Effects of muscle-tendon length on joint moment and power during sprint starts

The aim of this study was to examine the effects of muscle-tendon length on joint moment and power during maximal sprint starts. Nine male sprinters performed maximal sprint starts from the blocks that were adjusted either to 40 degrees or 65 degrees to the horizontal. Ground reaction forces were recorded at 833 Hz using a force platform and kinematic data were recorded at 200 Hz with a film camera. Joint moments and powers were analysed using kinematic and kinetic data. Muscle - tendon lengths of the medial gastrocnemius, soleus, vastus medialis, rectus femoris and biceps femoris were calculated from the set position to the end of the first single leg contact. The results indicated that block velocity (the horizontal velocity of centre of mass at the end of the block phase) was greater (P < 0.01) in the 40 degrees than in the 65 degrees block angle condition (3.39 +/- 0.23 vs. 3.30 +/- 0.21 m . s(-1)). Similarly, the initial lengths of the gastrocnemius and soleus of the front leg in the block at the beginning of force production until half way through the block phase were longer (P < 0.001) in the 40 degrees than in the 65 degrees block angle condition. The initial length and the length in the middle of the block phase were also longer in the 40 degrees than in the 65 degrees block angle condition both for both the gastrocnemius (P < 0.01) and soleus (P < 0.01-0.05) of the rear leg. In contrast, the initial lengths of the rectus femoris and vastus medialis of the front leg were longer (P < 0.05) in the 65 degrees than in the 40 degrees block angle condition. All differences gradually disappeared during the later block phase. The peak ankle joint moment (P < 0.01) and power (P < 0.05) during the block phase were greater in the 40 degrees than in the 65 degrees block angle condition for the rear leg. The peak ankle joint moment during the block phase was greater (P < 0.05) in the 40 degrees block angle for the front leg, whereas the peak knee joint moment of the rear leg was greater (P < 0.01) in the 65 degrees block angle condition. The results suggest that the longer initial muscle-tendon lengths of the gastrocnemius and soleus in the block phase at the beginning of force production contribute to the greater peak ankle joint moment and power and consequently the greater block velocity during the sprint start.     

Learning design and learning analytics in mobile and ubiquitous learning: A systematic review

Mobile and Ubiquitous Learning (m/u-learning) are finding an increasing adoption in education. They are often distinguished by hybrid learning environments that encompass elements of formal and informal learning, in activities that happen in distributed settings (indoors and outdoors), across physical and virtual spaces. Despite their purported benefits, these environments imply additional complexity in the design, monitoring and evaluation of learning activities. The research literature on learning design (LD) and learning analytics (LA) has started to deal with these issues. This paper presents a systematic literature review of LD and LA, in m/u-learning. Apart from providing an overview of the current research in the field, this review elicits elements of common ground between both communities, as shown by the similar learning contexts and complementary research contributions, and based on the research gaps, proposes to: address m/u-learning beyond higher education settings, reinforce the connection between physical and virtual learning spaces, and more systematically align LD and LA processes.     

Group-based intervention on attention and executive functions in the school context

The objective of the study was to examine the effects of a group-based behavioural, cognitive and skills training intervention (Maltti) provided in schools for elementary school pupils with attention and executive function (EF) deficits. The treatment effects were identified by comparing an intervention group (n = 46) with a waitlist control group (n = 26). Specific effects of the intervention on behavioural deficits in attention and EF in a classroom setting as well as on academic skills were examined. Our analysis indicated that significant intervention effects could be found in the behavioural manifestation of attentional and executive skills in the classroom setting among children (n = 30) who were evaluated as having moderate symptoms in the pre-intervention assessment. Positive effects of the intervention were also observed in arithmetic and reading skills. The severity level of pre-intervention attention and EF deficits did not moderate the results observed in the academic skills tests. The results of this study suggest that a combination of behavioural, cognitive and skills training methods applied in a school context can be effective in reducing attention and EF problems and enhancing the academic performance of children with attention and EF deficits.     

Specific predictors of length and frequency effects in German beginning readers: testing component processes of sublexical and lexical reading in the DRC

Reading and Writing - Reading a word requires several component processes. The dual route cascaded (DRC) model provides a characterization of these component processes and their involvement in...     

Improving Group Work Practices in Teaching Life Sciences: Trialogical Learning

Research in Science Education - Trialogical learning, a collaborative and iterative knowledge creation process using real-life artefacts or problems, familiarizes students with working life...     

Quality assessment in diverse disciplinary settings

Basic work in universities is carried out in departments representing diverse disciplinary communities. While tasks, goals, perspectives, and social values may vary considerably between different disciplines, it is difficult to find research texts dealing with the question whether, and how, such differences should be taken into account in quality management. The paper is based on a recent study on quality management in diverse disciplinary settings, in which thirty-three interviews have been carried out in Finland and in the UK, and on the author's previous studies on the disciplines under study. The paper provides some preliminary interpretations of the effects of basic disciplinary features on the suitability of approaches of quality assessment in four diverse disciplines (physics, biology, sociology and history).     

Questions,Instructions, and Modes of Listening in the Joint Production of Guided Action: A Study of Student–Teacher Collaboration in Handicraft Education

This article concerns a central issue in education as an institutional activity: instructions and their role in guiding student activities and understanding. In the study, we investigate the tensions between specifics and generalities in the joint production of guided action. This issue is explored in the context of handicraft education—or more specifically, a teacher education program in sloyd. Handicraft is particularly interesting when analysing instructions, since the purposes of instructions are often dual: (1) to bring about a broad, instructionally relevant mode of understanding artefacts (including their origin, aesthetics, etc.), and (2) to guide manual action in the production of such artefacts. In the article, a detailed analysis of an instructional sequence, which includes the production of two distinct types of embroideries, is reported. The analysis sheds light on the role of educational examples in sloyd as well as on the related issue concerning the distinctive difference between the activities of listening to instructions as part of a lecture, on the one hand, and, on the other, listening to instructions in order to be able to accomplish a task.     

Not Read,but Nevertheless Solved? Three Experiments on PIRLS Multiple Choice Reading Comprehension Test Items

Multiple-choice (MC) reading comprehension test items comprise three components: text passage, questions about the text, and MC answers. The construct validity of this format has been repeatedly criticized. In three between-subjects experiments, fourth graders (N ₁ = 230, N ₂ = 340, N ₃ = 194) worked on three versions of MC items from the Progress in International Reading Literacy Study 2001 reading comprehension test with relevant components successively deleted: “original version” (text, questions, MC-answers), “version without text” (questions, MC-answers), “version without text and without questions” (only MC-answers). Answering correctly the MC items became more difficult as the relevant information was eliminated. In the two narrative fictional texts presented, the students' performance of the version without text was not better than chance. Conversely in the informational (fictional) text, the students' performance of the version without text was better than chance. In the third condition, students' performance was never better than chance.