Annette J. Raynor

Strength, power, and coactivation in children with developmental coordination disorder

Strength, power, and coactivation levels were measured during knee extension and flexion tasks in 20 children (13 males, 7 females) with developmental coordination disorder (DCD) and 20 age-matched control children (12 males, 8 females). Participants were classified according to results obtained on the McCarron Assessment of Neuromuscular Development, with each group including two age levels: 6 to 7 and 9 to 10 years. Tasks were performed on a Biodex dynamometer under isometric and isokinetic conditions with surface EMG recorded from the vastus lateralis and biceps femoris muscles. Significant effects of group and age were observed for the measures of peak torque (isometric and isokinetic) and power, with the decreased power in the group with DCD being more apparent at higher velocities. A lower flexor-extensor percentage was recorded for the group with DCD but only under isokinetic conditions. From a neuromuscular perspective, the group with DCD had increased levels of coactivation (RMS agonist:RMS antagonist) during the isometric flexion and isokinetic extension actions. Possible causes of the strength and power deficits observed in children with DCD are discussed.

The application of a multi-dimensional assessment approach to talent identification in Australian football

ABSTRACT This study investigated whether a multi-dimensional assessment could assist with talent identification in junior Australian football (AF). Participants were recruited from an elite under 18 (U18) AF competition and classified into two groups; talent identified (State U18 Academy representatives; n = 42; 17.6 ± 0.4 y) and non-talent identified (non-State U18 Academy representatives; n = 42; 17.4 ± 0.5 y). Both groups completed a multi-dimensional assessment, which consisted of physical (standing height, dynamic vertical jump height and 20 m multistage fitness test), technical (kicking and handballing tests) and perceptual-cognitive (video decision-making task) performance outcome tests. A multivariate analysis of variance tested the main effect of status on the test criterions, whilst a receiver operating characteristic curve assessed the discrimination provided from the full assessment. The talent identified players outperformed their non-talent identified peers in each test (P < 0.05). The receiver operating characteristic curve reflected near perfect discrimination (AUC = 95.4%), correctly classifying 95% and 86% of the talent identified and non-talent identified participants, respectively. When compared to single assessment approaches, this multi-dimensional assessment reflects a more comprehensive means of talent identification in AF. This study further highlights the importance of assessing multi-dimensional performance qualities when identifying talented team sports.

Discriminating talent-identified junior Australian football players using a video decision-making task

Abstract This study examined if a video decision-making task could discriminate talent-identified junior Australian football players from their non-talent-identified counterparts. Participants were recruited from the 2013 under 18 (U18) West Australian Football League competition and classified into two groups: talent-identified (State U18 Academy representatives; n = 25; 17.8 ± 0.5 years) and non-talent-identified (non-State U18 Academy selection; n = 25; 17.3 ± 0.6 years). Participants completed a video decision-making task consisting of 26 clips sourced from the Australian Football League game-day footage, recording responses on a sheet provided. A score of “1” was given for correct and “0” for incorrect responses, with the participants total score used as the criterion value. One-way analysis of variance tested the main effect of “status” on the task criterion, whilst a bootstrapped receiver operating characteristic (ROC) curve assessed the discriminant ability of the task. An area under the curve (AUC) of 1 (100%) represented perfect discrimination. Between-group differences were evident (P < 0.05) and the ROC curve was maximised with a score of 15.5/26 (60%) (AUC = 89.0%), correctly classifying 92% and 76% of the talent-identified and non-talent-identified participants, respectively. Future research should investigate the mechanisms leading to the superior decision-making observed in the talent-identified group.

Notation analysis of skill expertise differences in netball

Notation analysis was used to assess decision making capability of expert and developmental athletes during 12 netball matches. Analysis of variance with repeated measures demonstrated experts produced a greater percentage of successful pass outcomes than the developmental athletes. High defensive pressure and higher decision making complexity negatively affected performance. These results suggest experts in comparison to their younger counterparts have developed the required skills to manage the defensive pressure and decision making complexity routinely experienced during game play, and as a result are able to more effectively select and execute the most appropriate passing option.

Performance Milestones in the Development of Expertise: Are They Critical?

Fifty-seven female netballers completed a training history profile to examine whether the achievement of performance milestones and/or accumulation of sport-specific practice were indicative of an athletes level of expertise. Similar to previous research, results revealed that expert and developmental athletes accumulated a greater number of hours in netball-specific practice relative to the recreational participants, but did not differ in the number of sports played or hours accumulated in non-netball specific practice. Interestingly, some performance milestones were achieved by the expert and developmental athletes earlier than the recreational participants, however, the developmental athletes achieved a number of milestones at an earlier age than the experts. These findings are discussed in relation to contemporary models of skill development, namely deliberate practice (Ericsson, Krampe, & Tesch-Römer, 1993) and the developmental model of sport participation (Côté, 1999) and the underpinning socio-environmental factors that may influence sport participation and subsequent development of expertise.

How specific is domain specificity: Does it extend across playing position?

OBJECTIVES The current study sought to examine the scope of domain specificity within a sport expertise context through the examination of positional specificity effects in the sport of netball. DESIGN Skilled goalers, centre court and defenders along with less skilled (novice) participants were tested on a video-based decision making task. METHODS Skilled and less skilled netballers completed a video-based decision making task, comprising scenarios from the three different positional areas in netball (goalers, centre court and defence). Participants completed the scenarios from the playing position they were most familiar with, followed by the remaining two positions in a counterbalanced order. RESULTS Analysis of the goaler and defence scenarios revealed that the skilled goalers and centre court players were significantly more accurate than the novice players, whilst the skilled defenders did not differ to the other three groups (skilled goalers, skilled centre court and novice). For the centre court scenarios the skilled centre court players and defenders were significantly more accurate than the novice players, whilst the skilled goalers did not differ to any of the groups. CONCLUSIONS Limited evidence was shown to support the theory that decision making is specific to the position being played with the goalers and the centre court players most accurate on the attack and centre court scenarios respectively.

Technical attributes of Australian youth soccer players: Implications for talent identification

Objectives To determine whether the technical ability of Australian youth soccer players could distinguish between various playing levels. Design A cross-sectional observational design was used with each player required to complete four technical tests. Methods Sixty-two participants were representatives of three cohorts of youth soccer in Australia: national elite (n = 18), state elite (n = 22) and sub-elite (n = 22). The technical tests used were Loughborough Short Passing Test (LSPT), long passing test (LPT), shooting test and speed dribbling, with all players familiarised with the tests prior to data collection. Differences between cohorts were analysed using a multiple analysis of variance test with follow-up analyses of variance and Tukey Honest Significant Difference post-hoc test, which were subsequently used to inform a sensitivity analysis, more specifically a bootstrapped receiver operating curve to determine cut-off scores for each variable. Results The national elite cohort scored better than state- and sub-elite cohorts on the LSPT, however, the state elite produced the fastest time before penalties. The sub-elite cohort scored less points on the LPT compared to both national- and state-elite cohorts, on both feet. In regards to speed dribbling, national-elite players were faster than both the state- and sub-elite cohorts. Shooting accuracy and velocity were able to discriminate the national- and sub-elite cohorts on the dominant foot, with shooting velocity on the nondominant foot being faster for the national elite compared to both the state- and sub-elite cohorts. Conclusions A number of differences in technical ability were identified between varying levels of Australian youth soccer players. Youth soccer coaches and sports scientists should use the cut-off scores for the technical tests in the talent identification and development process, with aspiring players aiming to reach these levels.

Self-Reported Physical Activity Using the International Physical Activity Questionnaire (IPAQ) in Australian Adults with Type 2 Diabetes, with and Without Peripheral Neuropathy

OBJECTIVES The aim of this study was to survey the level of self-reported physical activity in people with type 2 diabetes, with and without peripheral neuropathy. METHODS A sample of South Australian adults (n=481) 33 to 88 years of age who had type 2 diabetes, including 55 people with peripheral neuropathy, completed the International Physical Activity Questionnaire (IPAQ). Levels of self-reported physical activity were compared between those with and without peripheral neuropathy. RESULTS People with type 2 diabetes and peripheral neuropathy (median [Mdn]=1433; interquartile range [IQR]=495 to 3390 metabolic equivalent minutes per week [MET-min/wk]) were less physically active than those without peripheral neuropathy (Mdn=2106; IQR=876 to 4380 MET-min/wk) (p=0.04). A total of 49% of people with type 2 diabetes and peripheral neuropathy met physical activity recommendations of 150 minutes of at least moderate activity per week, compared to 57% of people with type 2 diabetes alone. CONCLUSIONS These findings demonstrate that people with type 2 diabetes and peripheral neuropathy reported being significantly less active than people with type 2 diabetes alone. People with type 2 diabetes and peripheral neuropathy need to be encouraged to perform higher levels of physical activity for biologic, physical and psychological benefits. Further studies using objective measures of physical activity are required to support these results.

Physical and anthropometrical attributes of Australian youth soccer players

Objectives To determine whether Australian youth soccer players of varying levels could be distinguished based on their anthropometrical and physical attributes. Design A cross-sectional observational design was used, involving six anthropometrical and physical tests for each player. Methods Participants represented three youth levels of competition, namely national elite (n = 18), state elite (n = 22) and sub-elite (n = 22). Anthropometrical and physical tests included standing height; body mass; 5, 10, 30 m sprint and 20 m ‘flying start’ sprint; zig-zag agility test; vertical jump and Yo-Yo Intermittent Recovery test level 1. A multiple analysis of variance for the main effect of cohort, with a follow-up ANOVA and Tukeys Honest Significant Difference were used to discern which attributes differed between each cohort. Receiver operating characteristic curves were calculated, providing cut-off values between cohorts. Results The national elite cohort was significantly taller than the state elite cohort (ES = 0.94) and faster than the sub-elite athletes across 30 m (ES = 0.79) and 20 m with a flying start (ES = 0.77) (P < 0.05). The national elite cohort had a significantly higher level of intermittent endurance, compared to the state elite athletes who also performed better than the sub-elite cohort. The discrepancy between groups in the Yo-Yo Intermittent Recovery test level 1 was exemplified by the receiver operating characteristic with 94.1% of national elite players running further than 1980 m, while 95.7% of state elite and 100% of sub-elite players failed to reach this distance (ES = 0.88–1.77). Conclusions It is evident that anthropometrical and physical attributes differ between youth cohorts, particularly intermittent endurance. It is important to use this knowledge to enhance the current processes used to identify future talent for success in Australian soccer.

Tactical skill in Australian youth soccer: Does it discriminate age-match skill levels?

Objectives Football Federation Australia (FFA) has identified that Australian athletes are proficient physically, however often lack the technical and tactical skills to excel internationally. The aim of the current study was to assess if a video-based decision-making test could discriminate different age-matched skill levels of talent in Australian soccer. Design Cross-sectional observational. Methods Sixty-two youth male soccer players completed a video-based decision-making test. Results An ANOVA test showed that the video-based test significantly discriminated between all three groups, with the national elite athletes selecting more correct responses than the state elite (65.3 ± 8.1%; 56.0 ± 9.1%, respectively). The state elite were more accurate than the sub-elite (45.9 ± 8.8%). Conclusions Results suggest that a video-based test may be a suitable tool to use in the selection of athletes as a measure of decision-making skill. The low accuracy scores, even for the national elite cohort, suggest that decision-making skill at the youth level has room for improvement and should be prioritised as an area for development.