147 resultados para Postural stability


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Purpose: Children`s postural alignment undergoes many adjustments due to the changes in body proportions during the stages of growth. The objective of this study was to quantitatively characterize and analyze spinal postural standards in 7- and 8-year-old children to verify which of the differences found were correlated to age and sex. Methods: Two hundred thirty public school students (Amparo, Sao Paulo, Brazil) aged 7 to 8 years were divided into groups according to postural alignment, which were further subdivided by sex and age, for comparison. Digital photos of upright Subjects were analyzed to evaluate posture. Lumbar and thoracic curvature, pelvic inclination, head posture, and lateral spine deviation were measured using CorelDraw (Ottawa, Canada) software guidelines and bone landmarks. Descriptive statistics and analysis of variance data analysis were utilized to verify differences among the groups. This was a cross-sectional, descriptive study. Results: Mean values for the variables analyzed were calculated. For lumbar lordosis, 7-year-old boys showed 38.49 degrees +/- 15.32 degrees in comparison to all other groups (42.29 degrees +/- 7.13 degrees). For thoracic kyphosis, the 7-year-old children presented 28.07 degrees +/- 7.73 degrees. and the 8-year-olds 30.32 degrees +/- 7.73 degrees. Pelvic inclination presented a mean value of 15.82 degrees +/- 5.46 degrees and single lateral spine deviation mean value of 3.48 degrees +/- 2.12 degrees. Conclusion: For the sample studied, differences based on sex and age were found for some of the body segments analyzed. The values found in this study may contribute to improved physiotherapeutic treatment when associated with other aspects of the clinical assessment and symptomatology. (J Manipulative Physiol Ther 2009;32: 154-159)

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Study design: Cross-sectional study. Objectives: To assess the importance of proprioceptive and vision information on different types of wheelchair seats with regard to postural control in paraplegic individuals during static posture. Setting: Centre of Rehabilitation at the University Hospital/FMRP-USP and Rehabilitation Outpatient Clinic at University Hospital/UNICAMP, Brazil. Methods: This study involved 11 individuals with paraplegia. All individuals were submitted to an evaluation of static balance with their eyes open and closed in three different types of seats: wheelchair seat, foam seat and gel seat. Balance evaluation was performed by using the Polhemus system, in which body displacements and anteroposterior and mediolateral speeds were assessed in a static seated position in the different types of seats. Data were analyzed using analysis of variance. The differences were considered at P<0.05. Results: No statistical differences were found between the three types of seats in terms of displacements and anteroposterior and mediolateral speeds, or between seats with individuals keeping their eyes open or closed (P>0.05). However, it was observed that body displacements were more prominent toward an anteroposterior than a mediolateral direction. Conclusion: This study suggests that individuals with paraplegia tend to exhibit a more anteroposterior body displacement than a mediolateral one, with no significant differences between the types of seats in both situations of eyes open and closed. Spinal Cord (2010) 48, 825-827; doi:10.1038/sc.2010.30; published online 30 March 2010

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This study aimed at answering the question: do people with high bone loss have greater postural instability? Groups were separated into group 1: women with normal bone mineral density, group 2: women with osteopenia, and group 3: women with osteoporosis. The balance was evaluated in four upright postural situations. Osteoporosis group had greater oscillation in the anteroposterior displacement in all situations compared to control group and the greatest mediolateral displacement in all situations compared to other groups. It is not known whether the presence of osteoporosis can be considered a factor aggravating the postural control. This study aimed at answering the question: do people with high bone loss have greater postural instability? This study was divided into three groups: group 1 (n = 20) consisting of women with normal bone mineral density, group 2 (n = 20) women with osteopenia, and group 3 (n = 20) women with osteoporosis. All the participants were submitted to evaluation of the balance using the Polhemus system in four upright postural situations. Osteoporosis group had greater oscillation in the anteroposterior displacement in all situations compared to control group. The osteoporosis group also showed the greatest mediolateral displacement in all situations compared to other groups. The results suggest that osteoporotic women had the worst balance, possibly due to the more pronounced body changes compared to non-osteoporotic women.

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The purpose of this study was to investigate whether the additional sensory information could improve postural control in individuals with unilateral anterior cruciate ligament (ACL) injury. Twenty-eight individuals with unilateral ACL injury (mean age 23.6, 26 males, 2 females) and 28 healthy young control subjects (mean age 22.1 years, 26 males, 2 females) participated in this study. Postural control was evaluated with subjects single-leg standing on a force platform with eyes closed under two sensory conditions: normal sensory information and light touch to a stationary bar (applied force below 1 N). Three trials of 30 5 were performed in each single-leg stance and in each sensory condition. Mean sway amplitude and predominant frequency of center of pressure were calculated for both anterior-posterior and medial-lateral directions. Individuals with ACL injury showed greater mean sway amplitude than healthy control individuals even though the predominant frequency was similar for both groups. Additional sensory information improved postural control performance in individuals with ACL injury and healthy control, with a greater effect observed for the ACL group. Based on these results, we suggest that reduction in postural control performance in individuals with ACL injury would be due to the reduction of sensory information provided by the ACL, but when sensory information is enhanced, postural control performance improves. These results have implications for novel approaches to improve stability in individuals with ACL injury. (c) 2008 Elsevier Ireland Ltd. All rights reserved.

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We present a comparative study of the physico-chemical properties, in vitro cytotoxicity and in vivo antibody production of surface-complexed DNA in EPC/DOTAP/DOPE (50/25/25% molar) liposomes and DOTAP/DOPE (50/50% molar) lipoplexes. The study aims to correlate the biological behavior and structural properties of the lipid carriers. We used DNA-hsp65, whose naked action as a gene vaccine against tuberculosis has already been demonstrated. Additionally, surface-complexed DNA-hsp65 in EPC/DOTAP/DOPE (50/25/25% molar) liposomes was effective as a single-dose tuberculosis vaccine. The results obtained showed that the EPC inclusion stabilized the DOTAP/DOPE structure, producing higher melting temperature and lower zeta potential despite a close mean hydrodynamic diameter. Resemblances in morphologies were identified in both structures, although a higher fraction of loaded DNA was not electrostatically bound in EPC/DOTAP/DOPE. EPC also induced a striking reduction in cytotoxicity, similar to naked DNA-hsp65. The proper immune response lead to a polarized antibody production of the IgG2a isotype, even for the cytotoxic DOTAP/DOPE. However, the antibody production was detected at 15 and 30 days for DOTAP/DOPE and EPC/DOTAP/DOPE, respectively. Therefore, the in vivo antibody production neither correlates with the in vitro cytotoxicity, nor with the structural stability alone. The synergistic effect of the structural stability and DNA electrostatic binding upon the surface of structures account for the immunological effects. By adjusting the composition to generate proper packing and cationic lipid/DNA interaction, we allow for the optimization of liposome formulations for required immunization or gene therapy. In a specific manner, our results contribute to studies on the tuberculosis therapy and vaccination. (C) 2009 Elsevier B.V. All rights reserved.

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Adjustments during postural control have been recognized in the process of the integration of movement and cognition. The objective of the present work was to describe postural changes and to verify if there is a correlation between postural adjustment and attention span in 7-month-old infants during 1 min of viewing an animated puppet. Method: Twenty-nine healthy infants (14 males) born from 31 to 39 weeks (median 36) were placed in a prone position and filmed watching a puppet during I min. The analysis of the images allowed us to catalogue the changes in position, the frequency of these changes, and the attention span. The following items were quantified: total number of infant positions, positions with weight transfer, changes in support, axis, decubitus, trunk and cervical movements, timing and pauses in visual attention. Results: Twenty-one infants stayed in the prone position during most of the recording, and eight chose sitting position before starting the session. Two groups were studied according to the main position throughout the filming, one in prone and the other in sitting positions, although they could rolling or crawling. For prone group the attention span was positively correlated with the number of positions with weight transfer (r = 0.53, p = 0.04), negatively correlated with trunk movements (r = -0.63, p = 0.01), and not correlated with birth or current weight. This work suggests that changes in the trunk movements and weight transfer are different traits related to the attention in 7-month-old infants. (C) 2008 Elsevier B.V.. All rights reserved.

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Background and Purpose-Functional MRI is a powerful tool to investigate recovery of brain function in patients with stroke. An inherent assumption in functional MRI data analysis is that the blood oxygenation level-dependent (BOLD) signal is stable over the course of the examination. In this study, we evaluated the validity of such assumption in patients with chronic stroke. Methods-Fifteen patients performed a simple motor task with repeated epochs using the paretic and the unaffected hand in separate runs. The corresponding BOLD signal time courses were extracted from the primary and supplementary motor areas of both hemispheres. Statistical maps were obtained by the conventional General Linear Model and by a parametric General Linear Model. Results-Stable BOLD amplitude was observed when the task was executed with the unaffected hand. Conversely, the BOLD signal amplitude in both primary and supplementary motor areas was progressively attenuated in every patient when the task was executed with the paretic hand. The conventional General Linear Model analysis failed to detect brain activation during movement of the paretic hand. However, the proposed parametric General Linear Model corrected the misdetection problem and showed robust activation in both primary and supplementary motor areas. Conclusions-The use of data analysis tools that are built on the premise of a stable BOLD signal may lead to misdetection of functional regions and underestimation of brain activity in patients with stroke. The present data urge the use of caution when relying on the BOLD response as a marker of brain reorganization in patients with stroke. (Stroke. 2010; 41:1921-1926.)

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The Schistosoma mansoni fatty acid binding protein (FABP), SmA, is a vaccine candidate against, S. mansoni and F hepatica. Previously, we demonstrated the importance of a correct fold to achieve protection in immunized animals after cercariae challenge [[10]. C.R.R. Ramos, R.C.R. Figueredo, T.A. Pertinhez, M.M. Vilar, A.L.T.O. Nascimento, M. Tendler, I. Raw, A. Spisni, P.L. Ho, Gene structure and M20T polymorphism of the Schistosoma mansoni Sm14 fatty acid-binding protein: structural, functional and immunoprotection analysis. J. Biol. Chem. 278 (2003) 12745-12751]. Here we show that the reduction of vaccine efficacy over time is due to protein dimerization and subsequent aggregation. We produced the mutants Sm14-M20(C62S) and Sm14M20(C62V) that, as expected, did not dimerize in SDS-PAGE. Molecular dynamics calculations and unfolding experiments highlighted a higher structural stability of these mutants with respect to the wild-type. In addition, we found that the mutated proteins, after thermal denaturation, refolded to their active native molecular architecture as proved by the recovery of the fatty acid binding ability. Sm14-M20(C62V) turned out to be the more stable form over time, providing the basis to determine the first 3D solution structure of a Sm14 protein in its apo-form. Overall, Sm14-M20(C62V) possesses an improved structural stability over time, an essential feature to preserve its immunization capability and, in experimentally immunized animals, it exhibits a protection effect against S. mansoni cercariae infections comparable to the one obtained with the wild-type protein. These facts indicate this protein as a good lead molecule for large-scale production and for developing an effective Sm14 based anti-helminthes vaccine. (C) 2008 Elsevier B.V. All rights reserved.

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This work aimed at an evaluation of the classical iodine method for quantification of vitamin C (L-ascorbic acid) in fruit juices, as well as at a search into the stability of this so popular vitamin under different conditions of pH, temperature and light exposition, in addition to a proposal of a new quantification method. Our results point to the persistent reversibility of the blue color of the starch-triiodide complex at the end point when using the classical iodine titration, and the overestimation of the true vitamin concentration in fruit juices. A new quantification method is proposed in order to overcome this problem. Surprising conclusions were obtained regarding the controversial stability of L-ascorbic acid toward atmospheric oxygen, at low pH, even in fruit juice and at room temperature, showing that the major problem concerned with aging of fruit juices is proliferation of microorganisms rather than expontaneous oxidation of L-ascorbic acid.

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Objective: The purpose of this study was to compare 2 different interventions, global postural reeducation (GPR) and static stretching exercises (SS), in the treatment of women with temporomandibular disorders (TMDs). Methods: A total of 28 subjects with TMDs were randomized into 2 treatment groups: GPR, where therapy involved muscle global chain stretching, or SS, with conventional static stretching; but only 24 completed the study. Eight treatment sessions lasting 40 minutes each (weekly) were performed. Assessments were conducted at baseline, immediately after treatment end, and 2 months later. Measurements included pain intensity at the temporomandibular joint, headache, cervicalgia, teeth clenching, ear symptoms, restricted sleep, and difficulties for mastication, using a visual analogue scale. In addition, electromyographic activity and pain thresholds were measured at the masseter, anterior temporalis, stemocleidomastoid, and upper trapezius muscles. Two-way analysis of variance with Tukey post hoc test was used for between-group comparisons. Significance level was .05. Results: Comparing the pain assessments using the visual analogue scale, no significant differences were seen with the exception of severity of headaches at treatment end (GPR, 3.92 +/- 2.98 cm; SS, 1.64 +/- 1.66 cm; P < .024). In addition, no significant differences were seen for pain thresholds and for electromyographic activity (P > .05). Conclusions: For the subjects in this study, both GPR and SS were similarly effective for the treatment of TMDs with muscular component. They equally reduced pain intensity, increased pain thresholds, and decreased electromyographic activity. (J Manipulative Physiol Ther 2010;33:500-507)

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Objectives: Collagen disorganization is one of the main degradation patterns found in unsuccessful adhesive restorations. The hypothesis of this study was that pretreatment using natural collagen cross-linking agents rich in proanthocyanidin (PA) would improve mechanical properties and stability over time of the dentin collagen and, thus, confer a more resistant and lasting substrate for adhesive restorations. Methods: PA-based extracts, from grape seed (GSE), cocoa seed (CSE), cranberry (CRE), cinnamon (CNE) and acai berry (ACE) were applied over the demineralized dentin. The apparent elastic modulus (E) of the treated dentin collagen was analyzed over a 12 month period. Specimens were immersed in the respective solution and E values were obtained by a micro-flexural test at baseline, 10, 30, 60, 120 and 240 min. Samples were stored in artificial saliva and re-tested after 3, 6 and 12 months. Data was analyzed using ANOVA and Tukey test. Results: GSE and CSE extracts showed a time-dependent effect and were able to improve [240 min (MPa): GSE = 108.96 +/- 56.08: CSE = 59.21 +/- 24.87] and stabilize the E of the organic matrix [12 months (MPa): GSE = 40.91 +/- 19.69; CSE = 42.11 +/- 13.46]. CRE and CNE extracts were able to maintain the E of collagen matrices constant over 12 months [CRE = 11.17 +/- 7.22; CNE = 9.96 +/- 6.11; MPa]. ACE (2.64 +/- 1.22 MPa) and control groups immersed in neat distilled water (1.37 +/- 0.69 MPa) and ethanol-water (0.95 +/- 0.33 MPa) showed no effect over dentin organic matrix and enable their degradation and reduction of mechanical properties. Significance: Some PA-based extracts were capable of improving and stabilizing collagen matrices through exogenous cross-links induction. (C) 2011 Elsevier Ltd. All rights reserved.

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Dentin bonding performed with hydrophobic resins using ethanol-wet bonding should be less susceptible to degradation but this hypothesis has never been validated. Objectives. This in vitro study evaluated stability of resin-dentin bonds created with an experimental three-step BisGMA/TEGDMA hydrophobic adhesive or a three-step hydrophilic adhesive after one year of accelerated aging in artificial saliva. Methods. Flat surfaces in mid-coronal dentin were obtained from 45 sound human molars and randomly divided into three groups (n = 15): an experimental three-step BisGMA/TEGDMA hydrophobic adhesive applied to ethanol (ethanol-wet bonding-GI) or water-saturated dentin (water-wet bonding-GII) and Adper Scotchbond Multi-Purpose [MP-GIII] applied, according to manufacturer instructions, to water-saturated dentin. Resin composite crowns were incrementally formed and light-cured to approximately 5 mm in height. Bonded specimens were stored in artificial saliva at 37 degrees C for 24h and sectioned into sticks. They were subjected to microtensile bond test and TEM analysis immediately and after one year. Data were analyzed with two-way ANOVA and Tukey tests. Results. MP exhibited significant reduction in microtensile bond strength after aging (24 h: 40.6 +/- 2.5(a); one year: 27.5 +/- 3.3(b); in MPa). Hybrid layer degradation was evident in all specimens examined by TEM. The hydrophobic adhesive with ethanol-wet bonding preserved bond strength (24 h: 43.7 +/- 7.4(a); one year: 39.8 +/- 2.7(a)) and hybrid layer integrity, with the latter demonstrating intact collagen fibrils and wide interfibrillar spaces. Significance. Coaxing hydrophobic resins into acid-etched dentin using ethanol-wet bonding preserves resin-dentin bond integrity without the adjunctive use of MMPs inhibitors and warrants further biocompatibility and patient safety`s studies and clinical testing. (C) 2009 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

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Introduction: In this study, we aimed to evaluate the long-term stability of anterior open-bite treatment with occlusal adjustment and the dentinal sensitivity caused by this procedure in the long term. Methods: The sample comprised 17 open-bite patients who experienced relapse of the negative vertical overbite after orthodontic treatment and were retreated with occlusal adjustment. The cephalometric changes were evaluated on lateral cephalograms obtained before and after the occlusal adjustment and in the long term (mean, 3.4 years after occlusal adjustment). Dentinal sensitivity was also evaluated before the occlusal adjustment, and 1.35 months, 4.61 months, and 3.4 years later. The cephalometric statuses between the 3 evaluations were compared with analysis of variance (ANOVA) and Tukey tests. The percentages of clinically significant relapse were calculated. To compare dentinal sensitivity at the several stages, nonparametric Friedman and Wilcoxon tests were performed. Results: Statistically significant relapse of anterior open bite occurred in 33.3% of the patients. Those who had the procedure before 21 years of age were most likely to experience relapse. Dentinal sensitivity remained within the normal range in the long term. Conclusions: Despite the statistically significant relapse of anterior open bite, clinically significant stability was found in 66.7% of the patients. (Am J Orthod Dentofacial Orthop 2010; 138:14.e1-14.e7)

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Introduction: The purpose of this study was to compare the occlusal stability of Class II malocclusion treatment with and without extraction of 2 maxillary premolars. Methods: A sample of 59 records from patients with complete Class II malocclusion was used. This sample was divided into 2 groups with the following characteristics: group 1, comprising 29 patients treated without extractions, and group 2, comprising 30 patients treated with extraction of 2 maxillary premolars. Dental cast measurements were obtained before and after treatment and at a minimum of 2.4 years after treatment. The pretreatment, posttreatment, and postretention occlusal statuses were evaluated with the peer assesment rating index. The occlusal indexes at the postretention stage and the posttreatment changes and percentages of posttreatment changes were compared with t tests. Results: The nonextraction and the 2 maxillary premolar extraction treatment protocols of complete Class II malocclusions had no statistically significant differences in occlusal stability. Conclusions: Finishing Class II malocclusion treatment with the molars in a Class II relationship has similar occlusal stability as finishing with the molars in a Class I relationship. (Am J Orthod Dentofacial Orthop 2010;138:16-22)

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Because of their multifactorial etiologies, dental and skeletal open bites are among the most difficult malocclusions to treat to a successful and stable result. Etiologic factors include vertical maxillary excess, skeletal pattern, abnormalities in dental eruption, and tongue-thrust problems. The purpose of this article was to report the treatment of an adult patient with a lateral open bite and a unilateral posterior crossbite. The treatment involved nonextraction therapy, including intermaxillary elastics, to obtain dentoalveolar extrusion in the region of the lateral open bite. The treatment results were successful and remained stable 2 years later. (Am J Orthod Dentofacial Orthop 2010;137:701-11)