Motor variability in sports: A non-linear analysis of race walking     

Ezio Preatoni  Manuela Ferrario  Giulia Donà  Joseph Hamill  Renato Rodano 《Journal of sports sciences》2013,31(12):1327-1336

Abstract

This aim of this study was to analyse the nature of movement variability and to assess whether entropy measures may represent a valuable synthetic index of neuromuscular organization. The regularity of kinematic/kinetic time series during race walking, the changes in the structure of intra-individual variability over the test session, and the influence of athletic skill in (inter)national rank athletes were investigated. Motion analysis techniques were used. Sample entropy (SampEn) was adopted to examine fluctuations in lower limb angles and ground reaction forces. The regularity of both original and surrogate time series was assessed and compared, by estimating SampEn, to verify the presence of non-linear features in movement variability. SampEn was statistically lower in the original data than in surrogates. In contrast, the regularity of time series did not change significantly throughout the subsequent intra-individual repetitions. Hip and ankle joint angles and vertical ground reaction force manifested increased entropy for skilled athletes. Results suggest that race walking variability was not only the product of random noise but also contained information about the inherent propriety of the neuro-musculo-skeletal system. Furthermore, they provide some indications about neuromuscular control of the lower limb joints during race walking gait, and about the differences between more and less skilled individuals.  相似文献   

List of Reviewers     

Coral Falco  Javier Molina-García  Octavio Álvarez  Isaac Estevan 《Sports biomechanics / International Society of Biomechanics in Sports》2013,12(4):381-382

The aim of this study was to investigate the effects of target distance on temporal and impact force parameters that are important performance factors in taekwondo kicks. Forty-nine taekwondo athletes (age = 24.5 ± 5.9 years; mass = 79.9 ± 10.8 kg) were recruited: 13 male experts, 21 male novices, 8 female experts, and 6 female novices. Impact force, reaction time, and execution time were computed. Three-way repeated measure ANOVAs revealed significant ‘distance’ effect on impact force, reaction time, and execution time (p = 0.001). Comparisons between distance conditions revealed that taekwondo athletes kicked with higher impact force from short distance (17.6 ± 7.5 N/kg) than from long distance (13.1 ± 5.7 N/kg) (p < 0.001), had lower reaction time from short distance (498 ± 90 ms) and normal distance (521 ± 111 ms) than from long distance (602 ± 121 ms) (p < 0.001), and had lower execution time from short distance (261 ± 69 ms/m) than from normal distance (306 ± 105 ms/m) or from long distance (350 ± 106 ms/m) (p = 0.003 and p < 0.001, respectively). In conclusion, target distance affected the kick performance; as distance increases, impact force decreased and reaction time increased. Therefore, when reaction to a simple visual stimulus is needed, kicking from a long distance is not recommended, as longer time is required to respond.  相似文献   

Pre-service Teachers’ False Beliefs in Superstitions and Pseudosciences in Relation to Science and Technology     

Fuertes-Prieto  Miguel Ángel  Andrés-Sánchez  Santiago  Corrochano-Fernández  Diego  Urones-Jambrina  Carmen  Delgado-Martín  Mª Laura  Herrero-Teijón  Pablo  Ruiz  Camilo 《Science & Education》2020,29(5):1235-1254

Science & Education - In order to increase scientific competence within the general population, it is important that teachers and educators have a realistic image of science and scientists,...  相似文献   

Combining verbal and visual cueing: Fostering learning pictorial content by coordinating verbal explanations with different types of visual cueing     

Glaser  Manuela  Schwan  Stephan 《Instructional Science》2020,48(2):159-182

Instructional Science - Multimedia learning scenarios in which a picture is the main focus often use combinations of verbal and visual cueing. Based on models of picture processing and multimedia...  相似文献   

What do we learn from docutainment? Processing hybrid television documentaries   总被引：1，自引：0，他引：1  

Manuela Glaser  Bärbel Garsoffky Stephan Schwan 《Learning and Instruction》2012,22(1):37-46

This study examined how hybrid documentary formats, which embed educational contents into narratives, are cognitively processed. Based on existing research and theories, two reception modes were identified: processing with a focus on the narrative plotline and processing with a focus on the thematic structure. In two experiments, two markers of narrative processing could be found for hybrid television documentaries: the experience of transportation and the narrative distance effect. In the first experiment, it could be shown that re-enactments and personal variables enhance the experience of transportation. The second experiment confirmed the narrative distance effect, which occurs independently of reception goals. This means that educational facts which are closely tied to the narrative plotline were learned better than distant facts, regardless of whether the recipients watched the documentary for information or entertainment purposes. The study supplements prior theories on hybrid processing and provides conditions under which narratives are appropriate for learning.  相似文献   

Brain,Brow, and Booty: Latina Iconicity in U.S. Popular Culture     

ISABEL MOLINA GUZMÁN  ANGHARAD N. VALDIVIA 《The Communication Review》2013,16(2):205-221

We were shooting on the steps of the Metropolitan Museum one night. It was lit romantically, and Jennifer was wearing an evening gown, looking incredibly stunning. Suddenly there must have been a thousand people screaming her name. It was like witnessing this icon. (Ralph Fiennes in the New York Times, 2002, p. 16, emphasis added)

This stamp, honoring a Mexican artist who has transcended “la frontera” and has become and icon to Hispanics, feminists, and art lovers, will be a further reminder of the continuous cultural contributions of Latinos to the United States. (Cecilia Alvear, President of National Association of Hispanic Journalists (NAHJ) on the occasion of the introduction of the Frida Kahlo U.S. postage st& 2001; emphasis added)

“Nothing Like the Icon on the Fridge” (column about Salma Hayek’s Frida by Stephanie Zacharek in the New York Times, 2002 Zacharek, S. 2002. The New Season/Movies; Nothing Like the Icon on the Fridge. The New York Times, : 41 Sep.8.Section ZA [Google Scholar]).  相似文献   

Spanish Secondary-School Science Teachers’ Beliefs About Science-Technology-Society (STS) Issues     

Ángel Vázquez-Alonso  Antonio García-Carmona  María Antonia Manassero-Mas  Antoni Bennàssar-Roig 《Science & Education》2013,22(5):1191-1218

This study analyzes the beliefs about science-technology-society, and other Nature of Science (NOS) themes, of a large sample (613) of Spanish pre- and in-service secondary education teachers through their responses to 30 items of the Questionnaire of Opinions on Science, Technology and Society. The data were processed by means of a multiple response model to generate the belief indices used as the bases for subsequent quantitative and qualitative analyses. Other studies have reported a negative profile of teachers’ understanding in this area, but the diagnosis emerging from the present work is more complex. There was a mix of appropriate beliefs coexisting with others that are inappropriate on the topics analyzed. The overall assessment, however, is negative since clearly teachers need to have a better understanding of these questions. There were scant differences between the pre- and in-service teachers, and hence no decisive evidence that the practice of teaching contributes to improving the in-service teachers’ understanding. These results suggest there is an urgent need to bring the initial and continuing education of science teachers up to date to improve their understanding of these topics of science curricula, and thus improve the teaching of science.  相似文献   

Teachers’ Concepts of Spatial Scale: An international comparison     

M. Gail Jones  Manuela Paechter  Chiung-Fen Yen  Grant Gardner  Amy Taylor  Thomas Tretter 《International Journal of Science Education》2013,35(14):2462-2482

Metric scale is an important concept taught as part of science curricula across different countries. This study explored metric and relative (body-length) scale concepts of inservice (N?=?92) and preservice (N?=?134) teachers from Austria, and Taiwan, and their concepts were compared with those of teachers from the USA. Participants completed three assessments: the Scale Anchoring Objects (SAO), Scale of Objects Questionnaire (SOQ), and a subsample of participants were interviewed with the Learning Scale Interview. A Rasch analysis was conducted with the SAO and SOQ and results showed that the Rasch model held for these assessments, indicating that there is an underlying common dimension to understanding scale. Further analyses showed that accuracy of knowledge of scale measured by the SAO and SOQ was not related to professional experience. There were significant differences in teachers’ accuracy of scale concepts by nationality. This was true for both metric and body-length SAO assessments. Post hoc comparisons showed that the Austrian and Taiwanese participants were significantly more accurate than the US sample on the SAO and SOQ. The Austrian participants scored significantly higher than the US and the Taiwanese participants. The results of the interviews showed that the Taiwanese experienced teacher participants were more likely to report learning size and scale through in-school experiences than the Austrian or the US participants. US teachers reported learning size and scale most often through participating in hobbies and sports, Taiwanese teachers reported learning scale through sports and reading, and Austrian teachers most often noted that they learned about scale through travel.  相似文献   

Being highly internationalised strengthens your reputation: an empirical investigation of top higher education institutions     

Blanca L. Delgado-Márquez  M. Ángeles Escudero-Torres  Nuria E. Hurtado-Torres 《Higher Education》2013,66(5):619-633

In an educational context characterised by globalisation, reputation constitutes a crucial issue for today’s higher education institutions. Internationalisation of higher education is often seen as a potential response to globalisation and, consequently, higher education has become increasingly internationalised during the past decade. In this paper, we investigate the relationship between internationalisation and reputation in top higher education institutions. Results reveal that internationalisation positively influences a university’s reputation but also moderates the relationship between the institution’s reputation and its institutional performance with regard to research quality, teaching quality and graduate employability.  相似文献   

Aerobic fitness and academic achievement: A systematic review and meta-analysis     

Celia Álvarez-Bueno  Charles H Hillman  Mairena Sánchez-López  Diana P. Pozuelo-Carrascosa  Vicente Martínez-Vizcaíno 《Journal of sports sciences》2020,38(5):582-589

ABSTRACT

This study aims to quantify the association between aerobic fitness and academic achievement, and determine how different aerobic fitness tests and individual demographic characteristics may modify this association. It includes 41 cross-sectional and 7 longitudinal studies focusing on children and adolescents, from MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, Cochrane Database and Web of Science. Pooled effect sizes (ES) were estimated for the association between aerobic fitness and specific domains of academic achievement. Subgroup analyses and meta-regressions were based on aerobic fitness tests and demographic characteristics. The ES for the association between aerobic fitness with language/reading-skills, mathematics-related skills and composite scores, were 0.23 (95% CI: 0.12; 0.34); 0.27 (95% CI: 0.19; 0.36) and 0.28 (95% CI: 0.12; 0.45), respectively. Subgroup analyses by aerobic fitness test modified these associations; additionally, analyses by sex or age showed differences between boys and girls as well as between children and adolescents. Finally, meta-regressions revealed a slight effect of body mass index on these associations. Cardiorespiratory fitness is positively associated with academic achievement. Associations were dependent on demographic and aerobic fitness test characteristics, being stronger in boys than in girls, and in children than in adolescents.

Systematic review registration: PROSPERO CRD42017069677  相似文献