1,721,043 research outputs found
Use of a passive marker motion capture device for measuring scapular kinematics: a feasibility study
No full textImpaired control of scapular rotation during a clinical dissociation test in people with a history of shoulder pain
No full textEccentric and concentric exercise of the triceps surae: an in vivo study of dynamic muscle and tendon biomechanical parameters
No full textTriceps surae eccentric exercise is more effective than concentric exercise for treating Achilles tendinopathy, however the mechanisms underpinning these effects are unclear. This study compared the biomechanical characteristics of eccentric and concentric exercises to identify differences in the tendon load response. Eleven healthy volunteers performed eccentric and concentric exercises on a force plate, with ultrasonography, motion tracking, and EMG applied to measure Achilles tendon force, lower limb movement, and leg muscle activation. Tendon length was ultrasonographically tracked and quantified using a novel algorithm. The Fourier transform of the ground reaction force was also calculated to investigate for tremor, or perturbations. Tendon stiffness and extension did not vary between exercise types (P = .43). However, tendon perturbations were significantly higher during eccentric than concentric exercises (25%-40% higher, P = .02). Furthermore, perturbations during eccentric exercises were found to be negatively correlated with the tendon stiffness (R2 = .59). The particular efficacy of eccentric exercise does not appear to result from variation in tendon stiffness or extension within a given session. However, varied perturbation magnitude may have a role in mediating the observed clinical effects. This property is subject-specific, with the source and clinical time-course of such perturbations requiring further research
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
The effect of eccentric and concentric calf muscle training on Achilles tendon stiffness
No full textObjective: To compare in vivo effects of eccentric and concentric calf muscle training on Achilles tendon stiffness, in subjects without tendinopathy. Methods: Thirty-eight recreational athletes completed 6 weeks eccentric (6 males, 13 females, 21.6?±?2.2 years) or concentric training (8 males, 11 females, 21.1?±?2.0 years). Achilles tendon stiffness, tendon modulus and single-leg jump height were measured before and after intervention. Exercise adherence was recorded using a diary. Results: All data are reported as mean?±?SD. Groups were matched for height and weight but the eccentric training group were more active at baseline (P?<?0.05). Tendon stiffness was higher in the eccentrically trained group at baseline compared to the concentrically trained group (20.9?±?7.3 N/mm v 13.38?±?4.66 N/mm; P?=?0.001) and decreased significantly after eccentric training (to 17.2 (?±?5.9) N/mm (P?=?0.035)). There was no stiffness change in the concentric group (P?=?0.405). Stiffness modulus showed similar changes to stiffness. An inverse correlation was found between initial, and subsequent, reduction in stiffness (r?=??0.66). Jump height did not change and no correlation between stiffness change and adherence was observed in either group (r?=?0.01). Conclusions: Six weeks of eccentric training can alter Achilles tendon stiffness while a matched concentric programme shows no similar effects. Studies in patients with Achilles tendinopathy are warranted. <br/
Clinical outcomes following motor control rehabilitation for shoulder impingement
No full textBackground: shoulder impingement is the most common pathology of all shoulder pain referrals. Impingement syndrome can cause functional disability and reduce quality of life and may contribute to the development of rotator cuff disease. The aim of the present study was to examine the effects of a motor control based exercise intervention for shoulder impingement patients. Methods: sixteen young adults with shoulder pain (mean age 24.61.6, range 18-34 years, 11 males) were recruited from the local community. Inclusion criteria were: current shoulder pain severe enough to limit activity for more than one week and impingement signs. Diagnostic ultrasound imaging was used to exclude participants with complete rotator cuff tears. Mean duration of shoulder symptoms was 16 months (range 4-36 months).Physical screening of pain participants was conducted in order to derive a clinical presentation of shoulder impingement using three clinical tests; Hawkins-Kennedy, Neer’s and Painful Arc. A 10 week motor control retraining package was targeted at correcting movement impairments of the scapula by re-educating muscle recruitment. There were two components to the package: 1) Motor control exercises to correct alignment and coordination, which involve a) controlling scapular orientation during active arm movements; b) muscle-specific exercises for trapezius and serratus anterior; 2) Commonly used manual therapy techniques to reduce joint and muscle restrictions. Participants underwent three data collection sessions; pre-intervention, immediately post-intervention and six months post-intervention (13 participants completed post). The and Disability Index (SPADI); other questionnaires included the Disabilities of Arm Shoulder and Hand (DASH), Oxford Shoulder Score (OSS), Short-Form 36 (SF-36), visual analogue scale (VAS) of pain.Results: the SPADI scores improved on average by 10(7) and 13(6) points at the 10 week and 6 months assessments respectively. These changes were statistically significant (p<0.001) and reachedthe Minimal Clinically Important Difference (MCID). Pain scores on the 10-point VAS also reduced immediately after and 6 months postintervention with a mean reduction of 3.4(1.5) and 4.3(2) respectively. DASH improved by 9.2(10.3) at 10 weeks and 11.8 (6.3) at 6 months, whilst small improvements were also seen in the OSS (4.74) and SF-36 physical scores (3.84.9). Immediately postintervention the physical tests for impingement syndrome were negative for 15/16 participants.Conclusions: the present findings suggest that a 10 week programme of specific motor control exercises can improve function and pain in young adults with shoulder impingement. Improvements persisted at 6 months but effectiveness in the longer-term needs to be examined and compared with other exercise interventions in a randomized controlled trial involving a wider age range of shoulder impingement patients.Disclosure statement: ll authors have declared no conflicts of interest<br/
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
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