On-field rehabilitation in football: current practice and perceptions. A survey of the English Premier League and Football League.

INTRODUCTION: Return to play related research is increasing rapidly, with two recent competency-based frameworks offering conceptualised support for on-field rehabilitation (OFR) decision-making. It is still unknown, however, who is responsible for OFR and how they typically select, monitor, and progress OFR processes. AIMS: The purpose of this study was to investigate current OFR practice within English professional football to support practitioners with decision-making and highlight opportunities for future research related to the design, monitoring, and progression of OFR. METHODS: Sixty-nine practitioners responsible for the design and implementation of OFR at 69 clubs (75% of the English Premier League and Football League) responded to a survey containing 30 questions (14 open and 16 closed). RESULTS: The main findings were that therapists (physiotherapists/sports therapists) have the largest influence on OFR, followed by physical performance coaches (sports scientists/strength and conditioning coaches), technical coaches and medical doctors. There was more agreement for the ordering of specific OFR drills earlier in the process when activities are easier to control. The most frequently reported objective monitoring tool was global positioning systems (GPS), with functional/clinical experience/expertise remaining subjectively vital. GPS outputs (e.g., sprint metrics and accelerations/decelerations) were most used for between session decision-making, with verbal communication being key for within session decision-making. CONCLUSION: Future research should use evidence of current practice, such as drill design and monitoring techniques, to explore drill-level analysis and give practitioners greater insights into which stage of current OFR frameworks specific drills fall, and how they might be more objectively progressed/regressed.

Selected, Deselected, and Reselected: A Case Study Analysis of Attributes Associated With Player Reselection Following Closure of a Youth Soccer Academy.

Considering the perceived benefit of early recruitment and the time and resources spent developing youth players, individuals released from talent development programmes are often re-recruited by rival academies. However, due to the contractual nature of many talent development programmes, limited empirical data exists on players deselected from (or reselected to) youth soccer academies. Adopting a novel case study approach, differences in skill, psychological, and physical attributes associated with reselection following closure of a junior-elite soccer academy were explored. Overall subjective coach ratings for skill, psychological, and physical abilities; subjective coach ratings for skill and psychological attributes; and physical fitness test performance of 79 junior-elite soccer players (U11-U17) were assessed as part of regular scheduled testing and monitoring practices prior to the academy closure. Reselection status was monitored and recorded for all players in the 6 months following the academy closure and was classified as a persistence/progression ("Reselected") or attrition ("Deselected") in playing level. Of the 79 released players, a total of 60 players (76%) were re-signed to a junior-elite academy within 6 months. Differences were observed for overall ratings of skill, psychological, and physical abilities in favor of the "Reselected" player group. "Reselected" players were also rated higher by coaches for all attributes categorized as skill and psychological, as well as performing better at all physical fitness tests. However, "Reselected" players were lesser in stature and body mass and less mature than "Deselected" players. Our findings suggest that reselection is not a product of anthropometric criteria and, therefore, a pathway for selection remains open for later maturing players. We also inform upon desirable qualities associated with player reselection and provide a case study approach of a unique, yet highly relevant, scenario for talent identification and development in youth soccer.

"He's Just a Wee Laddie": The Relative Age Effect in Male Scottish Soccer.

Significant structural, developmental, and financial constraints exist in Scottish soccer that may predicate a different approach to talent identification and development. To our knowledge, no published reports exist evaluating the prevalence of the relative age effect (RAE) in Scottish soccer players. Consequently, the aim of this study was to investigate the prevalence of the RAE among varied playing levels and ages of male Scottish youth soccer players. Birthdates of male youth players (n = 1,230) from U10 to U17 age groups and from playing levels: "Amateur" (n = 482), "Development" (n = 214), and "Performance" (n = 534), alongside a group of male Scottish senior professional players (n = 261) were recorded and categorized into quartiles (Q1 = January-March; Q2 = April-June; Q3 = July-September; and Q4 = October-December) and semesters (S1 = January-June and S2 = July-December) from the start of the selection year. Birthdates were analyzed for: (a) each playing level and (b) each age group irrespective of playing level. For the varied playing levels examined, an RAE was evident in "Development" and "Performance" playing levels only at youth level. When examining each age group, an RAE was observed in U12-U17 players only. While there was a slight asymmetry favoring Q1 born senior professional players, the RAE was not present within this group of our sample. Results from our study suggest that a bias in selecting individuals born earlier in the selection year may exist within male soccer academy structures, but not at amateur level. The asymmetry favoring chronologically older players at youth but not professional level questions the efficacy of this (un)conscious bias within male Scottish soccer players.

Research in Another un-Examined (RAE) context. A chronology of 35 years of relative age effect research in soccer: is it time to move on?

It is approximately 35 years since the publication of the first relative age effect paper in sport and despite the volume of empirical studies, book chapters, conference presentations, and column inches dedicated to this topic we appear to be no further on in eliminating or attenuating this discriminatory practice. This commentary argues that the ongoing use of univariate methods, focusing on primary or secondary analyses of birth-date data, unearthed from previously un-examined contexts is not conducive to stimulating discussion or providing empirical solutions to relative age effects. This paper concludes by suggesting a departure from the traditionally narrow view of relative age inquiry and instead consider the role of transdisciplinary research.

The Validity of an Updated Metabolic Power Algorithm Based upon di Prampero's Theoretical Model in Elite Soccer Players.

The aim of this study was to update the metabolic power (MP) algorithm (PV˙O2, W·kg-1) related to the kinematics data (PGPS, W·kg-1) in a soccer-specific performance model. For this aim, seventeen professional (Serie A) male soccer players (V˙O2max 55.7 ± 3.4 mL·min-1·kg-1) performed a 6 min run at 10.29 km·h-1 to determine linear-running energy cost (Cr). On a separate day, thirteen also performed an 8 min soccer-specific intermittent exercise protocol. For both procedures, a portable Cosmed K4b2 gas-analyzer and GPS (10 Hz) was used to assess the energy cost above resting (C). From this aim, the MP was estimated through a newly derived C equation (PGPSn) and compared with both the commonly used (PGPSo) equation and direct measurement (PV˙O2). Both PGPSn and PGPSo correlated with PV˙O2 (r = 0.66, p < 0.05). Estimates of fixed bias were negligible (PGPSn = -0.80 W·kg-1 and PGPSo = -1.59 W·kg-1), and the bounds of the 95% CIs show that they were not statistically significant from 0. Proportional bias estimates were negligible (absolute differences from one being 0.03 W·kg-1 for PGPSn and 0.01 W·kg-1 for PGPSo) and not statistically significant as both 95% CIs span 1. All variables were distributed around the line of unity and resulted in an under- or overestimation of PGPSn, while PGPSo routinely underestimated MP across ranges. Repeated-measures ANOVA showed differences over MP conditions (F1,38 = 16.929 and p < 0.001). Following Bonferroni post hoc test significant differences regarding the MP between PGPSo and PV˙O2/PGPSn (p < 0.001) were established, while no differences were found between PV˙O2 and PGPSn (p = 0.853). The new approach showed it can help the coaches and the soccer trainers to better monitor external training load during the training seasons.

A case study of the use of verbal reports for talent identification purposes in soccer: A Messi affair!

Using a two-study approach, the main purpose of this case study was to explore the use of a verbal reporting methodology to better understand the thought processes of soccer talent scouts during an in-situ talent identification environment. Study 1 developed a standardized coding-scheme to examine verbal cognitions during a single soccer game. Study 2 then utilized this methodology to examine two full-time recruitment staff trained in the use of concurrent verbal reporting before undertaking a live, in-game task. Participants also participated in a debrief interview following the game. The findings of the two studies suggest that developing a verbal reporting protocol is viable, however when applied in a live-game environment it is problematic. Future research should therefore consider a modified version of this task to further explore the cognitions of scouts whilst observing and identifying potential talent.

A Coding System to Quantify Powerful Actions in Soccer Match Play: A Pilot Study.

PURPOSE: The powerful activity profile of elite soccer match play has not been documented appropriately to inform specific maximal power assessment and development criteria. The aims of the current study were to develop a reliable  soccer-specific powerful action (SSPA) notational analysis coding system that could be used to compare frequency and durations of powerful actions during elite youth soccer match play. METHODS: Sixteen elite male English Premier League (EPL) Academy players (19 ± 1 yrs) were recorded by an individual camera during 16 competitive EPL U18 and U21 games. Video footage was analyzed using performance analysis software and SSPAs were coded according to the following categories: initial acceleration, leading acceleration, sprint, unilateral jump and bilateral jump. RESULTS: The SSPA coding system demonstrated very good inter- and intra-rater reliability (kappa coefficients ≥ 0.827). Elite youth EPL soccer players undertook significantly more initial (31 ± 9) and leading (37 ± 12) accelerations than sprints (8 ± 3; p = .014, d = 1.7, and p < .001, d = 1.7, respectively) and jumps (6 ± 5; p = .002, d = 1.7 and p < .001, d = 1.7, respectively). Players performed a significantly greater number of initial and leading accelerations with action durations below 1.5 s compared to above 1.5 s (p = .001, d = 1.6, and p = .002, d = 1.4), respectively. CONCLUSIONS: Our SSPA coding system provides a reliable observational instrument for quantifying the frequency and duration of powerful actions performed during elite soccer match play. In our sample of elite youth soccer players, horizontal accelerations of short duration (< 1.5 s) from different starting speeds appear the most dominant powerful action in elite youth soccer match play.

Why do bad balls get wickets? The role of congruent and incongruent information in anticipation.

Skilled anticipation is underpinned by the use of kinematic and contextual information. However, few researchers have examined what happens when contextual information suggests an outcome that is different from the event that follows. We aimed to bridge this gap by manipulating the relationship between contextual information and final ball location in a cricket-batting task. We predicted that when contextual information is congruent with the eventual outcome then anticipation would be facilitated. In contrast, when contextual information is incongruent, this would lead to a confirmation bias on kinematic information and result in decreased anticipation accuracy. We expected this effect to be larger in skilled performers who are more able to utilise context. Skilled and less-skilled cricket batters anticipated deliveries presented using a temporally occluded video-based task. We created conditions whereby contextual information and event outcome were either congruent or incongruent. There was a significant skill by condition interaction (p < 0.05). The skilled group anticipated significantly more accurately than the less-skilled group on the congruent trials. Both groups anticipated less accurately on incongruent trials, with the skilled participants being more negatively affected. Skilled performers prioritise contextual information and confirmation bias affects the use of kinematic information available later in the action.

The Work-Rate of Elite Hurling Match-Play.

Collins, DK, McRobert, A, Morton, JP, O'Sullivan, D, and Doran, DA. The work-rate of elite hurling match-play. J Strength Cond Res 32(3): 805-811, 2018-This study describes the global work-rate of elite hurling match-play and the influence which positional difference has on work-rate is considered. The movement of ninety-four players was recorded using global positioning system, sampling at 4 Hz in a total of 12 games. Data were classified according to the positional line on the field and period of the match. The total and high-speed distance of match-play was 7,617 ± 1,219 m (95% confidence interval [CI], 7,367-7,866) and 1,134 ± 358 m (95% CI, 1,060-1,206), respectively. The maximum speed attained was 29.8 ± 2.3 km·h with a mean speed of 6.1 ± 1 km·h. The second {271 ± 107 m (p = 0.001; effect size [ES] = 0.25)}, third (278 ± 118 m [p = 0.001; ES = 0.21]), and fourth quarter (255 ± 108 m [p = 0.001; ES = 0.31]) high-speed running distance differed significantly from that of the first quarter (330 ± 120 m). There was a significant difference in total (p = 0.001; ES = 0.01-0.85), high-speed running (p = 0.001; ES = 0.21-0.76), and sprint (p = 0.013; ES = 0.01-0.39) distance across the positions, with midfielders undertaking the highest volume of work, followed by the half-forward and half-back lines and finally the full-forward and full-back lines. A decrease in high-speed running distance seems to occur through out the game and in particular at the latter stages of each half. Distinct positional work profiles are evident. The present finding provide a context on which training which replicates the work-rate of match-play may be formulated, thus helping to improve the physical preparation of elite players.

What Performance Analysts Need to Know About Research Trends in Association Football (2012-2016): A Systematic Review.

BACKGROUND: Evolving patterns of match analysis research need to be systematically reviewed regularly since this area of work is burgeoning rapidly and studies can offer new insights to performance analysts if theoretically and coherently organized. OBJECTIVE: The purpose of this paper was to conduct a systematic review of published articles on match analysis in adult male football, identify and organize common research topics, and synthesize the emerging patterns of work between 2012 and 2016, according to the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. METHODS: The Web of Science database was searched for relevant published studies using the following keywords: 'football' and 'soccer', each one associated with the terms 'match analysis', 'performance analysis', 'notational analysis', 'game analysis', 'tactical analysis' and 'patterns of play'. RESULTS: Of 483 studies initially identified, 77 were fully reviewed and their outcome measures extracted and analyzed. Results showed that research mainly focused on (1) performance at set pieces, i.e. corner kicks, free kicks, penalty kicks; (2) collective system behaviours, captured by established variables such as team centroid (geometrical centre of a set of players) and team dispersion (quantification of how far players are apart), as well as tendencies for team communication (establishing networks based on passing sequences), sequential patterns (predicting future passing sequences), and group outcomes (relationships between match-related statistics and final match scores); and (3) activity profile of players, i.e. playing roles, effects of fatigue, substitutions during matches, and the effects of environmental constraints on performance, such as heat and altitude. CONCLUSION: From the previous review, novel variables were identified that require new measurement techniques. It is evident that the complexity engendered during performance in competitive soccer requires an integrated approach that considers multiple aspects. A challenge for researchers is to align these new measures with the needs of the coaches through a more integrated relationship between coaches and researchers, to produce practical and usable information that improves player performance and coach activity.

Effect of expertise on diagnosis accuracy, non-technical skills and thought processes during simulated high-fidelity anaesthetist scenarios.

Background: The expert performance approach can be used to examine expertise during representative field-based tasks, while collecting process-tracing measures such as think-aloud verbal reports. Collecting think-aloud verbal reports provides an insight into the cognitive mechanisms that support performance during tasks. Method: We examined the thought processes and performance of anaesthetists during simulated environments. Verbal reports of thinking and the anaesthetists' non-technical skills (ANTS) were recorded to examine cognitive processes, non-technical behaviours and diagnosis accuracy during fully immersive, high-fidelity medical scenarios. Skilled (n=6) and less skilled (n=9) anaesthetists were instructed to respond to medical scenarios experienced in theatre. Results: Skilled participants demonstrated higher diagnosis accuracy and ANTS scores compared to less skilled participants. Furthermore, skilled participants engaged in deeper thinking and verbalised more evaluation, prediction and deep planning statements. Conclusions: The ability to employ an effective cognitive processing strategy, more efficient non-technical behaviours and superior diagnosis is associated with superior performance in skilled participants.

Attacking and defensive styles of play in soccer: analysis of Spanish and English elite teams.

The aim of this study was to define and categorise different styles of play in elite soccer and associated performance indicators by using factor analysis. Furthermore, the observed teams were categorised using all factor scores. Data were collected from 97 matches from the Spanish La Liga and the English Premier League from the seasons 2006-2007 and 2010-2011 using the Amisco® system. A total of 19 performance indicators, 14 describing aspects of attacking play and five describing aspects of defensive play, were included in the factor analysis. Six factors, representing 12 different styles of play (eight attacking and four defensive), had eigenvalues greater than 1 and explained 87.54% of the total variance. Direct and possession styles of play, defined by factor 1, were the most apparent styles. Factor analysis used the performance indicators to cluster each team's style of play. Findings showed that a team's style of play was defined by specific performance indicators and, consequently, teams can be classified to create a playing style profile. For practical implications, playing styles profiling can be used to compare different teams and prepare for opponents in competition. Moreover, teams could use specific training drills directed to improve their styles of play.

Visual search behaviours and verbal reports during film-based and in situ representative tasks in volleyball.

Several researchers have explored the processes underlying perceptual-cognitive expertise, mainly using film-based studies. However, few have compared the extent to which data from film-based settings differ from those obtained through in situ collection. This gap in the literature is a relevant concern, since scientific research is used to provide guidance for designing training programmes. In this paper, eye movement recording and verbal reports of thinking were combined to explore the processes underpinning skilled performance in a representative volleyball task involving both film-based and in situ data collection. Nine volleyball players performed as backcourt defenders while wearing an eye-tracking device and providing verbal reports of thinking after each sequence. A number of significant differences were observed between the data gathered under film-based and in situ conditions. Namely, in the in situ condition participants employed longer fixations (728.11 ± 129.27 ms) than in the film condition (659.57 ± 178.06 ms), and there were differences in the nature of the fixation locations. With respect to verbal reports, participants exhibited superior level of sophistication in the in situ condition (2.57 ± 0.50 vs. 2.30 ± 0.84 in the film condition), while denoting a greater concern with the opponents under this condition (1.00 ± 0.73) than in the film condition (0.59 ± 0.60). These differences emerged despite task design and constraints being highly similar. No differences were apparent in the number of gaze fixations and fixation locations across conditions or in the number of verbalised condition concepts. Although exploratory, our data suggest that the mechanisms underpinning skilled decision-making in sports differ between film-based and in situ conditions.

How experts practice: a novel test of deliberate practice theory.

Performance improvement is thought to occur through engagement in deliberate practice. Deliberate practice is predicted to be challenging, effortful, and not inherently enjoyable. Expert and intermediate level Gaelic football players executed two types of kicks during an acquisition phase and pre-, post-, and retention tests. During acquisition, participants self-selected how they practiced and rated the characteristics of deliberate practice for effort and enjoyment. The expert group predominantly practiced the skill they were weaker at and improved its performance across pre-, post- and retention tests. Participants in the expert group also rated their practice as more effortful and less enjoyable compared to those in the intermediate group. In contrast, participants in the intermediate group predominantly practiced the skill they were stronger at and improved their performance from pretest to posttest but not on the retention test. Findings provide support for deliberate practice theory and give some insight into how experts practice and improve their performance beyond its current level.

The microstructure of practice activities engaged in by elite and recreational youth cricket players.

Practice plays an important role in skill acquisition, although not all practice is of equal quality. We examined the types of team practice activities in four groups of youth cricket players. The groups were recreational- and elite-children (9 to 12 years of age) and recreational- and elite-adolescent players (13 to 17 years of age). Time motion analysis recorded the duration in two types of practice activities, namely, Training Form and Playing Form. Training Form is mainly drill-type activities, whereas Playing Form is mainly games-based activities. Training Form activity is thought to contain fewer opportunities to develop the perceptual, cognitive and motor skills required for successful performance in competition when compared to Playing Form. Session duration was a mean value of 95, s = 29 min. All players combined spent 69% of session time in Training Form activity and 19% in Playing Form, with the remaining percentage of time spent in transition between activities. Recreational-children spent around half of their time in Playing Form activity, whereas both elite and adolescent groups spent little or no time in this activity. Findings from this research highlight a gap between research and practice that may not be optimal for skill acquisition.

Perceptual-cognitive skills and their interaction as a function of task constraints in soccer.

The ability to anticipate and to make decisions is crucial to skilled performance in many sports. We examined the role of and interaction between the different perceptual-cognitive skills underlying anticipation and decision making. Skilled and less skilled players interacted as defenders with life-size film sequences of 11 versus 11 soccer situations. Participants were presented with task conditions in which the ball was located in the offensive or defensive half of the pitch (far vs. near conditions). Participants' eye movements and verbal reports of thinking were recorded across two experiments. Skilled players reported more accurate anticipation and decision making than less skilled players, with their superior performance being underpinned by differences in task-specific search behaviors and thought processes. The perceptual-cognitive skills underpinning superior anticipation and decision making were shown to differ in importance across the two task constraints. Findings have significant implications for those interested in capturing and enhancing perceptual-cognitive skill in sport and other domains.

Contextual information influences diagnosis accuracy and decision making in simulated emergency medicine emergencies.

BACKGROUND: It is well documented that adaptations in cognitive processes with increasing skill levels support decision making in multiple domains. We examined skill-based differences in cognitive processes in emergency medicine physicians, and whether performance was significantly influenced by the removal of contextual information related to a patient's medical history. METHOD: Skilled (n=9) and less skilled (n=9) emergency medicine physicians responded to high-fidelity simulated scenarios under high- and low-context information conditions. RESULTS: Skilled physicians demonstrated higher diagnostic accuracy irrespective of condition, and were less affected by the removal of context-specific information compared with less skilled physicians. The skilled physicians generated more options, and selected better quality options during diagnostic reasoning compared with less skilled counterparts. These cognitive processes were active irrespective of the level of context-specific information presented, although high-context information enhanced understanding of the patients' symptoms resulting in higher diagnostic accuracy. CONCLUSIONS: Our findings have implications for scenario design and the manipulation of contextual information during simulation training.

The perceptual cognitive processes underpinning skilled performance in volleyball: evidence from eye-movements and verbal reports of thinking involving an in situ representative task.

An extensive body of work has focused on the processes underpinning perceptual-cognitive expertise. The majority of researchers have used film-based simulations to capture superior performance. We combined eye movement recording and verbal reports of thinking to explore the processes underpinning skilled performance in a complex, dynamic, and externally paced representative volleyball task involving in situ data collection. Altogether, 27 female volleyball players performed as centre backcourt defenders in simulated sessions while wearing an eye-tracking device. After each sequence, athletes were questioned concerning their perception of the situation. The visual search strategies employed by the highly-skilled players were more exploratory than those used by skilled players, involving more fixations to a greater number of locations. Highly-skilled participants spent more time fixating on functional spaces between two or more display areas, while the skilled participants fixated on the ball trajectory and specific players. Moreover, highly-skilled players generated more condition concepts with higher levels of sophistication than their skilled counterparts. Findings highlight the value of using representative task designs to capture performance in situ. Key pointsDecision-making in complex sports relies deeply on perceptual-cognitive expertise. In turn, the effect of expertise is highly dependent on the nature and complexity of the task.Nonetheless, most researchers use simple tasks in their research designs, risking not capturing performance in a meaningful way. We proposed to use a live action setting with a complex task design, representative of real world situations.We combined eye movement registration with collection of immediate retrospective verbal reports. Although the two data sets are not directly comparable, they may be used in a complementary manner, providing a deeper and fuller understanding of the processes underpinning superior performance.Highly-skilled players exhibited more exploratory visual search behaviors than their skilled counterparts, performing more fixations into more locations. They also attended more to functional spaces between two or more areas of the display. Furthermore, highly-skilled players produced more condition concepts and with superior level of sophistication, revealing a deeper and more meaningful attunement to the task constraints.

The effect of manipulating context-specific information on perceptual-cognitive processes during a simulated anticipation task.

We manipulated contextual information in order to examine the perceptual-cognitive processes that support anticipation using a simulated cricket-batting task. Skilled (N= 10) and less skilled (N= 10) cricket batters responded to video simulations of opponents bowling a cricket ball under high and low contextual information conditions. Skilled batters were more accurate, demonstrated more effective search behaviours, and provided more detailed verbal reports of thinking. Moreover, when they viewed their opponent multiple times (high context), they reduced their mean fixation time. All batters improved performance and altered thought processes when in the high context, compared to when they responded to their opponent without previously seeing them bowl (low context). Findings illustrate how context influences performance and the search for relevant information when engaging in a dynamic, time-constrained task.

Identifying the processes underpinning anticipation and decision-making in a dynamic time-constrained task.

A novel, representative task was used to examine skill-based differences in the perceptual and cognitive processes underlying performance on a dynamic, externally paced task. Skilled and less skilled soccer players were required to move and interact with life-size, action sequences involving 11 versus 11 soccer situations filmed from the perspective of a central defender in soccer. The ability of participants to anticipate the intentions of their opponents and to make decisions about how they should respond was measured across two separate experiments. In Experiment 1, visual search behaviors were examined using an eye-movement registration system. In Experiment 2, retrospective verbal reports of thinking were gathered from a new sample of skilled and less skilled participants. Skilled participants were more accurate than less skilled participants at anticipating the intentions of opponents and in deciding on an appropriate course of action. The skilled players employed a search strategy involving more fixations of shorter duration in a different sequential order and toward more disparate and informative locations in the display when compared with the less skilled counterparts. The skilled players generated a greater number of verbal report statements with a higher proportion of evaluation, prediction, and planning statements than the less skilled players, suggesting they employed more complex domain-specific memory representations to solve the task. Theoretical, methodological, and practical implications are discussed.