A biomechanical comparison of countermovement performance after short-term traditional and daily-undulated loaded vertical jump training

In order to assess lower extremity muscle mechanical properties in athletes, power-load characteristics during multi-joint tasks are frequently examined. This work compared 6 weeks of traditional (TP) and daily-undulated (DUP) periodized loaded countermovement jumping (CMJ). 20 amateur athletes (age: 24.2 ± 2.6 years, height: 175.6 ± 7.1 cm, body mass: 71.5 ± 7.7 kg, 10 males/10 females) exercised three times weekly using maximal CMJs with loads corresponding to 0%, 15% and 30% of body mass. Prior to the training period, subjects were once-only assigned by random to either the TP or DUP training scheme. Pre-to-post training, maximal center of mass (COM) -height, -take-off velocity, -power output and -impulse were compared during CMJ with additional loads corresponding to 0–30% of body mass. ANOVA (time * group) with repeated measures revealed significant (P < 0.05) temporal gains of maximal COM-height (2–11%), -take-off velocity (1–7%), -power (2–8%) and -impulse (3–9%) over most loading conditions for TP and DUP. However, ANOVA indicated no group effects for any outcome. Independent from the periodization model, maximal power output remained statistically unchanged with increased testing loads. For short-term conditioning periods, TP and DUP were equally effective in enhancing biomechanical jumping variables under varying loading conditions.     

Heart rate and movement pattern in street soccer for homeless women

Street soccer has been shown to be effective in improving cardiovascular and musculoskeletal fitness in homeless men, due to high heart rate (HR) and multiple intense actions. The purpose of this study was to investigate HR, movement pattern, rating of perceived exertion (RPE), flow and worry during street soccer for homeless women. Fifteen homeless women (30.3?±?5.0?years [± standard deviation, SD], 1.65?±?0.08?m, 65.1?±?11.0?kg, 5?±?4?years football experience) from three countries participated in 4?a-side street soccer games in Women’s Homeless World Cup 2015. Mean and peak HR were 174?±?7 and 188?±?10?beats per minute (bpm), respectively, and >160 bpm 76?±?23% of the playing time (11.1?±?2.6?min). Distance covered per minute was 68.6?±?8.9?m of which 82?±?14, 15?±?6 and 3?±?3% were covered with low- (0–9?km/h), moderate- (9–13?km/h) and high-speed (>13?km/h) running, respectively. The 43?±?5, 45?±?3 and 12?±?3% of the distance were covered running forward, sideways, and backward, respectively. Player Load was 9.2?±?1.7?arbitrary units (AU) per minute and the number of accelerations >1.5?ms^–2 was 15.3?±?2.7 per minute. The score for flow was high (5.5?±?0.8), whereas rating of perceived exertion (RPE) values (4.8?±?2.5) and the score for worry (4.6?±?1.3) were moderate. Street soccer for homeless women elicits high HR and a movement pattern comparable and for some parameters even higher than street soccer and recreational football for homeless and untrained men. Street soccer may be a suitable training intervention for homeless women, and especially moderate RPE and high flow score speaks in favour of an expectation of high participation and adherence.     

Knowledge sharing and rewards: a game-theoretical perspective

Shared databases are used as tools for knowledge management. But contributing knowledge to the database is a public-goods dilemma. Its specific features are multidimensionality of the goods, resource overlap, interdependency of group members and the lack of a marginal unit of return for individual contributions. An analytical model is presented describing the individual- and group-level payoff function. It shows that rewarding contributions with a cost-compensating bonus can be an effective solution not only at the individual level, but also at the group level. Whether or not a bonus system is self-supporting depends on the critical mass of people on average needing a contribution. This depends on the overlap of the people's resources and their interdependency.     

Development and reliability quantification of a novel test set-up for measuring footwear bending stiffness

Since footwear flexibility impacts functional design factors, numerous studies have investigated footwear bending stiffness. However, the various methods used to measure footwear bending stiffness have some limitations. Hence, the scope of this study was to develop and quantify the reliability of a novel test set-up for measuring footwear bending stiffness. A test set-up consisting of a hydraulic testing machine, a bending apparatus and a fixation unit was created that fulfilled the requirements specified in the initial phase of the study. The test set-up was evaluated by testing 15 different boots in three series of measurements. Bending stiffness of the boots ranged from 0.61 ± 0.03 to 2.38 ± 0.08 Nm/°. Two-way analysis of variance test yielded that the test set-up enabled the reliable measurement of footwear bending stiffness. Relative measurement uncertainty ranged from 1.3 to 6.1 %.     

Examining Middle School Students’ Engineering Design Processes in a Design Workshop

Design thinking has an important role in STEM education. However, there has been limited research on how students engage in various modalities throughout the design process in hands-on design tasks. To promote middle school students’ engineering literacy, it is necessary to examine the use of design modalities during design. Using a case study approach, we examine middle school students’ design stages and modalities during design activities. We also identify the patterns of design processes in the teams with different design outcomes. Drawing on theories in design thinking and embodied interaction, we proposed a framework and devised a video analysis protocol to examine students’ design stages and modalities. Middle school students attending a design workshop engaged in two design activities in teams of 3–4 people. The design sessions were video recorded and analyzed using the video analysis protocol. The teams engaged in the stages of planning, building, and testing, while employing the verbal, the visual, and the physical modalities. The teams that varied in design outcomes exhibited different patterns in the use of multiple modalities during the design stages. This study contributes to research on design thinking by proposing a framework for analyzing middle school students’ multimodal design processes and presenting data visualization methods to identify patterns in design stages and modalities. The findings suggest the necessity to examine students’ use of design modalities in the context of design stages and imply the potential benefits of using multiple modalities during design. The implications for future research and education practices are also discussed.

     

ECVET and ECTS credit equivalency in higher education – A bridge too far?

The implementation within Europe of a credit system for vocational education and training known as ECVET is a European Commission priority. The potential for permeability between the ECVET and European Credit Transfer and accumulation System (ECTS) was foreseen in the Recommendation to establish ECVET in 2009, while the Bruges Communique of 2010 called for the promotion of flexible links between vocational and higher education and increased coherence between ECVET and ECTS. To this end a significant number of EU-funded projects were undertaken to explore compatibility between ECVET and ECTS. This article reviews the findings of these projects and reflects on their success in terms of achieving this policy goal. These bridging projects identified several points of compatibility between the two credit systems and produced valuable tools and frameworks to facilitate such permeability. Achieving credit equivalency between ECVET and ECTS does not appear feasible, rather the evidence points to using a learning outcomes-based equivalency framework. However, this article calls into question the sustainability of these project results with regard to the lack of success in translating these findings into practice and the lack of co-ordinated efforts to implement these findings at a national or pan European level.     

Beyond linearity: Using IRT-scaled level models to describe the relation between prior proportional reasoning skills and fraction learning outcomes

Previous research on the role of prior skills like proportional reasoning skills for the development of mathematical concepts offers conclusions such as “more (prior skills) is better (for later learning).” Insights, which prior skill level goes along with which level of learning outcomes, may advance the understanding of the development of mathematical concepts. An exploratory approach is presented based on level models to describe the relation between symbolic proportional reasoning skills and fraction outcomes beyond linearity. Analyses draw on samples of German fourth to sixth graders from a scaling (2017, N = 325, 54.8% female) and longitudinal study (2018/2019, N = 436, 42.7% female). Particularly mastering natural and internal rational ratios in proportional reasoning seems relevant for successful fraction learning.