A multidisciplinary examination of fast bowling talent development in cricket

Research on expertise, talent identification and development has tended to be mono-disciplinary, typically adopting geno-centric or environmentalist positions, with an overriding focus on operational issues. In this thesis, the validity of dualist positions on sport expertise is evaluated. It is argued that, to advance understanding of expertise and talent development, a shift towards a multidisciplinary and integrative science focus is necessary, along with the development of a comprehensive multidisciplinary theoretical rationale. Dynamical systems theory is utilised as a multidisciplinary theoretical rationale for the succession of studies, capturing how multiple interacting constraints can shape the development of expert performers. Phase I of the research examines experiential knowledge of coaches and players on the development of fast bowling talent utilising qualitative research methodology. It provides insights into the developmental histories of expert fast bowlers, as well as coaching philosophies on the constraints of fast bowling expertise. Results suggest talent development programmes should eschew the notion of common optimal performance models and emphasize the individual nature of pathways to expertise. Coaching and talent development programmes should identify the range of interacting constraints that impinge on the performance potential of individual athletes, rather than evaluating current performance on physical tests referenced to group norms. Phase II of this research comprises three further studies that investigate several of the key components identified as important for fast bowling expertise, talent identification and development extrapolated from Phase I of this research. This multidisciplinary programme of work involves a comprehensive analysis of fast bowling performance in a cross-section of the Cricket Australia high performance pathways, from the junior, emerging and national elite fast bowling squads. Briefly, differences were found in trunk kinematics associated with the generation of ball speed across the three groups. These differences in release mechanics indicated the functional adaptations in movement patterns as bowlers’ physical and anatomical characteristics changed during maturation. Second to the generation of ball speed, the ability to produce a range of delivery types was highlighted as a key component of expertise in the qualitative phase. The ability of athletes to produce consistent results on different surfaces and in different environments has drawn attention to the challenge of measuring consistency and flexibility in skill assessments. Examination of fast bowlers in Phase II demonstrated that national bowlers can make adjustments to the accuracy of subsequent deliveries during performance of a cricket bowling skills test, and perform a range of delivery types with increased accuracy and consistency. Finally, variability in selected delivery stride ground reaction force components in fast bowling revealed the degenerate nature of this complex multi-articular skill where the same performance outcome can be achieved with unique movement strategies. Utilising qualitative and quantitative methodologies to examine fast bowling expertise, the importance of degeneracy and adaptability in fast bowling has been highlighted alongside learning design that promotes dynamic learning environments

COACH AND BIOMECHANIST KNOWLEDGE OF SPRINT RUNNING TECHNIQUE

The purpose of this study was to establish how coaches and biomechanists assess sprint running technique to increase understanding of current coaching and biomechanical practice leading to an identification of ways to improve coach-practitioner relationships. Australian sprint coaches (n=56) and international sport biomechanists (n=12) completed an online survey that asked questions relating to their knowledge of sprint running, current biomechanical-based practices and the coach-biomechanist relationship. A level of congruence was found in the two group’s understanding of sprinting technique with a number of similarities between aspects of the stance and swing phases especially around the instance of contact. There were key differences in the relative importance of the stance phase, arm movement and postural alignment of the body. The potential gaps in knowledge and practice suggested in this initial research create a foundation for further research into the coach-practitioner relationship and its overall effectiveness

INTERACTIVE BIOMECHANICS AND ELECTRONIC TEXTILES

This paper presents an overview of a wearable interactive system developed by CSIRO that uses electronic textiles to enable interactive biomechanical measurement and feedback. Textile strain sensors are used to measure limb motion with real-time data streaming and analysis that enables interactive feedback to assist with skill acquisition. The system can be used in diverse training and competition environments, as illustrated via examples in kicking, throwing and paddling

VALIDATION OF INERTIAL MEASUREMENT UNITS FOR TRACKING 100M SPRINT DATA

Wearable micro sensor measurement devices are a promising development in sports technology. This paper presents preliminary data evaluating the accuracy of an inertial measurement unit during 100m sprints against a criterion measure from a tripod-mounted Laveg laser. The inertial measurement units were found to be a valid tool for the analysis of peak velocity (r = 0.92) and average split velocities for splits after the first 10m (r = 0.85 - 0.95). Validation data suggests some caution should be taken in interpretation of the first lorn split (r = 0.32). Whilst data from the two devices for this split were correlated, the inertial measurement unit showed an overestimation for this parameter in comparison to the athlete velocity as measured by the laser. Further in-depth analysis should investigate this period

EFFECT OF SEATING CUSHIONS ON PRESSURE DISTRIBUTION IN WHEELCHAIR RACING

This study investigated the efficacy of pressure mapping technology in quantifying athlete-wheelchair interaction at the seating interface, and the influence of foam inserts on pressure (peak and average), and contact area. An XSENSOR LX100 pressure mat was located at the seating interface of six nationally ranked wheelchair racing athletes, who performed regular propulsion on treadmill. Substantial inter-athlete variation was observed on resulting pressure distribution (area and magnitude) for all athletes. Implementation of a foam insert did not impede recording ability, however did alter seating characteristics, lowering seating pressure (peak and average), and increasing contact area. This increase may enhance athlete-wheelchair interaction, which will likely result in a more powerful technique, and increased probability of winning races

Comparing inertial measurement units and marker-based biomechanical models during dynamic rotation of the torso

Inertial measurement units (IMUs) enable human movements to be captured in the field and are being used increasingly in high performance sport. One key metric that can be derived from IMUs are relative angles of body segments which are important for monitoring form in many sports. The purpose of this study was to a) examine the validity of relative angles derived from IMUs placed on the torso and pelvis; and b) determine optimal positioning for torso mounted sensors such that the IMU relative angles match closely with gold standard torso-pelvis and thorax-pelvis relative angle data derived from an optoelectronic camera system. Seventeen adult participants undertook a variety of motion tasks. Four IMUs were positioned on the torso and one was positioned on the pelvis between the posterior superior iliac spines. Reflective markers were positioned around each IMU and over torso and pelvis landmarks. Results showed that the IMUs are valid with the root mean square errors expressed as a percentage of the angle range (RMSE%) ranging between 1% and 7%. Comparison between the IMU relative angles and the torso-pelvis and thorax-pelvis relative angles showed there were moderate to large differences with RMSE% values ranging between 4% and 57%. IMUs are highly accurate at measuring orientation data; however, further work is needed to optimize positioning and modelling approaches so IMU relative angles align more closely with relative angles derived using traditional motion capture methods

SIMPLIFYING THE HIGH-PERFORMANCE BIOMECHANICAL ASSESSMENT OF HIGH JUMP TECHNIQUE

A multitude of technical performance parameters are used to quantify high jump technique in the Australian high-performance environment, which can be time-consuming to measure and interpret. The purpose of this study was to investigate the efficacy of principal component analysis and stepwise multiple linear regression to simplify high-performance high jump biomechanical reports. Five non-intuitive principal components were derived, and three technical performance parameters (difference in knee angles during take-off contact, lean angle through hip at take-off contact, take-off foot contact time) influenced the height cleared by elite high jump athletes. This study establishes a method for simplifying high jump biomechanical reports and identifies the most important variables that contribute to high jump success

Being Motivated to Protect : The Influence of Sexual Communal Motivations on Sexual Risk Taking

College-aged students are a high-risk population for unplanned pregnancy with 40% of women between the ages of 18-20 experiencing an unplanned pregnancy. This can cause physical, mental, and emotional stress resulting in withdrawal from college for the student. Communal motivation (being oriented towards other’s needs) positively predicts condom use. WISE interventions, a simple yet impactful type of interventions targeted towards addressing a problem, have been shown to be successful. Participants completed a sexual risk behavior measure, sexual risk-taking measure and communal motivations (CM) measure following a sexual health video, and reflection activity were participants either applied the sexual health information to their relationship (experimental) or reflected on the sexual health material presented (control). CM was positively correlated with number of sexual partners in the past 3 months, r(262) = .162,

THE OPTIMIZATION OF TRUNK POSITION FOR THE 2016 RIO PARALYPMIC WHEELCHAIR RACING FINALS

This research investigated the relationship between athlete aerodynamics (based on peak frontal area during recovery phase) and finishing position for athletes in the 100m- 5000m wheelchair Athletics events. A retrospective analysis was performed on T54 classified male and female finalists (n=86) at the 2016 Rio Paralympic Games. Medalling female athletes more consistently favoured an aerodynamic position than was observed for males, who may be more inclined to overcome additional resistive forces through powerful techniques due to enhanced strength capacities. Whilst aerodynamics does not appear the sole performance requirement for male athletes, time savings of up to 116s over a 5000m race can be obtained, if athletes improve their aerodynamics, without compromising force generating capacity, demonstrating its importance to athletes