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1.
ABSTRACT

The aim of this study was to compare the effects of 20 min neuromuscular training with a programme of 10 min in youth football players. 342 (15.4 ± 1.7 years) male football players from 18 teams were included, and cluster-randomized by team into two intervention groups. Both groups performed an injury prevention programme twice a week over five months using the same exercises but a different duration. The first intervention group (INT10, n = 175) performed the programme for 10 min, the second intervention group (INT20, n = 167) for 20 min. Primary outcomes were lower extremity (LE) injuries. Secondary outcomes were injury type, severity, mechanism and compliance to the intervention. 13 teams with 185 players were included for final analysis. No significant group difference was found between INT10 (6.37 per 1000 h) and INT20 (7.20 per 1000 h) for the incidence rate ratio of the lower extremities (IRR = 1.03, 95% confidence interval 0.59, 1.79), nor for the distribution of injury location, type, severity or mechanism. The results show that performing preventive exercises for 10 min is no less effective than 20 min in youth football players. Shorter training sessions can, therefore, be effectively used for injury prevention.  相似文献   
2.
引入模糊集定性比较分析(fuzzy-set qualitative comparative analysis,fsQCA)进行产学研协同创新绩效研究,改进基于对称性假设进行绩效测度的方法。理论分析和实证结果表明,改进后的测度方法可行而且易用,其优点在于采用条件集合和绩效之间的映射关系表征结果,不但能够进行数值大小的比较,而且其路径分析还有助于发现提升绩效的途径。  相似文献   
3.
外部网络关系对企业双元创新的影响结果存在较大争议,企业维持何种状态的外部网络关系会促进双元创新,影响机理中知识吸收能力起到怎样的作用,这是亟需研究的问题。对387家企业为样本进行问卷调查,运用结构方程模型法,以知识获取能力和知识实现能力为双重中介,探析外部网络关系对企业双元创新的影响。研究结果表明:外部网络关系不同维度对双元创新具有差异化影响;网络关系强度和网络关系密度的提高以及网络关系深度的适度降低有利于渐进性创新,网络关系深度和网络关系密度的提高以及网络关系强度的适度降低更有利于突破性创新;知识吸收能力在外部网络关系对双元创新的影响中发挥部分中介作用。  相似文献   
4.
The analysis of sport performance in competitive contexts has become synonymous with the use of a range of software applications and hardware e.g. heart rate monitors and gps systems. With the prevalence of technology in mind, a small but growing corpus of literature has begun to consider this phenomenon and its influence upon the coaching process. This study adds to this literature by detailing the autoethnographic experiences of a case study coach; Derek. A contextualised and richly described narrative account of Derek’s experience of using coaching applications is provided. Analysis of Derek’s narrative suggests that technology can be a useful means by which individuals make sense of their experience. Specifically, (1) technology can be a ‘ready-to-hand’ instrument that enhances the coaching process. Unfortunately, (2) technology may become the only and ‘calculative’ means by which individuals come to understand their performance. In such instances, it is important to note that (3) the videos we use to understand our performance are transformed and incomplete representations of lived athletic experiences. Thus, Derek’s story illustrates how technology can be both an enabler and barrier to athletes who wish to holistically understand their own lived experiences and engage in coach-athlete relationships. The accompanying analysis draws upon concepts from Heideggerian philosophy to add insight into the use of technology within the coaching process. In so doing, the study prompts coaches to critically view their coach-athlete relationships as situated in a wider world which contains, and can be mediated by, technology. In addition, Derek’s story (re)directs researchers and coaching practitioners interested in technology to a useful literature (philosophy of technology) which may further inform their understanding of coach-athlete relationships.  相似文献   
5.
《Research Policy》2019,48(8):103766
Organizations build strategic alliances with other firms with the intent of tapping into partners’ resources and capturing long-term value from these relationships. Such partnerships are typically governed by contractual or equity arrangements with clear mutual obligations. More recently, however, organizations have begun to seek strategic partnerships with open innovation communities, which are novel digitally enabled forms of organizing, and where contractual commitments are not possible. Thus, selecting the right open innovation community as an alliance partner becomes a more complex decision. We follow how the organizational decision makers, in two technology firms that were pioneers of forming strategic alliances with open innovation communities, developed metrics around making such decisions. We build upon Shah and Swaminathan’s (2008) contingency model of alliance partner selection and consider how it applies to the case of partnering with open innovation communities. This framework was useful in to frame our findings, yet our work recognizes and builds upon two key differences: 1) the evaluation metrics used in selecting an open innovation community were more focused on value creation than value capture; and 2) open ecosystem considerations, and not just partner-specific metrics, featured prominently in this type of alliance partner evaluation. We develop the notions of community and ecosystem health to refer to these new metrics.  相似文献   
6.
应用脉冲响应函数和阿尔蒙多项式滞后分布模型,对青岛市2005—2016年间的科技投入与产出的相关数据进行分析,证明青岛市科技投入与产出之间的长期均衡的正向影响关系;经测算得出青岛市科技投入与产出之间的滞后期为4年,在此基础上提出降低时滞效应、促进科技发展的对策建议。  相似文献   
7.
[目的/意义]在当前政府职能转变的背景下,政府与社会组织合作提供公共图书馆服务是公共图书馆管理体制改革的有效措施,也是公共图书馆事业发展的重要趋势。研究政府与社会组织的合作关系,不仅能够丰富相关理论成果,而且能为公共图书馆服务供给政社合作的发展提供参考。[目的/意义]通过文献调研、网络调研与实地调研相结合,论述公共图书馆服务供给政社合作关系的概念及特征,对公共图书馆服务供给政社合作关系中各主体的角色、政社合作关系的成因、政社合作关系的类型及形成过程进行深入分析。在此基础之上,提出公共图书馆服务供给政社合作关系可持续发展的对策。[结果/结论]良好合作关系的建立需要端正合作动机,完善合作制度,规范合作行为。  相似文献   
8.
This study aimed to examine the reliability of different power and velocity variables during the Smith machine bench press (BP) and bench press throw (BPT) exercises. Twenty-two healthy men conducted four testing sessions after a preliminary BP one-repetition maximum (1RM) test. In a counterbalanced order, participants performed two sessions of BP in one week and two sessions of BPT in another week. Mean propulsive power, peak power, mean propulsive velocity, and peak velocity at each tenth percentile (20–70% of 1RM) were recorded by a linear transducer. The within-participants coefficient of variation (CV) was higher for the load–power relationship compared to the load–velocity relationship in both the BP (5.3% vs. 4.1%; CV ratio = 1.29) and BPT (4.7% vs. 3.4%; CV ratio = 1.38). Mean propulsive variables showed lower reliability than peak variables in both the BP (5.4% vs. 4.0%, CV ratio = 1.35) and BPT (4.8% vs. 3.3%, CV ratio = 1.45). All variables were deemed reliable, with the peak velocity demonstrating the lowest within-participants CV. Based upon these findings, the peak velocity should be chosen for the accurate assessment of BP and BPT performance.  相似文献   
9.
[目的/意义]医暴舆论空间积聚的情感能量推动观点衍化并深刻影响事件发展趋势,识别不同维度的情感认知且关注能量特征可有效循迹医患冲突的情感焦点。[方法/过程]以情感维度为能量源、情感能量特征为能量波构建医暴舆论情感能量域空间模型,能量源基于关键词云划分为自我认知、民生民意、社会发展三大维度,能量波以各认知维度的情感倾向、情感强度与扩散速度综合刻画能量趋势,最终依据能量域模型立体剖析突发医暴事件舆论空间。[结果/结论]结果显示,能量域空间模型能够真实反映医暴舆论情感演化趋势;各能量源均持续积聚负向情感能量;民生民意为医暴舆论的情感焦点。  相似文献   
10.
This study compared the effects of two velocity loss thresholds during a power-oriented resistance training program on the mechanical capacities of lower-body muscles. Twenty men were counterbalanced in two groups (VL10 and VL20) based on their maximum power capacity. Both groups used the same exercises, relative intensity and repetition volume, only differing in the velocity loss threshold of each set (VL10: 10% vs. VL20: 20%). Pre- and post-training assessments included an incremental loading test and a 15-m linear sprint to assess the force- and load-velocity relationships and athletic performance variables, respectively. No significant between-group differences (P > 0.05) were observed for the force-velocity relationship parameters (ES range = 0.15–0.42), the MPV attained against different external loads (ES range = 0.02–0.18) or the 15-m sprint time (ES = 0.09). A high between-participants variability was reported for the number of repetitions completed in each training set (CV = 30.3% for VL10 and 29.4% for VL20). These results suggest that both velocity loss thresholds induce similar changes on the lower-body function. The high and variable number of repetitions completed may compromise the velocity-based approach for prescribing and monitoring the repetition volume during a power-oriented resistance training program conducted with the countermovement jump exercise.  相似文献   
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