Nonlinear Dynamic Measures of Walking in Healthy Older Adults: A Systematic Scoping Review.

BACKGROUND: Maintaining a healthy gait into old age is key to preserving the quality of life and reducing the risk of falling. Nonlinear dynamic analyses (NDAs) are a promising method of identifying characteristics of people who are at risk of falling based on their movement patterns. However, there is a range of NDA measures reported in the literature. The aim of this review was to summarise the variety, characteristics and range of the nonlinear dynamic measurements used to distinguish the gait kinematics of healthy older adults and older adults at risk of falling. METHODS: Medline Ovid and Web of Science databases were searched. Forty-six papers were included for full-text review. Data extracted included participant and study design characteristics, fall risk assessment tools, analytical protocols and key results. RESULTS: Among all nonlinear dynamic measures, Lyapunov Exponent (LyE) was most common, followed by entropy and then Fouquet Multipliers (FMs) measures. LyE and Multiscale Entropy (MSE) measures distinguished between older and younger adults and fall-prone versus non-fall-prone older adults. FMs were a less sensitive measure for studying changes in older adults' gait. Methodology and data analysis procedures for estimating nonlinear dynamic measures differed greatly between studies and are a potential source of variability in cross-study comparisons and in generating reference values. CONCLUSION: Future studies should develop a standard procedure to apply and estimate LyE and entropy to quantify gait characteristics. This will enable the development of reference values in estimating the risk of falling.

Anxiety on Quiet Eye and Performance of Youth Pistol Shooters.

In adults, longer quiet-eye (QE) durations have been associated with more successful sport performances and less deterioration in skill during anxiety-inducing situations. This study aimed to establish if QE patterns in youth are similar to those reported in adults. Ten youth shooters, age 13.13 ± 0.83 years, completed an air-pistol task under a control and an anxiety condition. Mixed-design 2 (performance outcome) × 2 (condition) ANOVA tests were conducted with two performance measures-objective and coach rated. No significant main or interaction effects were found. Unlike in adults, performance and anxiety did not differentiate QE duration in youth athletes, although QE duration was longer during good shots than poor shots across both performance measures, and the shortest durations were recorded during poor shots in the anxiety condition. This preliminary exploration encourages more research with youth athletes to determine the efficacy of QE patterns across different learners.

Children's perception of action boundaries and how it affects their climbing behavior.

There are some concerns that children today may be less calibrated to their action capabilities because of the "risk-free" culture that has proliferated during recent decades. This study investigated the extent to which judgments of reaching affordances presented in different directions (i.e., overhead, diagonal, and horizontal) are related to children's climbing behavior on a climbing wall. A sample of 30 schoolchildren from 6 to 11years old (20 boys and 10 girls) estimated maximum reach and grasp distances and subsequently attempted to climb across an indoor climbing wall. Children who perceived the extents of their reach more accurately completed the climb more often and more quickly. Judgments in the primary directions of climbing locomotion (horizontal and diagonal) were better predictors of success than vertical judgments. Judgments about whether objects are reachable and graspable are complex and influenced by various dynamic factors (including perceptual-motor calibration), and as such different levels of accuracy are likely in different reaching directions. It appears that young children are relatively sensitive to their action boundaries for climbing and, therefore, may be able to make informed decisions themselves about whether a surface is climbable.

Pre-movement and during-movement visual search behaviours vary depending on expertise and anxiety levels in ten-pin bowling.

This study investigated the pre-movement and during-movement visual search behaviour (VSB) and quiet eye (QE) of 11 elite versus 10 sub-elite ten-pin bowlers, performing under high-anxiety and low-anxiety conditions. Pre-movement and independent of expertise, bowlers had more fixations and directed them to more locations when performing under high-anxiety compared with low-anxiety. Elite bowlers fixated at more locations closer to the pins in pre-movement than during-movement, with pre-movement QE occurring mostly at the breakpoint and middle arrows. During movement however, bowlers fixated closer to the foul-line at the middle and right dots and arrows, with during-movement-QE occurring at the middle dots and right arrows. Elite bowlers recorded longer QE durations during-movement rather than pre-movement, albeit a later onset during the longish five-step approach prior to ball release compared with sub-elite bowlers. Our results suggest that QE during-movement instead of pre-movement could be more pertinent in differentiating expertise during sporting tasks with a long movement phase and far-aiming target. The relevance of pre-movement or movement-QE in characterising expertise and performance could therefore be sport-dependent. This should be considered when investigating skilled action and developing training programs for skill acquisition.

The influence of pitch dimensions on performance during small-sided and conditioned soccer games.

This study examined the influence of pitch dimensions in small-sided soccer games in shaping opportunities for performers to maintain ball possession, pass to teammates and shoot at goal. Fifteen amateur standard male participants (M = 21.87, σ = 1.96 years) played 5 v 5 small-sided soccer games in three varying pitch conditions (28 m × 14 m, 40 m × 20 m and 52 m × 26 m). Thirty sequences of play in each condition were selected for digitisation using TACTO software, allowing the capture of bi-dimensional displacement coordinate data of all players and the ball. The values of interpersonal distance between all attackers and immediate defenders and the relative distances of defenders to intercept a shot and a pass were computed as dependent variables. Results showed existence of fewer opportunities to maintain ball possession on smaller pitches, compared to medium and larger pitches. Conversely, the different dimensions set to the pitch did not influence opportunities for players to shoot at goal, or to perform passes to other teammates. By examining the specific spatial-temporal relationships of players and key-task constraints, the data from this study explain how effects of manipulating pitch dimensions of small-sided games might enhance opportunities for acquiring specific movement and decision-making skills.

Effect of different attentional instructions on the acquisition of a serial movement task.

Recent research in attentional focus of instruction has predominantly over-emphasized the investigation of discrete and continuous skills rather than serial skills. The purpose of this study was therefore to examine the effect of different attentional focus instructions on learning a serial skill task (i.e., taekwondo routine) in novice learners. It was predicted that the use of movement outcome instructions could enhance the learning of a serial skill as previously supported in studies examining the acquisition of discrete and continuous skills. Thirteen female participants were recruited for this study and were assigned to either movement form condition - control group (n = 7) or movement outcome condition - treatment group (n = 6). All participants underwent 12 practice sessions over an 8-week period with their respective instructional conditions with each session lasting 30 minutes. Video recording of the serial skill tasks (hand techniques, kicking techniques and 10-step routine) were captured at "the-twelfth-training session", "after 1-week", and "after 1-month". It was found that more participants in the treatment group obtained a higher score in all three serial skill tasks, especially in Mastery component of 'Kicking' techniques at 'after 1-week' (p < 0.05, r = 0.57). This study suggested that movement outcome instructions have positive medium effect on balance control for serial skill task, especially in kicking actions. Key PointsMovement outcome (MO) instructions have a positive impact on learning a serial task, especially in kicking actions.More functional coordination during movement executions for MO participants.Benefits for MO instructions may be individual specific.

An ecological dynamics approach to promote physical literacy and well-being of primary school children: a cluster randomised controlled trial study protocol.

BACKGROUND: Little is known about the impact of an ecological dynamics (ED) intervention (EDI) on primary school children's physical literacy and well-being in the Hong Kong context. The aim of this project is to introduce a physical literacy and well-being framework through an EDI that allows primary school children to develop good physical activity (PA) and daily behavioural habits. METHODS AND ANALYSIS: A four-arm (cluster) randomised controlled trial will be conducted to examine the effect of EDI on physical literacy and well-being in primary schools located in each of the 18 administrative districts of Hong Kong. Four classes in senior primary students (grade 4) at each school will be randomly assigned to the four different conditions. These participating schools will be equipped with sit-stand desks, PA recess facility and equipment, and sleep pillows. The research team will adopt both objective measures (aerobic fitness, fundamental movement skills, daily behaviour-physical activity and cognitive function) and self-reported measures (perceived physical literacy, quality of life, sleep quality) covering the elements and domains of physical literacy and well-being to examine the effects of EDIs at four time points, including baseline assessment, 3 months after intervention, postintervention and 3-month follow-up assessment. One-way analyses of variance (ANOVAs) will be used to test for differences in the baseline characteristics of participants between groups. Repeated measure ANOVAs and MANCOVA, with time (baseline, after intervention and follow-up) as within-subjects factor, and intervention group as between-subjects factors, will be used to evaluate the effects of different interventions on the students' physical literacy and well-being. A Bonferonni correction to the p value will be calculated to adjust for multiple tests. ETHICS AND DISSEMINATION: Ethical approval was sought from the Joint CUHK-NTEC Clinical Research Ethics Committee in Hong Kong (CREC Ref.No.:2024.027). The finding of this study will be disseminated via peer-reviewed journals, international conference presentations and academic lectures. For secondary analysis of the data, please contact the corresponding author for permission. TRIAL REGISTRATION NUMBER: ISRCTN84025914.

Is Prescription of Specific Movement Form Necessary for Optimal Skill Development? A Nonlinear Pedagogy Approach.

Purpose: Nonlinear Pedagogy (NLP) proposes that skill development is a nonlinear process, advocating the integration of variability into practice to facilitate individualized movement patterns. However, the influence of a NLP for skills that emphasize a specific movement form is relatively unknown. This study aimed to investigate the impact of a NLP approach when learning a movement form based skill. Method: Sixteen beginners in the power clean (PC), were randomly assigned into a linear pedagogy (LP) condition receiving instructions that prescribed explicit movement form, and a NLP condition presented with analogy-based instructions and two task constraints. Both conditions completed seven lessons across 4-weeks. Results: There were no significant differences in the quantity of exploration, with both conditions demonstrating a similar range of movement patterns. These findings were coupled with a significant improvement in performance accuracy (reduced forward movement of the barbell; F × D) for both conditions. No significant differences were detected in the distribution of barbell trajectory types, with type one, three and four trajectories being exhibited to a similar degree in both conditions. Conclusion: Findings from this study suggests both NLP and LP pedagogies can successfully develop movement form based skills. Overall, both NLP and LP approaches appear to positively influence skill development. These findings have important implications for practitioners suggesting that deviations from instructed technique in learners (i.e., LP approach) do not negatively impact performance. However, further research is needed to determine whether these approaches can more effectively facilitate learners' search for movement solutions that "fit" their individual abilities.

Different pedagogical approaches to motor imagery both demonstrate individualized movement patterns to achieve improved performance outcomes when learning a complex motor skill.

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.

The effect of nonlinear pedagogy on the acquisition of game skills in a territorial game.

Introduction: Nonlinear Pedagogy (NP), underpinned by Ecological Dynamics, provides a suitable pedagogical approach for practitioners (e.g., Physical Educators, coaches) to encourage exploratory learning that is learner-centered even in Traditional Sporting Games (TSG) that could be represented by invasion or territorial-like games. NP involves the manipulation of constraints which form boundaries for interacting components to self-organize, facilitating the emergence of goal-directed behaviours. Key pedagogical principles relating to representativeness, manipulation of constraints, awareness of focus of attention instructions, task simplification and the functional role of noise can encourage exploratory learning that helps develop 21st century competencies. This is in contrast to a Linear Pedagogy (LP) approach that is more teacher-centered and focuses on repetition in practices to promote movement form consistency in enhancing the acquisition of movement skills. Little is known about the effectivity of NP in the learning and transfer of invasion games. The aims of this study were to: (a) determine the impact of NP on the teaching and learning of an invasion game in the Physical Education (PE) context; (b) examine the transferability of game skills to other games in the same game category (i.e., floorball as a territorial game in this study). Methods: 224 (between 12 to 13 years old) students underwent a 10-week intervention program to learn to play an invasion game (football) with either a NP or LP approach (i.e., repetitive and prescriptive drills). Results: Performance outcome data were measured during Pre, Post, Retention, Transfer test 1 (larger playing area) and Transfer test 2 (floorball). Significant improvements in several performance outcome and game play measures in football was observed for the NP condition. Fewer improvements in the same measures were found for the LP condition. Discussion: Evidence for transfer of learning for NP was not as strong as anticipated although there was still some potential for encouraging transfer of learning. The key findings from this study further challenge the "one-size fits all" philosophy in the teaching of PE. Both LP and NP approaches would have a role to play in supporting teaching and learning which could be context dependent.

Advice from "pracademics" of how to apply ecological dynamics theory to practice design.

There has been an increase interest in knowing and enacting pedagogical approaches such as the Constraints-led Approach (CLA) and Nonlinear Pedagogy (NLP) which are underpinned by Ecological Dynamics in recent years among practitioners. While there seems to be a perceived uptake of such pedagogical approaches that encourages exploratory learning and the development of individualised movement solutions, there are still concerns on how these pedagogical approaches are enacted on the ground. In this paper, we the authors, as "pracademics", attempted to address some of the common concerns that we are aware of from our regular interactions with academics and practitioners. In brief, we highlighted some of the common challenges related to sense making concepts from Ecological Dynamics and building connections to practice. We stressed the need to invest time to think differently to create representative learning environment, rethink how assessment is to be done, finding a balance between theoretical jargon and practical application as well as intentionally situating coach development and support. We may not have all the answers, but we hope this paper could provide a useful starting point on how to apply Ecological Dynamics Theory to practice design.

Mindfulness, movement control, and attentional focus strategies: effects of mindfulness on a postural balance task.

We examined whether the momentary induction of state mindfulness benefited subsequent balance performance, taking into consideration the effects of dispositional mindfulness. We also tested whether our mindfulness induction, grounded in sustaining moment-to-moment attention, influenced the attentional focus strategies that were adopted by the participants during the balancing task. Balance performance was ascertained based on approximate entropy (ApEn) of the center of pressure (COP) data. The study involved 32 males (age: M = 22.8, SD = 1.94) who were randomly assigned to the mindfulness or control group. Using difference in pretest to posttest performance based on the medio-lateral movements as the dependent variable, the test for interaction showed that the mindfulness induction was more effective for participants with higher dispositional mindfulness. Participants who underwent mindfulness induction also reported greater use of external focus strategies than those in the control group. Results suggest that momentary mindful attention could benefit balance performance and affect the use of attentional focus strategies during movement control.

Validation of the Perception Neuron system for full-body motion capture.

Recent advancements in Inertial Measurement Units (IMUs) offers the possibility of its use as a cost effective and portable alternative to traditional optoelectronic motion capture systems in analyzing biomechanical performance. One such commercially available IMU is the Perception Neuron motion capture system (PNS). The accuracy of the PNS had been tested and was reported to be a valid method for assessing the upper body range of motion to within 5° RMSE. However, testing of the PNS was limited to upper body motion involving functional movement within a single plane. Therefore, the purpose of this study is to further validate the Perception Neuron system with reference to a conventional optoelectronic motion capture system (VICON) through the use of dynamic movements (e.g., walking, jogging and a multi-articular sports movement with object manipulation) and to determine its feasibility through full-body kinematic analysis. Validation was evaluated using Pearson's R correlation, RMSE and Bland-Altman estimates. Present findings suggest that the PNS performed well against the VICON motion analysis system with most joint angles reporting a RMSE of < 4° and strong average Pearson's R correlation of 0.85, with the exception of the shoulder abduction/adduction where RMSE was larger and Pearson's R correlation at a moderate level. Bland-Altman analysis revealed that most joint angles across the different movements had a mean bias of less than 10°, except for the shoulder abduction/adduction and elbow flexion/extension measurements. It was concluded that the PNS may not be the best substitute for traditional motion analysis technology if there is a need to replicate raw joint angles. However, there was adequate sensitivity to measure changes in joint angles and would be suitable when normalized joint angles are compared and the focus of analysis is to identify changes in movement patterns.

A Randomized Controlled Trial of a Blended Physical Literacy Intervention to Support Physical Activity and Health of Primary School Children.

BACKGROUND: The concept of physical literacy (PL) has been advocated as the need to create environments fostering sustainable engagement in PA. This study adopted ecological approach to evaluate the effectiveness of a blended PL intervention embedded into the school day to support children's PA and health. METHOD: Designed as a three-arm randomized controlled trial, a total of 79 participants (59.5% girls) were randomly assigned to: the "Quantity + Quality" blended PL group combining sit-stand desks and play-based recess (SSPlay), the "Quality" group with play-based recess only (Play) or the control group. The intervention lasted for 13 weeks, and all the variables were collected at baseline, post-intervention and 3-month follow-up. RESULTS: SSPlay and Play group significantly improved on two of the embodied PL domains, Physical Competence (- 2.96 vs - 5.15, p < 0.05) and Knowledge and Understanding (- 2.35 vs - 2.00, p < 0.05), total errors of cognitive flexibility (24.00 vs 12.92, p < 0.05), and this difference was maintained at follow-up (p < 0.05). Whilst there was no interaction effect between groups, and time effects were found for PA and planning from baseline to post-intervention. CONCLUSION: This was the first to adopt an ecological approach as an innovative strategy to provide the emergence of PA for children in Hong Kong. The blended intervention design that embedded both quantity and quality of PA into children's school day has shown promise in supporting children's all round development. PL intervention where environments are designed to increase the "Quantity + Quality" of children's everyday interactions has led to improvements in PA and health outcomes, which may provide insights for future studies to adopt cost-friendly and feasible measures for promoting children's PA in the school settings. TRIAL REGISTRATION: ChiCTR, ChiCTR2000035038. Registered 29 July 2020-Retrospectively registered. http://www.chictr.org.cn/hvshowproject.aspx?id=46038 .

Effects of a blended classroom-based intervention on aerobic fitness, motor skills, inhibition, and daytime sleepiness among Hong Kong children.

In response to the all-round development of primary school children, this study aimed to evaluate the effectiveness of a blended intervention program on children's health-related outcomes of aerobic fitness, motor skills, inhibition and daytime sleepiness in classroom settings. Three experimental conditions include: (1) the "Stand + Move" group combining sit-stand desks and physical activity (PA) recess, (2) "Move" group with PA recess only, and (3) Control group (CG; normal class schedule). A total of 64 primary school children (37.5% girls and 62.5% boys, M [SD] = 9.6 [0.61], BMI mean = 17.0 ± 3.0) participated in all assessments, including aerobic fitness, motor skills, inhibitory control, and daytime sleepiness. The baseline data collection starts from January 2019, with the intervention lasting for 13 weeks and followed by post-intervention and follow up tests conducted in July and October 2019. There was a significant interaction effect on aerobic fitness [F (2,76) = 10.62, p < 0.001, η2 = 0.22] after the intervention period, whereas no significant interaction was observed for other variables. Significant main effects were observed in aerobic fitness (pre - post: -11.75 and -7.22) for both experimental groups, with the blended group showing greater improvements immediately post the test, while motor skills only showed a significant increase at the three-month follow-up, with the greatest increase in the blended group (pre-follow-up: -2.50). For inhibition control and daytime sleepiness, better improvements were shown for the experimental groups than for the control group. The blended designed intervention, by incorporating multiple components as an innovative strategy to reconstruct children's traditional classroom environment in Hong Kong, has demonstrated improved physical and psychological development of school children. Clinical trial registration: ChiCTR, ChiCTR2000035038. Registered 29 July 2020 - Retrospectively registered. http://www.chictr.org.cn/hvshowproject.aspx?id=46038.

The Role of Nonlinear Pedagogy in Supporting the Design of Modified Games in Junior Sports.

Nonlinear Pedagogy has been advocated as an approach that views acquisition of movement skills with a strong emphasis on exploratory behaviors and the development of individualized movement skills. Underpinned by Ecological Dynamics, Nonlinear Pedagogy provides key ideas on design principles to support a teaching and learning approach that accounts for dynamic interactions among constraints in the evolution of movement behaviors. In the context of junior sports, the manipulation of task constraints is central to how games can be re-designed for children to play that are age and body appropriate so that the games can still capture the key elements of representativeness as compared to the adult form of the game. Importantly, these games offer suitable affordances that promote sensible play that could be transferable to other contexts. In this paper, we provide an in-depth discussion on how Nonlinear Pedagogy is relevant in supporting the design and development of modified games in the context of junior sports. Practical implications are also provided to share how games can be modified for meaningful play to emerge.

Teachers' Perceptions of Applying Contemporary Skill Acquisition Approaches in High School Physical Education.

Using contemporary skill acquisition approaches to skill learning appears to be a worthwhile pedagogical option for teachers and coaches in sports and Physical Education (PE). However, PE at the High School level in New Zealand has assessment components that are still underpinned by traditional and outdated skill learning theories. In response to this challenge, two motivated Heads of Department in PE undertook a department-wide professional development initiative to teach the national standard assessment via the use of a contemporary skill acquisition approach, which is student-centred, with an emphasis on enhancing exploratory learning and encouraging autonomy. Each department worked together over a 10-week period with a Higher Education specialist in skill acquisition to design and teach using contemporary skill acquisition approaches. Qualitative data was collected via semi-structured focus group interviews. Insightful data on the influence of teaching using contemporary skill acquisition approaches was acquired from the teachers in the two PE departments. It was found that substantial pedagogical practice changes were achieved by the teachers (e.g., less focus on ideal technique and more on varying the context). They also enjoyed the learning experience that the contemporary skill acquisition approach offered as compared to their previous experience of more traditional teaching approaches, which have a focus on knowledge acquirement with little opportunities for exploratory learning. In addition, from a practical perspective, teachers were observed to demonstrate greater engagement in professional conversations around learning and could see greater relevance in the transfer of learning in the use of contemporary skill acquisition approaches to other teaching contexts.

Acute effects of wearing compression knee-length socks on ankle joint position sense in community-dwelling older adults.

Functional proprioceptive information is required to allow an individual to interact with the environment effectively for everyday activities such as locomotion and object manipulation. Specifically, research suggests that application of compression garments could improve proprioceptive regulation of action by enhancing sensorimotor system noise in individuals of different ages and capacities. However, limited research has been conducted with samples of elderly people thus far. This study aimed to examine acute effects of wearing knee-length socks (KLS) of various compression levels on ankle joint position sense in community-dwelling, older adults. A total of 26 participants (12 male and 14 female), aged between 65 and 84 years, were randomly recruited from local senior activity centres in Singapore. A repeated-measures design was used to determine effects on joint position awareness of three different treatments-wearing clinical compression socks (20-30 mmHg); wearing non-clinical compression socks (< 20 mmHg); wearing normal socks, and one control condition (barefoot). Participants were required to use the dominant foot to indicate 8 levels of steepness (2.5°, 5°, 7.5°, 10°, 12.5°, 15°, 17.5°, and 20°), while standing on a modified slope box, in a plantar flexion position. Findings showed that wearing clinical compression KLS significantly reduced the mean absolute errors compared to the barefoot condition. However, there were no significant differences observed between other KLS and barefoot conditions. Among the KLS of various compression levels, results suggested that only wearing clinical compression KLS (20-30 mmHg) improved the precision of estimation of ankle joint plantar flexion movement, by reducing absolute performance errors in elderly people. It is concluded that wearing clinical compression KLS could potentially provide an affordable strategy to ameliorate negative effects of ageing on the proprioception system to enhance balance and postural control in community-dwelling individuals.

Perceptual-motor skill transfer: Multidimensionality and specificity of both general and specific transfers.

This paper aims to investigate perceptual-motor skill transfer, both through the specific as well as the general aspect of skill transfer. Specifically, we examined differences in skill transfer that occurred between participants who are skilled in practicing a perceptual motor activity involving striking with an implement and participants who are skilled in their own sports but are novice to striking task (i.e., batting an immobile ball). Skill transfer was assessed through the effect of practicing a new, novel task on the performance (ball velocity), intrinsic behavior (elbow and shoulder kinematic) as well as on the impetus for exploratory behavior (variability of elbow and shoulder kinematics) in the two groups of participants (n = 8 for each group), with reference to another group of expert participants (n = 8) for this batting task. Results showed that positive skill transfer was present and was multidimensional in the group of participants who have experience in using an implement in striking tasks. In addition, both specific transfer as well as general transfer were dependent on the task dynamics. More precisely, positive transfer was observed both through a sharing of similar movement patterns, an impetus for exploration and a direct transfer of performance in a novel task between groups who have experience in using an implement in striking tasks.

Dynamics of multi-articular coordination in neurobiological systems.

Although previous work in nonlinear dynamics on neurobiological coordination and control has provided valuable insights from studies of single joint movements in humans, researchers have shown increasing interest in coordination of multi-articular actions. Multi-articular movement models have provided valuable insights on neurobiological systems conceptualised as degenerate, adaptive complex systems satisfying the constraints of dynamic environments. In this paper, we overview empirical evidence illustrating the dynamics of adaptive movement behavior in a range of multi-articular actions including kicking, throwing, hitting and balancing. We model the emergence of creativity and the diversity of neurobiological action in the meta-stable region of self organising criticality. We examine the influence on multi-articular actions of decaying and emerging constraints in the context of skill acquisition. We demonstrate how, in this context, transitions between preferred movement patterns exemplify the search for and adaptation of attractor states within the perceptual motor workspace as a function of practice. We conclude by showing how empirical analyses of neurobiological coordination and control have been used to establish a nonlinear pedagogical framework for enhancing acquisition of multi-articular actions.