A review of models of vertical, leg, and knee stiffness in adults for running, jumping or hopping tasks     

BG Serpell  NB Ball  JM Scarvell  PN Smith 《Journal of sports sciences》2012,30(13):1347-1363

Abstract The 'stiffness' concept originates from Hooke's law which states that the force required to deform an object is related to a spring constant and the distance that object is deformed. Research into stiffness in the human body is undergoing unprecedented popularity; possibly because stiffness has been associated with sporting performance and some lower limb injuries. However, some inconsistencies surrounding stiffness measurement exists bringing into question the integrity of some research related to stiffness. The aim of this study was to review literature which describes how vertical, leg and knee stiffness has been measured in adult populations while running, jumping or hopping. A search of the entire MEDLINE, PubMed and SPORTDiscus databases and an iterative reference check was performed. Sixty-seven articles were retrieved; 21 measured vertical stiffness, 51 measured leg stiffness, and 22 measured knee stiffness. Thus, some studies measured several 'types' of stiffness. Vertical stiffness was typically the quotient of ground reaction force and centre of mass displacement. For leg stiffness it was and change in leg length, and for the knee it was the quotient of knee joint moments and change in joint angle. Sample size issues and measurement techniques were identified as limitations to current research.  相似文献   

Promoting Undergraduate Interest,Preparedness, and Professional Pursuit in the Sciences: An Outcomes Evaluation of the SURE Program at Emory University     

Benjamin Junge  Catherine Qui?ones  Jakub Kakietek  Daniel Teodorescu  Pat Marsteller 《CBE life sciences education》2010,9(2):119-132

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Vertical stiffness and muscle strain in professional Australian football     

Benjamin G. Serpell  Jennie M. Scarvell  Nick B. Ball  Paul N. Smith 《Journal of sports sciences》2014,32(20):1924-1930

Abstract

The purpose of this study was to establish if vertical stiffness was greater in professional Australian rules footballers who sustained a lower limb skeletal muscle strain compared to those who did not, and to establish if a relationship between age, or training history, and vertical stiffness existed. Thirty-one participants underwent weekly rebound jump testing on a force platform over two seasons. Vertical stiffness was calculated for injured players and the uninjured cohort 1 and 3 weeks prior to sustaining an injury and at the end of preseason. Eighteen athletes were in the “uninjured” cohort and 13 in the “injured” cohort. No significant difference in vertical stiffness was observed between groups (P = 0.18 for absolute stiffness; P = 0.08 for stiffness relative to body mass), within groups (P = 0.83 and P = 0.88, respectively) or for a time*cohort interaction (P = 0.77 and P = 0.80, respectively). No relationship between age and vertical stiffness existed (r = ?0.06 for absolute and relative stiffness), or training history and vertical stiffness (r = ?0.01 and 0.00 for absolute and relative stiffness, respectively) existed. These results and others lend to suggest that vertical stiffness is not related to lower limb muscle strain injury.  相似文献   

Trends in journal subscriptions 1986. London: The Publishers Association. 1987. 31 pp. ISBN 0–853–86–146–3.     

Michele Benjamin 《Learned Publishing》1988,1(3):147-148

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Educational administration and supervision in Japan     

Benjamin C. Duke 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1976,8(3):479-490

The administration and supervision of education represents one of the most controversial issues in post-war Japanese education. The basic issue is one of centralization or decentralization. The left wing teachers union favours local control, the conservative government, central control. The American Occupation established a system of local school boards which, as a result of political lobbying, were largely controlled by teachers union sympathisers. In 1956, four years after the end of the Occupation, the Japanese government eliminated the election of board members and replaced voluntary compliance with compulsory compliance with Ministry of Education objectives. This compulsory compliance was most clearly demonstrated in the central authorization of textbooks and in the implementation of theshunin system, which, the teachers union claims, introduces too many administrative positions into schools and further bureaucratized education. The Ministry claims that theshunin positions serve a guidance rather than an administrative function; the union on the other hand foresees the disruption of the unity of its rank and file members as a result of the insertion of a middle management wedge. Theshunin controversy clearly demonstrates how the administration of Japanese education has become enmeshed in partisan politics and Japanese history and tradition.  相似文献   

Letters     

Ernest T. Pascarella 《Educational technology research and development : ETR & D》1977,25(3):290-290

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Book reviews     

Benjamin Levin  Carol Nash  Jan Sundin  Jane Gaskell  Chad Gaffield 《Interchange》1993,24(4):447-458

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Publishers publicity and bibliographic databases     

Michele Benjamin 《Learned Publishing》1988,1(4):162-163

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The adversary hearing as a public forum     

Ernest R. House  Paul Thurston  Janice Hand 《Studies in Educational Evaluation》1984,10(2):111-123

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Huey long: Analysis of a demagogue     

Ernest G. Bormann 《Communication quarterly》2013,61(3):16-20

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