Interpersonal coordination tendencies supporting the creation/ prevention of goal scoring opportunities in futsal

(1)

This article was downloaded by: [University of Maastricht]

On: 26 June 2014, At: 16:46 Publisher: Taylor & Francis

Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UK

European Journal of Sport Science

Publication details, including instructions for authors and subscription information:

http://www.tandfonline.com/loi/tejs20

Interpersonal coordination tendencies supporting the creation/prevention of goal scoring opportunities in futsal

LuÍs Vilarâb, Duarte Araújoâc, Keith Davids^d, Bruno Travassosêf, Ricardo Duarteâ & João Parreira^b

a Department of Sport and Health, Faculty of Human Kinetics, Technical University of Lisbon, Lisbon, Portugal

b Faculty of Physical Education and Sports/Lusófona University of Humanities and Technologies, Lisbon, Portugal

c CIPER-Center for the Interdisciplinary Study of Human Performance, Lisbon, Portugal

d School of Human Movement Studies, Queensland University of Technology, Brisbane, Australia

e Department of Sports Sciences, University of Beira Interior, Covilhã, Portugal

f CIDESD – Research Center in Sports, Health and Human Development, Covilhã, Portugal Published online: 11 Oct 2012.

To cite this article: LuÍs Vilar, Duarte Araújo, Keith Davids, Bruno Travassos, Ricardo Duarte & João Parreira (2014)

Interpersonal coordination tendencies supporting the creation/prevention of goal scoring opportunities in futsal, European Journal of Sport Science, 14:1, 28-35, DOI: 10.1080/17461391.2012.725103

To link to this article: http://dx.doi.org/10.1080/17461391.2012.725103

PLEASE SCROLL DOWN FOR ARTICLE

Taylor & Francis makes every effort to ensure the accuracy of all the information (the “Content”) contained in the publications on our platform. However, Taylor & Francis, our agents, and our licensors make no

representations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of the Content. Any opinions and views expressed in this publication are the opinions and views of the authors, and are not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon and should be independently verified with primary sources of information. Taylor and Francis shall not be liable for any losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoever or howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use of the Content.

This article may be used for research, teaching, and private study purposes. Any substantial or systematic reproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any

form to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://

www.tandfonline.com/page/terms-and-conditions

(2)

ORIGINAL ARTICLE

Interpersonal coordination tendencies supporting the creation/

prevention of goal scoring opportunities in futsal

LUI´S VILAR^1,2, DUARTE ARAU´ JO^1,3, KEITH DAVIDS⁴, BRUNO TRAVASSOS^5,6, RICARDO DUARTE¹, & JOA˜ O PARREIRA²

1Department of Sport and Health, Faculty of Human Kinetics, Technical University of Lisbon, Lisbon, Portugal,²Faculty of Physical Education and Sports/Luso´fona University of Humanities and Technologies, Lisbon, Portugal,³CIPER-Center for the Interdisciplinary Study of Human Performance, Lisbon, Portugal,⁴School of Human Movement Studies, Queensland University of Technology, Brisbane, Australia,⁵Department of Sports Sciences, University of Beira Interior, Covilha˜, Portugal, and⁶CIDESDResearch Center in Sports, Health and Human Development, Covilha˜, Portugal

Abstract

Research on 1vs1 sub-phases in team sports has shown how one player coordinates his/her actions with his/her opponent and the location of a target/goal to attain performance objectives. In this study, we extended this approach to analysis of 5vs5 competitive performance in the team sport of futsal to provide a performance analysis framework that explains how players coordinate their actions to create/prevent opportunities to score goals. For this purpose, we recorded all 10 futsal matches of the 2009 Lusophony Games held in Lisbon. We analysed the displacement trajectories of a shooting attacker and marking defender in plays ending in a goal, a goalkeeper’s save, and a defender’s interception, at four specific moments during performance: (1) assisting attacker’s ball reception and (2) moment of passing, (3) shooter’s ball reception, and (4), shot on goal. Statistical analysis showed that when a goal was scored, the defender’s angle to the goal and to the attacker tended to decrease, the attacker was able to move to the same distance to the goal alongside the defender, and the attacker was closer to the defender and moving at the same velocity (at least) as the defender. This study identified emergent patterns of coordination between attackers and defenders under key competitive task constraints, such as the location of the goal, which supported successful performance in futsal.

Keywords:Performance, interpersonal coordination, futsal, ecological dynamics, constraints, dyadic systems

Introduction

In team sports, the way players interact intentionally or sub-consciously with others in space and time has been suggested to support high levels of performance (Schmidt, Fitzpatrick, Caron, & Mergeche, 2011).

For this purpose, ideas from ecological dynamics have been used to examine the spatial-temporal functional patterns of coordination emerging between immediate attackers and defenders perform- ing in dyadic (1vs1) systems (Arau´ jo, Davids, Bennett, Button, & Chapman, 2004; Davids, But- ton, Arau´ jo, Renshaw, & Hristovski, 2006). For example, in basketball, analyses of the distance of attackers and defenders to the basket revealed that a

symmetry-breaking process precipitated a shot at the basket, as the attacker passed the defender to de- stabilise the dyadic system (Arau´ jo et al., 2004). In other team sports, like association football and futsal (a type of 5-a-side Association Football played on an indoor court, under the governance of FIFA), instabilities in dyadic systems were shown to be created only when attackers were able to increase their speed relative to that of an immediate defender at critical values of interpersonal distance (ID) (Duarte, Arau´jo, Fernandes, et al., 2010; Passos et al.,2008). In rugby union,the angle of the defender attacker vector (measured relative to an imaginary horizontal line parallel to the try line) was revealed as a reliable variable that captures the two possible

Correspondence: Luı´s Vilar, Faculty of Physical Education and Sports/Luso´fona University of Humanities and Technologies, Lisbon 1749- 021, Portugal. E-mail:[email protected]

Vol. 14, No. 1, 2835, http://dx.doi.org/10.1080/17461391.2012.725103

#2012 European College of Sport Science

Downloaded by [University of Maastricht] at 16:46 26 June 2014

(3)

outcomes of play: a try scored by the attacker or a successful tackle by the defender (Passos et al., 2009).

However, in some field invasion games, especially netball, lacrosse and futsal, the goal area is not a perpendicular line running along the field, but a very specific target area located on-field, such as a goal or a bounded net. This distinct game setting may act as a different constraint on performance behaviours in team sports. For example, it is expected that the attacker does not need to be closer to the goal than the defender to score. Rather, the attacker may need to promote instability in the defender’s alignment between him/her and the goal location. Thus, the angle and distances to the goal of the individuals in a dyadic system may be critical dependent variables that need to be simultaneously considered in this small group of field invasion games. Additionally, in order for an attacker to score a goal in competitive performance environments, it is expected that he/she needs to establish successful spatial-temporal relationships with a marker in two different consecutive phases of play. These are: (1)before receiving the ball, the attacker needs to create space away from a marker to receive the ball; and (2),while maintaining ball possession, the attacker needs to create space away from a marking defender to shoot the ball at goal.

Therefore, research is also needed to investigate the spatial-temporal characteristics of emergent coordination of an attacker seeking to shoot at goal, and the nearest marker, before and after the ball is received during competitive team game performance.

In this paper, we sought to examine the coordination patterns of attackers and defenders with respect to key task constraints on performance (e.g. locations of the goal and the ball), that enable the creation/prevention of opportunities to score goals during team sports. By also observing inter- individual interactions during the build up of play before an attacker receives the ball, results were expected to enhance understanding of the interpersonal patterns of coordination that illustrate how attackers are able to create space to receive an assisting pass to shoot at goal.

Method

This study was conducted within the guidelines of the American Psychological Association and the protocol was approved by a local university ethics committee.

Data collection

Seventy-one players (M25.31, SD4.73 years) from five national teams played 10 futsal games in the 2009 Lusophony Games held in Lisbon. All

matches were recorded with a digital video camera (25 Hz) located above and behind the short axis of a futsal court. Ninety sequences of play, in which a pass from a teammate preceded an attacker’s shot at goal, were randomly selected for movement analysis, according to three different performance outcomes:

ending in a goal (n30), a goalkeeper’s save (n30) and an interception by the nearest defender (n30).

The selected data sequences were timed from the moment of the last clock interruption before a goal was scored, to the moment the ball entered or missed the goal after a shot or the defensive team intercepted the shot on goal.

Data analysis

The movement displacement trajectories from all players in the 90 identified goal sequences were captured using a digital video camera and digitised with TACTO software package. This package allowed us to replay the selected performance footage in slow video motion and, after a digitising procedure, export the 2D displacement coordinates of the players in virtual coordinates (i.e. in pixels) (Fernandes, Folgado, Duarte, & Malta,2010). This digitising procedure consisted of following the mid- dle point between the feet of each player (working point) with a mouse cursor, since this point repre- sents the projection of the player’s centre of gravity on the ground (Duarte, Arau´ jo, Fernandes, et al., 2010). A bi-dimensional direct linear transformation method (2D-DLT) was used to convert pixel coordinates into actual pitch coordinates (i.e. in metres) (Duarte et al.,in press). Data were filtered using a Butterworth low pass filter, with a cut-off frequency of 6 Hz (Winter, 2005). The bottom left corner of the futsal court was assigned a coordinate value of zero. The longitudinal dimension (i.e. the length of the field) was assigned to the y-axis and the lateral dimension (i.e. the width) was attributed to the x-axis.

Beginning with the x and y coordinates of each player and the ball, we computed the distances between all outfield defenders to the attacker who performed the shot at goal, defining the nearest defender to the shooter in each time frame (i.e.

shooting attacker-marking defender dyad). From the x and y coordinate values of the shooter and the marking defender we calculated the following four dependent variables for statistical analysis:

Defender’s angle to the goal and the attacker (DA).

Calculated by recording the inner product of the defender’s vector to the centre of the goal, and the defender’s vector to the attacker (seeFigure 1A).

Analysis of scoring opportunities in futsal 29

(4)

Relative distance to the goal (RDG).Calculated as the difference between the attacker’s distance to the centre of the goal and the defender’s distance to the centre of the goal (Figure 1B).

Interpersonal distance. Computed as the attacker’s vectorial distance to the defender (Figure 1C).

Relative velocity (RV). Calculated as the difference between the running velocity of the attacker and the defender (Figure 1D).

The values of each of the four variables for each performance outcome were recorded at four key moments of play in the build up to a goal being scored or a ball being intercepted: (1) the time at which the assisting attacker received the ball; (2) the time at which the assisting attacker passed the ball to the shooter; (3) the time at which the shooter received the ball; and (4) the time at which the attacker shot the ball at goal. All data were computed in MATLAB^† R2008a software (The MathWorks Inc, Natick, MA, USA).

Dependent variables were analysed using a 4(Moment)3(Outcome) mixed-design ANOVA, in which the moments of play (assisting attacker received the ball, assisting attacker passed the ball, shooter received the ball and attacker shot at goal)

was the within-participants factor, and outcome of play (goal, goalkeeper’s save and defender’s interception) was the between-participants factor. The sphericity assumption for the repeated measures variable (i.e. the within-participants factor) and the interaction effects were checked using Mauchly’s test of sphericity. When a violation of the sphericity assumption was apparent, the Greenhouse-Geisser correction procedure was used to adjust the degrees of freedom (Schutz & Gessaroli,1987). The equality of variances assumption for the between-participants factor was assumed because groups were composed of an equal sample size (Field, 2005, p. 324).

Observed significant effects were followed up using Bonferroni post hoc tests. The level of significance was set at pB0.05. All statistical analyses were computed using SPSS^† 19.0 software (IBM SPSS Inc., Chicago, USA).

Reliability

One of the 90 goal sequences subjected to data analysis was selected at random and the movement displacement trajectories of the ball and players (n11) were re-digitised by the same experimenter.

The real world coordinate data (i.e. in meters) were then assessed for intra-digitiser reliability using

Figure 1. Illustration of the different variables analyzed in this investigation: Panel A(a) nearest defender’s (D) angle to the attacker (A) and the center of the goal; Panel Brelative distance to the goal computed by the difference between the attacker’s (A) distance to the center of the goal (b) and his nearest defender’s (D) distance to the center of the goal (c); Panel Cinterpersonal distance (d) between the attacker (A) and his nearest defender (D); Panel Drelative velocity computed by the difference between the attacker’s (A) velocity (e) and his nearest defender’s (D) velocity (f) adapted from Vilar, Arau´ jo, Davids, & Button (2012).

(5)

technical error of measurement (TEM) and coefficient of reliability (R) (Goto & Mascie-Taylor, 2007). The intra-tem measure was calculated by (SD²/2N), where D is the difference between the two measurements, and N is the sample size. The coefficient of reliability, which ranges from 0 (not reliable) to 1 (complete reliability), was calculated by 1-(TEM²/SD²), whereSD is the standard deviation of all measurements. The intra-TEM measure yielded mean values of 0.245 metres (2.53%), 0.255 metres (2.45%) and 0.414 metres (2.46%) for data on positioning of attackers, defenders and the ball, respectively. The coefficient of reliability showed high internal consistency of the data for the attackers (r0.97), defenders (r0.95) and ball (r0.99).

Results

Defender’s angle to the goal and the attacker

A significant effect was observed for the moments of play X outcomes of play interactions, F(4.42,192.31)2.97, pB0.05, h²0.064, suggesting that the influence of outcomes of play on DA differed during the performance periods investigated.Post hoc tests for interaction effects showed that, between the moments of ball reception by the assisting player and the shot on goal, the mean values of DA increased in plays ending in a defender’s interception (M21.82, SE6.97), while decreas- ing in plays ending in a goal (M 27.29, SE14.28,pB0.05;Table I).

Statistical analyses also revealed a significant main effect for outcomes of play, F(2,87)18.83, pB0.001, h²0.30, suggesting that, regardless of moments of play, there were statistical differences in the mean values of DA between the emergent outcomes of play. Post hoc tests on outcomes of play showed that the mean values of DA were significantly higher in plays ending in a defender’s interception (M135.77, SE5.99) than in plays ending in a goal (M84.15, SE5.99, pB0.001) and in a goalkeeper’ save (M104.71, SE5.99, pB0.01).

No main effect was found for moments of play, F(2.21,192.31)1.81,p0.05, h²0.02 suggesting that, regardless of outcomes of play, there were no statistical differences in the mean values of DA at the investigated moments of play (Figure 2).

Relative distance to the goal

A statistically non-significant effect was observed for moments of play X outcomes of play interactions, F(4.52,199.33)0.29,p0.05,h²0.01, suggesting that the influence of outcomes of play on RDG did not change at the key performance times examined. In addition, statistical analysis showed no main effects for moments of play, F(2.29,199.33)1.71,p0.05, h²0.02 suggesting that, regardless of performance outcomes, RDG did not significantly differ at the different moments of play.

However, significant main effects were observed for outcomes of play, F(2,87)9.73, pB0.001, h²0.18 suggesting that, regardless of moments of play, there were statistical differences in RDG between the investigated outcomes of play. Post hoc tests showed that the mean values of RDG in plays ending in goals (M0.05, SE3.89) were significantly lower than in plays ending in a defender’s interception (M2.48, SE3.89,pB0.001).

Interpersonal distance

Statistically significant effects were observed for the moments of play X outcomes of play interactions, F(3.93,170.79)4.74, pB0.001, h²0.10, suggesting that the influence of outcomes of play on ID changed between the key moments of play that we examined. Post hoc tests on significant interactions showed that, between the times of the assisting player’s reception of the ball and the eventual shot on goal, the mean values of ID decreased significantly less in plays ending in a goal (M 0.44, SE0.27) than in plays ending in a defender’s interception (M 2.27,SE0.48, pB0.05).

Table I. Results from the mixed-model ANOVA tests examining the main effects of outcomes of play, moments of play and outcomes of play X moments of play on the: (1) defender’s angle to the attacker and the goal (DAG); (2) relative distance to the goal (RDG); (3) interpersonal distance (ID) and (4) relative velocity (RV)

Outcomes Moments Outcomes Moments

Variables F df1 df2 F df1 df2 F df1 df2

DA 18.83 2.00 87.00** 1.81 2.21 192.31 2.97 4.42 192.31*

RDG 9.73 2.00 87.00** 1.71 2.29 199.33 0.29 4.52 199.33

ID 1.78 2.00 87.00 30.62 1.96 170.79** 4.74 3.93 170.79**

RV 0.81 2.00 58.00 13.90 2.35 204.41** 3.03 4.67 204.41*

Note:Fresult of the ANOVA test; df1degrees of freedom between groups; df2degrees of freedom within groups.

*pB0.05; **pB0.001.

(6)

Statistical analysis showed no main effect for outcomes of play, F(2,58)1.78, p0.05, h²0.06 suggesting that, regardless of moments of play, there were no statistical differences in ID values between plays ending in goal, in a goalkeeper save and in a defender’s interception. However, a significant main effect was observed for moments of play F(1.96,170.79)30.62, pB0.001, h²0.26 suggesting that, regardless of outcomes of play, ID differed during the performance periods investigated.Post hocanalyses revealed that the mean values of ID at the moment the attacker shot on goal (M2.38, SE0.12) were significantly lower than at all previous investigated moments, that is, at the moments of ball reception by the assisting player (M3.89, SE0.25, pB0.001), the assisting player’s pass (M4.17, SE0.26, pB0.001) and the ball reception by the shooter (M3.55, SE0.22, pB0.001). In addition,post hocanalyses on moments of play effects also revealed that the mean values of ID were significantly higher at the

moments of the assisting player’s pass (M4.17, SE0.26) than at the shooter’s ball reception (M3.55,SE0.22,pB0.001) (Figure 3).

Relative velocity

Significant effects were observed for the moments of play X outcomes of play interactions, F(4.67,204.41)3.03,pB0.05,h²0.07, suggesting that the influence of outcomes of play on RV changed at the performance times considered. Post hoctests for interaction effects showed that, between the moments of ball reception by the assisting player and the shot on goal, the mean values of RV increased in plays ending in a goal (M0.10, SE0.54), but decreased in plays ending in a goalkeeper’s save (M 1.61,SE0.51,pB0.05) and in a defender’s interception (M 2.15,SE0.38, pB0.01). In addition, between the moments of ball reception by the assisting player and shooter’s reception, the mean values of RV decreased signifi-

Goal GK’s save DEF’s interception

AR AP SR SG

0 30 60 90 120 150 180

Defender’s angle to the goal and the attacker (degrees)

(A)

(B)

AR AP SR SG

0 3 6

Relative distance to the goal (m)

Figure 2. Mean values and standard deviations of the (A) defender’s angles to the goal and the attacker and the (B) relative distance to the goal, for the three types of the outcomes of play at the four instances prior to the shot at goal: moment of ball reception by the assisting player (AR), moment of pass initiation by the assisting player (AP), moment of ball reception by the shooting player (SR) and moment of shot at goal (SG).

(7)

cantly less in plays ending in a goal (M 0.01, SE0.55) than in plays ending in a defender’s interception (M 1.94, SE0.43, pB0.05).

Statistical analysis showed no main effects for outcomes of play, F(2,58)0.81, p0.05, h²0.03, suggesting that, regardless of moments of play, there were no statistical differences in the mean values of RV between plays ending in a goal, in a goalkeeper’s save and in a defender’s interception. However, a significant main effect was observed for moments of play, F(2.35,204.41)13.90, pB0.001, h².14 suggesting that, regardless of outcomes of play, there were differences in the mean values of RV at the examined performance times. More precisely, post hoc tests showed that the mean values of RV were significantly higher at the moment of ball reception by the assisting player (M0.78,SE0.20) than at the moments of the shooter’s reception of the pass (M 0.46, SE0.23, pB0.01) and the shot on goal (M 0.44, SE0.20, pB0.001). In addi-

tion, the mean values of RV were significantly higher at the moment of the assisting player’s pass (M0.66, SE0.21) than at the moments of a shooter’s reception of a pass (M 0.46,SE0.23, pB0.01) and the shot on goal (M 0.44, SE0.20, pB0.001).

Discussion

In this study, we aimed to identify coordination patterns emerging between an attacking player and a marking defender during competitive performance in futsal. In this section, we discuss our findings regard- ing each dependent variable selected for analysis.

Defender’s angle to the goal and the attacker

Results suggested that an attacker did not need to be completely ahead of a defender (closer to the goal) to score in futsal, compared to data observed in 1vs1

AR AP SR SG

0 2 4 6 8

Interpersonal distance (m)

AR AP SR SG

0 1.5 3

Relative velocity (m/s)

Goal GK’s save DEF’s interception

(A)

(B)

Figure 3. Mean values and standard deviations of the (A) interpersonal distance and the (B) relative velocity, for the three types of the outcomes of play at the four instances prior to the shot at goal: moment of ball reception by the assisting player (AR), moment of pass initiation by the assisting player (AP), moment of ball reception by the shooting player (SR) and moment of shot at goal (SG).

(8)

sub-phases of other team sports such as rugby union (Passos et al., 2009). Promoting a misalignment in the defender’s relative position between the goal and the attacker was enough to allow an attacker to score a goal. This result concurs with other data from the team sport of futsal reported by Travassos et al.

(in press) showing that attackers try to promote a misalignment in the positioning of a defender relative to the ball and the goal, whereas defenders try to couple their displacement in relation to the ball and goal locations in order to decrease the available space for opponents’ actions.

Results also showed that when the defender’s angle to the goal and the attacker was not significantly small until the final moment of play (i.e. when the shot on goal occurred), the goalkeeper tended to intercept the ball. One possible explanation for this observation may be that when the defender regained his position in between the attacker and the goal (i.e.

increased the value of DA), the defender may have constrained the attacker to shoot before he was certain of scoring a goal, creating the appropriate conditions for the goalkeeper to save the shot on goal. This result can be interpreted based on the time for intercepting the ball’s trajectory, as observed in previous studies of passing in futsal (Travassos et al., 2012) and in a 2v1sub-phase of rugby union (Correia, Arau´ jo, Craig, & Passos,2011).

The significant main effect found between plays ending in a defender’s shot interception and plays ending in a goal and in a goalkeeper’s save, suggested that the mean values of the DA were different during the period of time considered in this research (i.e.

from the moment of the assisting player’s reception of the ball until the shot occurred). This finding implies that the attacker explored the positional misalignment of the defender in order to gain an advantagebefore the assisting player actually received the ball.

Relative distance to the goal

Results suggested that when a shot on goal success- fully emerged from inter-individual interactions, the RDG was significantly lower than when the defender intercepted the ball’s trajectory. This finding may imply that by standing at the same distance to the goal at the moment of shooting, the attacker sought to ensure that the defender had no time to intercept the ball’s trajectory before it reached the goal.

Moreover, at the moment of shooting the mean values of RDG decreased significantly in plays ending in a goalkeeper’s save than in plays ending in goals, suggesting that the defender may have constrained the attacker to shoot sooner than necessary.

A significant main effect was found between plays ending in a defender’s interception, and plays ending in both a goal being scored and in a goalkeeper’s

save. These findings suggest that, when considering 5vs5 competitive performance environments, the time at which the attacker acquired a similar distance value to the target area as the marking defender occurred before the assisting player received the ball.

Because in 1vs1 sub-phases of team sports there are no assisting players, in such setting it is not possible to record and analyse the interpersonal interactions of attackers and defenders prior to and after the ball has been passed to create a shooting opportunity.

Interpersonal distance

Results suggested that when an attacker scored a goal, he was able to maintain a significantly larger distance value between him and a marking defender.

This distance value was not only significantly larger when the attacker had the ball in his possession, but also while he moved to afford a passing opportunity for his attacking teammate. This finding suggests that a large ID value may be important not only to perform a successful shot at goal, but also to create a successful assisted pass. This observation is in line with previous research in 1v1 sub-phases of team sports suggesting that ball interceptions tend to occur under small values of attackerdefender IDs, in different team sports like football (Duarte, Arau´ jo, Gazimba, et al., 2010) and rugby union (Passos et al., 2008). Conversely, these data suggested that defenders should begin to decrease their distance to a nearest attackerbeforea pass is made to that player.

This argument is supported by the interaction effects found for moments of play X outcomes of play.

In addition, even if the attacker had increased sufficient distance to a marking defender to shoot the ball at goal, results suggested that a defender should continue to reduce the ID with the attacker. This tactic is likely to constrain the attacker to shoot earlier than necessary in order to score a goal, creating an advantage for the defensive team. These data demonstrate how the defender’s performance might actively constrain the interpersonal interactions developed with an immediate attacker, which may influence the performance outcomes in his favour. Our results on IDs contrasted with data reported by Headrick et al. (2012), who showed effects of proximity to goal as a key influence on interpersonal interactions in 1v1 dyads. They showed that in 1v1 sub-phases in football, in regions of the pitchfarfrom a goal being attacked, the value of a defender’s distance to the ball was lower than in pitch areascloserto the targeted goal.

Relative velocity

Results suggested that to score a goal the attacker maintained a high velocity both before and after

(9)

receiving the ball. This strategy might have pre- vented the defender from getting close enough to the attacker and intercept the ball’s trajectory.

The significant main effects of the moment of play found at the time of the assisting player’s pass and the shooter’s reception of the ball suggested that, at these periods of time, changes in this performance variable constrained the emergence of distinct outcomes of play, as also observed in studies of dribbling in soccer (Duarte, Arau´jo, Gazimba, et al., 2010) and running with the ball in rugby union (Passos et al.,2009). When a defender is not able to increase running velocity before a shooter receives the ball, an assisting pass and a shot can occur without interception. This finding suggests that the displacement of a defender before receiving the ball constrained the attackers’ possibilities for action in order for him to attain the necessary performance conditions to control the ball and shoot at goal without a defender intercepting the ball. This suggestion is supported by the interaction effects found for moments of play X outcomes of play.

Conclusions

In this paper, we used ecological dynamics as a theo- retical explanation of the creation/prevention of opportunities to score goals during the team game of futsal.

We extended existing knowledge on performance analysis providing an alternative method to more conventional approaches by considering the active role of the opponents in shaping each other’s performance behaviours and influencing outcomes of play.

Distinctive patterns of movement coordination between a shooter, a closest defender and the location of the ball were identified that led to the creation/prevention of opportunities to score goals.

These required relationships of an attacker with the defender and the goal were also shown to emerge before an assisting player received the ball to create a shooting opportunity. In addition, these findings suggested that, even when the defender was not able to intercept the ball’s trajectory, he might have constrained an attacker to shoot earlier than he/she needed to, providing the goalkeeper with possible conditions to intercept the shot at goal. Future research should examine not only the dependence between the variables considered in this paper, but also the interpersonal coordination tendencies between assisting attackers andtheir marking defenders that may constrain performance outcomes in competitive team games like futsal.

References

Arau´ jo, D., Davids, K., Bennett, S., Button, C., & Chapman, G.

(2004). Emergence of sport skills under constraints. In A.M.

Williams, & N.J. Hodges (Eds.), Skill Acquisition in sport:

Research, theory and practice(pp. 409433). London: Routle- dge, Taylor & Francis.

Correia, V., Arau´ jo, D., Craig, C., & Passos, P. (2011). Prospec- tive information for pass decisional behavior in rugby union.

Human Movement Science,30(5), 984997.

Davids, K., Button, C., Arau´ jo, D., Renshaw, I., & Hristovski, R.

(2006). Movement models from sports provide representative task constraints for studying adaptive behavior in human movement systems.Adaptive Behavior,14(1), 7395.

Duarte, R., Arau´ jo, D., Fernandes, O., Fonseca, C., Correia, V., Gazimba, V., et al. (2010). Capturing complex human behaviors in representative sports contexts with a single camera.

Medicina,46(6), 408414.

Duarte, R., Araujo, D., Freire, L., Folgado, H., Fernandes, O., &

Davids, K. (in press). Intra- and inter-group coordination patterns reveal collective behaviors of football players near the scoring zone.Human Movement Science. doi: 10.1016/j.humov.

2012.03.001

Duarte, R., Arau´ jo, D., Gazimba, V., Fernandes, O., Folgado, H., Marmeleira, J., et al. (2010). The ecological dynamics of 1v1 sub-phases in association football. The Open Sports Sciences Journal,3, 1618.

Fernandes, O., Folgado, H., Duarte, R., & Malta, P. (2010).

Validation of the tool for applied and contextual time-series observation.International Journal of Sport Psychology,41, 63 64.

Field, A. (2005). Discovering statistics using SPSS (2nd ed.).

London: SAGE publications.

Goto, R., & Mascie-Taylor, C. (2007). Precision of measurement as a component of human variation. Journal of Physiological Anthropology,26(2), 253256.

Headrick, J., Davids, K., Renshaw, I., Arau´ jo, D., Passos, P., &

Fernandes, O. (2012). Proximity-to-goal as a constraint on patterns of behaviour in attackerdefender dyads in team games. Journal of Sports Sciences, 30(3), 247253. doi:

10.1080/02640414.2011.640706

Passos, P., Araujo, D., Davids, K., Gouveia, L., Milho, J., &

Serpa, S. (2008). Information-governing dynamics of attackerdefender interactions in youth rugby union.Journal of Sports Sciences,26(13), 14211429.

Passos, P., Arau´ jo, D., Davids, K., Gouveia, L., Serpa, S., Milho, J., et al. (2009). Interpersonal pattern dynamics and adaptive behavior in multiagent neurobiological systems: Conceptual model and data.Journal of Motor Behavior,41(5), 445459.

Schmidt, R. C., Fitzpatrick, P., Caron, R., & Mergeche, J. (2011).

Understanding social motor coordination.Human Movement Science,30(5), 834845.

Schutz, R., & Gessaroli, M. (1987). The analysis of repeated measures designs involving multiple dependent variables.

Research Quarterly for Exercise and Sport,58(2), 132149.

Travassos, B., Arau´ jo, D., Davids, K., Vilar, L., Esteves, P., &

Correia, V. (2012). Informational constraints shape emergent functional behaviours during performance of interceptive actions in team sports. Psychology of Sport & Exercise, 13, 216223.

Travassos, B., Arau´ jo, D., Duarte, R., & McGarry, T. (in press).

Spatiotemporal coordination patterns in futsal (indoor football) are guided by informational game constraints. Human Movement Science. doi: 10.1016/j.humov.2011.10.004 Vilar, L., Arau´ jo, D., Davids, K., & Button, C. (2012). The role of

ecological dynamics in analysing performance in team sports.

Sports Medicine,42(1), 110.

Winter, D. (2005). Biomechanics and motor control of human movement(3rd ed.). New York: John Wiley & Sons.