Analysis of the motor behaviour of people without specific dance training in improvisation tasks: Influence of mirror and partner.

This study aims to analyse the influence of the mirror and/or partner constraints on the motor creativity of women without specific training in dance during improvisation tasks, in order to contribute to the knowledge of creativity in the field of sports science and movement-based practices. We studied the exploratory behaviour and emerging movement patterns of 12 women who performed four improvisations under the following situations: individual without mirror; individual with mirror; partner without mirror; and partner with mirror. The dynamic overlap qd(t) was calculated to identify the exploratory dynamics composed of the exploratory amplitude and the rate of change between movement configurations. To determine emerging movement patterns, a principal component analysis was carried out by ad hoc routines prepared. A mixed linear model was performed to find out the influence of the different constraints on the exploratory behaviour. The results indicate that the presence of the mirror seems to provoke a decrease in the exploratory behaviour. In addition, partner improvisation favoured coupling and imitation dynamics among the participants. Likewise, the most recurrent emergent movement pattern was walking while moving the arms. It would be advisable to take the influence of these constraints into consideration depending on the improvisation purpose and the experience level of female participants.

The diagonal positioning of the goals modifies the external training load and the tactical behaviour of young football players.

The aim of this study was to identify how positioning the goals in diagonal configurations on the pitch modifies the external training load and the tactical behaviour of young football players during small-sided games. Four teams of five outfield players and a goalkeeper played six small-sided games of five minutes' duration in three different scenarios: 1) Control: goals placed one in front of the other; 2) Right diagonal goals: goals placed in the right-hand corner of the offensive half-pitch; and 3) Left diagonal goals: goals placed in the left-hand corner of the offensive half-pitch. The positioning-derived data from each player were collected with 10-Hz GPS units and were used to compute external load and tactical variables. Regarding the external load variables, differences were mainly focused on distance covered while walking in defence and game pace (variability), with higher values for the diagonal scenarios. Also, the length/width ratios in offence and defence were most likely lower in diagonal scenarios. In conclusion, the results showed that players' adaptations to the environmental constraints of positioning the goals diagonally were the enhancement of the width team variable and the variability of the length.

Training or Synergizing? Complex Systems Principles Change the Understanding of Sport Processes.

There is a need to update scientific assumptions in sport to promote the critical thinking of scientists, coaches, and practitioners and improve their methodological decisions. On the basis of complex systems science and theories of biological evolution, a systematization and update of theoretical and methodological principles to transform the understanding of sports training is provided. The classical focus on learning/acquiring skills and fitness is replaced by the aim of increasing the diversity/unpredictability potential of teams/athletes through the development of synergies. This development is underpinned by the properties of hierarchical organization and circular causality of constraints, that is, the nestedness of constraints acting at different levels and timescales. These properties, that integrate bottom-up and top-down all dimensions and levels of performance (from social to genetic), apply to all types of sport, ages, or levels of expertise and can be transferred to other fields (e.g., education, health, management). The team as the main training unit of intervention, the dynamic concept of task representativeness, and the co-adaptive and synergic role of the agents are some few practical consequences of moving from training to synergizing.

Effects of Temporary Numerical Imbalances on Collective Exploratory Behavior of Young and Professional Football Players.

The aim of this study was to explore how the use of temporary numerical imbalances during small-sided Game SSGs affects team's exploratory behaviors (i.e., variety and quantity of responses given in an ever-changing game context and its rate of change) in different age groups. Two different age groups (under-15 and under-23) of football players participated in the study. For each age group, three teams of five players played six small-sided games of 5 min duration in different conditions: (i) numerical balance (GK + 4 vs. 4 + GK); (ii) temporary numerical imbalance, which consisted of a numerical change of teammates and opponents every one minute. Latitude and longitude GPS coordinates were used to determine the positioning-derived variables. The dynamic overlap (i.e. the measure of average similarity of the game patterns that take place in increasingly larger time intervals) was used to provide information of the rate and breadth of exploratory behavior. The results revealed that the long-term exploratory breadth increased for the under-23 age group. Non-clear effects were found for the short-term rate of exploration, but with an increasing trend. In the under-15 group, the exploratory behavior was more likely to increase in the long term. The increase for the short-term rate of exploration was unclear, but it follows an increasing trend. These results suggest that the use of temporary numerical imbalances could offer coaches more dynamic training situations and different adaptive training environments similar to matches.

On the Relatedness and Nestedness of Constraints.

The purpose of this opinion paper is providing a platform for explaining and discussing the relatedness and nestedness of constraints on the basis of four claims: (a) task constraints are distributed between the person and the environment and hence are relational variables, (b) being relational, task constraints are also emergent properties of the organism/environment system, (c) constraints are nested in timescales, and (d) a vast set of constraints are correlated through circular causality. Theoretical implications for improving the understanding of the constraints-led approach and practical applications for enhancing the manipulation of constraints in learning and training settings are proposed.

Free Play with Certain Equipment Constrains the Emergence of Exploratory Behavior and Physical Activity in Preschoolers.

The aim of this study was to establish whether various types of play equipment differentially constrain exploratory behavior and spontaneous physical activity patterns in preschoolers when they play freely with them. Fourteen children, 3-4 years old, played with four different types of equipment. The children wore an accelerometer and data were analyzed taking into account overall physical activity, the time spent at different intensity levels of move-ment, and the entropy of the time series. All trials were video-recorded and a systematic observation instrument was used to register actions and interactions with partners and equipment. The data were subsequently analyzed by means of principal component analysis (PCA) and the dynamic overlap order parameter, to identify the rate and breadth of exploratory behavior on different time scales. Our results revealed that the children were physically less active when playing with portable and small equipment. The PCA showed that when playing without equipment, the children usually played standardized games, like playing tag, in groups. Movement patterns were more or less varied depending on the equip-ment, and thus some equipment constrained the emergence of different types of games or motor behavior.

Dynamics of tactical behaviour in association football when manipulating players' space of interaction.

The analysis of positional data in association football allows the spatial distribution of players during matches to be described in order to improve the understanding of tactical-related constraints on the behavioural dynamics of players. The aim of this study was to identify how players' spatial restrictions affected the exploratory tactical behaviour and constrained the perceptual-motor workspace of players in possession of the ball, as well as inter-player passing interactions. Nineteen professional outfield male players were divided into two teams of 10 and 9 players, respectively. The game was played under three spatial constraints: a) players were not allowed to move out of their allocated zones, except for the player in possession of the ball; b) players were allowed to move to an adjacent zone, and; c) non-specific spatial constraints. Positional data was captured using a 5 Hz interpolated GPS tracking system and used to define the configuration states of players for each second in time. The configuration state comprised 37 categories derived from tactical actions, distance from the nearest opponent, distance from the target and movement speed. Notational analysis of players in possession of the ball allowed the mean time of ball possession and the probabilities of passing the ball between players to be calculated. The results revealed that the players' long-term exploratory behaviour decreased and their short-term exploration increased when restricting their space of interaction. Relaxing players' positional constraints seemed to increase the speed of ball flow dynamics. Allowing players to move to an adjacent sub-area increased the probabilities of interaction with the full-back during play build-up. The instability of the coordinative state defined by being free from opponents when players had the ball possession was an invariant feature under all three task constraints. By allowing players to move to adjacent sub-areas, the coordinative state became highly unstable when the distance from the target decreased. Ball location relative to the scoring zone and interpersonal distance constitute key environmental information that constrains the players' coordinative behaviour. Based on our results, dynamic overlap is presented as a good option to capture tactical performance. Moreover, the selected collective (i.e. relational) variables would allow coaches to identify the effects of training drills on teams and players' behaviour. More research is needed considering these type variables to understand how the manipulation of constraints induce a more stable or flexible dynamical structure of tactical behaviour.

Effects of Pitch Area-Restrictions on Tactical Behavior, Physical, and Physiological Performances in Soccer Large-Sided Games.

Gonçalves, B, Esteves, P, Folgado, H, Ric, A, Torrents, C, and Sampaio, J. Effects of pitch area-restrictions on tactical behavior, physical and physiological performances in soccer large-sided games. J Strength Cond Res 31(9): 2398-2408, 2017-The aim of this study was to identify how pitch area-restrictions affect the tactical behavior, physical, and physiological performances of players during soccer large-sided games. A 10 vs. 9 large-sided game was performed under 3 experimental conditions: (a) restricted-spacing, the pitch was divided into specific areas where players were assigned and they should not leave it; (b) contiguous-spacing, the pitch was divided into specific areas where the players were only allowed to move to a neighboring one; (c) free-spacing, the players had no restrictions in space occupation. The positional data were used to compute players' spatial exploration index and also the distance, coefficient of variation, approximate entropy, and frequency of near-in-phase displacements synchronization of players' dyads formed by the outfield teammates. Players' physical and physiological performances were assessed by the distance covered at different speed categories, game pace, and heart rate. Most likely higher values were found in players' spatial exploration index under free-spacing conditions. The synchronization between dyads' displacements showed higher values for contiguous-spacing and free-spacing conditions. In contrast, for the jogging and running intensity zones, restricted-spacing demanded a moderate effect and most likely decrease compared with other scenarios (∼20-50% to jogging and ∼60-90% to running). Overall, the effects of limiting players' spatial exploration greatly impaired the coadaptation between teammates' positioning while decreasing the physical and physiological performances. These results allow for a better understanding of players' decision-making process according to specific task rules and can be relevant to enrich practice task design, such that coaches acknowledge the differential effect by using specific pitch-position area restrictions.

Emergence of Exploratory, Technical and Tactical Behavior in Small-Sided Soccer Games when Manipulating the Number of Teammates and Opponents.

The effects that different constraints have on the exploratory behavior, measured by the variety and quantity of different responses within a game situation, is of the utmost importance for successful performance in team sports. The aim of this study was to determine how the number of teammates and opponents affects the exploratory behavior of both professional and amateur players in small-sided soccer games. Twenty-two professional (age 25.6 ± 4.9 years) and 22 amateur (age 23.1 ± 0.7 years) male soccer players played three small-sided game formats (4 vs. 3, 4 vs. 5, and 4 vs. 7). These trials were video-recorded and a systematic observation instrument was used to notate the actions, which were subsequently analyzed by means of a principal component analysis and the dynamic overlap order parameter (measure to identify the rate and breadth of exploratory behavior on different time scales). Results revealed that a higher the number of opponents required for more frequent ball controls. Moreover, with a higher number of teammates, there were more defensive actions focused on protecting the goal, with more players balancing. In relation to attack, an increase in the number of opponents produced a decrease in passing, driving and controlling actions, while an increase in the number of teammates led to more time being spent in attacking situations. A numerical advantage led to less exploratory behavior, an effect that was especially clear when playing within a team of seven players against four opponents. All teams showed strong effects of the number of teammates on the exploratory behavior when comparing 5 vs 7 or 3 vs 7 teammates. These results seem to be independent of the players' level.

Soft-assembled Multilevel Dynamics of Tactical Behaviors in Soccer.

This study aimed to identify the tactical patterns and the timescales of variables during a soccer match, allowing understanding the multilevel organization of tactical behaviors, and to determine the similarity of patterns performed by different groups of teammates during the first and second halves. Positional data from 20 professional male soccer players from the same team were collected using high frequency global positioning systems (5 Hz). Twenty-nine categories of tactical behaviors were determined from eight positioning-derived variables creating multivariate binary (Boolean) time-series matrices. Hierarchical principal component analysis (PCA) was used to identify the multilevel structure of tactical behaviors. The sequential reduction of each set level of principal components revealed a sole principal component as the slowest collective variable, forming the global basin of attraction of tactical patterns during each half of the match. In addition, the mean dwell time of each positioning-derived variable helped to understand the multilevel organization of collective tactical behavior during a soccer match. This approach warrants further investigations to analyze the influence of task constraints on the emergence of tactical behavior. Furthermore, PCA can help coaches to design representative training tasks according to those tactical patterns captured during match competitions and to compare them depending on situational variables.

Timescales for exploratory tactical behaviour in football small-sided games.

The aim of this study was to identify the dynamics of tactical behaviour emerging on different timescales in football small-sided games and to quantify short- and long-term exploratory behaviour according to the number of opponents. Two teams of four professional male footballers played small-sided games against two different teams with a variable number of opponents (3, 5 and 7). Data were collected using a combination of systematic observation and a non-differential global positioning system (15 Hz). The temporal diversity and structural flexibility of the players were determined by calculating the dynamic overlap order parameter q, entropy and trapping strength. Analysis of the exploratory dynamics revealed two different timescales, forming a different metastable landscape of action for each constraint. Fast dynamics lasted on average a few seconds and consisted of changes in tactical patterns. The long timescale corresponded to the shared tasks of offence and defence lasting tens of seconds. The players' tactical diversity decreased with an increasing number of opponents, especially in defence. Manipulating numerical imbalance is likely to promote changes in the diversity, unpredictability and flexibility of tactical solutions. The fact that the temporally nested structure of constraints shaped the emergence of tactical behaviour provides a new rationale for practice task design. The manipulation of numerical imbalance on the timescale of a few tens of seconds, on which the exploratory behaviour of players saturates, may help coaches to optimise the exploratory efficiency of the small-sided games.

Heart Rate, Time-Motion, and Body Impacts When Changing the Number of Teammates and Opponents in Soccer Small-Sided Games.

The purpose of this study was to determine the internal (heart rate) and external load (body load, distance covered, and exertion index) during different types of unbalanced soccer small-sided games (SSGs) in professional (PRO) and amateur (AMA) players. In 2 separated sessions (PRO and AMA), participants played 3 SSG formats (4vs3, 4vs5, and 4v7). Data were analyzed from the fixed team's perspective (4vsX) according to the number of opponents (3, 5 and 7) and from the variable team (3 + Xvs4) according to the teammates (without teammates, 2 and 4 teammates). The time-motion and body impact data were collected using a nondifferential global positioning system with integrated heart rate measurement. Differences in internal and external workload between the game formats were compared using Cohen's dunb effect sizes with 95% confidence intervals. Results reveal that the higher the number of players involved in the task, the lower the internal and external workload. The analysis also showed different teammates and opposition-related trends that need to be considered when planning and monitoring training performance. Playing in low-inferiority (4vs3 and 4vs5) had higher physiologic impact to players than the other higher unbalanced situations. This evidence was similar to both PRO and AMA players; however, the PRO presented higher physical and lower physiological responses across games. Our results suggest that coaches should consider the usage of unbalanced SSG formats to simultaneously facilitate the emergence of defensive and offensive proficient scenarios also representing opportunities to increase the practice workload.

Kinematic parameters that influence the aesthetic perception of beauty in contemporary dance.

Some experiments have stablished that certain kinematic parameters can influence the subjective aesthetic perception of the dance audience. Neave, McCarty, Freynik, Caplan, Hönekopp, and Fink (2010, Biology Letters 7 221-224) reported eleven movement parameters in non-expert male dancers, showing a significant positive correlation with perceived dance quality. We aim to identify some of the kinematic parameters of expert dancers' movements that influence the subjective aesthetic perception of observers in relation to specific skills of contemporary dance. Four experienced contemporary dancers performed three repetitions of four dance-related motor skills. Motion was captured by a VICON-MX system. The resulting 48 animations were viewed by 108 observers. The observers judged beauty using a semantic differential. The data were then subjected to multiple factor analysis. The results suggested that there were strong associations between higher beauty scores and certain kinematic parameters, especially those related to amplitude of movement.

Identifying and analyzing motor skill responses in body movement and dance.

The present article analyzes the diversity of motor skills related to three different kinds of instructions: descriptive, metaphoric, and kinesic, with a special emphasis on the detection of temporal patterns (T-patterns). Twelve undergraduates studying sport and physical education, but without experience in dance, were observed during 24 lessons of Body Movement, a discipline based on creative dance, mime dance, and motor skill improvisation. Using observational methodology and technology applied to movement, the aim of this article was to adapt the Observational instrument of Motor Skills (OSMOS) (Castañer, Torrents, Anguera, & Dinusová, 2008) so as to create an instrument capable of analyzing the motor skill responses generated in lessons of Body Movement and Dance. The results, as reflected by the T-patterns detected, show that (1) participants try to generate their own motor skills but copy some fundamental components of the instructions, and (2) the criterion of stability in two configurations (support and axial) is the predominant category. Sequential and coordinated locomotion also appears to be very relevant.