1,720,960 research outputs found
Differences in wrist movements during a clinical hand function test
No full textA large normative data set of upper limb movements has been collected using passive reflective markers placed on the forearm, wrist, hand and fingers. Movements were captured by a Vicon motion analysis system whilst undertaking a clinical hand function assessment, the Southampton Hand Assessment Procedure. Light and heavyweight versions of objects were tested and initial results have shown interesting variations that correspond with physiological and functional approaches to movement
Enforcing cyclic movements of the upper limb for movement analysis systems
No full textAnalysing the movement of the upper limb is difficult due to the variability and complexity of the mechanics available to complete any given task. When combining a clinical hand function assessment with the analysis of cyclic movement patterns clinicians are able to generate an independent assessment of function, in conjunction with waveforms of movement during a prehensile task, which is clinically relevant.Applying repetitive tasks to facilitate movement analysis is quite common and usually incorporates the use of Activities of Daily Living (ADL) [1,2] or reach-to-grasp tasks [3,4]. In 2001, Fowler, et al., employed an adapted version of a hand function test in order to provide more stable movement patterns [5]
Measuring pressures at the sock/stump interface in lower limb amputees: a pilot study
No full textAn estimated 5000 people in the United Kingdom require a lower-limb amputation each year, and of these, some 53% are transtibial and 39% transfemoral. Three-quarters of all referrals for a lower limb amputation are caused by dysvascularity, infection accounted for 8% and trauma 7%.The stump/sock interface is critical in the successful return of military amputees to active duty as it forms the mechanical interface between the subject and the prosthesis. Weight bearing, uneven pressures and friction through the residual limb need to be carefully managed to avoid skin breakdown, pressure sores and infection. Additionally the quality of the fit is fundamental for the comfort of the wearer. If the prosthesis is uncomfortable to wear or difficult to use, the amputee will be less inclined to wear it. Accurate measurement of pressures and shear forces acting on the stump is vital to achieving optimum fit and alignment of a prosthetic limb. Previous research into pressure distributions during standing and gait at the stump/socket interface has produced varied results.Direct pressure measurements during stepping-up, stepping-down and during the timed-up-and-go test have yet to be measured.Research into pressure distribution and skin/stump integrity appears to fall along a continuum with aspects of engineering in the development of pressure sensors at one extreme and qualitative research investigating skin condition and prosthesis use adherence on the other extreme<br/
Validation and application of a computational model for wrist and hand movements using surface markers
Full text linkA kinematic model is presented based on surface marker placement generating wrist, metacarpal arch, fingers and thumb movements. Standard calculations are used throughout the model and then applied to the specified marker placement. A static trial involving eight unimpaired participants was carried out to assess inter-rater reliability. The standard deviations across the data were comparable to manual goniometers. In addition, a test retest trial of ten unimpaired participants is also reported to illustrate the variability of movement at the wrist joint, metacarpal arch, and index finger as an example of model output when repeating the same task many times. Light and heavyweight versions of the tasks are assessed and characteristics of individual movement strategies presented. The participant trial showed moderate correlation in radial/ulnar deviation of the wrist ( = 0 65), and strong correlation in both metacarpal arch joints ( = 075 and = 085), the MCP ( = 079), and PIP ( = 087) joints of the index finger. The results indicate that individuals use repeated strategies of movement when lifting light and heavyweight versions of the same object, but showed no obvious repeated pattern of movement across the population
Quantifying soft tissue artefacts and imaging variability in motion capture of the fingers
No full textThis study assessed the accuracy of marker-based kinematic analysis of the fingers, considering soft tissue artefacts (STA) and marker imaging uncertainty. We collected CT images of the hand from healthy volunteers with fingers in full extension, mid- and full-flexion, including motion capture markers. Bones and markers were segmented and meshed. The bone meshes for each volunteer’s scans were aligned using the proximal phalanx to study the proximal interphalangeal joint (PIP), and using the middle phalanx to study the distal interphalangeal joint (DIP). The angle changes between positions were extracted. The HAWK protocol was used to calculate PIP and DIP joint flexion angles in each position based on the marker centroids. Finally the marker locations were ‘corrected’ relative to the underlying bones, and the flexion angles recalculated. Static and dynamic marker imaging uncertainty was evaluated using a wand. A strong positive correlation was observed between marker- and CT-based joint angle changes with 0.980 and 0.892 regression slopes for PIP and DIP, respectively, and Root Mean Squared Errors below 4°. Notably for the PIP joint, correlation was worsened by STA correction. The 95% imaging uncertainty interval was < ± 1° for joints, and < ± 0.25 mm for segment lengths. In summary, the HAWK marker set’s accuracy was characterised for finger joint flexion angle changes in a small group of healthy individuals and static poses, and was found to benefit from skin movements during flexion.</p
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
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