Virtual reality head-mounted goggles increase the body sway of young adults during standing posture.

The aim of this study was to investigate the effects of wearing virtual reality head-mounted goggles (VR) on body sway in young adults. We run two experiments, in which we compared the body sway while standing during the conditions of 1) wearing and non-wearing VR with eyes-opened (experiment #1), 2) wearing and no-wearing VR with eyes-closed (experiment #2), and 3) wearing VR with eyes-opened when the scene was turned on and off (experiment #2). Forty-four (experiment #1) and fifteen (experiment #2) young adults were instructed to remain as still as possible on a force plate for 60-s and performed three trials in each quiet standing condition. The center of pressure (CoP) displacement, mean velocity, root mean square (RMS), area and median frequency of sway were calculated in both experiments. In the experiment #1, wearing VR condition with eyes-opened largely increased the AP and ML CoP displacement, AP mean velocity, AP and ML RMS, and area (p < 0.05) compared to non-wearing VR with eyes-opened. In the experiment #2, no differences were found for any conditions (eyes-closed and eyes-opened with turned on and off VR scene). In conclusion, wearing VR head-mounted goggles increased body sway of young adults during standing postural task, when the individuals were with eyes-opened. However, the effects of wearing VR head-mounted goggles on body sway disappeared when the individuals were with eyes-closed or the google scene was turned off the scene compared to not wearing VR head-mounted goggles with eyes-closed or turned on scene, respectively.

Controle autonômico do coração e fração de ejeção na fase crônica do acidente vascular encefálico / Autonomic control of the heart and stroke volume in the chronic phase of cerebrovascular accident / Control autonómico del corazón y fracción de eyección en la fase crónica del accidente vascular encefálico

Introdução: Sujeitos acometidos por acidente vascular encefálico (AVE) podem apresentar alterações na estrutura e função do coração e na modulação autonômica. Objetivo: Verificar função autonômica e cardíaca sistólica em homens após AVE, e se estas variáveis estão associadas. Métodos: Foram avaliados oito homens, com idade entre 55 e 65 anos, acometidos por lesão cerebrovascular há pelo menos seis meses e todos com hemiparesia. Foram realizadas as seguintes avaliações: 1) Ecocardiografia, para avaliar a função cardíaca sistólica. 2) Registro da frequência cardíaca (FC) e dos intervalos R-R (IRR), batimento a batimento, para avaliação do controle neural do coração. Esses dados foram analisados no domínio da frequência, por meio das análises dos seguintes componentes espectrais: alta frequência; baixa frequência e a razão BF/AF. Foi aplicado o teste de correlação de Pearson (p ≤ 0,05). Resultados: Características demográficas, antropométricas e fisiológicas: Idade = 58,62 ± 2,88 anos; IMC = 27,41 ± 5,33 kg/m2 ; BF = 61,78 ± 26,79 (un); AF = 38,23 ± 26,79 (un); BF/AF = 3,41 ± 3,38; FE = 0,65 ± 0,04. Não houve correlação estatisticamente significativa entre os índices espectrais BF e AF com fração de ejeção e a presença de fatores de risco para AVE. Conclusão: No presente estudo, a fração de ejeção do ventrículo esquerdo encontra-se normal e o controle neural do coração pode estar normal ou não, mesmo na presença de fatores de risco para o AVE. .

Introduction: Subjects affected by cerebrovascular accident (CVA) may show changes in the structure and function of the heart and autonomic modulation. Objective: To assessautonomic and cardiac systolic function in men after stroke, and whether these variables are associated. Methods: Eight men aged between 55 and 65 years were evaluated, all suffering from cerebrovascular injury and with hemiparesis for at least six months. The following evaluations were performed: 1) echocardiography to evaluate systolic cardiac function; 2) Record the heart rate (HR) and RR intervals (RRI), beat by beat, to assess neural control of the heart. These data were analyzed in the frequency domain, by means of spectral analysis of the following components: high frequency, low frequency and LF/HF ratio. The Pearson correlation test was applied (p ≤0.05). Results: Demographic. anthropometric and physiological characteristics: Age = 58.62 ± 2.88 years; BMI = 27.41 ± 5.33 kg/m2; LF = 61.78 ± 26.79 (un); HF = 38.23 ± 26.79 (un); LF/HF = 3.41 ± 3.38; EF = 0.65 ± 0.04. There was no statistically significant correlation between the spectral indices of low (LF) and high frequency (HF) with stroke volume and the presence of risk factors for CVA. Conclusion: In the present study, the stroke volume of the left ventricle is normal and the neural control of the heart may be normal or not, even in the presence of risk factors for CVA. .

Introducción: Los sujetos acometidos por accidente vascular encefálico (AVE) pueden presentar alteraciones en la estructura y función del corazón y en la modulación autonómica. Objetivo: Verificar función autonómica y cardíaca sistólica en hombres después de AVE, y si estas variables están asociadas. Métodos: Fueron evaluados ocho hombres, con edad entre 55 y 65 años, acometidos por lesión cerebrovascular desde hace por lo menos seis meses y todos con hemiparesia. Fueron realizadas las siguientes evaluaciones: 1) Ecocardiografía, para evaluar la función cardíaca sistólica. 2) Registro de la frecuencia cardíaca (FC) y de los intervalos R-R (IRR), latido a latido, para evaluación del control neural del corazón. Esos datos fueron analizados en el dominio de la frecuencia, a través del análisis de los siguientes componentes espectrales: alta frecuencia; baja frecuencia y la razón BF/AF. Fue aplicado el test de correlación de Pearson (p ≤ 0,05). Resultados: Características demográficas, antropométricas y fisiológicas: Edad = 58,62 ± 2,88 años; IMC = 27,41 ± 5,33 kg/m2; BF = 61,78 ± 26,79 (un); AF = 38,23 ± 26,79 (un); BF/AF = 3,41 ± 3,38; FE = 0,65 ± 0,04. No hubo correlación estadísticamente significativa entre los índices espectrales BF y AF con fracción de eyección y la presencia de factores de riesgo para AVE. Conclusión: En el presente estudio, la fracción de eyección del ventrículo izquierdo se encuentra normal y el control neural del corazón puede estar normal o no, aún ante la presencia de factores de riesgo para el AVE. .