ABSTRACT
Spinal traction is a physical intervention that provides constant or intermittent stretching axial force to the lumbar vertebrae to gradually distract spinal tissues into better alignment, reduce intervertebral disc (IVD) pressure, and manage lower back pain (LBP). However, such axial traction may change the normal lordotic curvature, and result in unwanted side effects and/or inefficient reduction of the IVD pressure. An alternative to axial traction has been recently tested, consisting of posteroanterior (PA) traction in supine posture, which was recently shown effective to increase the intervertebral space and lordotic angle using MRI. PA traction aims to maintain the lumbar lordosis curvature throughout the spinal traction therapy while reducing the intradiscal pressure. In this study, we developed finite element simulations of mechanical therapy produced by a commercial thermo-mechanical massage bed capable of spinal PA traction. The stress relief produced on the lumbar discs by the posteroanterior traction system was investigated on human subject models with different BMI (normal, overweight, moderate obese and extreme obese BMI cases). We predict typical traction levels lead to significant distraction stresses in the lumbar discs, thus producing a stress relief by reducing the compression stresses normally experienced by these tissues. Also, the stress relief experienced by the lumbar discs was effective in all BMI models, and it was found maximal in the normal BMI model. These results are consistent with prior observations of therapeutic benefits derived from spinal AP traction.
ABSTRACT
Automatic thermal and mechanical massage beds support self-managed treatment, including reduction of pain and stress, enhanced circulation, and improved mobility. As the devices become more sophisticated (increasing the degrees of freedom), it is essential to identify the settings that best target the desired tissue. To that end, we developed an MRI-derived model of the lower back and simulated the physiological effects of a commercial thermal-mechanical massage bed. Here we specifically estimated the tissue temperature and increased circulation under steady-state conditions for typical thermal actuator settings (i.e., 45-65°C). Energy transfer across nine tissues was simulated with finite element modeling (FEM) and the resulting heating was coupled to blood flow with an empirically-guided model of temperature-dependent circulation. Our findings indicate that thermal massage increases tissue temperature by 3-8°C and 1-3°C at depths of 2 and 3 cm, respectively. Importantly, due to the rapid (non-linear) increase of circulation with local temperature, this is expected to increase blood flow four-fold (4x) at depths occupied by deep tissue and muscle. These predictions are consistent with prior clinical observations of therapeutic benefits derived from spinal thermal massage.
ABSTRACT
ABSTRACT Introduction The association between socioeconomic status (SES) and the level of physical activity (PA) at school has not been studied at length. Objective To describe the association between SES and the intensity of physical activity during recess in elementary school children as well as the space dedicated to physical activity. Methods A total of 212 children (110 boys and 102 girls) who were enrolled in the fourth, fifth and sixth grade of elementary school at the time participated in this study. The subjects were divided into 4 levels according to the marginalization index (MI). The geographical location of the schools and the available area were calculated using Google Maps Pro (GMP) software.1 Physical activity level was measured using accelerometry.2 Comparisons of different levels of PA with respect to marginalization indices and sex were investigated using one-way analysis of variance. The association between health variables and PA was determined through the Pearson correlation coefficient. Results Results indicated that the level and intensity of PA during recess are associated with socioeconomic status and the social marginalization index, as well as sex, age, and infrastructure. Conclusion The higher the level of social marginalization, the lower the level of PA and the smaller the space dedicated to PA. Level of Evidence III; Comparative retrospective study.
RESUMO Introdução A associação entre o nível socioeconômico (NSE) e o nível de atividade física (AF) no âmbito escolar tem sido pouco estudada. Objetivo Descrever a associação entre o NSE e a intensidade da AF durante o recreio em crianças de ensino fundamental e também o espaço dedicado à atividade física. Métodos Participaram 212 crianças (110 meninos e 102 meninas) que, na ocasião do estudo, estavam no quarto, quinto e sexto ano do ensino fundamental. O número de sujeitos foi dividido em quatro níveis de acordo com o índice de marginalização (IM). A localização geográfica das escolas e a área disponível foram calculadas com o software Google Maps Pro (GMP).1 O nível de atividade física foi medido por acelerometria.2 As comparações dos diferentes níveis de AF com relação aos índices de marginalização e sexo foram analisadas por variância unidirecional. A associação entre as variáveis de saúde e a AF foi determinada pela correlação de Pearson. Resultados Os resultados indicaram que o nível e a intensidade de AF durante o recreio estão associados ao nível socioeconômico e ao índice de marginalização social, bem como a sexo, idade e infraestrutura. Conclusões Quanto maior foi o nível de marginalização social, menor o espaço para praticar e o nível de AF. Nível de Evidência III; Estudo retrospectivo comparativo.
RESUMEN Introducción La asociación entre el nivel socioeconómico (NSE) y el nivel de actividad física (AF) en el ámbito escolar ha sido poco estudiada. Objetivo Describir la asociación entre el NSE y la intensidad de la AF durante el recreo en niños de enseñanza fundamental y también el espacio dedicado a la actividad física. Métodos Participaron 212 niños (110 niños y 102 niñas) que, en la ocasión del estudio, estaban en cuarto, quinto y sexto año de la enseñanza fundamental. El número de sujetos fue dividido en cuatro niveles de acuerdo con el índice de marginalización (IM). La localización geográfica de las escuelas y el área disponible fueron calculadas con el software Google Maps Pro (GMP).1 El nivel de actividad física fue medido por acelerometría.2 Las comparaciones de los diferentes niveles de AF con relación a los índices de marginalización y sexo fueron analizadas por variancia unidireccional. La asociación entre las variables de salud y la AF fue determinada por la correlación de Pearson. Resultados Los resultados indicaron que el nivel y la intensidad de AF durante el recreo están asociados al nivel socioeconómico y al índice de marginalización social, bien como a sexo, edad e infraestructura. Conclusiones Cuanto mayor sea el nivel de marginalización social, menor será el espacio para practicar y el nivel de AF. Nivel de Evidencia III; Estudio retrospectivo comparativo.
