138 research outputs found

    On the citation lifecycle of papers with delayed recognition

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    Delayed recognition is a concept applied to articles that receive very few to no citations for a certain period of time following publication, before becoming actively cited. To determine whether such a time spent in relative obscurity had an effect on subsequent citation patterns, we selected articles that received no citations before the passage of ten full years since publication, investigated the subsequent yearly citations received over a period of 37 years and compared them with the citations received by a group of papers without such a latency period. Our study finds that papers with delayed recognition do not exhibit the typical early peak, then slow decline in citations, but that the vast majority enter decline immediately after their first – and often only – citation. Middling papers’ citations remain stable over their lifetime, whereas the more highly cited papers, some of which fall into the “sleeping beauty” subtype, show non-stop growth in citations received. Finally, papers published in different disciplines exhibit similar behavior and did not differ significantly

    The kiss of death? : the effect of being cited in a reviewon subsequent citations

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    This article inquires into recent claims that citation in a review article provokes a decline in a paper’s later citation count, these being instead given to the review. Using the Science Citation Index Expanded, we looked at the yearly percentages of lifetime citations of papers published in 1990 first cited in review articles in 1992 and 1995 in the field of biomedical research, and found no significant change to occur following review, regardless of the papers’ citation activity or specialty. Further comparison was made with papers from the field of clinical research, but yielded no meaningful results to support the notion that review articles have any substantial effect on the citation count of the papers they review

    The production of knowledge in Canada : consolidation and diversification

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    The Canadian innovation system is composed of four main sectors: university, hospital, government, and industry. This paper analyzes each sector’s strengths and weaknesses in terms of its scientific production. It is shown that Canadian science is increasingly produced in international collaboration and that all sectors are collaborating increasingly with each other.Le système d'innovation canadien est compose de quatre principaux secteurs : universitaire, hospitalier, gouvernemental et industriel. Cet article analyse les forces et les faiblesses de chaque secteur en tenant compte de la production scientifique. Les auteurs montrent que la science canadienne est de plus en plus le produit d'une collaboration internationale et que tous les secteurs collaborent de plus en plus entre eux

    Effect of pelvic stabilization and hip position on trunk extensor activity during back extension exercises on a roman chair

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    Objective: To assess the effect of pelvic stabilization and hip position on the electromyographic activity of trunk extensors during Roman chair exercise. A secondary objective was to compare genders. Design: Repeated measures. Subjects: Eleven men and 11 women volunteers. Methods: Five trunk flexion-extension cycles for 3 Roman chair conditions: (i) pelvis unrestrained; (ii) pelvis restrained; and (iii) hip at 40° flexion. Electromyographic signals were recorded on the back muscles, as well as on the gluteus maximus and biceps femoris. The percentage of electro¬myographic amplitude relative to the maximal activity was used to assess the level of muscular activation of each muscle group across the exercises. Results: For both genders, the Roman chair conditions did not influence the activity of the back and gluteus muscles. The hip-at-40°-flexion condition significantly reduced the activity of the biceps femoris (average of 4–18%) relative to the other 2 conditions. Gender differences were observed on the activity of the biceps femoris in all Roman chair conditions. Conclusion: The hip-at-40°-flexion condition would allow the Roman chair exercise to train the targeted back muscles more specifically by overloading them over a longer duration in order to induce physiological changes

    Machine Learning Applications in Spine Biomechanics

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    Spine biomechanics is at a transformation with the advent and integration of machine learning and computer vision technologies. These novel techniques facilitate the estimation of 3D body shapes, anthropometrics, and kinematics from as simple as a single-camera image, making them more accessible and practical for a diverse range of applications. This study introduces a framework that merges these methodologies with traditional musculoskeletal modeling, enabling comprehensive analysis of spinal biomechanics during complex activities from a single camera. Additionally, we aim to evaluate their performance and limitations in spine biomechanics applications. The real-world applications explored in this study include assessment in workplace lifting, evaluation of whiplash injuries in car accidents, and biomechanical analysis in professional sports. Our results demonstrate potential and limitations of various algorithms in estimating body shape, kinematics, and conducting in-field biomechanical analyses. In industrial settings, the potential to utilize these new technologies for biomechanical risk assessments offers a pathway for preventive measures against back injuries. In sports activities, the proposed framework provides new opportunities for performance optimization, injury prevention, and rehabilitation. The application in forensic domain further underscores the wide-reaching implications of this technology. While certain limitations were identified, particularly in accuracy of predictions, complex interactions, and external load estimation, this study demonstrates their potential for advancement in spine biomechanics, heralding an optimistic future in both research and practical applications

    Biomechanical differences between expert and novice workers in a manual material handling task.

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    The objective was to verify whether the methods were safer and more efficient when used by expert handlers than by novice handlers. Fifteen expert and fifteen novice handlers were recruited. Their task was to transfer four boxes from a conveyor to a hand trolley. Different characteristics of the load and lifting heights were modified to achieve a larger variety of methods by the participants. The results show that the net moments at the L5/S1 joint were not significantly different (P > .05) for the two groups. However, compared to the novices, the experts bent their lumbar region less ( experts = 54° (SD = 11°) ; novices = 66° (15°) but bent their knees more (experts ≈ 72°( SD ≈ 30°) ; novices ≈ 53°( SD ≈ 33°), which brought them closer to the box. The handler's posture therefore seems to be a major aspect that should be paid specific attention, mainly when there is maximum back loading. Keywords: Manual material handling, lifting, expert, low back load, ergonomic intervention. Statement of Relevance: The findings of this research will be useful for improving manual material handling training programs. Most biomechanical research is based on novice workers, and adding information about the approach used by expert handlers in performing their tasks will help provide new avenues for reducing the risk of injury caused by this demanding physical task. Acknowledgements: The present research project was funded by the Robert-Sauvé Occupational Health and Safety Research Institute (IRSST) of Quebec. Special thanks go to the expert and novice subjects and the industries that participated in this project.

    Assessment of the paraspinal muscles of subjects presenting an idiopathic scoliosis: an EMG pilot study

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    BACKGROUND: It is known that the back muscles of scoliotic subjects present abnormalities in their fiber type composition. Some researchers have hypothesized that abnormal fiber composition can lead to paraspinal muscle dysfunction such as poor neuromuscular efficiency and muscle fatigue. EMG parameters were used to evaluate these impairments. The purpose of the present study was to examine the clinical potential of different EMG parameters such as amplitude (RMS) and median frequency (MF) of the power spectrum in order to assess the back muscles of patients presenting idiopathic scoliosis in terms of their neuromuscular efficiency and their muscular fatigue. METHODS: L5/S1 moments during isometric efforts in extension were measured in six subjects with idiopathic scoliosis and ten healthy controls. The subjects performed three 7 s ramp contractions ranging from 0 to 100% maximum voluntary contraction (MVC) and one 30 s sustained contraction at 75% MVC. Surface EMG activity was recorded bilaterally from the paraspinal muscles at L5, L3, L1 and T10. The slope of the EMG RMS/force (neuromuscular efficiency) and MF/force (muscle composition) relationships were computed during the ramp contractions while the slope of the EMG RMS/time and MF/time relationships (muscle fatigue) were computed during the sustained contraction. Comparisons were performed between the two groups and between the left and right sides for the EMG parameters. RESULTS: No significant group or side differences between the slopes of the different measures used were found at the level of the apex (around T10) of the major curve of the spine. However, a significant side difference was seen at a lower level (L3, p = 0.01) for the MF/time parameter. CONCLUSION: The EMG parameters used in this study could not discriminate between the back muscles of scoliotic subjects and those of control subject regarding fiber type composition, neuromuscular efficiency and muscle fatigue at the level of the apex. The results of this pilot study indicate that compensatory strategies are potentially seen at lower level of the spine with these EMG parameters

    An Experimental Approach to Examining Psychological Contributions to Multisite Musculoskeletal Pain.

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    The present study examined the prospective value of pain catastrophizing, fear of pain, and depression in the prediction of multisite musculoskeletal pain following experimentally induced delayed-onset muscle soreness (DOMS). The study sample consisted of 119 (63 females, 56 males) healthy university students. Measures of pain catastrophizing, fear of pain, and depression were completed prior to the DOMS induction procedure. Analyses revealed that pain catastrophizing and fear of pain prospectively predicted the experience of multisite pain following DOMS induction. Analyses also revealed that women were more likely to experience multisite pain than men. There was no significant relation between depressive symptoms and the experience of multisite pain. The discussion addresses the mechanisms by which pain catastrophizing and fear of pain might contribute to the spreading of pain. Clinical implications of the findings are also addressed. Perspective: The results of this experimental study suggest that pain catastrophizing and fear of pain might increase the risk of developing multisite pain following musculoskeletal injury
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