Straight sprinting is the most frequent action in goal situations in professional football

Abstract

The present study aimed to analyse the influence of speed and power abilities in goal situations in professional football.

During the second half of the season 2007/08, videos of 360 goals in the first German national league were analysed by visual inspection. For the assisting and the scoring player the situations immediately preceding the goal were evaluated. The observed actions were categorised as: no powerful action, rotation (around the body's centre-line), straight sprint, change-in-direction sprint, jump, or a combination of those categories.

Two hundred and ninety-eight (83%) goals were preceded by at least one powerful action of the scoring or the assisting player. Most actions for the scoring player were straight sprints (n = 161, 45% of all analysed goals, P < 0.001) followed by jumps (n = 57, 16%), rotations and change-in-direction sprints (n = 22, 6% each). Most sprints were conducted without an opponent (n = 109, P < 0.001) and without the ball (n = 121, P < 0.001). Similarly, for the assisting player the most frequent action was a straight sprint (n = 137, P < 0.001) followed by rotations (n = 28), jumps (n = 22) and change-in-direction sprints (n = 18). The straight sprints were mostly conducted with the ball (n = 93, P = 0.003).

In conclusion, straight sprinting is the most frequent action in goal situations. Power and speed abilities are important within decisive situations in professional football and, thus, should be included in fitness testing and training.     

Dynamics of mental model construction from text and graphics

When students read for learning, they frequently are required to integrate text and graphics information into coherent knowledge structures. The following study aimed at analyzing how students deal with texts and how they deal with graphics when they try to integrate the two sources of information. Furthermore, the study investigated differences between students from different school types and grades. Forty students from grades 5 and 8 from higher track and lower track of the German school system were asked to process and integrate texts and graphics in order to answer items from different levels of a text–picture integration taxonomy. Students’ eye movements were recorded and analyzed. Results suggest fundamentally different functions of text and graphics, which are associated with different processing strategies. Texts are more likely to be used according to a coherence-formation strategy, whereas graphics are more likely to be used on demand as visual cognitive tools according to an information-selection strategy. Students from different tracks of schooling revealed different adaptivity with regard to the requirements of combining text and graphic information.     

Between-limb asymmetry in kinetic and temporal characteristics during bilateral plyometric drop jumps from different heights

ABSTRACT

This study investigated the between-limb asymmetry in kinetic and temporal characteristics during bilateral plyometric drop jumps from different heights. Seventeen male basketball players performed drop jumps from 3 heights on two platforms in randomized orders. Vertical ground reaction force data were analysed with respect to the lead limb (i.e. the limb stepping off the raised platform first) and trail limb. Peak forces and loading rates of each limb were calculated. The absolute time differential between the two limbs at initial ground contact and takeoff were determined. The frequency of symmetrical landing and taking off with “both limbs together” were counted using 3 time windows. Results showed that the lead limb displayed higher peak forces and loading rates than the trail limb across all heights (p <.05). As drop height increased, the absolute time differentials decreased at initial ground contact (p <.001) but increased at takeoff (p =.035). The greater the preset time window, the more landings and takeoffs were classified as bilaterally symmetrical. In conclusion, higher drop heights allowed subjects to become more bilaterally symmetrical in the timing of landing but this reduction in temporal asymmetry did not accompany with any reduction in kinetic asymmetry.     

Will you be my friend? A multilevel network analysis of friendships of students with and without special educational needs backgrounds in inclusive classrooms

The objective of this study was to determine the relationship between having a special educational needs background (SEN) and the likelihood of having friends in inclusive classes. We assumed that a combination of individual, dyadic and contextual variables can sufficiently explain the relation between a SEN diagnosis and the likelihood of friendship. Data analysis was based on a cross-sectional sample of students (N = 1241) in second and third grade primary-school classes. To address the different levels adequately, the present study improves upon previous research in two ways: First, the sociometric data were analyzed with the p2 model, a specialized multilevel network model. Second, the study focused solely on friendships and emphasized the concept’s unique features with respect to inclusive education. Data analysis indicated that students with SEN had a decreased probability of becoming friends with their classmates compared to students without SEN. Even when individual, dyadic, and contextual variables were included into the model, the association between a SEN diagnosis and the likelihood of friendship persisted. The implications of the results are discussed with respect to their implications for inclusive teaching practice.     

Academic sell-out: how an obsession with metrics and rankings is damaging academia

Increasingly, academics have to demonstrate that their research has academic impact. Universities normally use journal rankings and journal impact factors to assess the research impact of individual academics. More recently, citation counts for individual articles and the h-index have also been used to measure the academic impact of academics. There are, however, several serious problems with relying on journal rankings, journal impact factors and citation counts. For example, articles without any impact may be published in highly ranked journals or journals with high impact factor, whereas articles with high impact could be published in lower ranked journals or journals with low impact factor. Citation counts can also be easily gamed and manipulated, and the h-index disadvantages early career academics. This paper discusses these and several other problems and suggests alternatives such as post-publication peer review and open-access journals.     

Does 3D Make Sense for Hollywood? The Economic Implications of Adding a Third Dimension to Hedonic Media Products

This article examines the economic effect of the 3D feature on movie success by using secondary data from all movies released in digital 3D between 2004 and 2011, and a 2D control sample. Using propensity score matching, the authors provide evidence for a sample selection bias that leads to an overestimation of the 3D effect if not accounted for. Matching results show that 3D movies are, on average, not economically advantageous when compared with 2D “twins.” However, subsequent weighted least squares regression analyses find that the impact of 3D on movie success varies in a non-linear, inverted U-shaped way with a “trend” variable that measures the point in time of a movie release and with a number of movie genres. A post-hoc analysis shows that a consumer's decision to attend a 3D screening of a 3D movie (instead of a 2D screening) is influenced by several factors, including whether the film is originally shot in 3D or the 3D element is added during postproduction.