Validity and Reliability of Smartphone App for Evaluating Postural Adjustments during Step Initiation.

The evaluation of anticipatory postural adjustments (APAs) requires high-cost and complex handling systems, only available at research laboratories. New alternative methods are being developed in this field, on the other hand, to solve this issue and allow applicability in clinic, sport and hospital environments. The objective of this study was to validate an app for mobile devices to measure the APAs during gait initiation by comparing the signals obtained from cell phones using the Momentum app with measurements made by a kinematic system. The center-of-mass accelerations of a total of 20 healthy subjects were measured by the above app, which read the inertial sensors of the smartphones, and by kinematics, with a reflective marker positioned on their lumbar spine. The subjects took a step forward after hearing a command from an experimenter. The variables of the anticipatory phase, prior to the heel-off and the step phase, were measured. In the anticipatory phase, the linear correlation of all variables measured by the two measurement techniques was significant and indicated a high correlation between the devices (APAonset: r = 0.95, p < 0.0001; APAamp: r = 0.71, p = 0.003, and PEAKtime: r = 0.95, p < 0.0001). The linear correlation between the two measurement techniques for the step phase variables measured by ques was also significant (STEPinterval: r = 0.56, p = 0.008; STEPpeak1: r = 0.79, p < 0.0001; and STEPpeak2: r = 0.64, p < 0.0001). The Bland−Altman graphs indicated agreement between instruments with similar behavior as well as subjects within confidence limits and low dispersion. Thus, using the Momentum cell phone application is valid for the assessment of APAs during gait initiation compared to the gold standard instrument (kinematics), proving to be a useful, less complex, and less costly alternative for the assessment of healthy individuals.

Wearable Inertial Sensor Approach for Postural Adjustment Assessments during Predictable Perturbations in Sport.

INTRODUCTION: Evidence supports the importance of efficient postural control to improve performance in sports. This involves the use of strategies such as anticipatory posture adjustments and compensatory adjustments. Technology makes analysis and assessments in sports cheaper, while being valid and reliable compared to the gold-standard assessment equipment. OBJECTIVES: This article aimed to test the validity and reliability of signals extracted from the sensor's accelerometer (Metamotion C), by comparing it to the data obtained from the gold-standard equipment (a three-dimensional video-motion-capture system). DESIGN: Observational, cross-sectional study. METHODS: We exposed 20 healthy young standing people to the pendulum impact paradigm, which consisted of predictable anteroposterior disturbances applied at the shoulder level. In order to measure this, we observed the acceleration of the center of mass in the anticipatory and compensatory phase of the disturbance and compared the signals of the two devices (Metamotion C and a motion-capture system). RESULTS: The validation results showed the significant linear correlation of all variables with a moderate to large correlation of r ≥ 0.5 between the devices. In contrast, the reliability results between sessions obtained by filming were all significant and above 0.75, indicating excellent reliability. The APAonset variable had a reasonable to high intra-class correlation in the anticipatory phase. In the compensatory phase, the CPAtime variable showed an excellent correlation. CONCLUSIONS: Metamotion C proved reasonably valid and highly reliable in measuring the center of mass acceleration compared to the camera system in both the anticipatory and compensatory phases.

Comparison of inertial records during anticipatory postural adjustments obtained with devices of different masses.

Background: Step initiation involves anticipatory postural adjustments (APAs) that can be measured using inertial measurement units (IMUs) such as accelerometers. However, previous research has shown heterogeneity in terms of the population studied, sensors used, and methods employed. Validity against gold standard measurements was only found in some studies, and the weight of the sensors varied from 10 to 110 g. The weight of the device is a crucial factor to consider when assessing APAs, as APAs exhibit significantly lower magnitudes and are characterized by discrete oscillations in acceleration paths. Objective: This study aims to validate the performance of a commercially available ultra-light sensor weighing only 5.6 g compared to a 168-g smartphone for measuring APAs during step initiation, using a video capture kinematics system as the gold standard. The hypothesis is that APA oscillation measurements obtained with the ultra-light sensor will exhibit greater similarity to those acquired using video capture than those obtained using a smartphone. Materials and Methods: Twenty subjects were evaluated using a commercial lightweight MetaMotionC accelerometer, a smartphone and a system of cameras-kinematics with a reflective marker on lumbar vertebrae. The subjects initiated 10 trials of gait after a randomized command from the experimenter and APA variables were extracted: APAonset, APAamp, PEAKtime. A repeated measures ANOVA with post-hoc test analyzed the effect of device on APA measurements. Bland-Altman plots were used to evaluate agreement between MetaMotionC, smartphone, and kinematics measurements. Pearson's correlation coefficients were used to assess device correlation. Percentage error was calculated for each inertial sensor against kinematics. A paired Student's t-test compared th devices percentage error. Results: The study found no significant difference in temporal variables APAonset and PEAKtime between MetaMotionC, smartphone, and kinematic instruments, but a significant difference for variable APAamp, with MetaMotionC yielding smaller measurements. The MetaMotionC had a near-perfect correlation with kinematic data in APAonset and APAamp, while the smartphone had a very large correlation in APAamp and a near-perfect correlation in APAonset and PEAKtime. Bland-Altman plots showed non-significant bias between smartphone and kinematics for all variables, while there was a significant bias between MetaMotionC and kinematics for APAamp. The percentage of relative error was not significantly different between the smartphone and MetaMotionC. Conclusions: The temporal analysis can be assessed using ultralight sensors and smartphones, as MetaMotionC and smartphone-based measurements have been found to be valid compared to kinematics. However, caution should be exercised when using ultralight sensors for amplitude measurements, as additional research is necessary to determine their effectiveness in this regard.

Anticipatory postural adjustments in older versus young adults: a systematic review and meta-analysis.

BACKGROUND: Anticipatory postural adjustments (APAs) are a feedforward mechanism triggered in advance to a predictable perturbation, to help the individual counteract mechanical effects that the disturbance may cause. Whether or not this strategy is compromised in the elderly is not a consensus in the literature. METHODS: In this systematic review with meta-analysis, we investigated aging effects on postural control, based on anticipatory postural adjustments (APAs). We selected 11 eligible articles of the following databases: Lilacs, SciELO, PubMed, Cochrane Central, Embase, and CINAHL, involving 324 research participants, assessing their methodological quality and extracting electromyographic, posturographic, and kinematic measurements. We included studies that investigated the occurrence of APAs in healthy younger and older adults, published before 10th August 2022, in English. Studies involving participant with conditions that may affect balance or that did not report measures of onset or amplitude of electromyography (EMG), COP, or kinematics were excluded. To analyze the aggregated results from these studies, we performed the analysis based on the outcome measures (EMG, COP, or kinematic measures) used in individual studies. We calculated differences between younger and older adult groups as the mean differences between the groups and the estimated effect. Egger's test was conducted to evaluate whether this meta-analysis had publication bias. RESULTS: Through this review, older adults showed no significant difference in the velocity to perform a movement compared to the younger adults (MD 0.95, 95% CI -0.86, 2.76, I2 = 82%), but both muscle onset and center of pressure (COP) onset were significantly more delayed in older than in younger adults: erector spinae (MD -31.44, 95% CI -61.79, -1.09, I2 = 95%); rectus abdominis (RA) (MD -31.51, 95% CI -70.58, -3.57, I2 = 85%); tibialis anterior (TA) (MD -44.70, 95% CI -94.30, 4.91, I2 = 63%); soleus (SOL) (MD -37.74, 95% CI -65.43, -10.05, I2 = 91%); gastrocnemius (GAS) (MD -120.59, 95% CI -206.70, -34.49, I2 = 94%); quadriceps (Q) (MD -17.42, 95% CI -34.73, -0.12, I2 = 0%); biceps femoris (BF) (MD -117.47, 95% CI -192.55, -42.70, I2 = 97%); COP onset (MD -45.28, 95% CI -89.57, -0.98, I2 = 93%), and COP apa (COPapa) (MD 2.35, 95% CI -0.09, 4.79, I2 = 64%). These changes did not seem to be linked to the speed of movement but possibly to age-related physiological changes that indicated decreased motor control during APAs in older adults. CONCLUSIONS: Older adults use different postural strategies that aim to increase the safety margin and stabilize the body to perform the movement, according to the requirements imposed, and this should be considered in rehabilitation protocols. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD420119143198.

Validity and reliability of a smartphone-based assessment for anticipatory and compensatory postural adjustments during predictable perturbations.

BACKGROUND: Postural adjustments involve displacements of the center of mass (COM), controlled by the central nervous system (CNS), to maintain equilibrium whilst standing. Postural adjustments can be anticipatory (APAs) or compensatory (CPAs), and are triggered to counteract predictable perturbations. RESEARCH QUESTION: Is the new smartphone application, Momentum, a valid and reliable tool for the assessment of body balance, by measuring APAs and CPAs using accelerometer readings? METHODS: 20 young adults were exposed to external predictable perturbations induced at the shoulder level, whilst standing. COM linear acceleration was recorded by Momentum (extracting data from a smartphone's accelerometer) and a 3D motion capture system. RESULTS: The key results demonstrated a very high, significant correlation (r ≥ 0.7, p < 0.05) between the two device settings in the APA parameters, which obtained r = 0.65, denoting a high correlation. Considering the reliability, variables that are compensatory in nature are presented on a scale of good to excellent in measurement methods, kinematics, and Momentum. However, the anticipatory variables presented excellent reliability only for the kinematics. SIGNIFICANCE: These experiments show that Momentum is a valid method for measuring COM acceleration under predictable perturbations and is reliable for compensatory events.

Postural Adjustments and Kinematic Index Finger Features in Frail Older Adults under Different Equilibrium Constraints.

Background: Anticipatory postural adjustments (APAs) are significantly affected by age and may represent restrictions on functional independence. Previous studies in young adults have already highlighted that changing postural stability (i.e., seated vs. upright posture) affects the motor planning and APAs. In frail older adults (FOAs), the effect of these different conditions of postural stability have not yet been established, and the present study aimed to disentangle this issue. Methods: Participants executed an arm-pointing task to reach a diode immediately after it turned on, under different conditions of stability (seated with and without foot support and in an upright posture). A kinematic profile of the index finger and postural electromyographic data were registered in their dominant-side leg muscles: tibialis anterior, soleus, rectus femoris, and semitendinosus. Results: The main finding of this study was that the adopted posture and body stabilization in FOAs did not reflect differences in APAs or kinematic features. In addition, they did not present an optimal APA, since postural muscles are recruited simultaneously with the deltoid. Conclusion: Thus, FOAs seem to use a single non-optimal motor plan to assist with task performance and counterbalance perturbation forces in which they present similar APAs and do not modify their kinematics features under different equilibrium constraints.

Anticipatory Postural Adjustments and kinematic arm features when postural stability is manipulated.

Beyond the classical paradigm that presents the Anticipatory Postural Adjustments (APAs) as a manner to create forces that counteract disturbances arising from the moving segment during a pointing task, there is a controversial discussion about the role APAs to facilitate the movement and perform a task accurately. In addition, arm kinematics features are classically used to infer the content of motor planning for the execution and the control of arm movements. The present study aimed to disentangle the conflicting role of APAs during an arm-pointing task in which the subjects reach a central diode that suddenly turns on, while their postural stability was manipulated. Three postures were applied: Standing (Up), Sit without feet support (SitUnsup) and Sit with feet support (SitSup). We found that challenging postural stability induced an increase of the reaction time and movement duration (observed for the SitUnsup compared to SitSUp and Up) as well as modified the upper-limb velocity profile. Indeed, a greater max velocity and a shorter deceleration time were observed under the highest stability (SitSup). Thus, these Kinematics features reflect less challenging task and simple motor plan when the body is stabilized. Concerning the APAs, we observed the presence of them independently of the postural stability. Such a result strongly suggests that APAs act to facilitate the limb movement and to counteract perturbation forces. In conclusion, the degree of stability seems particularly tuned to the motor planning of the upper-limb during a pointing task whereas the postural chain (sitting vs. standing) was also determinant for APAs.

Condições potencialmente ameaçadoras à vida no ciclo gravídico-puerperal / Condiciones potencialmente amenazantes para la vida en el ciclo gravídico puerperal / Potentially life-threatening conditions determinants in pregnancy-puerperal cycle

ABSTRACT Objetivo: Descrever as principais condições potencialmente ameaçadoras à vida de mulheres durante o ciclo gravídico e puerperal e variáveis relacionadas a esses agravos. Método: Estudo do tipo documental, descritivo e quantitativo, realizado com prontuários de gestantes, parturientes e puérperas internadas em hospital de média complexidade, que apresentaram Condições Potencialmente Ameaçadoras à Vida (CPAV). Foram excluídos os de acesso impossibilitado por estarem sob judice. A amostra foi temporal e a análise univariada. Resultados: Inclui-se 181 prontuários. A maioria das condições ocorreu em mulheres de 16 a 34 anos de idade (61,3%), união estável (60,8%), pardas (31,5%), sem renda ocupacional (29,2%), multíparas (28,87%), com complicações no primeiro trimestre gestacional (32,6%). Verificaram-se a realização de um número insuficiente de consultas (13,8%), dados referentes ao pré-natal ignorados (68%). As principais CPAV foram as síndromes hemorrágicas (28,2%), hipertensivas (25,4%) e infecção (13,3%). Como desfecho, foram observados prevalência de aborto não especificado (22,1%), morte perinatal por doença infecciosa e parasitária da mãe (2,2%). Conclusão: As principais CPAV foram as síndromes hemorrágicas, hipertensivas e infecções. Como desfecho, foram observados alta hospitalar, aborto, referenciamento à UTI, morte perinatal e morte materna.

RESUMEN Objetivo: describir las principales condiciones potencialmente amenazantes para la vida de las mujeres durante el ciclo gravídico y puerperal, además de las variables relacionadas con estos agravios. Método: estudio del tipo documental, descriptivo y cuantitativo, realizado con registros médicos de gestantes, parturientes y puérperas internadas en hospital de mediana complejidad, que presentaron Condiciones Potencialmente Amenazantes a la Vida (CPAV). Se excluyeron los de acceso imposibilitado por estar bajo juicio. La muestra fue temporal y el análisis univariado. Resultados: se incluyen 181 registros médicos. La mayoría de las condiciones ocurrió en mujeres de 16 a 34 años de edad (61,3%), unión estable (60,8%), pardas (31,5%), sin ingreso ocupacional (29,2%), multíparas (28,87%), con complicaciones en el primer trimestre gestacional (32,6%). Se constató un número insuficiente de consultas (13,8 %), datos relativos al prenatal ignorados (68 %). Las principales CPAV fueron los trastornos hemorrágicos (28,2%), hipertensivos (25,4%) e infecciosos (13,3%). Como resultado, se observaron: prevalencia de aborto no especificado (22,1%), muerte perinatal por enfermedad infecciosa y parasitaria de la madre (2,2%). Conclusión: las principales CPAV fueron los trastornos hemorrágicos, hipertensivos e infecciones. Como resultado, se observó alta hospitalaria, aborto, referencia a la UCI, muerte perinatal y muerte materna.

ABSTRACT Objective: To describe the main conditions potentially threatening the lives of women during the pregnancy and puerperal cycle and variables related to these diseases. Method: Documentary, descriptive and quantitative study, conducted with medical records of pregnant women, women giving birth and puerperal women hospitalized in a hospital of medium complexity, who presented Potentially Life Threatening Conditions (PLTC). Those with access unable to be sob judice were excluded. The sample was temporal and the analysis was univariate. Results: This includes 181 medical records. Most conditions occurred in women aged 16 to 34 years (61.3%), stable union (60.8%), brown (31.5%), without occupational income (29.2%), multiparous (28.87%), with complications in the first gestational trimester (32.6%). There was an insufficient number of consultations (13.8%), data regarding prenatal care ignored (68%). The main CPAV were hemorrhagic syndromes (28.2%), hypertensive (25.4%) and infection (13.3%). As an outcome, we observed a prevalence of unspecified miscarriage (22.1%), perinatal death from infectious and parasitic disease of the mother (2.2%). Conclusion: The main CPAV were hemorrhagic, hypertensive and infections syndromes. As an outcome, hospital discharge, miscarriage, ICU referral, perinatal death and maternal death were observed.

Association between job satisfaction and workers' quality of life in a public maternity hospital in the far north of Brazil / Associação entre satisfação no trabalho e qualidade de vida de trabalhadores em uma maternidade pública no extremo norte do Brasil

Abstract Objectives: to correlate the levels of job satisfaction (JS) and quality of life (QOL) of public maternity workers. Methods: quantitative and correlational cross-sectional study. Sample composed of 199 state public servants, of both genders, of different age groups and professions, working at the Women's Hospital Mother Luzia (WHML), in Macapá (AP). Three questionnaires were used: Sociodemographic, Job Satisfaction S20/23 and WHOQOL-Brief. Statistical analysis was performed by Pearson correlation and analysis of variance, with statistical significance at 5%. Results: most of the sample consisted of women (84.2%), aged between 30 and 39 years (40.7%), with a partner (64.3%), practicing physical activity (50.8%). With university education, (61.8%), income up to four minimum wages (53.3%), worked in two or more jobs (53.7%); and weekly workload of up to 30 hours (79.4%). They reported job dissatisfaction (75.4%). The average overall QOL was 65.62 (± 12.45). JS was associated with QOL (p<0.001) and number of jobs (p = 0.019). QOL was associated with male gender (p= 0.022), income (p= 0.004), ST (p <0.001), physical activity (p= 0.067) and workload (p= 0.011). The correlations between JS and QOL were all significant. Conclusions: the quality of life of WHML workers was directly and progressively associated with job satisfaction, which meant that higher levels of job satisfaction favored the quality of life.

Resumo Objetivos: correlacionar os níveis de satisfação no trabalho (ST) e qualidade de vida (QV) de trabalhadores de maternidade pública. Métodos: estudo transversal quantitativo e correlacional. Amostra composta por 199 servidores públicos estaduais, de ambos os sexos, de diversas faixas etárias e profissões, atuantes no Hospital da Mulher Mãe Luzia (HMML), em Macapá (AP). Foram utilizados três questionários: Sociodemográfico, Satisfação no Trabalho S20/23 e WHOQOL-Breve. A análise estatística foi realizada por Correlação de Pearson e análise de variâncias, com significância estatística em 5%. Resultados: maioria mulheres (84,2%), idade entre 30 e 39 anos (40,7%), com compa-nheiro (64,3%), praticante de atividade física (50,8%). Com nível superior, (61,8%), renda até quatro salários-mínimos (53,3%), trabalhavam em dois ou mais empregos (53,7%); e carga horária semanal de até 30 horas (79,4%). Referiram insatisfação laboral (75,4%). A média de QV geral foi 65,62 (±12,45). A ST associou-se a QV (p<0,001) e número de empregos (p=0,019). A QV associou-se ao sexo masculino (p=0,022), renda (p=0,004), ST (p<0,001), atividade física (p=0,067) e carga horária (p=0,011). As correlações entre ST e QV foram todas significativas. Conclusões: a Qualidade de Vida dos trabalhadores do HMML associou-se à satisfação no trabalho de maneira direta e progressiva, o que significou que níveis mais altos de satisfação no trabalho favoreceram a qualidade de vida.

Impact of peginterferon alpha-2b and ribavirin treatment on liver tissue in patients with HCV or HCV-HIV co-infection.

OBJECTIVE: To evaluate the effect of treatment with peginterferon alpha-2b and ribavirin on liver histology in patients with chronic hepatitis C (CHC) with or without HIV infection. METHODS: Patients received peginterferon alpha-2b (1.5 micro/kg/week during the first 4 weeks; 1.0 micro/kg/week thereafter) plus ribavirin (800-1200 mg/day, adjusted for weight) for 24 (genotypes 2/3) or 48 weeks (genotypes 1/4). Paired liver biopsy specimens were obtained at baseline and at the end of follow-up. RESULTS: 108 paired biopsy specimens were available: 67 from HCV-monoinfected and 41 from co-infected patients. At the end of follow-up, necroinflammatory activity (NIA) was significantly reduced (P<0.001), and fibrosis scores improved by > or = 1 point (Ishak et al criteria) in 65.7% of HCV-monoinfected patients. In co-infected patients, NIA was significantly reduced (P<0.001), and fibrosis scores improved by > or = 1 point in 42.5% of cases. In both groups, results were better for patients who attained sustained virological response (SVR). HCV RNA was undetectable in the second biopsy specimens of all patients who attained SVR. CONCLUSION: Liver fibrosis is reduced significantly after a course of therapy in patients with chronic hepatitis C. Reduction of fibrosis is more significant in patients who are monoinfected with HCV and in those who attained SVR.

Efeito da pressão positiva contínua nas vias aéreas sobre os volumes pulmonares em portadores de doença pulmonar obstrutiva crônica / Effect of the continuous positive airway pressure over pulmonary volumes in chronic obstructive pulmonary disease

Introdução: Em pacientes com doença pulmonar obstrutiva crônica (DPOC), a ventilação não-invasiva com pressão positiva reduz o trabalho respiratório e melhora a ventilação alveolar. O objetivo do presente estudo foi avaliar os efeitos imediatos da pressão positiva contínua nas vias aéreas (CPAP) sobre os parâmetros funcionais em portadores de DPOC. Metodologia: Em um ensaio clínico não randomizado e aberto, foram avaliados 11 portadores de DPOC moderada ou grave, estáveis clinicamente. Todos os pacientes foram avaliados antes e depois da aplicação de dois diferentes níveis de CPAP (7 e 11 cmH2O). Resultados: Dos 11 pacientes estudados, 6 eram homens e 5 eram mulheres, com média de idade de 70,72 anos. A capacidade vital forçada (CVF) aumentou após a aplicação dos dois níveis de CPAP, mais acentuadamente após a CPAP de 11 cmH2O (p<0,05). Capacidade pulmonar total (CPT), capacidade residual funcional (CRF) e volume residual (VR) mostraram tendência à redução, porém sem atingir relevância estatística (p>0,05). Conclusão: A aplicação da CPAP aumenta rapidamente a CVF em pacientes portadores de DPOC.

Introduction: In patients with chronic obstructive pulmonary disease (COPD), noninvasive positive pressure ventilation reduces the work of breathing and improves alveolar ventilation. The aim of the present study was to evaluate the immediate effects of the continuous positive airway pressure (CPAP) over pulmonary volumes in chronic obstructive pulmonary disease. Methodology: This was an open, non-randomized clinical trial involving 11 clinically stable patients with COPD moderate or severe. All were evaluated before and after of the utilisation of two different level of CPAP (7 and 11 cmH2O). Results: Of the 11 patients studied, 6 were male, and 5 were female, with a mean age of 70.72 years. Forced vital capacity (FVC) increasedafter of the utilisation of two different level of CPAP, specially after CPAP of 11 cmH2O (p<0,05). Total lung capacity (TLC), functional residual capacity (FRC) and residual volume (RV) decreased, however without significant change (p>0,05). Conclusion: The utilisation of the CPAP increase quickly FVC in patients with COPD.