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Alexis Herbaut Pascale Chavet Maxime Roux Nils Guéguen Christophe Gillet Franck Barbier 《European Journal of Sport Science》2016,16(8):1121-1129
This study investigated the immediate effects of reducing the shoe drop (i.e. the difference between the heel and the forefoot height) on the kinematics and kinetics of the lower extremities of children tennis players performing a tennis-specific movement. Thirteen children tennis players performed a series of simulated open stance forehands wearing 3 pairs of shoes differing only in the drop: 0 (D0), 6 (D6) and the control condition of 12?mm (D12). Two embedded forceplates and a motion capture system were used to analyse the ground reaction forces and ankle and knee joint angles and moments of the leading lower limb. In D6 compared with D12, the peak impact force was reduced by 24% (p?=?.004) and the ankle was less dorsiflexed at foot strike (p?=?.037). In D0 compared with D12, the peak impact force was reduced by 17% (p?=?.049), the ankle was less dorsiflexed at foot strike (p?=?.045) and the knee was more flexed at foot strike (p?=?.007). In addition, 4 out of 13 participants (31%) presented a forefoot strike pattern for some of the trials in D0. No difference was observed across shoe conditions for the peak knee extensor moment (p?=?.658) or the peak ankle plantarflexor moment (p?=?.071). The results provide preliminary data supporting the hypothesis that for children tennis players, using a 6-mm lower shoe drop might reduce heel impact forces and thus limit potentially impact-related injuries. 相似文献
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Maxime Caru François Lalonde Hugo Gravel Chantal Daigle François Tournoux Vincent Jacquemet 《European Journal of Sport Science》2016,16(8):1005-1013
The protective action of remote ischaemic preconditioning (RIPC) has been demonstrated in the context of surgical interventions in cardiology. Application of RIPC to sports performance has been proposed, but its effect on the electrocardiogram (ECG) during exercise remains unknown. This exploratory study aims to measure the changes in ventricular repolarization observed during exercise following RIPC in healthy subjects. In an experimental randomized crossover study, 17 subjects underwent two bouts of constant load exercise tests at 75% and 115% of gas exchange threshold (GET). Prior to exercise, they were allocated to either control or RIPC intervention with four cycles of 5?min of ischaemia followed by 5?min of reperfusion. ECG was continuously recorded during the protocol. QT and RR intervals were measured every 30?s (on an average tracing of the preceding 10?s). Although the time course of RR intervals did not differ between the two interventions (p?=?.56 at 75% GET and p?=?.74 at 115% GET), a significant shortening of QT intervals (measured from Q onset to T end) was observed during exercise (mean?±?standard deviation of RIPC vs. control: ?32?±?19?ms at 75% GET (p?.001) and ?34?±?12?ms at 115% GET (p?.001)) as well as during recovery (?21?±?8?ms at 75% GET (p?.001) and ?16?±?11?ms at 115% GET (p?.001)). This effect was not present at rest. These RIPC-related changes were clearly identifiable on the QT–RR loops after hysteresis reduction. RIPC therefore induces heart rate-independent shortening of QT intervals that is revealed during exercise. 相似文献
3.
Alexis Herbaut Emilie Simoneau-Buessinger Franck Barbier Christophe Gillet Maxime Roux Nils Guéguen 《European Journal of Sport Science》2017,17(10):1261-1269
Compared to traditional tennis shoes, using 0-drop shoes was shown to induce an immediate switch from rear- to forefoot strike pattern to perform an open stance tennis forehand for 30% of children tennis players. The purpose of the study was to examine the long-term effects of a gradual reduction in the shoe drop on the biomechanics of children tennis players performing open stance forehands. Thirty children tennis players participated in 2 laboratory biomechanical test sessions (intermediate: +4 months and final: +8 months) after an inclusion visit where they were randomly assigned to control (CON) or experimental (EXP) group. CON received 12-mm-drop shoes twice, whereas EXP received 8?mm then 4-mm-drop shoes. Strike index indicated that all CON were rearfoot strikers in intermediate and final test sessions. All EXP were rearfoot strikers in intermediate test session, but half the group switched towards a forefoot strike pattern in final test session. This switch resulted in a decreased loading rate of the ground reaction force (?73%, p?=?.005) but increased peak ankle plantarflexors moment (+47%, p?=?.050) and peak ankle power absorption (+107%, p?=?.005) for these participants compared with CON. Biomechanical changes associated with the long-term use of partial minimalist shoes suggest a reduction in heel compressive forces but an increase in Achilles tendon tensile forces. 相似文献
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In the recent debate on the use of averages of ratios (AoR) and ratios of averages (RoA) for the compilation of field-normalized citation rates, little evidence has been provided on the different results obtained by the two methods at various levels of aggregation. This paper provides such an empirical analysis at the level of individual researchers, departments, institutions and countries. Two datasets are used: 147,547 papers published between 2000 and 2008 and assigned to 14,379 Canadian university professors affiliated to 508 departments, and all papers indexed in the Web of Science for the same period (N = 8,221,926) assigned to all countries and institutions. Although there is a strong relationship between the two measures at each of these levels, a pairwise comparison of AoR and RoA shows that the differences between all the distributions are statistically significant and, thus, that the two methods are not equivalent and do not give the same results. Moreover, the difference between both measures is strongly influenced by the number of papers published as well as by their impact scores: the difference between AoR and RoA is greater for departments, institutions and countries with low RoA scores. Finally, our results show that RoA relative impact indicators do not add up to unity (as they should by definition) at the level of the reference dataset, whereas the AoR does have that property. 相似文献
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Songning Zhang Michael Wortley Julia Freedman Silvernail Daniel Carson Maxime R. Paquette 《运动与健康科学(英文)》2012,1(2):114-120
PurposeThe purpose of this study was to examine effects of a sport version of a semi-rigid ankle brace (Element?) and a soft ankle brace (ASO) on ankle biomechanics and ground reaction forces (GRFs) during a drop landing activity in subjects with chronic ankle instability (CAI) compared to healthy subjects with no history of CAI.MethodsTen healthy subjects and 10 subjects who had multiple ankle sprains participated in the study as the control and unstable subjects, respectively. The CAI subjects were age, body mass index and gender matched with the control subjects. The arch index and ankle functions of the subjects were measured in a subject screening session. During the biomechanical test session, participants performed five trials of drop landing from 0.6 m, wearing no brace (NB), Element? brace and ASO brace. Simultaneous recording of three-dimensional kinematic (240 Hz) and GRF (1200 Hz) data were performed.ResultsThe CAI subjects had lower ankle functional survey scores. The arch index and deformity results showed greater arch deformity of Element? against a static load than in NB and ASO due to greater initial arch position held by the brace. CAI participants had greater eversion velocity than healthy controls. The ASO brace reduced the first peak vertical GRF whereas Element? increased 2nd peak vertical GRF. Element? brace reduced eversion range of motion (ROM) and peak eversion velocity compared to NB and ASO. In addition, Element? reduced dorsiflexion ROM and increased peak plantarflexion moment compared to NB and ASO.ConclusionResults of static arch measurements and dynamic ankle motion suggest that the restrictions offered by both braces are in part due to more dorsiflexed ankle positions at contact, and higher initial arch position and stiffer ankle for Element?. 相似文献
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Fatma Fourati-Jamoussi Michel J.F. Dubois Maxime Agnès Valérie Leroux Loïc Sauvée 《European Journal of Engineering Education》2019,44(4):570-588
ABSTRACTThe potential relationships between innovation and sustainability processes, in engineering education, is neither obvious nor simple, especially when innovation, generally speaking, is promoted regardless of sustainability. We used UniLaSalle (In January 2016, the ‘Institut Polytechnique LaSalle Beauvais’, a French engineering school, merged with another higher education engineering school (ESITPA, Rouen). Both campuses (Beauvais and Rouen) have a common name: UniLaSalle (www.unilasalle.fr). As the interview began during 2015, this article only describes the situation of the Beauvais campus.) as a ‘living Lab’ to identify and analyse the reasons for the integration of innovation and Sustainable Development (SD) in training programmes. The aim is to explore, in a perception and reflective approach, how SD can be understood as a driver for specific innovation attitudes in higher education engineering school. This paper adopts an empirical approach based on a qualitative study, using NVivo 9 software to analyse non-numerical data. Our research suggests that SD can be a structural driver for innovation if it is integrated in a transdisciplinarity approach and not just as a discipline per se. 相似文献
8.
Jacqui Gingras 《Learning Inquiry》2009,3(3):177-191
Inquiring into the theoretical underpinnings of dietetic curriculum provides a means for further understanding who dietitians
are (identity) and what dietitians do (performativity). Since dietetic curriculum exists as a structural influence on the
dietetic student identity, it is worth inquiring into how such a structure is theoretically informed, especially considering
that until now, this process has not be undertaken. This research attempts to illuminate how dietetic knowledge is generated
and how various institutional structures reinforce this knowledge. Since dietetic education in Canada is standardized by a
means of national accreditation, the accreditation texts were analyzed following a poststructural discourse analysis method.
Those aspects of the Accreditation Manual concerning dietetic education were scrutinized to illuminate the presence/absence of curricular theory, knowledge assumptions,
and educational values. Findings of the discourse analysis indicate that there is no explicit curricular theory framing dietetic
education, learning processes are sequential and apolitical, and dietetic knowledge is decontextualized from the social world.
These findings have implications for dietetic education, the scholarship of teaching and learning within the profession, and
dietetic epistemology. With further attention to these issues it is hoped that dietetic educators will be encouraged to reflect
on the historical and theoretical foundations of their curricula and will consider how teaching and learning, and ultimately
dietetic knowledge could be enhanced through a socially integrated feminist science of food and nutrition. 相似文献
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Maxime Ouellet 《The Information Society》2013,29(1):20-27
Beginning with a reading of Marx proposed by the critical theory of value, the assumptions of Fuchs (2010) and Arvidsson and Colleoni (2012) in the debate on value creation in informational capitalism are analyzed. The theorization of immaterial labor proposed by these authors is limited in its capacity to articulate a radical critique of political economy. Since the immaterial labor theory is marked by the absence of a dialectical critique of knowledge forms constituted under capitalism, it cannot advance Marx's push for a critique of the categories of political economy. The dynamics of capitalism entail a process of alienation that is not limited to exploiting the work done immediately by the producers; they also generate an alienation of forms of knowledge: the alienation of the “general intellect” itself. 相似文献