A descriptive study of step alignment and foot positioning relative to the tee by professional rugby union goal-kickers

This study describes foot positioning during the final two steps of the approach to the ball amongst professional rugby goal-kickers. A 3D optical motion capture system was used to test 15 goal-kickers performing 10 goal-kicks. The distance and direction of each step, as well as individual foot contact positions relative to the tee, were measured. The intra- and inter-subject variability was calculated as well as the correlation (Pearson) between the measurements and participant anthropometrics. Inter-subject variability for the final foot position was lowest (placed 0.03 ± 0.07 m behind and 0.33 ± 0.03 m lateral to the tee) and highest for the penultimate step distance (0.666 ± 0.149 m), performed at an angle of 36.1 ± 8.5° external to the final step. The final step length was 1.523 ± 0.124 m, executed at an external angle of 35.5 ± 7.4° to the target line. The intra-subject variability was very low; distances and angles for the 10 kicks varied per participant by 1.6–3.1 cm and 0.7–1.6°, respectively. The results show that even though the participants had variability in their run-up to the tee, final foot position next to the tee was very similar and consistent. Furthermore, the inter- and intra-subject variability could not be attributed to differences in anthropometry. These findings may be useful as normative reference data for coaching, although further work is required to understand the role of other factors such as approach speed and body alignment.     

A topography of free kicks in soccer

ABSTRACT

This study investigates the spatial relationship of performance variables for soccer free kicks. In order to suggest ways in which players might optimise their performance, we collected data from free kicks (<35 m to goal line) of two German Bundesliga seasons (2013/14, 2014/15) (n = 1624). In the analysis, we applied the ISO-map approach using colour gradients to visualise the mean values of a variable on a 2D-map of the pitch. Additionally, variograms were used to describe the degree of spatial dependence of the free kick variables. Results show that DENSITY, TYPE OF PLAY, PLAYERS IN WALL, DISTANCE TO WALL and RULE VIOLATION were strongly spatially dependent. Centrality and proximity to the goal increased the variables PLAYERS IN WALL, RULE VIOLATIONS and INTERRUPTION TIME, and the ratio of goals scored increased from 5.9% (central far) to 10.9% (central near). In 70.9% of the shots, players preferred a switched laterality, which did not result in a higher success rate. Furthermore, there was no statistical advantage for the defensive team when DISTANCE TO WALL was below 9.15 m or when there was a RULE VIOLATION. Crosses had a success rate (i.e., first controlled ball contact after the cross) of 20.8%. Played with natural laterality, they were 5% more successful than with switched laterality. Crosses from the right side outside the penalty box were 10% more successful than from the left side. Therefore, it might be worthwhile practising the defence of balls coming from this side.     

High-intensity efforts in elite soccer matches and associated movement patterns,technical skills and tactical actions. Information for position-specific training drills

ABSTRACT

This study aimed to translate movement patterns, technical skills and tactical actions associated with high-intensity efforts into metrics that could potentially be used to construct position-specific conditioning drills. A total of 20 individual English Premier League players’ high-intensity running profiles were observed multiple times (n = 100) using a computerised tracking system. Data were analysed using a novel high-intensity movement programme across five positions (centre back [CB], full-back [FB], central midfielder [CM], wide midfielder [WM] and centre forward [CF]). High-intensity efforts in contact with the ball and the average speed of efforts were greater in WMs than CBs, CMs and CFs (effect sizes [ES]: 0.9–2.1, P < 0.05). WMs produced more repeated efforts than CBs and CMs (ES: 0.6–1.3, P < 0.05). In possession, WMs executed more tricks post effort than CBs and CMs (ES: 1.2–1.3, P < 0.01). FBs and WMs performed more crosses post effort than other positions (ES: 1.1–2.0, P < 0.01). Out of possession, CFs completed more efforts closing down the opposition (ES: 1.4–5.0, P < 0.01) but less tracking opposition runners than other positions (ES: 1.5–1.8, P < 0.01). CFs performed more arc runs before efforts compared to CBs, FBs and WMs (ES: 0.9–1.4, P < 0.05), however, CBs completed more 0–90° turns compared to FBs, CMs and WMs (ES: 0.9–1.1, P < 0.01). The data demonstrate unique high-intensity trends in and out of possession that could assist practitioners when devising position-specific drills.     

Simulation of Fragment Impact on Multi-Layer Targets Using Contact Method

Cased explosives generate highly energetic fragments as their casing breaks up. Due to the complexity of casing fragment related behavior such as embedment, perforation and ricochet, it may be insufficient to use equivalent triangular pressure loading in fragment impact simulations. This simplified method may over- or under-predict the target response. Recently, a procedure using contact techniques has been proposed to overcome such difficulties. It has been shown that the new method has the inherent capability in modeling the multi-piece and multi-hit fragment impact problems in a more realistic way. To investigate the applicability of the proposed method to simulations involving multi-layer penetration, the selected problems of fragment impact on multi-layer targets are described in this paper. It is demonstrated that this method is capable of predicting the complicated multi-layer structural response caused by fragment impact and penetration. Modeling procedures and some technical issues are also discussed.     

Special educational needs in mainstream secondary school physical education: learning support assistants have their say

Learning support assistants (LSAs) gained more political and academic attention in Britain after Estelle Morris announced that schools of the future would include more trained staff to support learning to higher standards. LSAs, thus, should form an integral part of the culture of all school departments in Britain, including physical education (PE). The paper uses Antonio Gramsci's concept of hegemony to explore the processes and practices that shape the views and experiences of LSAs and ultimately the extent to which they facilitate an inclusive culture in PE. A web survey gathered the views and experiences of LSAs vis-à-vis the inclusion of pupils with special educational needs (SEN) in mainstream secondary school PE in North-West England. A modified version of the tailored design method participant contact strategy resulted in 343 LSAs starting the web survey, with 154 (45%) following it through to completion. All quantitative data were analysed using Microsoft Excel whilst qualitative data were subjected to thematic analysis. This entailed the identification of recurring themes and patterns present in the data. The findings highlight the hegemonic status of English, maths and science when it comes to the allocation of SEN resources, which most LSAs support and often reinforce. PE is particularly disadvantaged in this hierarchy of subject priority. The majority of LSAs have not received PE-specific training, which brings into question their ability to facilitate inclusion in PE. Moreover, many schools do not appear to value the involvement of LSAs in the planning of differentiated lessons, which could have a negative impact on the PE experiences of some pupils with SEN given that LSAs are perhaps most aware of the specific learning needs of the pupils they support.     

Community,identity and contested notions of place: a study of Haitian recreational soccer players in the Dominican Republic

Soccer is a sport not commonly associated with the Dominican Republic given the positioning of baseball as the national game. Yet, for some migrant groups in the country, such as those from Haiti, soccer plays an important part in their lives. Haitians have used soccer as a way to unite their communities and establish a sense of place. This paper assesses how these Haitian migrants use the game as a means of creating a community and developing a common focal point. Through participant observations and semi-structured interviews, this work may help us construct new understandings of the ways in which migrants use sport to assimilate to new surroundings and retain links to home.     

Momentum sequence and environmental climate influence levels of perceived psychological momentum within a sport competition

The present study examined the influence of momentum sequence (positive vs. negative) and environmental climate (hot–wet vs. neutral) on supporters’ (i.e. virtual observers’) reported levels of perceived psychological momentum (PM) during a simulated cycling competition. Participants supported one of two competing cyclists involved in a race that was displayed on a screen in a lecture hall. The race scenario was manipulated so that the supported cyclist appeared to undergo either a positive or negative momentum sequence. In addition, participants were either exposed to a hot–wet environmental climate or to a neutral environmental climate while observing the race scenario. According to the results, reported levels of PM were higher in the positive momentum sequence condition than in the negative momentum sequence condition, consistent with the notion that supporters’ PM is influenced by a positivity bias, and reported levels of PM were also found to be higher in the hot–wet climate condition than in the neutral climate condition, consistent with the notion that environmental climate is a contextual factor that influences PM through the operation of a causal augmenting mechanism.