Phase analysis in maximal sprinting: an investigation of step-to-step technical changes between the initial acceleration,transition and maximal velocity phases

Abstract

The aim of this study was to investigate spatiotemporal and kinematic changes between the initial acceleration, transition and maximum velocity phases of a sprint. Sagittal plane kinematics from five experienced sprinters performing 50-m maximal sprints were collected using six HD-video cameras. Following manual digitising, spatiotemporal and kinematic variables at touchdown and toe-off were calculated. The start and end of the transition phase were identified using the step-to-step changes in centre of mass height and segment angles. Mean step-to-step changes of spatiotemporal and kinematic variables during each phase were calculated. Firstly, the study showed that if sufficient trials are available, step-to-step changes in shank and trunk angles might provide an appropriate measure to detect sprint phases in applied settings. However, given that changes in centre of mass height represent a more holistic measure, this was used to sub-divide the sprints into separate phases. Secondly, during the initial acceleration phase large step-to-step changes in touchdown kinematics were observed compared to the transition phase. At toe-off, step-to-step kinematic changes were consistent across the initial acceleration and transition phases before plateauing during the maximal velocity phase. These results provide coaches and practitioners with valuable insights into key differences between phases in maximal sprinting.     

Gender Differences in Mathematics Self-concept Across the World: an Exploration of Student and Parent Data of TIMSS 2015

International Journal of Science and Mathematics Education - Using data from the Trends in International Mathematics and Science Study (TIMSS) 2015 assessment of fourth-grade students in 32...     

The importance of design in learning from node-link diagrams

Diagrams organize by location. They give spatial cues for finding and recognizing information and for making inferences. In education, diagrams are often used to help students understand and recall information. This study assessed the influence of perceptual cues on reading behavior and subsequent retention. Eighty-two participants were assigned to one of four versions of a node-link diagram. The diagram consisted of header cells on the left and on top. These header cells organized the information in the body cells, which were connected by arrows. We used a between-subjects design with diagram orientation (header types on top or on the left) and cues orientation (arrows top–down or left–right) as independent variables. Reading process was measured through eye-tracking. Learning performance was assessed with a post test. The results showed that perceptual cues and header content had an additive effect on reading behavior. The reading patterns were strongest when the arrows and category headers both pointed in the same direction. This was reflected in recall. Participants performed better on post-test questions oriented on categories.     

Adults'' Tolerance of Cries: An Experimental Investigation of Acoustic Features

Variations in the aversiveness of a newborn's distress cry were examined using experimental manipulation of 3 acoustic features of the cry (fundamental frequency, intonation, spectral complexity) and of the information given to subjects about the infant's health status. The subjects (N = 164 medical students) were allowed to control the sound pressure level (range: 50 dB [A]-105 dB[A]) of the different cry versions by repeatedly pressing a button (operant titration). For the nonmanipulated (original) cry version, the accepted sound pressure level decreased as fundamental frequency increased at above 610 Hz. This effect was modified by experimental manipulation of spectral complexity as well as intonation. A preference of intonated cries over monotonous cries was most pronounced between 534 and 686 Hz. Significant interactions of the information variable with the intonation and the complexity variables suggest that the listener's reaction to certain physical cry characteristics can be altered substantially by inducing different cognitive sets.     

School Size Effects on Achievement in Secondary Education Evidence from the Netherlands,Sweden and the USA 1

ABSTRACT

In this article the results of an investigation into the relation between school size and achievement are reported. The findings relate to mathematics achievement in Dutch, Swedish and American secondary education and to science achievement in the Netherlands. The analyses sought to provide an answer to the following questions:

(1) Is school size related to achievement independently of student background characteristics such as sex, achievement motivation, socio‐economic status and cognitive aptitude? (2) Is the effect of school size related to any of the aforementioned background characteristics? (3) Does the effect of school size on achievement differ between the educational systems of the Netherlands, Sweden and the USA? (4) Is the effect of school size the same for different measures of student achievement (mathematics versus science)?

It was hypothesized that school size would be most strongly related to achievement in the USA. The analyses, however, revealed little empirical evidence for the existence of school size effects on achievement in any of the three countries, possibly because school size and curriculum comprehensiveness are not strongly related in these countries.

Because the investigations involved the analysis of five separate datasets, the research outcomes revealed some useful additional information with respect to the robustness of the detected relations between the five covariates and student achievement.

     

Motivation and learning physics

Being involved in science education we cannot avoid confronting the problem of students' waning interest in physics. Therefore, we want to focus on arguments developed by new theoretical work in the field of motivation. Especially, we are attracted by the theory of motivation featured by Deci and Ryan, because it is related to an assumptions of human development similar to our own approach. Beneath elements of cognitive development, motivation is seen as a basic concept to describe students' learning in a physics classroom. German students at lower and upper secondary level regard physics as very difficult to learn, very abstract and dominated by male students. As a result physics at school continuously loses importance and acceptance although a lot of work has been done to modernise and develop the related physics courses. We assume that knowing about the influence of motivation on learning physics may lead to new insights in the design of classroom settings. Referring to Deci and Ryan, we use a model of motivation to describe the influence of two different teaching strategies (teacher and discourse oriented) on learning. Electrostatics was taught in year 8. The outcomes of a questionnaire which is able to evaluate defined, motivational states are compared with the interpretation of the same student's interaction in the related situation of the physics classroom. The scales of the questionnaire and the categories of analysis of the video-recording are derived from the same model of motivation.     

Students’ Preconceptions and Perceptions of Science-Oriented Studies

Do non-science, technology, engineering, and mathematics (STEM) students’ views about STEM studies correspond with how STEM students actually perceive these studies? This paper deals with this issue by comparing higher education students’ attitudes towards STEM studies between those who actually did a STEM study and those who did not. The attitudes of the first category of students have been referred to as perceptions and the attitudes of the second category as preconceptions. The study included 1,935 students in higher education. The results confirm both small and large differences between the preconceptions and perceptions, and show significant differences between suitably qualified students (i.e. eligible for STEM studies) and other students. At the end of this paper, we will discuss the implications of this study for future research and offer some suggestions for practice.