007°C [0.001,0.013], P = 0.035). Once HA, C (0.021 ± 0.002°C·min?1) was similar to NC (0.025 ± 0.002°C·min?1) (0.004°C [?0.003,0.011], P = 0.216). Hand cooling when HA (0.021 ± 0.002°C·min?1) was similar to when NHA (0.020 ± 0.003°C·min?1) (P = 0.77). In conclusion, when NHA, C provided greater cooling rates than NC. Once HA, C and NC provided similar cooling rates.  相似文献   
910.
This meta-analysis investigated the maturation-related pattern of adaptations to resistance training in boy athletes. We included studies examining the effects of 4–16-week resistance training programmes in healthy boy athletes aged 10–18 years. Pooled estimates of effect size for change in strength across all studies (n = 19) were calculated using the inverse–variance random effects model for meta-analyses. Estimates were also calculated for groups based on likely biological maturity status (“before”, “during” and “after” peak height velocity). Using the standardised mean difference, resistance training increased strength across all groups (effect size = 0.98, [CI: 0.70–1.27]). Strength gains were larger during (1.11 [0.67–1.54]) and after (1.01 [0.56–1.46]) peak height velocity than before (0.5 [?0.06–1.07]). Adaptations to resistance training are greater in adolescent boys during or after peak height velocity. These findings should help coaches to optimise the timing of training programmes that are designed to improve strength in boy athletes.  相似文献   
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