577 resultados para Perry,Chris
Resumo:
Footwear is designed to reduce injury, and enhance performance. However, the effect footwear has on foot and ankle kinematics currently remains unknown. Acknowledging the need for improved understanding, multi-segment models of the foot-shoe complex need to be established to both describe and quantify the effect footwear has on the foot and ankle during stance phase of gait. The purpose of this study was to quantify how footwear alters the kinematics of the foot inside the shoe during stance phase of walking gait.
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In 1999 Richards compared the accuracy of commercially available motion capture systems commonly used in biomechanics. Richards identified that in static tests the optical motion capture systems generally produced RMS errors of less than 1.0 mm. During dynamic tests, the RMS error increased to up to 4.2 mm in some systems. In the last 12 years motion capture systems have continued to evolve and now include high-resolution CCD or CMOS image sensors, wireless communication, and high full frame sampling frequencies. In addition to hardware advances, there have also been a number of advances in software, which includes improved calibration and tracking algorithms, real time data streaming, and the introduction of the c3d standard. These advances have allowed the system manufactures to maintain a high retail price in the name of advancement. In areas such as gait analysis and ergonomics many of the advanced features such as high resolution image sensors and high sampling frequencies are not required due to the nature of the task often investigated. Recently Natural Point introduced low cost cameras, which on face value appear to be suitable as at very least a high quality teaching tool in biomechanics and possibly even a research tool when coupled with the correct calibration and tracking software. The aim of the study was therefore to compare both the linear accuracy and quality of angular kinematics from a typical high end motion capture system and a low cost system during a simple task.
Resumo:
Over the past decade our understanding of foot function has increased significantly[1,2]. Our understanding of foot and ankle biomechanics appears to be directly correlated to advances in models used to assess and quantify kinematic parameters in gait. These advances in models in turn lead to greater detail in the data. However, we must consider that the level of complexity is determined by the question or task being analysed. This systematic review aims to provide a critical appraisal of commonly used marker sets and foot models to assess foot and ankle kinematics in a wide variety of clinical and research purposes.
Resumo:
The complex interaction of the bones of the foot has been explored in detail in recent years, which has led to the acknowledgement in the biomechanics community that the foot can no longer be considered as a single rigid segment. With the advance of motion analysis technology it has become possible to quantify the biomechanics of simplified units or segments that make up the foot. Advances in technology coupled with reducing hardware prices has resulted in the uptake of more advanced tools available for clinical gait analysis. The increased use of these techniques in clinical practice requires defined standards for modelling and reporting of foot and ankle kinematics. This systematic review aims to provide a critical appraisal of commonly used foot and ankle marker sets designed to assess kinematics and thus provide a theoretical background for the development of modelling standards.
Resumo:
Footwear is designed to reduce injury and enhance performance. However, the effect footwear has on foot and ankle kinematics currently remains unknown. Acknowledging the need for improved understanding, the aim of this study was to describe the effect footwear has on the kinematics of a multi segment foot during stance phase of walking gait.
Resumo:
The subtalar joint has been presumed to account for most of the pathologic motion in the foot and ankle, but research has shown that motion at other foot joints is greater than traditionally expected. Although recent research demonstrates the complexity of the kinematic variables in the foot and ankle, it still fails to expand our knowledge of the role of the musculotendinous structures in the biomechanics of the foot and ankle and how this is affected by in-shoe orthoses. The aim of this study was to simulate the effect of in-shoe foot orthoses by manipulation of the ground reaction force (GRF) components and centre of pressure (CoP) to demonstrate the resultant effect on muscle force in selected muscles during both the rearfoot loading response and stance phase of the gait cycle. We found that any medial wedge increases ankle joint load during gait cycle, while a lateral wedge decreases the joint load during the stance phase.
Resumo:
This paper reports on a mathematics project conducted with six Torres Strait Islander schools and communities by the research team at the YuMi Deadly Centre at QUT. Data collected is from a small focus group of six teachers and two teacher aides. We investigated how measurement is taught and learned by students, their teachers and teacher aides in the community schools. A key focus of the project was that the teaching and learning of measurement be contextualised to the students’ culture, community and home languages. A significant finding from the project was that the teachers had differing levels of knowledge and understanding about how to contextualise measurement to support student learning. For example, an Indigenous teacher identified that mathematics and the environment are relational, that is, they are not discrete and in isolation from one another, rather they mesh together, thus affording the articulation and interchange among and between mathematics and Torres Strait Islander culture.
Resumo:
The tax expenditures concept has been part of the Australian tax review system since 1973. In view of the fact that tax expenditures are considered part of the tax-transfer system, and that paragraph 9 of the terms of reference for the Review Panel requires a consideration of all relevant tax expenditures, we can be confident that they will be considered once again in the final report of Australia’s Future Tax System Review Panel. However, an examination of previous Government and Parliamentary reviews suggests that few of the resulting recommendations are adopted. Previous recommendations have resulted in the acknowledgement of and concern over tax expenditures, but have led to only one significant advancement: the publication of an annual tax expenditures statement. It is apparent that Brooks in his paper aims to ensure, and makes a compelling case for, the significance and central role tax expenditures should play in the Review Panel deliberations. In doing so, Brooks explores the concept itself as well as the conceptual implications impacting on the more pragmatic aspects of tax expenditure analysis. At the outset, Brooks explains why tax expenditures cannot be evaluated using traditional criteria of equity, neutrality, and simplicity, but rather can only be understood and evaluated using budgetary criteria.
Resumo:
The global financial crisis that impacted on all world economies throughout 2008 and 2009. This impact has not been confined to the finance industries but has had a direct and indirect impact on the property industry worldwide from both an ownership and investment perspective. Property markets have experienced various levels of impact from this event, but universally the greatest impact has been on the traditional commercial and industrial property sectors from the investor perspective, with investment and superannuation funds reporting significant declines in the reported value of these investments. Despite the very direct impact of these declining property markets, the GFC has also had a very significant indirect impact on the various property professions and how these professions are now operating in this declining property market. Of particular interest is the comparison of the property market forecasts in late 2007 to the actual results in 2008/2009.
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The role of networks and their contribution to sustaining and developing creative industries is well documented (Wittel 2001; Kong 2005; Pratt 2007). This article argues that although networks operate across geographical boundaries, particularly through the use of communication technologies, the majority of studies have focussed on the ways in which networks operate in a) specific inner-urban metropolitan regions or b) specific industries. Such studies are informed by the geographical mindset of creative city proponents such as Florida (2002) and Landry (2000) in which inner-urban precincts are seen as the prime location for creative industries activity, business development and opportunity. But what of those creative industries situated beyond the inner city? Evidence in Australia suggests there is increasing creative industries activity beyond the inner city, in outer-suburban and ex-urban areas (Gibson & Brennan-Horley 2006). This article identifies characteristics of creative industries networks in outer-suburban locations in Melbourne and Brisbane. It argues that supporting and sustaining creative industries networks in these locations may require different strategies than those applied to inner-city networks. The article thus contributes to the growing understanding of the cultural economic geography of creative industries.
Resumo:
Nineteen studies met the inclusion criteria. A skin temperature reduction of 5–15 °C, in accordance with the recent PRICE (Protection, Rest, Ice, Compression and Elevation) guidelines, were achieved using cold air, ice massage, crushed ice, cryotherapy cuffs, ice pack, and cold water immersion. There is evidence supporting the use and effectiveness of thermal imaging in order to access skin temperature following the application of cryotherapy. Thermal imaging is a safe and non-invasive method of collecting skin temperature. Although further research is required, in terms of structuring specific guidelines and protocols, thermal imaging appears to be an accurate and reliable method of collecting skin temperature data following cryotherapy. Currently there is ambiguity regarding the optimal skin temperature reductions in a medical or sporting setting. However, this review highlights the ability of several different modalities of cryotherapy to reduce skin temperature.
Resumo:
Applying ice or other forms of topical cooling is a popular method of treating sports injuries. It is commonplace for athletes to return to competitive activity, shortly or immediately after the application of a cold treatment. In this article, we examine the effect of local tissue cooling on outcomes relating to functional performance and to discuss their relevance to the sporting environment. A computerized literature search, citation tracking and hand search was performed up to April, 2011. Eligible studies were trials involving healthy human participants, describing the effects of cooling on outcomes relating to functional performance. Two reviewers independently assessed the validity of included trials and calculated effect sizes. Thirty five trials met the inclusion criteria; all had a high risk of bias. The mean sample size was 19. Meta-analyses were not undertaken due to clinical heterogeneity. The majority of studies used cooling durations >20 minutes. Strength (peak torque/force) was reported by 25 studies with approximately 75% recording a decrease in strength immediately following cooling. There was evidence from six studies that cooling adversely affected speed, power and agility-based running tasks; two studies found this was negated with a short rewarming period. There was conflicting evidence on the effect of cooling on isolated muscular endurance. A small number of studies found that cooling decreased upper limb dexterity and accuracy. The current evidence base suggests that athletes will probably be at a performance disadvantage if they return to activity immediately after cooling. This is based on cooling for longer than 20 minutes, which may exceed the durations employed in some sporting environments. In addition, some of the reported changes were clinically small and may only be relevant in elite sport. Until better evidence is available, practitioners should use short cooling applications and/or undertake a progressive warm up prior to returning to play.
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Grant Stevens is ambivalent. The young Brisbane artist made his name with a series of computer-generated animated-text videos that explore clichés but seem undecided as to whether they are trivial and vacuous, profound and authentic or somehow both at once. Stevens plunders mass-media sources (the familiar image repertoire dished up by Hollywood, television, pop music and the Internet) as readymade content. He explores this everyday language, sometimes for its ambiguity, but more often for its almost uncanny lucidity. Resembling meditation and relaxation guides, his recent videos beg the question: what made us so anxious? This book examines Stevens' artistic output over the first ten years of his practice. It includes essays by Mark Pennings and Chris Kraus.
Resumo:
The role of networks and their contribution to sustaining and developing creative industries is well documented (Wittel 2001, Kong 2005, Pratt, 2007). This article argues that although networks operate across geographical boundaries, particularly through the use of communication technologies, the majority of studies have focussed on the ways in which networks operate among creative industry workers located in a) specific inner-urban metropolitan regions or b) specific industries. Such studies are informed by the geographical mindset of creative city proponents such as Florida (2002) and Landry (2000) in which inner-urban precincts are seen as the prime location or ‘hub’ for creative industries activity, business development and opportunity. But what of those creative industries situated beyond the inner city? Evidence in Australia suggests that there is increasing creative industries activity beyond the inner city, in outer-suburban and ex-urban areas (Gibson and Brennan-Horley 2006). This article identifies features of networks operating two outer-suburban locations.
Resumo:
This note examines the productive efficiency of 62 starting guards during the 2011/12 National Basketball Association (NBA) season. This period coincides with the phenomenal and largely unanticipated performance of New York Knicks’ starting point guard Jeremy Lin and the attendant public and media hype known as Linsanity. We employ a data envelopment analysis (DEA) approach that includes allowance for an undesirable output, here turnovers per game, with the desirable outputs of points, rebounds, assists, steals, and blocks per game and an input of minutes per game. The results indicate that depending upon the specification, between 29 and 42 percent of NBA guards are fully efficient, including Jeremy Lin, with a mean inefficiency of 3.7 and 19.2 percent. However, while Jeremy Lin is technically efficient, he seldom serves as a benchmark for inefficient players, at least when compared with established players such as Chris Paul and Dwayne Wade. This suggests the uniqueness of Jeremy Lin’s productive solution and may explain why his unique style of play, encompassing individual brilliance, unselfish play, and team leadership, is of such broad public appeal.