Komar John

This study aimed to quantify the break shot characteristics and identify their significance in predicting the game outcomes in 9-ball tournaments. The break shots of 275 frames (241 men’s, 34 women’s) of professional tournaments were analyzed from two aspects: (1) cue ball position, represented by the distance between the cue ball and the table center, and (2) ball distribution, indicated by the standard deviation of Voronoi cell areas determined from all remaining balls on the table. Spearman correlation and binary logistic regression were utilized to identify associations and to predict the frame outcomes, respectively. Results showed that the more balls falling into the pockets during the break, the more clustered the remaining balls (rs = 0.232, p < 0.001). The closer the cue ball ending toward the table center, the more balls potted in the visit immediately after the break (rs = −0.144, p = 0.027). Neither cue ball position nor ball distribution could predict table clearance or winning of a frame. In conclusion, pocketing more balls during the break is associated with more clustered balls remaining on the table. Parking the cue ball near the table center after the break can facilitate potting more balls immediately after.

The main purpose of the research was to describe the daily screen media habits and non-screen media habits like indoor and outdoor play, and sleep of preschool children aged 2 to 6 years from Singapore, South Korea, Japan, and Finland using a content-validated online questionnaire (SMALLQ®) and unsupervised cluster analysis. Unsupervised cluster analysis on 5809 parent-reported weekday and weekend screen and non-screen media habits of preschool children from the four countries resulted in seven emergent clusters. Cluster 2 (n = 1288) or the Early-screen media, screen media-lite and moderate-to-vigorous physical activity-lite family made up 22.2% and Cluster 1 (n = 261) or the High-all-round activity and screen media-late family made up 4.5%, respectively represented the largest and smallest clusters among the seven clusters that were emergent from the pooled dataset. Finland was best represented by Cluster 2 and Japan was best represented by Cluster 3 (High-screen media-for-entertainment and low-engagement family). Parents from Finland and Japan displayed greater homogeneity in terms of the screen media and non-screen media habits of preschool children than the parents from South Korea and Singapore. South Korea was best represented by Clusters 6 (Screen media-physical activity-engagement hands-off family) and 7 (Screen media-lite, screen media-late and high-physical activity family). Singapore was best represented by Clusters 4, 5, 6 and 7, and these clusters ranged from Low all-round activity-high nap time family to Screen media-lite, screen media-late and high-physical activity family. Future research should explore in-depth reasons for the across-country and within-country cluster characteristics of screen media and non-screen media habits among preschool children to allow for more targeted interventions.

Introduction The constraints-led approach (CLA) and more generally a complex systems perspective on motor learning emphasizes the role of perceptual-motor exploration during learning in order to ensure the acquisition of a highly individualized, adapted and adaptable movement pattern. Recent studies have shown that human beings have a strong tendency to exploit already stable patterns rather than looking for new potentially more efficient patterns. In order to shape the amount of exploration, we implemented two learning designs based on a CLA where constraints were used to limit the boundaries of the perceptual-motor workspace of the learners. We sought to highlight how practitioners can play with the perceptual motor workspace boundaries in order to i) promote the use of exploratory behaviours and ii) guide the learner towards task-relevant functional areas.
Method For the experiment, twenty-four beginners in breaststroke swimming were allocated to three groups of learning: a control group receiving only the goal of the learning, an analogy group receiving the goal of learning accompanied by an analogy about “how to perform”, a pacer group receiving information on the goal of learning and the use of a metronome to continuously push them to “perform better”. Based on their assigned group, each learner then followed a learning protocol of 16 sessions with a 10*25m swimming distance per session with the goal of increasing the stroke length for a fixed swimming speed. Both performance (i.e., stroke length) and motor behaviour (i.e., arm-leg coordination) were collected for each session. The arm-leg coordination patterns were computed by the continuous relative phase between knee and elbow angles. Thereafter, a cluster analysis was performed on the coordination in order to get a qualitative label for every cycle performed during the entire process of learning. Based on the use of cluster analysis, an exploration/exploitation ratio was calculated and the increase in performance was determined based on the increase in stroke length.
Results and Discussion With reference to the exploration/exploitation ratio, our results showed that additional temporary constraints led learners to increase both the nature of their exploration and also the quantity of their exploration. In the meantime, the three groups showed an equivalent final performance enhancement. The aim of manipulating the constraints was not only to push the learner out of his comfort zone, but also to provide relevant information about “where” to explore during learning. For this purpose, the use of analogy appeared as the most relevant constraint to encourage the emergence of efficient behaviour. Interestingly the impact of the analogy was modified by adding the metronome, showing an interaction effect of both constraints. The group using the metronome exhibited different behaviours as compared to the analogy group and showed an increase in exploration during learning compared to the control group. However, although the metronome constantly pushed the learner to improve performance, it did not actually lead to a better improvement of performance when compared to the analogy group. The simple assumption that the constraints forced the learner to explore therefore does not seem a mandatory condition to promote an exploratory learning. Rather, the qualitative nature of the constraint seems the most relevant characteristic that can be manipulated to promote an exploratory learning by guiding the learner within the perceptual motor workspace.

The research aims were to examine the relationships between parent and child digital media use and to describe the characteristics of the top and bottom quartiles of child digital media use in meeting the 24 h integrated guidelines for sleep, physical activity, and sedentary behaviour. Parent-reported on- and off-screen habits and quality of life of children were collected from 1481 parents of preschool children aged 2–5 years in 2019. Significant relationships were detected between parent and child digital media use (weekday, r = 0.274; weekend, r = 0.421, p < 0.05) with no sex difference in daily child digital media use (p > 0.05). Age of first exposure to fixed screens, daily digital media use, and physical play durations were significantly different between heavy (child-TQ) and light (child-BQ) child users of digital media (p < 0.05). Parental perceived importance of child digital media use and parental awareness and practice of guidelines for child digital media use differed significantly between parents of child-TQs and parents of child-BQs (p < 0.05). The number of 24 h movement guidelines met between child-TQs and child-BQs differed (p < 0.05). Parents voiced serious concerns for child digital media use, including addiction (75–76%), poor eyesight (73%), access to inappropriate content (73–74%), a lack of parent–child interaction (65%), poor sleep (49–55%), and a lack of physical activity (55–59%), but these findings did not translate to parental enforcement of the guidelines. Parent education on how to get the best digital media use outcomes for preschool children is recommended.

Reinforcement learning has been used as an experimental model of motor skill acquisition, where at times movements are successful and thus reinforced. One fundamental problem is to understand how humans select exploration over exploitation during learning. The decision could be influenced by factors such as task demands and reward availability. In this study, we applied a clustering algorithm to examine how a change in the accuracy requirements of a task affected the choice of exploration over exploitation. Participants made reaching movements to an unseen target using a planar robot arm and received reward after each successful movement. For one group of participants, the width of the hidden target decreased after every other training block. For a second group, it remained constant. The clustering algorithm was applied to the kinematic data to characterize motor learning on a trial-to-trial basis as a sequence of movements, each belonging to one of the identified clusters. By the end of learning, movement trajectories across all participants converged primarily to a single cluster with the greatest number of successful trials. Within this analysis framework, we defined exploration and exploitation as types of behaviour in which two successive trajectories belong to different or similar clusters, respectively. The frequency of each mode of behaviour was evaluated over the course learning. It was found that by reducing the target width, participants used a greater variety of different clusters and displayed more exploration than exploitation. Excessive exploration relative to exploitation was found to be detrimental to subsequent motor learning.

Non-proficient demonstration, gross motor skill assessment, and subjective feedback are but a few of the perennial problems in physical education (PE). These problems stand to benefit from a technology-based solution that uses human pose estimation to guide learning. In this approach, a criterion motor action is embedded in a deep-learning algorithm (DLA). A learner can view this motor action on an iPad and uses its kinematic signatures to guide practice. The learner’s movement is captured by the device and the recorded motor action enters the DLA for computation of movement proficiency. The output of the DLA is a quantitative index that informs the learner how well the movement has been executed. In this way, the learner gains timely and objective feedback. A separate device held by the PE teacher collates the quantitative indices from other students in the class. Collectively, the information facilitates the teacher’s selection of instructional strategies.

In the twenty-first century the Physical Education (PE) landscape is ever changing, with students being immersed increasingly in technologically driven learning environments. Therefore, there is a need to understand how Information and Communication Technology (ICT) are impacting learning opportunities. Specifically, how pedagogical practices could benefit from the development of ICT. This study investigated the effect of using ICT in PE when it is accompanied by a pedagogical innovation to promote students’ motivation. Thirty participants from 5 different indoor climbing PE classes were involved. Three experimental conditions were used: (1) Control, a regular climbing lesson, where traditional climbing holds are used, (2) Placebo climbing lesson, where participants climbed on an instrumented climbing wall with electronic climbing holds but the content of the lesson was similar to the regular condition, and (3) Nonlinear Pedagogy climbing lesson, where participants also climbed on the instrumented wall but with technology used in this context to implement innovative tasks routed on Nonlinear Pedagogy concepts (i.e., fostering motor exploration). Participants were involved in all three conditions and at the end of each condition, and they completed a survey set on their experiences in the climbing lessons. Compared to the control and placebo conditions, external regulation and tension scores were significantly lower and enjoyment scores were significantly higher during the Nonlinear Pedagogy climbing lesson. These results indicated that when integrated with a clear pedagogical purpose, ICT could positively impact learners.

Cognitive training techniques such as motor imagery (MI)–cognitive simulation of movement, has been found to successfully facilitate skill acquisition. The MI literature emphasizes the need to accurately imitate key elements of motor execution to facilitate improved performance outcomes. However, there is a scarcity of MI research investigating how contemporary approaches to motor learning, such as nonlinear pedagogy (NLP), can be integrated into MI practice. Grounded in an ecological dynamics approach to human movement, NLP proposes that skilled action is an emergent process that results from continuous interactions between perceptual information of the environment and movement. This emergent process can be facilitated by the manipulation of key task constraints that aim to encourage learners to explore movement solutions that satisfy individual constraints (e.g., height and weight) and achieve successful performance outcomes. The aim of the present study was to explore the application of a NLP approach to MI approach for skill acquisition. Fourteen weightlifting beginners (two female and 12 male) participated in a 4-week intervention involving either NLP (i.e. analogy-based instructions and manipulation of task constraints) or a linear pedagogy (LP; prescriptive instructions of optimal technique, repetition of same movement form) to learn a complex weightlifting derivative. Performance accuracy, movement criterion (barbell trajectory type), kinematic data, and quantity of exploration/exploitation were measured pre-mid-post intervention. No significant differences (p = .438) were observed in the amount of exploration between LP (EER = 0.41) and NLP (EER = 0.26) conditions. Equivalent changes in rearward displacement (R×D) were observed with no significant differences between conditions for technique assessments 1, 2, or 3 (p = .13 - .67). Both NLP and LP conditions were found to primarily demonstrate ‘sub-optimal’ type 3 barbell trajectories (NLP = 72%; LP = 54%). These results suggest that MI instructions prescribing a specific movement form (i.e., LP condition) are ineffective in restricting available movements to a prescribed technique but rather the inherent task constraints appear to ‘force’ learners to explore alternative movement solutions to achieve successful performance outcomes. Although MI instructions prescribing specific techniques have previously supported improved skill development, the current findings indicate that learners may self-organise their movements regardless of MI instructions to satisfy individual and task constraints while achieving improved performance. Therefore, it may be beneficial to consider scripts that are more outcome focused and incorporate task constraints to facilitate learners’ inherent exploration of individual task solutions.

This narrative review seeks to compare the various ways in which motor creativity has been measured and to critically evaluate those methods within the context of our contemporary understanding of motor creativity. Eligible studies included those of any study design, experimental or observational, as long as motor creativity was measured. Three databases (i.e., PubMed, Scopus, and ScienceDirect) were searched from the earliest possible start dates to December 2021. No risk of bias assessment was performed as the study outcomes were not the focus of the review. After screening for eligibility, 23 articles were included for review, all having measured motor creativity. Of the 23 articles, 16 measured generic motor creativity, while the remaining seven measured task-specific motor creativity. Furthermore, 16 of the studies tested motor creativity with largely static environmental constraints, while the remaining seven were conducted with dynamic environmental constraints. Using a contemporary understanding of motor creativity, most motor creativity tests presently do not possess sufficient task specificity and environmental dynamism, which may not provide an appropriate context for the emergence of creative motor action.