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41.
The aims of this study were to: (1) determine whether the number of pedometer counts recorded by adolescents differs according to the adiposity of the participant or location on the body; (2) assess the accuracy and reliability of pedometers during field activity; and (3) set adolescent pedometer-based physical activity targets. Seventy-eight 11- to 15-year-old Boy Scouts completed three types of activity: walking, fast walking and running. Each type was performed twice. Participants wore three pedometers and one activity monitor during all activities. Participants were divided into groups of normal weight (BMI < 85th percentile) and at risk of being overweight (BMI > or = 85th percentile). Intra-class correlations across the three activities indicated reliability (r = 0.51 - 0.92, P < 0.001). This conclusion was supported by narrow limits of agreement that were within a pre-set range that was practically meaningful. Multivariate analysis of covariance indicated adiposity group differences, but this difference was a function of the increased stature among the larger participants (P < 0.001). Ordinary least-squares regression models and multi-level regression models showed positive associations between the number of pedometer and activity monitor counts recorded by the three groups of participants during all activities (all P < 0.001). The mean number of counts recorded for all participants during the fast walk was 127 counts per minute. In conclusion, the pedometers provided an accurate assessment of adolescent physical activity, and a conservative estimate of 8000 pedometer counts in 60 min is equivalent to 60 min of moderate to vigorous physical activity.  相似文献   
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The purpose of this study was to quantify the reliability of kinematic and kinetic variables using a sample of pre-peak-height-velocity (PHV) male athletes sprinting on a non-motorised treadmill. Following variables were measured and their normative data presented, average and peak velocity, average and peak power, average and peak horizontal force, average and peak vertical force, average step frequency, average step length, average work. Twenty-five participants performed three 5-s all-out sprints from a standing split start on a non-motorised treadmill on three separate occasions. Per cent change in the means (-3.66 to 3.35%) and coefficients of variation (0.56–7.81%) were thought reliable for all variables. However, average step rate, average horizontal force and average vertical force did not meet the standards (≥0.70) set for acceptable intraclass correlation coefficients (ICC). Due to the homogeneous group, it was expected to receive low ICC values. Therefore, youth sprinting performance can be tested reliably on a non-motorised treadmill, especially if the per cent change in the mean and CV are deemed the important reliability measures. Normative data are given for the participant’s age as well as their maturity level for kinematic and kinetic variables.  相似文献   
43.
Numerous studies have confirmed direct health effects of interventions with a physical activity component on students without providing sufficient information on the contents or the degree to which the programs have been carried out. The empirical evidence of the indirect health effects of physical education is weaker. In this article the focus is placed on the evaluation of the indirect health effects, such as the enhancement of physical activity and its psychological determinants (e.g. motivation, attitudes, self-efficacy and knowledge) of the health promotion program HealthyPEP, using a quasi-experimental design with 516 sixth grade students. When taking into account the contents of HealthyPEP and the degree of implementation, it was clear that the program had different effects on the two genders whereby girls evaluated HealthyPEP in a more positive way compared to boys. In girls, positive tendencies were observed on rational cognitive determinants (e.g. knowledge and attitudes towards sports). The contents of HealthyPEP must be further optimized in the future to achieve positive indirect health effects also on boys.  相似文献   
44.
This review presents a conceptual framework and supporting evidence that links impaired motor control after sport-related concussion(SRC)to increased risk for musculoskeletal injury.Multiple studies have found that athletes who are post-SRC have higher risk for musculoskeletal injury compared to their counterparts.A small body of research suggests that impairments in motor control are associated with musculoskeletal injury risk.Motor control involves the perception and processing of sensory information and subsequent coordination of motor output within the central nervous system to perform a motor task.Motor control is inclusive of motor planning and motor learning.If sensory information is not accurately perceived or there is interference with sensory information processing and cognition,motor function will be altered,and an athlete may become vulnerable to injury during sport participation.Athletes with SRC show neuroanatomic and neurophysiological changes relevant to motor control even after meeting return to sport criteria,including a normal neurological examination,resolution of symptoms,and return to baseline function on traditional concussion testing.In conjunction,altered motor function is demonstrated after SRC in muscle activation and force production,movement patterns,balance/postural stability,and motor task performance,especially performance of a motor task paired with a cognitive task(i.e.,dual-task condition).The clinical implications of this conceptual framework include a need to intentionally address motor control impairments after SRC to mitigate musculoskeletal injury risk and to monitor motor control as the athlete progresses through the return to sport continuum.  相似文献   
45.
This research examines whether parental homework involvement mediates the relationship between family background and educational outcomes such as academic achievement and academic self-concept. Data from two studies in which grade 8 students (N = 1274 and N = 1911) described their parents’ involvement in the homework process were reanalyzed via structural equation modeling. Perceived parental homework interference and perceived homework-related conflict were negatively related to students’ academic development, whereas perceived parental support and perceived parental competence to help with homework were positively related to academic outcomes. Although there were small associations between some aspects of parental homework involvement and family background variables, parental homework involvement did not mediate the relationship between family background and educational outcomes. Findings highlight the need for differentiated conceptualizations of parental homework involvement as well as detailed analyses of the processes underlying the association between family background and educational outcomes.  相似文献   
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As the number of young children displaying challenging behavior in early childhood grows, so too does the need to implement evidence-based practices that prevent challenging behavior. Positive Behavior Support (PBS) provides a framework of tiered interventions focused on promoting social-emotional development and preventing challenging behavior. This study investigated the effects of consultation on teachers’ implementation of universal PBS practices and children’s academic engagement. A multiple-baseline design was applied across four preschool classrooms serving children from 33 to 63 months of age. A strong relationship was documented between consultation and teachers’ implementation of PBS skills. High levels of academic engagement were maintained following consultation. Implications of the results are provided for applications of universal PBS practices in early childhood settings.  相似文献   
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The Counting Online Usage of Networked Electronic Resources (COUNTER) Code of Practice and Standardized Usage Statistics Harvesting Initiative (SUSHI) are two standards whose successful adoption will greatly assist librarians in performing accurate and timely usage analysis of their online collections and thus make more informed collection management decisions. Variations in how these standards have been applied by content providers to their SUSHI and COUNTER implementation are currently impacting their widespread adoption. The standards themselves are not broken—what is needed is concise guidelines on their implementation. This column reviews some of the roadblocks that impede consistent implementation of these standards as well as proposes recommendations that could form the basis of a community profile for these standards.  相似文献   
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