Representative learning design in springboard diving: Is dry-land training representative of a pool dive?

Enriching Athlete-Environment Interactions in Youth Sport: The Role of a Department of Methodology

The aim of this insights paper is to propose how the theory of ecological dynamics may invite re-consideration of how sport scientists could support performance, learning and development of children and youth in sports programmes. We seek to outline why learning should be individualised and contextualised, based on the specific needs of learners, such as children and youth, women and disabled athletes in sport. Case examples from individual and team sports are presented to illustrate how constraints can be designed to enrich interactions of children and youth with different performance environments, based on integrating principles of specificity and generality in learning and development. These case examples suggest how a collaborative effort by sport scientists and coaches in children and youth sport may be undertaken in a department of methodology to enrich learning and performance.

Angular velocity around the longitudinal axis in combination with head movements of springboard divers during twisted somersaults

The ability of springboard divers to perform and control difficult elements with multiple twisted somersaults before entering the water is of great interest for coaches and researchers. In order to produce twists within somersaults, divers use both 'contact' and 'aerial' techniques. After completing body axes rotations, head movements seem to be important, as they enable visual information in the air. The current study aims at investigating angular velocities around the longitudinal axis in combination with head movements of 13 springboard divers during twisted somersaults. Divers performed forward and backward somersaults with different numbers of half twists. The results revealed maximum longitudinal axis angular velocities between 500°/s and 1300°/s. Moreover, results showed that the use of contact technique was greater in twisted somersaults with backward approaches, and thus higher angular velocities could be achieved. While finishing the twists, head movements in the opposite direction to the longitudinal axis rotation occurred, which allow divers to orient themselves. Twist speeds influenced athletes' head movements to have greater angles and greater rotational velocities. Therefore, it is concluded that fast head movements are necessary in difficult twisted dives to allow orientation in the short phase between finishing the twist and entering the water surface.

A Proposed Framework to Describe Movement Variability within Sporting Tasks: A Scoping Review

Movement variability is defined as the normal variations in motor performance across multiple repetitions of a task. However, the term "movement variability" can mean different things depending on context, and when used by itself does not capture the specifics of what has been investigated. Within sport, complex movements are performed repeatedly under a variety of different constraints (e.g. different situations, presence of defenders, time pressure). Movement variability has implications for sport performance and injury risk management. Given the importance of movement variability, it is important to understand the terms used to measure and describe it. This broad term of "movement variability" does not specify the different types of movement variability that are currently being assessed in the sporting literature. We conducted a scoping review (1) to assess the current terms and definitions used to describe movement variability within sporting tasks and (2) to utilise the results of the review for a proposed framework that distinguishes and defines the different types of movement variability within sporting tasks. To be considered eligible, sources must have assessed a sporting movement or skill and had at least one quantifiable measure of movement variability. A total of 43 peer-reviewed journal article sources were included in the scoping review. A total of 280 terms relating to movement variability terminology were extracted using a data-charting form jointly developed by two reviewers. One source out of 43 (2%) supplied definitions for all types of movement variability discussed. Moreover, 169 of 280 terms (60%) were undefined in the source material. Our proposed theoretical framework explains three types of movement variability: strategic, execution, and outcome. Strategic variability describes the different approaches or methods of movement used to complete a task. Execution variability describes the intentional and unintentional adjustments of the body between repetitions within the same strategy. Outcome variability describes the differences in the result or product of a movement. These types emerged from broader frameworks in motor control and were adapted to fit the movement variability needs in sports literature. By providing specific terms with explicit definitions, our proposed framework can ensure like-to-like comparisons of previous terms used in the literature. The practical goal of this framework is to aid athletes, coaches, and support staff to gain a better understanding of how the different types of movement variability within sporting tasks contribute to performance. The framework may allow training methods to be tailored to optimise the specific aspects of movement variability that contribute to success. This review was retrospectively registered using the Open Science Framework (OSF) Registries ( https://osf.io/q73fd ).

Effects of manipulating specific individual constraints on performance outcomes, emotions, and movement phase durations in Rugby Union place kicking

Place kicks present valuable opportunities to score points in Rugby Union, contributing almost half of all points scored at international level. From an ecological dynamics perspective, place kickers adapt to interacting task, environmental, and individual constraints in performance environments. The aim of this study was to analyse effects of specific manipulations of individual constraints (fatigue; expectation for success) on place kicking performance, movement phase durations, heart rate and self-reported emotions. Under representative task and environmental constraints on an outdoor training pitch, 12 experienced, male place kickers completed four testing sessions under every combination of manipulated high/low expectation for success and manipulated levels of high/low acute fatigue. Within each session of 12 place kicks, performance outcomes from three kicking locations of varying difficulty were recorded. ANOVA revealed a two-way interaction between fatigue and expectation manipulations on mean success percentage (p < 0.05), with higher success under low fatigue + low expectation (M ± SD = 58 ± 13%) and high fatigue + high expectation (M ± SD = 56 ± 14%), compared with separate manipulations of high expectation (M ± SD = 49 ± 14%) or high fatigue (M ± SD = 51 ± 14%). There were no significant effects on any movement phase durations. Manipulating expectation significantly heightened mean heart rate (p < 0.05) and influenced emotions reported by place kickers, including higher anger scores when there was high expectation for success. Coaches are encouraged to integrate place kicking into representative game scenarios in practice environments to faithfully represent key performance constraints (e.g. fatigue; expectation for success) in preparing kickers for competitive situations.

Impacts of squat attempt weight selection and success on powerlifting performance

BACKGROUND

To date, there is no evidence to support the optimal competition strategy for success in powerlifting competitions. The purpose of this study was to analyse Powerlifting (PL) competition data to assess the relationship between squat attempts, the success of each lift attempt, and weight increase between attempts, with winning.

METHODS

10,672 individual competition entries (males: n = 6617, females: n = 4,055) were included within the analysis from 'raw' Powerlifting Australia sanctioned competitions held between 2008 and 2019. We reported Cohen's d, statistical significance, 95% confidence intervals and the univariate odds of winning an event. Factors were assessed by separate simple logistic regression and reported as an odds ratio.

RESULTS

Overall, first squat attempt weight for those who won was on average 7.0kg greater (P<0.001, d=0.14 [0.10, 0.18]) than for non-winners. In the total sample, athletes selected opening attempts which were an average of 92% of their achieved maximum on the day with 93.5% of competitors improving on this weight in subsequent attempts. Winners had a 0.5kg (P<0.001, d=0.10 [0.06, 0.14]) greater absolute increase in weight between first and second lift attempts than non-winners. Overall, ~68% of winners successfully lifted their third attempt weight compared to ~64% of non-winners (P<0.001).

CONCLUSIONS

A powerlifting athlete's odds of winning a competition overall are significantly increased by selecting a larger opening squat attempt weight than competitors and completing the attempt successfully. The opening squat may be one of the most important lifts during competition.

Coaches' perspective towards skill acquisition in swimming: What practice approaches are typically applied in training?

This study aimed to explore the experiential knowledge and preferred training approaches of elite swimming coaches in regards to general skill development and then looking specifically at the freestyle stroke. A qualitative thematic analysis approach was employed to identify, analyse and report themes within the content of the collected data. Twenty elite swimming coaches participated in semi-structured interviews. Several themes revealed that the most common training practices employed to improve skill learning included the use of task decomposition (part-task) techniques. The findings also indicated that swimming coaches believe practice should be specific/representative to the intended performance outcomes. It is believed that such viewpoints may have been influenced by coaches' interaction with skill acquisition consultants and may have also shaped some coaches use of variants of constraints manipulation in their practice design. While swimming coaches seem to mix both traditional and contemporary skill acquisition theories in their training prescriptions, the traditional approach is dominant as evidenced by coaches seeking to reinforce "perfect" swimming technique and mechanical consistency. Considering coaches' experiential knowledge and training prescriptions may benefit future research protocols and better facilitate the transfer of empirical findings to coaching practice.

Assessment of elite junior tennis serve and return practice: A cross-sectional observation

Practice tasks that more closely represent the demands of competition are thought to augment skill learning and transfer. This study observed the serve and return performances of junior grand slam tennis and used this benchmark to evaluate the representativeness of serve and return practice among elite junior tennis players. The serve and return behaviour of 26 junior tennis players competing in junior Australian Open grand slam matches were observed and compared with the serve and return practice behaviours of 12 elite junior tennis players over an 8-week period. The variables measured included the number of serves/returns landing in, serve/return type, serve direction and the variability of practised skills. Serve and return practice contributed to <13% of total practice time, with each skill predominately practised in isolation. Compared to the matchplay benchmark, players typically had less success (i.e., fewer serves/returns landing in the court), were less variable in shot selection and hit fewer serves to the extremities of the service box. As task representativeness increased fewer differences between practice and matchplay were observed. Tennis serve and return practice could be improved by better simulating specific competition affordances, providing greater opportunities to practice serve/return tactics and/or increasing the variability of practised skills.

Analysis of Cricket Ball Type and Innings on State Level Cricket Batter's Performance

Background: The aim of this investigation was to compare the type of cricket balls utilized and innings on cricket batting performance in the First-Class Australian competition.

Methods: Batting performance measures of 43 state level cricket batters were collected from two seasons of the Sheffield shield tournament (N = 60 games) that incorporated both Kookaburra^™ (n = 30 games) and Duke^™ (n = 30 games) cricket balls.

Results: First-innings batting performances were significantly greater for the average number of runs scored (37.5 ± 13.4 vs. 31.2 ± 11.3), balls faced (60.7 ± 26.2 vs. 49.9 ± 23.6), boundary 4s (3.8 ± 1.9 vs. 2.9 ± 1.4), and boundary 6s (0.2 ± 0.3 vs. 0.1 ± 0.3) scored per game (p < 0.05), as well as centuries scored (5.74 ± 8.56 vs. 1.49 ± 5.14%) compared to second innings performances (p < 0.05). There were no differences for any batting performance measures as a result of ball type (p > 0.05). However, significantly more wickets were taken by pace bowlers during Duke^™ ball games (85.0 ± 12.8 vs. 76.4 ± 13.9%), while relatively more wickets were taken by spin bowlers during Kookaburra^™ ball games (14.2 ± 12.5 vs. 22.0 ± 14.1%; p < 0.05).

Conclusions: Cricket batting performance was comparable in games involving the Kookaburra^™ or Duke^™ ball. However, pace bowlers were more successful transferring their skill to the Duke^™ ball, while spin bowlers were more successful with the KB^™ ball. Subsequently, batters may be able to effectively adapt their movement technique, and transfer their skill to the Duke^™ ball conditions. Future research is suggested to examine the influence of the cricket playing surface’s deterioration on cricket batter’s interceptive performance.

Enhancing skill transfer in tennis using representative learning design

Representative Learning Design advocates that practice should simulate the demands of competition. The effectiveness of increased task representativeness to improve serving skill of junior tennis players was assessed after a six-week intervention. Thirty-three participants (15.4 ± 1.9 years of age) were assigned to one of the three groups; "serve only" (participants served to no opponent), "serve return" (participants served to an opponent and hit no extra shots) or "serve +3^rd" (participants served to an opponent and hit one extra shot). Using the validated representative practice assessment tool (RPAT) tasks were considered to be low, moderate and high in task representativeness, respectively. Participants hit 56 serves, twice weekly for 6-weeks. Pre and post serving performances were assessed via a skill test and in-situ matchplay using SportsCode and HawkEye ball tracking, respectively. Serve speed, landing locations, serve angle and positional advantage was obtained for 1^st and 2^nd serves. The relationship between increasing representativeness and increased skill acquisition was not linear, rather different behaviours emerged. For example, when hitting 2^nd serves in matchplay, the low and moderate representative groups prioritised speed over placement while the high representative group prioritised placement over speed. Coaches therefore need to carefully individualise representativeness to an athletes' specific needs.

Development of a Skill Acquisition Periodisation Framework for High-Performance Sport

Unlike physical training, skill acquisition does not currently utilise periodisation to plan, monitor and evaluate programs. Development of a skill acquisition periodisation framework would allow for systematic investigation into the acute and longitudinal effectiveness of such interventions. Using the physical training literature as a reference point, a skill-training periodisation framework was developed for use in high-performance sport. Previous research undertaken in skill acquisition was used to provide support for the framework. The specificity, progression, overload, reversibility and tedium (SPORT) acronym was adopted. Each principle was then re-conceptualised so that it related to relevant skill acquisition principles. Methods for the measurement and analysis of each principle are provided and future directions for the longitudinal assessment of skill acquisition are discussed. The skill acquisition periodisation framework proposed in this study represents an opportunity for the principles relating to skill acquisition training to be measured in a systematic and holistic manner. This can also allow for a more sophisticated evaluation of the efficacy of longitudinal training programmes and interventions designed for sustained skill enhancement.

Taekwondo Fighting in Training Does Not Simulate the Affective and Cognitive Demands of Competition: Implications for Behavior and Transfer

Enhancing practice design is critical to facilitate transfer of learning. Considerable research has focused on the role of perceptual information in practice simulation, yet has neglected how affect and cognition are shaped by practice environments and whether this influences the fidelity of behavior (Headrick et al., 2015). This study filled this gap by examining the fidelity of individual (cognition, affect, and actions) and interpersonal behavior of 10 highly skilled Australian Taekwondo athletes fighting in training compared to competition. Interpersonal behavior was assessed by tracking location coordinates to analyze distance-time coordination tendencies of the fighter-fighter system. Individual actions were assessed through notational analysis and approximate entropy calculations of coordinate data to quantify the (un)predictability of movement displacement. Affect and cognition were assessed with mixed-methods that included perceptual scales measuring anxiety, arousal, and mental effort, and post-fight video-facilitated confrontational interviews to explore how affect and cognitions might differ. Quantitative differences were assessed with mixed models and dependent t-tests. Results reveal that individual and interpersonal behavior differed between training and competition. In training, individuals attacked less (d = 0.81, p < 0.05), initiated attacks from further away (d = -0.20, p < 0.05) and displayed more predictable movement trajectories (d = 0.84, p < 0.05). In training, fighters had lower anxiety (d = -1.26, p < 0.05), arousal (d = -1.07, p < 0.05), and mental effort (d = -0.77, p < 0.05). These results were accompanied by changes in interpersonal behavior, with larger interpersonal distances generated by the fighter-fighter system in training (d = 0.80, p < 0.05). Qualitative data revealed the emergence of cognitions and affect specific to the training environment, such as reductions in pressure, arousal, and mental challenge. Findings highlight the specificity of performer-environment interactions. Fighting in training affords reduced affective and cognitive demands and a decrease in action fidelity compared to competition. In addition to sampling information, representative practice needs to consider modeling the cognitions and affect of competition to enhance transfer.

Quantifying the Degree of Movement Dissimilarity between Two Distinct Action Scenarios: An Exploratory Approach with Procrustes Analysis

Game consoles allow subjects to perform movements which are visually similar to the movements performed in ‘real’ world scenarios. Beyond entertainment, virtual reality devices are being used in several domains: sports performance; motor rehabilitation; training of risk professions. This article presents the Procrustes method to measure the degree of dissimilarity between movements performed in ‘real’ and ‘virtual’ scenarios. For this purpose, the 501 darts game and a video darts game played on a console were used. The participants’ arm throwing movements were video recorded and digitized. The matrices of x and y coordinates of the movements of the wrist, elbow, and shoulder in both performance scenarios were subjected to the Procrustes method. The wrist displays the most extreme dissimilarity values (higher than elbow and shoulder). Results also revealed smaller dissimilarity values for movements performed under the same conditions (e.g., real–real) and larger dissimilarity values between movements performed in different scenarios.

Individual-Environment Interactions in Swimming: The Smallest Unit for Analysing the Emergence of Coordination Dynamics in Performance?

Displacement in competitive swimming is highly dependent on fluid characteristics, since athletes use these properties to propel themselves. It is essential for sport scientists and practitioners to clearly identify the interactions that emerge between each individual swimmer and properties of an aquatic environment. Traditionally, the two protagonists in these interactions have been studied separately. Determining the impact of each swimmer's movements on fluid flow, and vice versa, is a major challenge. Classic biomechanical research approaches have focused on swimmers' actions, decomposing stroke characteristics for analysis, without exploring perturbations to fluid flows. Conversely, fluid mechanics research has sought to record fluid behaviours, isolated from the constraints of competitive swimming environments (e.g. analyses in two-dimensions, fluid flows passively studied on mannequins or robot effectors). With improvements in technology, however, recent investigations have focused on the emergent circular couplings between swimmers' movements and fluid dynamics. Here, we provide insights into concepts and tools that can explain these on-going dynamic interactions in competitive swimming within the theoretical framework of ecological dynamics.

Effects of coordination and manipulation therapy for patients with Parkinson disease

PURPOSE

To determine the effects of a new exercise training regimen, i.e. coordination and manipulation therapy (CMT), on motor, balance, and cardiac functions in patients with Parkinson disease (PD).

MATERIALS AND METHODS

We divided 36 PD patients into the CMT (n = 22) and control (n = 14) groups. The patients in the CMT group performed dry-land swimming (imitation of the breaststroke) and paraspinal muscle stretching for 30 min/workday for 1 year. The control subjects did not exercise regularly. The same medication regimen was maintained in both groups during the study. Clinical characteristics, Unified Parkinson's Disease Rating Scale (UPDRS) scores, Berg balance scale (BBS) scores, mechanical balance measurements, timed up and go (TUG) test, and left ventricular ejection fraction (LVEF) were compared at 0 (baseline), 6, and 12 months. Biochemical test results were compared at 0 and 12 months. The primary outcome was motor ability. The secondary outcome was cardiac function.

RESULTS

In the CMT group, UPDRS scores significantly improved, TUG test time and step number significantly decreased, BBS scores significantly increased, and most mechanical balance measurements significantly improved after 1 year of regular exercise therapy (all p < 0.05). In the control group, UPDRS scores significantly deteriorated, TUG test time and step number significantly increased, BBS scores significantly decreased, and most mechanical balance measurements significantly worsened after 1 year (all P < 0.05). LVEF improved in the CMT group only (P = 0.01).

CONCLUSIONS

This preliminary study suggests that CMT effectively improved mobility disorder, balance, and cardiac function in PD patients over a 1-year period.

Performing a forward dive with 5.5 somersaults in platform diving: simulation of different technique variations

Performing dives with multiple somersaults is an inherent component of competitive diving. In individual international competitions, dives are performed from a 1- or 3-m springboard as well as from a 10-m platform, and divers use different technique variations in accelerating and decelerating rotation about the somersault axis. Therefore, the first aim of this study was to evaluate the effect of different technique variations in accelerating and decelerating rotation about the somersault axis in a 109C dive (4.5 forward somersault in a tucked posture) by means of a multi-body computer simulation model based on the real performance of an expert diver. The second aim was to evaluate the feasibility of adding an additional somersault rotation to the 109C dive. The results revealed that different technique variations accounted for different amounts of gain and loss in somersault rotation, whereas no isolated technique variation accounted for an additional somersault rotation. Applying an optimized technique variation together with an increase in angular and linear momentum allowed the simulation model to perform a forward dive with 5.5 somersaults under achievable biomechanical constraints (1011C dive). It is concluded that the 1011C would be a feasible skill for a diver whose sensory-motor system is adequately adapted to withstand angular velocities of approximately 1200°/s and who is able to perform a double tucked somersault in a split-tuck posture above the platform level. Implications for changes in training practices and platform equipment are discussed.