Medicine and Health Sciences Commons^™

The Mechanics Of Front Leg Loading During Cricket Fast Bowling: Delivery Variations, Spell Demands, And The Effects Of Strength Training, Samuel J. Callaghan

Theses: Doctorates and Masters

The goal of fast bowling in cricket is to dismiss a batsman for as few runs as possible. To assist this goal, fast bowlers will attempt to maximise ball release velocity (BRV) to decrease the decision-making and stroke execution time of the opposing batsmen. Fast bowlers will also employ various delivery lengths (i.e. short, good and full) to assist in affecting a batsman’s stroke execution.

Several issues remain to be addressed with regards to the biomechanical assessment of fast bowling. This is particularly evident when analysing fast bowling performance (i.e. BRV), the implications of front foot loading (i.e. vertical and …

High-Intensity Interval Eccentric Cycling: Acute And Chronic Effects, Marcin Lipski

Theses: Doctorates and Masters

Eccentric cycling training has been prescribed in continuous and low intensities protocols, based on concentric cycling parameters. While the lower metabolic demand of eccentric than concentric cycling is advantageous for clinical or ‘at-risk’ populations, it is a disadvantage for cardiovascular and pulmonary adaptations. High-intensity interval protocols may increase both, strength and endurance. Thus, this research project compared i) an incremental concentric and eccentric cycling test until exhaustion for the relationship between power output and physiological parameters <Study1>; ii) interval and continuous eccentric cycling protocols for oxygen consumption, perceived exertion and enjoyment <Study 2>; and iii) aerobic performance, muscle …

An Investigation Into The Creation Of Goal Scoring Opportunities In Women’S International Football; And A Comparison To Men’S International Football, Mark Scanlan

Theses: Doctorates and Masters

Football is the most popular sport in the world, played in over two hundred countries and it is governed by the Fédération Internationale de Football Association (FIFA), who host a World Cup every four year for both men and women. Women’s football is growing in terms of popularity, with this growth in popularity, research into the women’s game has begun to emerge. However, to date there is very little published research in women’s football that describes effective attacking strategies and the creation of goal scoring opportunities (GSO). Video of each match (52) from the Women’s World Cup (Canada 2015) was …

Assessment Of Joint Kinetics In Elite Sprint Cyclists, Lynne Munro

Theses: Doctorates and Masters

Sprint cycling requires the production of explosive muscle power outputs up to very high pedalling rates. The ability to assess muscular function through the course of the sprint would aid training practices for high-level performers. Inverse dynamics provides a non-invasive means of estimating the net muscle actions acting across any joint contributing to movement. However, analysis of joint kinetics requires motion-capture techniques that present some unique challenges for cycling. This thesis presents three studies investigating the application of a custom-designed force pedal system to examine the joint kinetics of elite trained track sprint cyclists. To provide the basis for selecting …

Neuromuscular Factors Contributing To Reductions In Muscle Force After Repeated, High-Intensity Muscular Efforts, Benjamin J. C. Kirk

Theses: Doctorates and Masters

Fatigue can accumulate sufficiently to limit muscular force production during repeated, forceful muscle contractions, including those that occur in the occupational, clinical and athletic settings. Fatigue during such efforts is likely to result from disturbances to multiple processes in the nervous system and muscle. However, previous research examining the mechanisms underpinning fatigue have typically required subjects to perform low-level constant-force contractions or to repeat maximal efforts in a single set format. Such tasks do not translate well to occupational, daily living or athletic situations where high-intensity, yet submaximal, repeated efforts may be performed in work bouts (or sets) with brief …

The Effect Of Maximal Isometric Training On Doublet-Induced Force Enhancement And Its Relationship With Changes In Voluntary Rate Of Force Development, David Vernon Murray

Theses: Doctorates and Masters

Motor unit double discharges (i.e. doublets), which are excitatory potentials that occur at shorter-than-normal intervals (e.g. 5-10 ms) during normal muscle activation, are known to cause muscle force to exceed that predicted from a standard, linear summation of twitch forces. However, although a marked increase in the occurrence of motor unit doublets at the onset of a contraction has been observed after explosive-type exercise training, and has been correlated with changes in RFD (Van Cutsem et al., 1998), little is known about the influence of strength training on the physiological and biomechanical benefits derived from the phenomenon. The present research …

Effects Of Long-Term Participation In Tennis On Cognitive Function In Elderly Individuals, Scott Culpin

Theses: Doctorates and Masters

Many studies have reported the relationship between exercise and cognition with conflicting results. This may be due to differences in intervention durations, session lengths, intensities, and type of exercise. It has been suggested that exercises requiring greater cognitive demand such as football, basketball and racquet sports, are protective against cognitive decline, compared to less cognitively demanding exercises such as swimming, cycling and running, however, research concerning exercise types are currently limited. The present study tested the hypothesis that elderly individuals who had been regularly playing tennis more than 10 years, would have greater cognitive function than those who had been …

The Influence Of A Simulated Olympic Distance Cycle Exercise On Subsequent Running Economy And Biomechanics In Triathletes, Chantelle Du Plessis

Theses: Doctorates and Masters

The multidisciplinary sport of triathlon provides a good model for testing whether a secondary task can be negatively affected by a preceding task, especially when movement patterns are different. Research suggests that cycling exercise impairs subsequent running performance by altering a runner’s economy and various mechanics (or technique-related) parameters. However, this is not an unambiguous finding. Furthermore, movement patterns are self-optimised during cycling and running to minimise the energy cost, yet the relationship between running mechanics and economy are not clear when different locomotor tasks are performed in succession

Two research studies were conducted with the focus of describing and …

Bone Fracture Incidence, Measurement And Adaptation: An Exploration Through The Continuum From Incidence To Measurement And Adaptation, Mark Jenkins

Theses: Doctorates and Masters

This research encompasses four studies exploring bone adaptation, fracture incidence, and preventative measures to decrease fracture risk and increase bone health. Study one was a clinical audit exploring incidence rates for appendicular fractures in children in Western Australia over ten years. Diagnostic and remedial approaches were explored in studies two, three and four by examining the between-day reliability of upper limb scans; reliability of the osteogenic index (OI) for upper-body strength and power exercises; and the diagnostic value or utility of using pQCT in disease profiling, respectively. Fracture rates in the limbs of children were found to be increasing each …

Gender Differences In Physical Performance Characteristics Of Competitive Surfers, Joanna Parsonage

Theses: Doctorates and Masters

Competitive surfing is judged on the performance and complexity of innovative and progressive manoeuvres. As such, surfers require the physical attributes of strength and power in both the upper and lower-body in order to facilitate performance. To date, there remains limited research pertaining to the physical performance characteristics of competitive female surfers, making it difficult to quantify the current gender gap in performance attributes. Therefore, the purpose of this thesis was fivefold: (1) to describe and compare the gender differences in physical performance characteristics of competitive surfers; (2) to investigate the reliability and validity of the isometric push-up (IPU), dynamic …

A Profile Of Game Style, Physical, Technical And Tactical Skills, And The Pathways That Underpin Expertise In Australian Youth Soccer Players, Bradley Scott Keller

Theses: Doctorates and Masters

The attainment of expertise has been the focus of research in many domains including music, chess and sport. This research has progressed with many theories detailing the best way to develop expertise and nurture talent in sport. Soccer is a multifaceted sport which requires a number of physical, technical and tactical skills to be successful, making it difficult to achieve expertise. Although Australia’s performance on the international stage is improving, there is a lack of evidence to inform the most effective development pathways to support the next wave of talented youth soccer players. Therefore, the aim of the thesis was …

Braking Ground Reaction Force During 90deg Sidestep Cut And Its Relationship To Leg Muscle Strength, Walter Yu

Theses: Doctorates and Masters

Previous studies on change of direction (COD) have reported that braking is an important factor for COD performance. However, previous studies have focused on the plant step and the penultimate step (PEN), thus little is known about deceleration before these steps. This study compared ground reaction forces (GRF) of two braking steps, the PEN and the step prior to PEN (PEN-1), the entry and exit velocity of the COD, and muscle function measures (leg press and leg curl one-repetition maximum, isometric and isokinetic strength, and drop jump performance) between faster and slower participants for a 90^o sidestep cut. This …