1,721,023 research outputs found
The measurement of the kinematics of the human spine using video fluoroscopy and image processing
No full textThe motion between the segments of the human spine intimately reflects the state of their soft-tissue linkages. Despite this, the diagnosis of mechanical disorders of the spine suffers from lack of acceptable ways of quantifying such intersegmental motion in living subjects. This thesis establishes a technique for obtaining such kinematic information by extrapolating from co-ordinates placed on digitised images from X-ray motion sequences. This provides a low radiation-dose, accurate and detailed method for the analysis of the kinematics of the lumbar spine in the coronal and sagittal planes and of the cervical spine in the saggittal plane. The technique, in addition, reduces the operator involvement with measurement and calculation traditionally associated with such issues. The indices used in this thesis are intervertebral angles and instantaneous centres of rotation (ICRs). Using a calibration model and human volunteer subjects the possibility for determining the former to an accuracy of 2o was established. For ICRs, provided the rotation of the segment in question exceeds 7o, the error and variation in their determination is consistently less than the range of currently accepted normality. Examples of detailed intersegmental motion patterns in asymptomatic and symptomatic human subjects are given and tentative interpretations offered. However, the clinical relevance of such findings must await the application of perhaps future generations of this system to large numbers of patients suffering from mechanical disorders of the spine.</p
Third prize: chiropractic and the national health care system: a basis for partnership in the UK
No full textBackground: Changes in United Kingdom (UK) health care policy and legislation have the potential to radically change care for patients with musculoskeletal conditions by widening access to manipulation services under its National Health Service (NHS).Objective: To investigate chiropractors’ past and current provision of musculoskeletal services for NHS patients and optimal future arrangements.Methods: One thousand forty-two UK chiropractors on professional registers were sent a 2-part questionnaire. The profession was divided into 2 groups and each group answered part of the questionnaire from either a practitioner or patient perspective.Results: Sixty-nine percent responded. Of these, 29% had previously provided services for NHS patients, and 18% were currently providing them, reporting moderate to high levels of satisfaction. Ninety-five percent were interested in future arrangements but on a part-time basis and in a way that most closely resembled private practice.Conclusion: The majority of UK chiropractors favor future partnership with the NHS. National health care reform and the statutory self-regulation of chiropractors have brought this closer to a more widespread reality. However, to prosper in this setting, the profession may benefit from a greater understanding of the competing priorities and constraints faced by NHS purchasers, who, for their part, should be prepared to implement policy based on evidence
Cervical Spine Kinematics Database from Fluoroscopic Imaging
Full text linkThis dataset includes kinematic measures derived from high-resolution fluoroscopic imaging of cervical vertebrae during controlled motion tasks.
Key Features:
Data Formats: Available in MATLAB (.mat) and Excel formats.
Detailed Data: Includes participant age and sex, and radiation dose.
Kinematic Measures: Vertebral body positions, Vertebral angles, intervertebral translation, and disc height using methods by Frobin et al.
Imaging Details: Derived from 1024x1024 16-bit images at 15 frames per second.
Data Collection Protocol:
Participants performed flexion and extension movements using a motorised motion frame during fluoroscopic imaging, ensuring precise alignment.
Applications:
Ideal for research on cervical spine motion, spinal manipulation effects, and biomechanical modelling.
For detailed methods, refer to Branney, Jonathan, Breen, Alexander, du Rose, Alister, Mowlem, Philip, and Breen, Alan (2024). Disc degeneration and cervical spine intervertebral motion: a cross-sectional study in patients with neck pain and matched healthy controls
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
Midlumbar lateral flexion stability measured in healthy volunteers by in vivo fluoroscopy
No full textStudy Design: prospective fluoroscopic and electromyographic study of coronal plane lumbar spine motion in healthy male volunteers.Objectives: assess the intervertebral motion profiles in healthy volunteers for symmetry, regularity, and neutral zone laxity during passive recumbent lateral bending motion.Summary of background data: previous continuous in vivo motion studies of the lumbar spine have mainly been limited to active, weight-bearing, flexion-extension (sagittal plane) motion. No data are available for passive lateral bending or to indicate the motion profiles when muscle activity is minimized.Methods: thirty asymptomatic male volunteers underwent video-fluoroscopy of their lumbar spines during passive, recumbent lumbar lateral bending through 80° using a motor-driven motion table. Approximately 120 consecutive images of segments L2–L5 were captured, and the position of each vertebra was tracked throughout the sequence using automated frame-to-frame registration. Reference intervals for intervertebral motion parameters were calculated. Surface electromyography recordings of erector spinae were obtained in a similar group of volunteers using the same protocol without fluoroscopy to determine to what extent the motion was completely passive.Results: correlations between intervertebral and lumbar motion were always positive in controls and asymmetry was less than 55% of intervertebral range. The upper reference interval for the slope of intervertebral rotation in the first 10° of trunk motion did not exceed 0.46 for any level. Muscle electrical activity during the motionwas very low. Examples from patient studies showed markedly different results.Conclusion: these results suggest that reference limits from asymptomatic data for coronal plane passive recumbent intervertebral motion may be a useful resource forinvestigating the relationship between symptoms of chronic (nonspecific) low back pain and biomechanics and in the clinical assessment of patients and interventionsthat target the passive holding elements of the spine. Data pooling from multiple studies would be necessary to establish a complete database<br/
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