Lyndell Bruce

Acute effects of static stretching on hip flexor and quadriceps flexibility, range of motion and foot speed in kicking a football

The purpose of this research was to determine the effect of static stretching in a warm-up on hip flexor and quadriceps flexibility as measured by a modified Thomas test and on range of motion (ROM) of the leg and foot speed at impact in kicking a football with maximum effort. Sixteen Australian Rules (AR) footballers performed two different warm-ups on different days. One warm-up involved five minutes of sub-maximum running followed by seven practice kicks, while the other also included 4.5 minutes static stretching of the hip flexors and quadriceps after the running. A modified Thomas test was conduced before and after each warm-up. Players performed maximum effort drop punt kicks into a net while being videotaped to determine the ROM of the kicking leg and foot speed at impact with the ball. There were no significant changes in flexibility (p > 0.05) as a result of either warm-up and there were no significant differences between the warm-ups in the kicking variables (p > 0.05). It was concluded that the Thomas test may not have been sensitive to possible acute changes in flexibility from the warm-ups, and that stretching had no influence on kicking ROM or foot speed, possibly because of the complexity of the kicking skill.

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.

The use of skill tests to predict status in junior Australian football

Abstract This study examined whether skill tests were predictive of status in junior Australian football. Players were recruited from the 2013 under 18 (U18) West Australian Football League competition and classified into two groups: elite (state U18 squad representative; n = 25; 17.9 ± 0.5 years) and subelite (nonstate U18 squad representative; n = 25; 17.3 ± 0.6 years). Both groups completed the Australian football kicking (AFK) and Australian football handballing (AFHB) tests, assessing kicking accuracy/ball speed and handballing accuracy on dominant and nondominant sides. A multivariate analysis of variance (MANOVA) modelled the main effect of “status”, whilst logistic regression models were built for the predictive analysis using the same test parameters. Between-group differences were noted across all parameters, with the combination of kicking accuracy and ball speed on the dominant and nondominant sides being the best predictor of status for the AFK test (wi = 0.25, AUC = 89.4%) and the combination of accuracy on the dominant and nondominant sides being the best predictor of status for the AFHB test (wi = 0.80, AUC = 88.4%). The AFK and AFHB tests are predictive of status, suggesting that their use is warranted as a means of talent identification in junior Australian football.

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.

Reliability and validity of a GPS-enabled iPhoneTM “app” to measure physical activity

Abstract This study assessed the validity and reliability of an iPhoneTM “app” and two sport-specific global positioning system (GPS) units to monitor distance, intensity and contextual physical activity. Forty (23 female, 17 male) 18–55-year-olds completed two trials of six laps around a 400-m athletics track wearing GPSports ProTM and WiSpiTM units (5 and 1 Hz) and an iPhoneTM with a Motion X GPSTM “app” that used the inbuilt iPhoneTM location services application programming interface to obtain its sampling rate (which is likely to be ≤1 Hz). Overall, the statistical agreement, assessed using t-tests and Bland–Altman plots, indicated an underestimation of the known track distance (2.400 km) and average speed by the Motion X GPSTM “app” and GPSports ProTM while the GPSports WiSpiTM device overestimated these outcomes. There was a ≤3% variation between trials for distance and average speed when measured by any of the GPS devices. Thus, the smartphone “app” trialled could be considered as an accessible alternative to provide high-quality contextualised data to enable ubiquitous monitoring and modification of programmes to ensure appropriate intensity and type of physical activity is prescribed and more importantly adhered to.

The relationship between game-based performance indicators and developmental level in junior Australian football: Implications for coaching.

ABSTRACT Identifying performance differences between juniors at different stages of a talent pathway may assist with the development of prospective talent. This study investigated the relationship between game-based performance indicators and developmental level in junior Australian football (AF). Players were categorised into 2 groups according to developmental level; U16 and U18. Physical and technical skill performance indicators were collated for all U16 (n = 200) and U18 (n = 244) participants of their respective 2014 national championships. Data were acquired from all 28 games (12 U16, 16 U18); resulting in 1360 player observations (568 U16, 792 U18). Microtechnology and a commercial provider facilitated the quantification of 15 performance indicators. Generalised estimating equations (GEEs) modelled the extent to which these performance indicators were associated with developmental level. The GEE model revealed that “contested marks” and “contested possessions” had the strongest association with the U16 level, while “total marks” and “clearances” had the strongest association with the U18 level. The remaining performance indicators were not developmentally discriminant. These results indicate that there are distinctive features of gameplay more associated with the U16 and U18 levels in AF. Coaches may wish to consider these results when constructing training drills designed to minimise developmental gaps.

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.