1,721,217 research outputs found
Is a portable pressure plate an alternative to force plates for measuring postural stability and interlimb coordination of quiet standing balance control?
No full textIntroduction: Center-of-pressure (COP) synchronization and symmetry can inform adaptations in balance control following one-sided sensorimotor impairments (e.g., stroke). As established force plates are impossible to transport, we aimed to criterion validate a portable pressure plate for obtaining reliable COP synchronization and symmetry measures, next to conventional postural stability measures. Methods: Twenty healthy adults participated. In a single session, three 40-s eyes-open and eyes-closed quiet stance trials were performed per plate-type, randomly ordered. Individual-limb COPs were measured to calculate between-limb synchronization (BLS) and dynamic control asymmetry (DCA). Net COP (i.e., limbs combined) area, amplitude, and velocity were used to describe anteroposterior (AP) and mediolateral (ML) postural stability. Criterion validity was evaluated using Spearman correlations (r) and Bland-Altman plots. Test-retest reliability was tested using intraclass correlation coefficients (ICC). Results: Strong correlations (r > 0.75) and acceptable reliability (ICC > 0.80) were found regarding individual-limb COP velocity and DCA, net COP ML amplitude and AP and ML velocities. Bland-Altman plots yielded possible proportional bias; the pressure plate systematically underestimated COP scores by force plates and a larger error associated with a larger measurement. Conclusions: Despite correlations between instruments and sufficient reliability for measuring postural stability and DCA, this technical note strongly suggests, due to a systematic deviation, using the same plate-type to accurately assess performance change within subjects longitudinally over time.Funding
The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The authors would like to acknowledge funding by the Research Foundation Flanders (FWO), Belgium who provided JS a doctoral (PhD) grant for strategic basic research (application number 1S64819N) to conduct this research.
Acknowledgments
The authors would like to thank Charlotte Johnson for writing assistance, and the following M.Sc. students for aiding data collection and subject recruitment: Heleen Leurs, Carolien Van de Perck, Silke Van Goubergen, Gabriela Wimberska, Denice Kliebisch, and Sofia Lopez-Cotarelo Flemons
Time spent in rehabilitation and effect on measures of activity after stroke
No full textThis is a protocol for a Cochrane Review (Intervention). The objectives are as follows:·To establish if greater time spent in rehabilitation results in greater improvement in measures of activity than less time spent in rehabilitation.·To assess the effect of total time spent (in minutes) in rehabilitation on activity/activity limitations following stroke.·To assess the effect of rehabilitation schedule on activity/activity limitations following stroke in terms of: ·average minutes of rehabilitation provided per week; ·average frequency of rehabilitation provided per week; ·total duration of rehabilitation.<br/
The effect of time spent in rehabilitation on activity limitation and impairment after stroke
No full textBackground: Stroke affects millions of people every year and is a leading cause of disability, resulting in significant financial cost and reduction in quality of life. Rehabilitation after stroke aims to reduce disability by facilitating recovery of impairment, activity, or participation. One aspect of stroke rehabilitation that may affect outcomes is the amount of time spent in rehabilitation, including minutes provided, frequency (i.e. days per week of rehabilitation), and duration (i.e. time period over which rehabilitation is provided). Effect of time spent in rehabilitation after stroke has been explored extensively in the literature, but findings are inconsistent. Previous systematic reviews with meta-analyses have included studies that differ not only in the amount provided, but also type of rehabilitation. Objectives: To assess the effect of 1. more time spent in the same type of rehabilitation on activity measures in people with stroke; 2. difference in total rehabilitation time (in minutes) on recovery of activity in people with stroke; and 3. rehabilitation schedule on activity in terms of: a. average time (minutes) per week undergoing rehabilitation, b. frequency (number of sessions per week) of rehabilitation, and c. total duration of rehabilitation. Search methods: We searched the Cochrane Stroke Group trials register, CENTRAL, MEDLINE, Embase, eight other databases, and five trials registers to June 2021. We searched reference lists of identified studies, contacted key authors, and undertook reference searching using Web of Science Cited Reference Search. Selection criteria: We included randomised controlled trials (RCTs) of adults with stroke that compared different amounts of time spent, greater than zero, in rehabilitation (any non-pharmacological, non-surgical intervention aimed to improve activity after stroke). Studies varied only in the amount of time in rehabilitation between experimental and control conditions. Primary outcome was activities of daily living (ADLs); secondary outcomes were activity measures of upper and lower limbs, motor impairment measures of upper and lower limbs, and serious adverse events (SAE)/death. Data collection and analysis: Two review authors independently screened studies, extracted data, assessed methodological quality using the Cochrane RoB 2 tool, and assessed certainty of the evidence using GRADE. For continuous outcomes using different scales, we calculated pooled standardised mean difference (SMDs) and 95% confidence intervals (CIs). We expressed dichotomous outcomes as risk ratios (RR) with 95% CIs. Main results: The quantitative synthesis of this review comprised 21 parallel RCTs, involving analysed data from 1412 participants. Time in rehabilitation varied between studies. Minutes provided per week were 90 to 1288. Days per week of rehabilitation were three to seven. Duration of rehabilitation was two weeks to six months. Thirteen studies provided upper limb rehabilitation, five general rehabilitation, two mobilisation training, and one lower limb training. Sixteen studies examined participants in the first six months following stroke; the remaining five included participants more than six months poststroke. Comparison of stroke severity or level of impairment was limited due to variations in measurement. The risk of bias assessment suggests there were issues with the methodological quality of the included studies. There were 76 outcome-level risk of bias assessments: 15 low risk, 37 some concerns, and 24 high risk. When comparing groups that spent more time versus less time in rehabilitation immediately after intervention, we found no difference in rehabilitation for ADL outcomes (SMD 0.13, 95% CI −0.02 to 0.28; P = 0.09; I
2 = 7%; 14 studies, 864 participants; very low-certainty evidence), activity measures of the upper limb (SMD 0.09, 95% CI −0.11 to 0.29; P = 0.36; I
2 = 0%; 12 studies, 426 participants; very low-certainty evidence), and activity measures of the lower limb (SMD 0.25, 95% CI −0.03 to 0.53; P = 0.08; I
2 = 48%; 5 studies, 425 participants; very low-certainty evidence). We found an effect in favour of more time in rehabilitation for motor impairment measures of the upper limb (SMD 0.32, 95% CI 0.06 to 0.58; P = 0.01; I
2 = 10%; 9 studies, 287 participants; low-certainty evidence) and of the lower limb (SMD 0.71, 95% CI 0.15 to 1.28; P = 0.01; 1 study, 51 participants; very low-certainty evidence). There were no intervention-related SAEs. More time in rehabilitation did not affect the risk of SAEs/death (RR 1.20, 95% CI 0.51 to 2.85; P = 0.68; I
2 = 0%; 2 studies, 379 participants; low-certainty evidence), but few studies measured these outcomes. Predefined subgroup analyses comparing studies with a larger difference of total time spent in rehabilitation between intervention groups to studies with a smaller difference found greater improvements for studies with a larger difference. This was statistically significant for ADL outcomes (P = 0.02) and activity measures of the upper limb (P = 0.04), but not for activity measures of the lower limb (P = 0.41) or motor impairment measures of the upper limb (P = 0.06). Authors' conclusions: An increase in time spent in the same type of rehabilitation after stroke results in little to no difference in meaningful activities such as activities of daily living and activities of the upper and lower limb but a small benefit in measures of motor impairment (low- to very low-certainty evidence for all findings). If the increase in time spent in rehabilitation exceeds a threshold, this may lead to improved outcomes. There is currently insufficient evidence to recommend a minimum beneficial daily amount in clinical practice. The findings of this study are limited by a lack of studies with a significant contrast in amount of additional rehabilitation provided between control and intervention groups. Large, well-designed, high-quality RCTs that measure time spent in all rehabilitation activities (not just interventional) and provide a large contrast (minimum of 1000 minutes) in amount of rehabilitation between groups would provide further evidence for effect of time spent in rehabilitation.
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Time-dependency of test-retest reliability and measurement error of center-of-pressure synchronization and symmetry during quiet standing within specific frequencies in early sub-acute stroke
No full textBackground: People with unilateral sensorimotor impairments after a stroke exhibit poor between-limb synchronization and asymmetries in balance control by relying on their less-affected side to maintain stability during standing. Therefore, there is a growing consensus to include center-of-pressure metrics as between-limb synchronization and dynamic control asymmetry when investigating balance improvements poststroke. However, the test-retest reliability of these metrics remains under-investigated, hindering uptake of these assessments in future stroke rehabilitation and recovery studies. Research question: First, are three immediate test-repetitions necessary for obtaining reliable synchronization and asymmetry scores in individuals with sub-acute stroke, or can fewer repetitions suffice? Second, does timing of assessments at 3-, 5-, 8-, and 12-weeks poststroke affect these estimates' test-retest reliability and measurement error? Methods: Thirty stroke survivors with moderate-to-severe motor impairments were tested at 3-, 5-, 8-, and 12weeks poststroke. At each timepoint, they completed three 40-second quiet standing trials on a dual force plate which measured center-of-pressure signals separately on each side. We calculated between-limb synchronization (i.e., cross-correlation) and dynamic control asymmetry (i.e., symmetry index) using the original centerof-pressure signal, and after decomposition into high and low (cut-off 0.4 Hz) frequency bands. Intraclass correlation coefficients (ICC) and Bland-Altman plots were used to assess test-retest reliability and measurement error. A cut-off was used to determine acceptable reliability (ICC>0.75). Results: Between-limb synchronization and dynamic control asymmetry showed good-to-excellent reliability (ICCs=0.80-0.97) across three repetitions at all timepoints. Reducing to two repetitions yielded acceptable reliability (ICC=0.77-0.95) for dynamic control asymmetry and high-frequency measures, yet insufficient reliability for between-limb synchronization. At the 3-weeks timepoint, ICCs were generally lower, with more error, compared to later timepoints. Conclusion: Novel performance metrics quantifying synchronization and asymmetry of balance control can be reliably obtained during the early sub-acute phase if three test-repetitions are administered per assessment.JS received a strategic basic research doctoral (PhD) fellowship by the Research Foundation Flanders (FWO), Belgium (application no.1S64819N) for conducting the TARGEt studies; AvH received a doctoral (PhD) fellowship from the special reserach fund DOCPRO, University of Antwerp, Belgium (application no.44607) for the analyses set forth here
God Is a Repenting God: Taking Biblical Theology Seriously in Systematic Theology:A Case Study
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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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