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   

Validity and reliability of a linear positional transducer across commonly practised resistance training exercises     

Harry F. Dorrell  Joseph M. Moore  Mark F. Smith  Thomas I. Gee 《Journal of sports sciences》2019,37(1):67-73

This study investigated the validity and reliability of the GymAware PowerTool (GPT). Thirteen resistance trained participants completed three visits, consisting of three repetitions of free-weight back squat, bench press, deadlift (80% one repetition maximum), and countermovement jump. Bar displacement, peak and mean velocity, peak and mean force, and jump height were calculated using the GPT, a three-dimensional motion capture system (Motion Analysis Corporation; 150 Hz), and a force plate (Kistler; 1500 Hz). Least products regression were used to compare agreeability between devices. A within-trial one-way ANOVA, typical error (TE; %), and smallest worthwhile change (SWC) were used to assess reliability. Regression analysis resulted in R² values of >0.85 for all variables excluding deadlift mean velocity (R² = 0.54–0.69). Significant differences were observed between visits 3-2 for bench press bar displacement (0.395 ± 0.055 m; 0.383 ± 0.053 m), and deadlift bar displacement (0.557 ± 0.034 m; 0.568 ± 0.034 m). No other significant differences were found. Low to moderate TE (0.6–8.8%) were found for all variables, with SWC ranging 1.7–7.4%. The data provides evidence that the GPT can be used to measure kinetic and kinematic outputs, however, care should be taken when monitoring deadlift performance.  相似文献   

Mary Elizabeth (Betty) Feeney, 1918–2000     

T. Mark Hodges 《Journal of the Medical Library Association》2001,89(3):329

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Civility and diversity     

Mark Bauerlein 《Academic Questions》2004,17(4):70-76

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Professional ethics     

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

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Constructivisms and Relativisms: A Shopper‘s Guide     

Bickhard  Mark H. 《Science & Education》1997,6(1-2):29-42

Diverse forms of constructivism can be found in the literature today. They exhibit a commonality regarding certain classical positions that they oppose - a unity in their negative identities - but a sometimes wild multiplicity and incompatibility regarding the positive proposals that they put forward. In particular, some constructivisms propose an epistemological idealism, with a concomitant relativism, while others are explicitly opposed to such positions, and move in multifarious different directions. This is a potentially confusing situation, and has resulted in some critics branding all constructivisms with the charge of relativism, and throwing out the baby with the bath water. In addition, since the epistemological foundations of even non-relativist constructivisms are not as familiar as the classical positions, there is a risk of mis-interpretation of constructivisms and their consequences, even by some who endorse them, not to mention those who criticize. Because I urge that some version of constructivism is an epistemological necessity, this situation strikes me as seriously unfortunate for philosophy, and potentially dangerous for the practice of education.  相似文献   

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   

Longitudinal Analyses of Academic Achievement     

Gary L. Williamson  Mark Appelbaum  Alex Epanchin 《Journal of Educational Measurement》1991,28(1):61-76

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Editorial: Literacy or Literacies?     

Mark Reid 《English in Education》1997,31(3):1-2

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