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Effect of shoe design on distance running injury risk and performance
No full textIn the 1960s, the soles of distance running shoes began their structural evolution from flat uncushioned leather to multilayered synthetic rubber and foam. The defining feature of these modern running shoes was the introduction of a ramped cushioned midsole, and then later, the use of less compliant materials inserted medially into shoes worn by pronators and over-pronators. This combination of cushioning, ramp and varying degrees of pronation control remain the key features of shoe design today and the focus of running shoe prescription by health care professionals. In 2009, I co-authored a systematic review that asked whether this approach to running shoe prescription was evidence based. Whilst it came as a shock to many and was met with a degree of anger by some, the answer to this question was quite simply “No”. No longitudinal randomised controlled trials (RCTs) had been undertaken to assess the safety or efficacy of this approach despite having been considered the gold standard for several decades. This paper is presented in Chapter 2. In the 9 years that have followed, there has been a flurry of interest in filling this void of evidence and I provide an updated review of this literature in Chapter 1, as well as reviewing the epidemiology of running injuries, theories of injury causation including the barefoot hypothesis and further evolutions in shoe design. In Chapter 3 I present a cross-sectional survey of 1790 Australian recreational runner’s attitudes to research participation. Given the absence of randomised controlled trials studying running shoes in the literature I sought to assess what types of runners were prepared to participate in randomised controlled trials and the shoe types that they were prepared to test. I also wanted to know whether the cost barrier posed in purchasing shoes for such a study could be reduced by asking participants to contribute to the cost of the shoes they were asked to test. The responses to this survey suggested that a large adequately powered RCT is possible with an Australian cohort, but that interventions involving uncushioned shoes or barefoot running would be difficult to recruit for, as would studies of sub-populations of runners such as older runners, novices, orthotic wearers and runners with injuries involving sites other than the knee or calf. Promisingly, 85% of runners were prepared to contribute to the cost of their intervention shoes. The hypothesis that barefoot running may be superior to running in shoes is explored in Chapter 4. Presented are the findings of a pilot RCT of 28 novice distance runners, 17 who undertook the 12-week structured training program on a grass athletics track in bare feet with the remainder completing the training program in a ramped cushioned shoe with pronation control. In this study I asked (i) whether recruitment, compliance and retention could be achieved at sufficient levels to undertake a full scale barefoot running RCT, (ii) whether barefoot running on a grass track was hazardous in terms of injuries to the plantar surface of the foot, and (iii) to provide sample size estimates for future studies into the effects of barefoot running on injury rates enjoyment of running, motivation, and improvement in speed, endurance and running economy. The pilot RCT failed to meet its recruitment, compliance and retention targets and significant modifications to the study design are proposed to improve these outcomes. Barefoot running was found to be low risk for plantar surface injuries. Barefoot running was found to be associated with potentially beneficial effects on motivation and enjoyment of running.
Chapter 5 presents the findings of a RCT of 41 recreational distance runners who self-identified as heel-strikers. They were randomly allocated to either receive advice to change their foot-strike to a non-rearfoot strike and wear a 4mm ramped cushioned shoe with a rubber membrane forefoot cushioning system, or continue their self-assessed heel strike gait in a 12mm ramped cushioned shoe. This study sought to collect preliminary data on the combined effects of this deliberate change in foot-strike and shoe type on 5km time trial performance, injury rates, motivation, comfort and enjoyment. No conclusions could be drawn as no statistically significant differences were observed and the lack of statistical power prevented conclusions being drawn from these negative findings. In Chapter 6 I ask whether flat uncushioned, flat cushioned, 1-5mm ramped and >5mm ramped cushioned differentially affect training volume, injury rates, 5km performance, motivation, enjoyment of running or shoe comfort when runners are given shoe group specific transition advice but control their own adaptation strategy. An RCT of 157 recreational distance runners is reported where participants were randomly allocated to transition into either a flat uncushioned, flat cushioned, 1-5mm cushioned or >5mm ramped cushioned running shoe over 12 months. Only the flat uncushioned group differed from the >5mm ramped cushioned group with a reduced distance run in the intervention shoe and a decreased rating of the comfort of the shoe. No conclusion could be drawn from the lack of statistically significant association between shoe group and injury rates, 5km performance, motivation, or enjoyment of running due to the study being under-powered. In Chapter 7 I present an updated synthesis of the best evidence to date for the role of cushioning, ramp, pronation control and barefoot running in injury prevention, distance running performance, enjoyment, motivation and shoe comfort. Areas of residual uncertainty are identified, and suggestions are made for both future research and re-negotiating the relationship between research and industry to ensure that running shoe science achieves its simplest objectives - helping runners to enjoy running fast and injury free
Towards an integrated framework of big data capabilities in the construction industry: A systematic literature review
No full textGeneration of data in the construction industry is increasing exponentially, becoming bigger and varied due to the use of sophisticated devices. This is necessitated by the call for automating the construction process. Getting valuable insights from data has taken the centre-stage of digitalization in the business world, through big data applications. Big data describes the application of advanced technologies to mine insights from datasets to solve problems. Studies have recommended the benefits of big data in the construction industry, though scanty, but cognizance is not given to what it takes for the industry to realize to the fullest, the benefits of big data. This study identified big data capabilities across different disciplines required in the construction industry through a systematic literature review. Four major big data capabilities thus organizational strategy, data, technology and people were identified from literature through qualitative synthesis. The research was limited to peer reviewed articles indexed in Web of Science and Scopus. The findings together with antecedents of innovation from the Schumpeter's theory of innovation led to conceptualization of a process framework for big data capabilities in the construction industry. The framework consists of antecedents to innovation, big data capabilities and outcomes. The study addressed the gap of big data capabilities deficit in the construction industry. Practically, the framework can serve as a guide for construction organizations interested in adopting big data in their operations
Robust inference of two-dimensional strain fields from diffraction-based measurements
No full textDiffraction-based methods have become an invaluable tool for the detailed assessment of residual strain and stress within experimental mechanics. These methods typically measure a component of the average strain within a gauge volume. It is common place to treat these measurements as point measurements and to interpolate and extrapolate their values over the region of interest. Such interpolations are not guaranteed to satisfy the physical properties of equilibrium and applied loading conditions. In this paper, we provide a numerically robust algorithm for inferring two dimensional, biaxial strain fields over a region of interest from diffraction-based measurements that satisfies equilibrium and any known loading conditions. By correctly treating the measurements as gauge volume averages rather than point-wise the algorithm has better performance when large gauge volumes and subsequently shorter beam-times are used. This algorithm is demonstrated on simulation and experimental data and compared to natural neighbour interpolation with linear extrapolation and is shown to provide a more accurate strain field
Characteristics of chronic ankle instability and the role of joint mobilisation
No full textChronic ankle instability (CAI) is the occurrence of giving way and/or recurrent sprain and/or feelings of instability of a previously injured ankle. Compared to a simple ankle sprain, the additional morbidity and additional costs incurred due to diagnostic imaging related to CAI create significant economic and other societal consequences. Direct costs can include consultations with physicians, physiotherapists and other health professionals, diagnostic imaging and various hospital expenses, while indirect costs may arise from productivity losses, absenteeism (from school, work and sports) and diminished levels of physical activity resulting in economic burden on the healthcare system and for the individual patient. Rehabilitation of CAI commonly involves manual therapy procedures applied to joints in the ankle region, such as non-thrust passive joint mobilisation, high-velocity thrust manipulation and mobilisation with movement (MWM) as described by Brian Mulligan. These techniques largely involve a continuum of skilled passive movements of joints that are applied at different speeds and amplitudes. The overall aims of this thesis were to explore the clinical characteristics of CAI and to determine the effects of joint mobilisation in CAI. This thesis comprises four studies designed to meet these aims, presented as five manuscripts which have either been published in peer-reviewed journals or are in the process of review or submission. Study 1 is a systematic review and meta-analysis undertaken to evaluate the current evidence for joint mobilisation in the clinical rehabilitation of ankle sprains, using the previously published body of literature. Based upon this investigation, joint mobilisation appears to be beneficial for improving dynamic balance immediately after application and dorsiflexion range of movement in the short-term in chronic ankle sprains. The results of this study also suggested that the combination of MWM and associated fibular repositioning taping is more likely to exhibit a clinical benefit than other assessed mobilisation techniques, and potentially supporting the hypothesis of Brian Mulligan that the distal fibula is displaced anteriorly in CAI.
Study 2 explored the position of the distal fibula in relation to the position of the distal tibia in CAI using weight-bearing radiographs. The findings of this study indicated that there is a more anteriorly positioned fibula in individuals with CAI compared to individuals with healthy ankles when assessed in a weight-bearing position, consistent with Mulligan’s hypothesis. Notably, this study was the first to use weight-bearing radiographs to measure the fibula position in CAI.
Study 3 investigated other clinical characteristics of CAI including ankle dorsiflexion range of motion, balance, self-reported function, pain and pressure pain threshold which have not been consistently reported, or for which little research has been published in the previous literature. It was found that individuals with CAI exhibit a multi-factorial presentation including impaired ankle dorsiflexion range, reduced static and dynamic balance, lower self-reported function and greater pain intensity, compared to individuals with healthy ankles. Despite the persistence of pain often reported in CAI, no evidence was found to suggest maladaptive central nervous system sensitisation (nociplastic pain). Study 4 involved a randomised controlled trial (RCT) to investigate the effects of MWM of the distal tibio-fibular joint with fibular repositioning taping on fibular position and other clinical characteristics of CAI. The protocol for this study was published, and in contrast to almost all previously published studies of this manual therapy technique, highlighted the long-term nature of the trial with a one year follow-up. The immediate and short-term findings revealed no significant differences in any of the outcomes measured except for improvements in two self-reported function subscales (pain and sports on the foot and ankle outcome score (FAOS) questionnaire) in the placebo (detuned laser) intervention group. The long-term results were still being collected at the time of the submission of this thesis so are not reported or considered in the discussion. The body of work contained in this thesis extends our current understanding of CAI and its clinical management. The results have implications for the identification of the features of CAI and for improving its treatment using joint mobilisation. Reproduction of the contained research using more homogeneous samples of CAI may permit a greater understanding of this persistent condition and how it responds to manual therapy. In addition, the use of weight-bearing radiographs in future studies to assess fibula position may be a more functional method. Other future directions for research and implications for clinical practice are discussed in detail in relation to the results of each of the studies in this thesis
The search for an integrated policy: challenges to Australian national interest in the Asia-Pacific, 1921–57
No full textThis dissertation examines the development of a distinct Australian foreign policy over the years 1921–57. The period under study was one of immense upheaval for Australia as the nation navigated economic crises, the threat of aggressive Japanese expansion and the sifting power distributions underway in the Asia-Pacific region as the world transitioned from British leadership to that of United States of America. Successive Australian governments carefully observed these global and regional forces, searching for a policy in response. This dissertation argues that the policy that developed was an integrated one—that is, one that sought to balance Australia’s particular geopolitical circumstances with great powers relations and, in assessing the value of these relationships, ensure that the nation’s trade, defence and diplomatic interests were served. This dissertation identifies a marked continuity in how Australia’s political elite approached foreign policy over the years 1921–57. In the midst of the economic and strategic uncertainty of the interwar years, policymakers determined the need to reorient policymaking to Australia’s immediate region and acknowledged that neither the policies of Britain nor the US completely served the national interest. The government accordingly sought to intervene in the policies of the great powers to ensure the national interest was safeguarded. This thesis traces how this geopolitically informed, interventionist approach to foreign policy went on to inform policymaking throughout the 1940s and 1950s. In doing so, this thesis identifies a comprehensive and explicitly pragmatic approach in Australia’s foreign policy tradition that has not been previously acknowledged
Self-recognition of mental health problems in a rural Australian sample
No full textObjective: Although mental health literacy has increased in recent years, mental illness is often under-recognised. There has been little research conducted on mental illness in rural areas; however, this can be most prominent in rural areas due to factors such as greater stigma and stoicism. The aim of this study is to create a profile of those who are most and least likely to self-identify mental health problems among rural residents with moderate- to-high psychological distress. Design: Secondary analysis of a longitudinal postal survey. Setting: Rural and remote New South Wales, Australia. Participants: Four-hundred-and-seventy-two community residents. Main outcome measure: Participants completed the K10 Psychological Distress Scale, as well as the question 'In the past 12 months have you experienced any mental health problems?' The characteristics of those who reported moderate/high distress scores were explored by comparing those who did and did not experience mental health problems recently. Results: Of the 472 participants, 319 (68%) with moderate/high distress reported a mental health problem. Reporting a mental health problem was higher among those with recent adverse life events or who perceived more stress from life events while lower among those who attributed their symptoms to a physical cause. Conclusions: Among a rural sample with moderate/high distress, one-third did not report a mental health problem. Results suggest a threshold effect, whereby mental health problems are more likely to be acknowledged in the context of additional life events. Ongoing public health campaigns are necessary to ensure that symptoms of mental illness are recognised in the multiple forms that they take
Intertrial RT variability affects level of target-related interference in cued task switching
No full textIn cued task switching, performance relies on proactive and reactive control processes. Proactive control is evident in the reduction in switch cost under conditions that promote advance preparation. However, the residual switch cost that remains under conditions of optimal proactive control indicates that, on switch trials, the target continues to elicit interference that is resolved using reactive control. We examined whether posttarget interference varies as a function of trial‐by‐trial variability in preparation. We investigated target congruence effects on behavior and target‐locked ERPs extracted across the response time (RT) distribution, using orthogonal polynomial trend analysis (OPTA). Early N2, late N2, and P3b amplitudes were differentially modulated across the RT distribution. There was a large congruence effect on late N2 and P3b, which increased with RT for P3b amplitude, but did not vary with trial type. This suggests that target properties impact switch and repeat trials equally and do not contribute to residual switch cost. P3b amplitude was larger, and latency later, for switch than repeat trials, and this difference became larger with increasing RT, consistent with sustained carryover effects on highly prepared switch trials. These results suggest that slower, less prepared responses are associated with greater target‐related interference during target identification and processing, as well as slower, more difficult decision processes. They also suggest that neither general nor switch‐specific preparation can ameliorate the effects of target‐driven interference. These findings highlight the theoretical advances achieved by integrating RT distribution analyses with ERP and OPTA to examine trial‐by‐trial variability in performance and brain function
Analysis of microscopy images: modelling and reconstruction
No full textComputer-aided image analysis plays a vital role in modern medicine by introducing algorithms and techniques to extract the desired information and features out of raw images. This valuable information helps clinicians and researchers to get a better insight into disorders in different organs, such as brain tumour, lung and breast cancer, and treat them more successfully. In neuroscience, the analysis of cells and vessels in the brain highly depends on the microscopy image analysis. This thesis contributes to this field in three parts: 1- modelling of microscopy images and generating synthetic image dataset, 2- proposing a novel algorithm to segment clump of nuclei from histopathological images, 3- proposing a new tracing algorithm to reconstruct and quantify microglial cells. In the first part of this thesis we focus on modelling microscopy images and generating realistic synthetic images with known ground truths which offer a means of assessing algorithm performance. We propose a synthesizer for neuron nucleus micro-environment using Gaussian mixture model (GMM) and Perlin noise function. Nucleus shapes are generated by spline interpolation of random points on elliptical shapes. The textures of the foreground (nuclei) and the background are generated via Perlin noise, and then assigned intensities generated by applying GMM to the real data. The cell orientations are also implemented via Perlin noise to mimic the behaviour of the actual neuron cells. In the second part of this thesis we propose a novel method of segmentation applicable to variety of histopathological images stained for different proteins, with high speed, accuracy and level of automation. Our algorithm is initiated by applying a new locally adaptive thresholding method on watershed regions. Followed by a new splitting technique based on multilevel thresholding and the watershed algorithm to separate clustered nuclei. Finalized by a model-based merging step to eliminate oversegmentation and a model-based correction step to improve segmentation results. In the last part of this thesis we propose an automated method to reconstruct microglia, and quantify their features from 2D/3D image datasets. Multilevel thresholding is employed to segment soma volumes and recognize foreground voxels. Then, we propose a tracing process to connect seed points sampled from the foreground and form the skeleton of the branches. The thickness of the branches are estimated during a pruning process. The reconstructed data is then quantified and written in SWC standard file format. We have applied our methods to various image datasets for which the evaluated results show our methods outperform the state-of-the-art methods in terms of accuracy, precision, F1-measure, and computational time
Relationships between reading ability and child mental health: moderating effects of self-esteem
No full textObjective: Children with reading difficulties are at elevated risk for externalising (e.g., conduct disorder) and internalising (e.g., anxiety and depression) mental health problems. Reading ability is also negatively associated with self-esteem, a consistent predictor of child and adolescent mental health more broadly. This study examined whether self-esteem moderated and/or mediated relationships between reading ability and mental health. Method: One hundred and seventeen children (7-12 years) completed standardised reading assessments (Castles and Coltheart Test 2; CC2) and self-report measures of mental health (Strengths and Difficulties Questionnaire; SDQ) and self-esteem (Coopersmith Self-esteem Inventory). Non-verbal intelligence (IQ) was measured using the block design and matrix reasoning subscales of the Wechsler Abbreviated Scale of Intelligence, and was controlled for in all multivariate analyses. Results: Reading ability was negatively associated with internalising symptoms. This relationship was not moderated by self-esteem. Poor readers also reported more total difficulties and externalising symptoms, but only at low levels of self-esteem. There was no evidence that self-esteem mediated relationships between reading ability and mental health. Conclusions: Poor reading was associated with internalising symptoms. Self-esteem moderated the impact of reading ability on total difficulties and externalising symptoms, with high self-esteem buffering against negative impacts of poor reading. However, the reliability of the self-esteem scale used in the study was poor and findings need replication using a reliable and valid self-esteem measure, as well as other measures of child mental health. If replicated, future research should examine whether interventions aiming to improve self-esteem can reduce the risk of externalising problems in children with reading difficulties
Comparison of the physical and technical demands of cricket players during training and match-play
No full textThis study aimed to determine which training method (net-based sessions or center-wicket simulations) currently used in national level and U19 male players cricket provided a more physical and technical match-specific training response. The heart rate, rating of perceived exertion, and movement patterns of 42 male cricket players were measured across the various training and match formats. Video analysis was coded retrospectively to quantify technical loads based on the cricket skills performed. Magnitude-based inferences were based on the standardization of effect and presented with ±90% confidence intervals. Regardless of playing position, differences in physiological demands between training modes and match-play were unclear, with the exception of higher heart rates in fielders during traditional net sessions (mean heart rate: d = −2.7 [−4.7 to −0.7]; 75% of maximum heart rate: d = −1.7 [−3.2 to −0.2]). Typically, the movement demands of center-wicket simulations were similar or greater than match-play, which was most evident in the distance traveled at a high intensity within each playing position (batsmen: d = 6.4 [3.7–9.2]; medium-fast bowlers: d = 1.71 [0.1–3.3]; spin bowlers: d = 6.5 [0.01–13.0]; fielders: d = 0.8 [−0.2 to 1.7]). The technical demands of traditional net cricket training exceeded that of a typical match for each playing position. Specifically, fast bowlers delivered a greater number of balls during net-bowling compared with a match (d = −2.2 [−3.6 to 0.9]). In conclusion, center-wicket simulations more closely matched the physical demands of a One-Day match within batsmen and spin bowlers, whereas traditional cricket training often exceeded match-specific demands