Reviewing the Variability-Overuse Injury Hypothesis: Does Movement Variability Relate to Landing Injuries?     

Andrew D. Nordin  Janet S. Dufek 《Research quarterly for exercise and sport》2019,90(2):190-205

Purpose: Overuse injuries are common in sport, but complete understanding of injury risk factors remains incomplete. Although biomechanical studies frequently examine musculoskeletal injury mechanisms, human movement variability studies aim to better understand neuromotor functioning, with proposed connections between overuse injury mechanisms and changes in motor variability. Method: In a narrative review, we discuss the variability-overuse injury hypothesis, which suggests repeated load application leads to mechanical tissue breakdown and subsequent injury when exceeding the rate of physiological adaptation. Due to the multidisciplinary nature of this hypothesis, we incorporate concepts from motor control, neurophysiology, biomechanics, as well as research design and data analysis. We therefore summarize multiple perspectives while proposing theoretical relationships between movement variability and lower extremity overuse injuries. Results: Experimental data are presented and summarized from published experiments examining interactions between experimental task demands and movement variability in the context of drop landing movements, along with comparisons to previous movement variability studies. Conclusion: We provide a conceptual framework for sports medicine researchers interested in predicting and preventing sports injuries. Under performance conditions with greater task demands, we predict reduced trial-to-trial movement variability that could increase the likelihood of overuse injuries.  相似文献   

Professional ethics     

Andrew R. J. Yeaman 《TechTrends》2004,49(2):14-17

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Accurate assessment of the brake torque on a rope-braked cycle ergometer     

Gordon  R. S.  Franklin  K. L.  Baker  J.  Davies  B. 《Sports Engineering》2004,7(3):131-138

Sports Engineering - A Monark cycle ergometer is a device globally used in physiological studies to measure the work and energy levels of exercising humans. In this paper a rope-braked cycle...  相似文献   

Borderless Higher Education in Continental Europe     

Davies  John L. 《Minerva》2001,39(1):27-48

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Assessing School Readiness: Validity and Bias in Preschool and Kindergarten Teachers' Ratings     

Andrew J. Mashburn  Gary T. Henry 《Educational Measurement》2004,23(4):16-30

As a part of efforts to evaluate and monitor the increasing public investment in early childhood education, teachers are being asked to assess children's school readiness. In this study, preschool teachers and kindergarten teachers rated children's skills in three areas (kindergarten readiness, academic skills, and communication skills), and these ratings were compared with direct assessments of the children's skills. Ratings by both groups of teachers tended to be more highly related to basic skills, such as counting and number naming, than to abilities such as solving applied problems and using expressive and receptive vocabulary. Preschool teachers' ratings had a lower association with children's observed skills and abilities than kindergarten teachers' ratings. Ratings of children attending Head Start were systematically inflated, but this relationship was mediated to a significant extent by the teachers' levels of education. More educated teachers rated children in a manner consistent with the children's directly assessed skills. Implications of these findings for informing future efforts to assess school readiness by using teacher ratings are discussed.  相似文献   

The value of structured abstracts in information retrieval from MEDLINE     

Andrew Booth  Alan O&#x;Rourke 《Health information and libraries journal》1997,14(3):157-166

Objective: To determine whether information retrieval might be enhanced by making each component of a structured abstract a separately searchable field. Design: Parallel searches on records arranged so that each abstract could either be searched in its entirety or as a collection of structured fields. Subjects: Records about cardiovascular disease downloaded from MEDLINE and tested against clinical questions derived from a concurrent survey of CD-ROM use in three health science libraries. Intervention: The investigators identified terms used to structure abstracts on MEDLINE and imported the abstracts into an Idealist database prior to searching using keywords from clinical questions. Measurements and main results: recall and precision rates are given for each question in the ‘structured’ and the ‘unstructured’ set of records. Conclusions: Use of structured, rather than unstructured, abstracts improves precision at the ex-pense of recall and places heavier demands upon the searcher’s skill in choosing the correct fields within the abstract to search. Further investigation requires more accurate simulation of MEDLINE software that utilizes features such as MeSH terms, explode, facilities and delimiters.  相似文献   

The Future of English     

Chris Davies 《English in Education》1991,25(3):28-31

The unity of "unitary" English, subsuming "language" and "literature", has always been a central tenet of NATE thinking and a basic assumption of most progressive practice, and is now enshrined in the National Curriculum¹. In this article, however, Chris Davies makes the scandalous proposal that the time has come when "language" and "literature", radically transformed, would be better separated.  相似文献   

A comparison of the anthropometric, strength, endurance and flexibility characteristics of female elite and recreational climbers and non-climbers.     

S Grant  T Hasler  C Davies  T C Aitchison  J Wilson  A Whittaker 《Journal of sports sciences》2001,19(7):499-505

There is limited information on the anthropometry, strength, endurance and flexibility of female rock climbers. The aim of this study was to compare these characteristics in three groups of females: Group 1 comprised 10 elite climbers aged 31.3 +/- 5.0 years (mean +/- s) who had led to a standard of 'hard very severe'; Group 2 consisted of 10 recreational climbers aged 24.1 +/- 4.0 years who had led to a standard of 'severe'; and Group 3 comprised 10 physically active individuals aged 28.5 +/- 5.0 years who had not previously rock-climbed. The tests included finger strength (grip strength, finger strength measured on climbing-specific apparatus), flexibility, bent arm hang and pull-ups. Regression procedures (analysis of covariance) were used to examine the influence of body mass, leg length, height and age. For finger strength, the elite climbers recorded significantly higher values (P < 0.05) than the recreational climbers and non-climbers (four fingers, right hand: elite 321 +/- 18 N, recreational 251 +/- 14 N, non-climbers 256 +/- 15 N; four fingers, left hand: elite 307 +/- 14 N, recreational 248 +/- 12 N, non-climbers 243 +/- 11 N). For grip strength of the right hand, the elite climbers recorded significantly higher values than the recreational climbers only (elite 338 +/- 12 N, recreational 289 +/- 10 N, non-climbers 307 +/- 11 N). The results suggest that elite climbers have greater finger strength than recreational climbers and non-climbers.  相似文献   

Cerebral activity prior to motion task performance: an electroencephalographic study     

D Collins  G Powell  I Davies 《Journal of sports sciences》1991,9(3):313-324

Cerebral activity, as reflected by power in the alpha waveband (8-13 Hz), was examined prior to the performance of three tasks with different effort and accuracy requirements. The study aimed to further investigate changes in activity observed in an earlier study in which expert karate performers exhibited significant increases in alpha band power during preparation for a training task. In contrast to the earlier research, the high effort task produced a significant decrease in 'alpha' power prior to performance. 'Alpha' power prior to the high accuracy task showed significant differences mediated by the outcome. Successful performance was preceded by higher levels of 'alpha' power than unsuccessful attempts. The reported use of a cognitive strategy on the first task produced a significant difference in activity, lower alpha power being associated with the use of such a technique.  相似文献   

Reform and UK Higher Education in the Enterprise Era     

Andrew Ryder 《Higher Education Quarterly》1996,50(1):54-70

Higher education in the United Kingdom is centrally funded, centrally planned, and insulated from market forces. It bears many similarities to the non-market centrally planned economies (CPEs) of the former Soviet Union and Eastern Europe while they struggled to reform but to retain a system of planning and central control. Examination of UK higher education and the CPEs before the transformation to market based systems highlights some of the issues facing higher education today. It also highlights the need for reforms, as well as the difficulties involved in them. Such comparison can also bring home problems faced by reformers in the transition economies.
Despite allegedly extensive reforms in UK higher education, the sector faces problems like those facing the centrally planned economies of Eastern Europe and the former USSR in the 1970s and 80s. Parallels in a number of areas are particularly striking.  相似文献