The effect of unilateral balance training on postural control of the contralateral limb     

Christian Schlenstedt  Michel Arnold  Martina Mancini  Günther Deuschl  Burkhard Weisser 《Journal of sports sciences》2017,35(22):2265-2271

To investigate the impact of unilateral balance training on postural control of the trained and contralateral limb in healthy elderly. Fifty-one healthy old adults were randomly assigned into training group (TG) and control group (CG). Participants of the TG performed unilateral balance training (dominant (DOM) leg) over 4 weeks (4×/week). Centre of pressure analysis was performed at baseline, 5 weeks follow-up and 9 weeks follow-up under the following conditions: (1) one-leg stance without additional task, (2) one-leg stance with motor task and (3) one-leg stance with cognitive task. From baseline to 5 weeks follow-up, a mixed analysis of variance detected a significant time × group interaction for the DOM leg (P < 0.05), indicating higher improvement of the TG in comparison to CG. No significant interaction effect was found for the non-DOM leg. Within the TG, the non-DOM leg significantly improved in mean velocity (P = 0.001) and anterior–posterior range (P < 0.001). Unilateral balance training was effective to improve postural control of the trained leg. The effect on the contralateral leg was small and not significant within this study design. Improvements were retained after 4 weeks without training. A tendency is given that unilateral balance training might be beneficial to improve postural control of the contralateral leg.  相似文献   

Is salivary cortisol moderating the relationship between salivary testosterone and hand-grip strength in healthy men?     

Blair T. Crewther  Andrew G. Thomas  Steve Stewart-Williams  Liam P. Kilduff  Christian J. Cook 《European Journal of Sport Science》2017,17(2):188-194

This study examined the moderating effect of cortisol (C) on the relationship between testosterone (T) and hand-grip strength (HGS) in healthy young men. Sixty-five males were monitored for salivary T, C and HGS before and 15?min after a short bout (5?×?6-s trials) of sprint cycling exercise. Sprint exercise promoted (p?<?.05) positive changes in T (6.1?±?24.9%) and HGS (3.4?±?7.5%), but a negative C response (?14.4?±?33.1%). The T and C measures did not independently predict HGS, but a significant T?×?C interaction was found in relation to these outcomes. Further testing revealed that pre-test T and HGS were negatively associated (p?<?.05), but only in men with high C levels. The exercise changes in T and HGS were also negatively related in men with low C levels (p?<?.05), but no relationship was seen in men with high C levels. In summary, complex relationships between T and HGS emerged when considering C as a moderating variable. The pre-test combination of high C and low T levels favoured absolute HGS, whereas low pre-test C levels and a smaller T change were linked to larger HGS changes. These associations suggest that, in the current format, T is not necessarily anabolic to muscle strength in healthy young men. Such complexities could also explain some of the inconsistent T relationships with physical performance in lesser trained male populations.  相似文献   

Accuracy between optical and inertial motion capture systems for assessing trunk speed during preferred gait and transition periods     

Martin Kokholm Fleron  Niels Christian Hauerbach Ubbesen  Francesco Battistella  David Leandro Dejtiar 《Sports biomechanics / International Society of Biomechanics in Sports》2019,18(4):366-377

Motion capture through inertial sensors is becoming popular, but its accuracy to describe kinematics during changes in walking speed is unknown. The aim of this study was to determine the accuracy of trunk speed extracted using an inertial motion system compared to a gold standard optical motion system, during steady walking and stationary periods. Eleven participants walked on pre-established paths marked on the floor. Between each lap, a 1-second stationary transition period at the initial position was included prior to the next lap. Resultant trunk speed during the walking and transition periods were extracted from an inertial (240 Hz sampling rate) and an optical system (120 Hz sampling rate) to calculate the agreement (Pearson’s correlation coefficient) and relative root mean square errors between both systems. The agreement for the resultant trunk speed between the inertial system and the optical system was strong (0.67 < r ≤ 0.9) for both walking and transition periods. Moreover, relative root mean square error during the transition periods was greater in comparison to the walking periods (>40% across all paths). It was concluded that trunk speed extracted from inertial systems have fair accuracy during walking, but the accuracy was reduced in the transition periods.  相似文献   

Core executive functions are selectively related to different facets of motor competence in preadolescent children     

Sebastian Ludyga  Uwe Pühse  Markus Gerber  Christian Herrmann 《European Journal of Sport Science》2019,19(3):375-383

Background: Although accumulating evidence suggests that motor and cognitive development is interrelated, only a few studies have investigated links between executive function and motor control. Therefore, the present cross-sectional study examined the relationship between motor competences and core components of executive functioning, including inhibitory control, working memory and cognitive flexibility. Methods: In 89 preadolescent children, motor competences were assessed using the MOBAK-5 test battery. Additionally, all participants completed computer-based versions of the Flanker task, which included standard and switch blocks, and the 2-Back task. Results: Partial correlations (correcting for age, gender and body mass index) revealed that locomotor skills were associated with the adjusted hit-rate on the 2-Back task (r?=?0.34) whereas object control was linked with conflict score on the Flanker task (r?=??0.39). In contrast, there was no correlation between switch costs and motor competences. Conclusion: In preadolescent children, high competences in locomotor skills and object control skills are associated with high performance on specific executive function tasks. This finding supports the current view that motor competences and cognitive control share some common underlying processes.  相似文献   

“Good” organisational reasons for “ineffectual” research: Evaluating summative evaluation of museums and galleries     

Maurice Davies  Christian Heath 《Cultural Trends》2014,23(1):57-69

New displays, galleries and exhibitions in museums and galleries are increasingly subject to summative evaluations, wide-ranging investigations that examine how visitors respond to and engage with particular initiatives. These evaluations provide insights into the behaviour and attitudes of visitors and the ways in which particular exhibitions, exhibits and information resources facilitate engagement, participation and learning. Unfortunately, however, summative evaluation has relatively little impact either on the particular initiative or more generally in contributing to our knowledge of visitor behaviour and understanding of best practice. In this paper, we suggest that the relative lack of impact of summative evaluation is not primarily due to any methodological shortcomings or the idiosyncrasies of some of the approaches that are used. Rather, the organisational and institutional context in which summative evaluation is commissioned, undertaken and received can impose contradictory demands and undermine the opportunity of learning from and applying the findings of evaluation.  相似文献   

The Stanford-Binet mental age and the WISC-R test age: A comparison study     

Geoffrey W. Sutton  James R. Koller  Barry T. Christian 《Psychology in the schools》1982,19(3):287-289

The Stanford-Binet and WISC-R were administered to 100 students (CA—6 to 15 years) to determine the comparability of the age equivalent scores obtained from each test. The limited range of test age (TA) values in the WISC-R Manual required the use of extrapolated values for some subjects. The results indicated that, for subjects whose WISC-R scores fell within the TA table, the Binet MAs and WISC-R TAs were comparable (p>.05). However, when the use of extrapolated TAs was required, the scores were not comparable (p<.05). Implications for test age and mental age equivalency were discussed.  相似文献   

Tracing the links between science and technology: An exploratory analysis of scientists’ and inventors’ networks   总被引：1，自引：0，他引：1  

Stefano Breschi  Christian Catalini 《Research Policy》2010,39(1):14-26

The paper provides an exploratory analysis of the research networks linking scientists working in an open science environment, and researchers involved in the private technology domain. The study combines data on scientific co-authorship with data on patent co-invention, at the level of individual researchers, for three science-intensive technology fields, i.e. lasers, semiconductors and biotechnology, in order to assess the extent of the overlap between the two communities and to identify the role of key individuals in the process of knowledge transfer. Our findings reveal that the extent of the connectedness among scientists and inventors is rather large, and that particular individuals, i.e. authors-inventors, who act as gatekeepers and bridge the boundaries between the two domains, are fundamental to ensuring this connectivity. These individuals tend to occupy prominent positions in the scientific and the technological networks. However, our results also show maintaining a very central position in the scientific network may come at the expense of being able to fill a similarly central position in a technological network (and vice versa). Finally, preliminary analysis of the institutional origins of authors-inventors shows that one characteristic, distinctive of Europe compared to the United States, is associated with the relatively lower involvement of corporate scientists at the intersection between the two worlds of science and technology.  相似文献   

On organs & organizations     

Christian Schmidhauser 《Performance Improvement》2004,43(6):20-23

  相似文献   

Affective training for bottom line results     

Miki Lane  Christian Mangin 《Performance Improvement》1991,30(9):1-6

  相似文献   

An adaptive human performance system for adaptive enterprises     

Christian Joye 《Performance Improvement》2005,44(6):38-43

  相似文献