1,720,986 research outputs found
Muscle activation of vastus medialis obliquus and vastus lateralis during a dynamic leg press exercise with and without isometric hip adduction
No full textObjectives: To investigate the effects of submaximal and vigorous isometric hip adduction on the vastus medialis obliquus (VMO) and vastus lateralis (VL) activity during the leg press exercise from 90 degrees of knee flexion until full extension. ;Design: Experimental. ;Setting: University biomechanics laboratory. ;Participants: Ten healthy male college students. ;Main outcome measures: Electromyographic (EMG) activation of VMO, VL and hip adductor longus (HAL) of the dominant leg were recorded during double leg press (LP), leg press with submaximal isometric hip adduction force (LP+), and leg press with vigorous isometric hip adduction force (LP++). The VMO, VL muscle activation, as well as the VMO/VL ratio between different leg press exercises were analyzed by MANOVA over concentric and eccentric phases, and in 15 degrees increments of knee flexion motion. The effect size was calculated. ;Results: Neither LP+ nor LP++ changed the overall VMO-VL activation patterns. Specific to knee angle, however, small to medium effect size was shown with incorporation of isometric hip adduction to the leg press exercise for VMO/VL ratio. ;Conclusion: Targeted training using the leg press exercise to the last 45 degrees of knee extension/flexion with vigorous hip adduction may be useful in promoting a greater VMO/VL ratio. (C) 2012 Elsevier Ltd. All rights reserved
Predictors of treatment response to strengthening and stretching exercise for patellofemoral pain: an examination of patellar alignment
No full text[[abstract]]Background
Closed kinetic chain and quadriceps strengthening, combined with flexibility exercises of the lower limb musculature, is a common treatment for patellofemoral pain syndrome (PFPS). The effectiveness has been well documented; however, very little is known about which factors predict treatment success.
Methods
A total of 43 female subjects with PFPS participated in an eight-week progressive leg press (LP) strengthening and stretching exercise program. A decrease of 1.5 cm on a 10 cm visual analog scale (VAS) score was used as an indicator for treatment success. The baseline patellar tilt angle difference (PTA-d) due to quadriceps contraction prior to treatment was evaluated as a predictor of treatment success. The logistic regression and receiver operating characteristics (ROC) curve analysis were performed to investigate the predictive value of PTA-d.
Results
PTA-d could significantly predict the treatment success of LP strengthening and stretching exercises. The odds ratio (OR) for having an unsuccessful outcome was 1.19 (95% confidence interval (CI), 1.03−1.39, P < 0.021) per degree increment of PTA-d. The most optimal cut-off value for the clinical discrimination of treatment success after LP strengthening and stretching exercise was − 1.5° of PTA-d (sensitivity = 0.74, specificity = 0.71). The area under the ROC curve was 0.73 (standard error = 0.08).
Conclusions
Female patients with PFPS whose quadriceps contraction reduced the lateral patellar tilt prior to LP strengthening and stretching exercise treatment are more likely to experience pain relief. It seems clinically important to check dynamic patellar tilt characteristics before treatment to aid in clinical decision making
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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