A new device to measure isometric strength in upper limbs: comparison between dominant and non-dominant limbs*

Univ Estadual Paulista, Dept Mecan, Guaratingueta, SP, BrazilFac Med ABC, Dept Morfol & Fisiol, Santo Andre, SP, BrazilUniversidade Federal de São Paulo UNIFESP, Dept Med, Disciplina Cardiol, São Paulo, BrazilFac Tecnol São Paulo FATEC, São Paulo, BrazilUniv Fed Sao Carlos, Dept Educ Fis & Motricidade Humana, BR-13560 Sao Carlos, SP, BrazilUniversidade Federal de São Paulo UNIFESP, Dept Med, Disciplina Cardiol, São Paulo, BrazilWeb of Scienc

Evaluation of rotator cuff muscle strength in healthy individuals

OBJECTIVE: To compare the strength generated by the rotator muscles of the shoulder joint between the right upper limb and left upper limb among healthy individuals. METHODS: To evaluate the muscle strength of upper limbs from isometric contractions in the horizontal direction (rotation) an isometric dynamometer was used, equipped with transducers, signal conditioning, a data acquisition board, and finally, a computer. Study participants were 22 male military subjects, aged between 18 and 19 years old, body mass between 57.7 and 93.0 kg (71.8 ± 9.45 kg) and height between 1.67 and 1.90 m (1.75 ± 0.06 m), healthy and without clinical diseases or any type of orthopedic injury in the muscle skeletal system. RESULTS: The internal rotation in the right upper limb (RUL) was higher than the average strength of internal rotation in the left upper limb (LUL) (p = 0.723). The external rotation strength in RUL was lower than the average strength of external rotation in the LUL (p=0.788). No statistical difference was observed by comparing the strength values of all isometric strength tests. CONCLUSION: For the sample and methodology used to assess muscle strength, there was no statistical difference between the strength generated by the muscles of the rotator cuff of the right and left upper limbs. Experimental Study

Modelamento Multicorpo do Sistema Musculoesquelético/Multibody modeling of the Musculoskeletal System

RESUMO Vários sistemas podem ser tratados com formalismos multicorpos: mecanismos de máquinas em geral, robôs industriais e manipuladores, estruturas espaciais, motores e, ainda, sistemas biomecânicos. A locomoção ou marcha humana e animal podem ser estudadas através de formalismos multicorpos.Nos últimos anos, diversos trabalhos relacionados à biomecânica, e utilizando formalismos multicorpos, têm sido apresentados. Muitos estudos in vitro e in vivo têm sido realizados, objetivando descrever o potencial de sobrecarga nas articulações do corpo humano e de modelos animais. O objetivo desta revisão foi apresentar estudos envolvendo o modelamento matemático aplicado à bioengenharia, biomecânica e engenharia biomédica. Conclui-se que o modelamento matemático é uma ferramenta muito útil, barata e não invasiva que vem contribuir nos estudos envolvendo o sistema multicorpo mecânico e complexo, que é o corpo humano.   Palavras chave: Modelamentomulticorpo, corpo humano, sistema musculoesquelético.   ABSTRACT Several systems can be treated with multibody formalisms: mechanisms of general machinery, industrial robots and manipulators, space structures, engines, and also biomechanical systems. The locomotion or human gait can be studied using multibody formalisms. Several studies related to biomechanics, and using multibody formalisms, have been presented in recent years. Many studies in vitro and in vivo have been carried out, aiming to describe the potential overload in the joints of the human body and animal models. The aim of this review was to present studies involving mathematical modeling applied to bioengineering, biomechanics and biomedical engineering. We have concluded that mathematical modeling is a useful, inexpensive and noninvasive tool which comes to contribute in studies involving the mechanical and complex multibody system which is the human body.   Key words: Multibodymodeling, human body, musculoskeletal system

Geoprocessamento para identificar padrões do perfil de nascimentos na região do Vale do Paraíba

OBJETIVO: aplicar técnicas de geoprocessamento para a análise espacial do perfil de nascimentos por município. MÉTODOS: foi um estudo ecológico e exploratório com dados do Sistema de Informações de Saúde sobre nascidos vivos de 2004 e utilizando técnicas de geoprocessamento. Foram estimadas as autocorrelações espaciais das variáveis: parto cesáreo, escolaridade materna, baixo peso ao nascer, escore de Apgar de cinco minutos, prematuridade, número de consultas e mães adolescentes, além do mapa com o índice de desenvolvimento humano. Foi utilizada a estatística I de Moran para detecção de agregados de eventos no espaço, pelo programa TerraView 3.1.3 (desenvolvido pelo Instituto Nacional de Pesquisas Espaciais - INPE e de acesso público). Foram construídos mapas espaciais com estas variáveis e estimados os coeficientes de correlação de Pearson. RESULTADOS: os resultados mostraram que as proporções de nascidos vivos de mães com escolaridade acima de primeiro grau e de cesáreas, apresentaram padrão espacial visualmente identificável e autocorrelação espacial significativa. O baixo peso ao nascer, a prematuridade, o índice de Apgar, o número de consultas de pré-natal e o de mães adolescentes apresentaram padrão espacial aleatório, demonstrando que, nesta escala de análise, estes indicadores não discriminaram grupos de risco, apesar do seu inquestionável valor preditivo para morbimortalidade infantil em nível individual. Houve correlação positiva entre parto cesáreo e escolaridade, e entre parto cesáreo e índice de desenvolvimento humano e correlação negativa entre mães adolescentes e índice de desenvolvimento humano, com significância estatística (p<0,05). CONCLUSÕES: esta metodologia permitiu identificar aglomerados espaciais para as variáveis parto cesáreo e escolaridade materna, além de aprofundar o conhecimento sobre o perfil de nascimentos nos municípios, apresentando potencial no direcionamento de ações voltadas para áreas específicas.PURPOSE: to apply geoprocessing techniques for the spatial birth profile analysis of each municipality. METHODS: ecological and exploratory study, using data from the Health Information System about born alive babies in 2004, and using geoprocessing techniques. The spatial autocorrelations of the variables: cesarean section, mother's schooling, low birth weight, Apgar score at five minutes, prematurity, number of medical appointments and adolescent mothers, besides the map with the index of human development were estimated. For the detection of spatial events aggregates, Moran's I M statistics, through the program Terra View 3.13 (developed by INPE and available to the public) was used. Spatial maps with those variables were built, and Pearson's correlation coefficients, estimated. RESULTS: results have shown that the rate of born alive babies, from mothers with school level over primary school and from cesarean sections, presented a spatial pattern visually identifiable and significant spatial self-correlation. Low birth weight, prematurity, Apgar score, number of pre-natal appointments and adolescent mothers have presented a random spatial pattern, showing that, in this analysis scale, those markers have not discriminated the risk groups, despite their unquestionable predictive value for children's morbidity-mortality at individual level. There has been a positive correlation between cesarean section and schooling, and between cesarean section and human development index; and a negative correlation between adolescent mothers and human development index, with statistical significance (p<0.05). CONCLUSIONS: this methodology has allowed us to identify spatial clusters for the variables cesarean section and mother's schooling, besides deepening our knowledge on birth profile in the municipalities, presenting good potential on how to direct actions for specific areas.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Evaluation of balance with test of strategies of balance on a force platform

International audienceINTRODUCTION: In clinical practice, the balance is usually rated by various field tests involving distinct protocols and methodologies (FIGUEIREDO; LIMA, GUERRA, 2007). These tests are easy to use and of low cost, but are mostly subjective and of unkown results on how they correlate with the objective measures determined by posturography tests using a force platform (DUARTE; FREITAS, 2010). OBJECTIVE: The objective is to evaluate and to compare the displacement of the center of pressure (CP) of a healthy individual with an individual diagnosed with disease Ménièri through a force platform and after to connect with the reactive equilibrium strategy used. MATERIAL AND METHODS: In this paper, the test of reactive strategies of balance (SHUMWAY-COOK, WOOLLACOTT, 1995) was applied within the support base on a force platform built in the laboratory of Biomechanics FEG/UNESP. The measure was made on two male volunteers, one 34 years old and healthy, and the other 54 years old diagnosed as Ménièri Disease. The angular variations between ankle and knee, knee and hip, and ankle and hip were also analyzed. Then, the results of displacement of the CP were compared and after they were associated with the reactive equilibrium strategy through the angular variation measurements used. The equipment used to capture and analyze data was a Spider 8 from HBM and the software used for signal processing was Catman Easy®. The test was recorded and its analysis was performed with ImageJ® software. RESULTS: The analysis of data showed that the healthy patient presented anteroposterior displacement larger than the one from the patient with the disease (135mm, 130mm, respectively) and both presented the same medial-lateral displacement (39mm). For the angular variation of the segments, they were larger in all segments in the individual with the disease, and the largest difference was observed in the knee/hip segment (2,6° on healthy individual and 7,6° on bearer of disease). CONCLUSION: These results suggests that the voluntary bearer of Ménièri Disease used an abnormal strategy of balance, using the knees and hips in order to keep the displacement of the center of pressure within his base of support, and that the healthy voluntary used the normal strategy. A wider study is necessary to achieve more consistent data, however it is already possible to draw a line of reasoning about the investigation. Other field tests will also be performed in order to verify the sensorial systems of more dependency and of less effectiveness for the maintenance of postural balance

Sistema de Aquisição de Baixo Custo para um Dinamômetro Biomédico / Acquisition system of a low cost biomedical dynamometer

Objetivo: criar um Sistema de Aquisição de baixo custo, otimizando um dispositivo de fabricação própria. Método: Para tanto, foi idealizado um sistema dedicado, o qual é alimentado por uma bateria central de 12V. A ponte completa de “Wheatstone” é alimentada pela bateria central, regulada em 9V. Resultados: O sinal dos extensômetros apresenta uma variação de 0 a 30 mV, o qual é amplificado e filtrado por um Condicionador de Sinais de fabricação própria, usando um LM 324. O sinal elétrico então passa a variar de 0 a 5V, que serão tratados em uma entrada analógica de um Microcontrolador PIC. Os testes para registro e interpretação dos dados ocorrem através do software  MyOpenLab. Conclusão: O trabalho está em andamento e os primeiros resultados sugerem que o sistema será capaz de mensurar a força muscular de forma precisa e com custo reduzido.   Palavras chave: Dinamômetro, Força Muscular, Engenharia Biomédica.    Objective: to create a purchasing system for optimizing a low cost device fabrication itself. Method: For this purpose was designed a system which is powered by a 12V battery center. The full bridge of "Wheatstone" is powered by the central battery set to 9V. Results: The sign of the strain has a range of 0 to 30 mV which is amplified filtered by a signal conditioner own manufacturing using an LM 324. The electrical signal then passes to vary from 0 to5V which will be processed in an analog input of PIC microcontroller. Tests for the registration and interpretation of data are through software MyOpenLab. Conclusion: The work is in progress and initial results suggest that the system will be able to measure muscular strength accurately and cost-effective.  Keywords: Dynamometry, Muscle Strength, Biomedical Engineer

Evaluation de l'équilibre posturale par la mesure simultanée du CoP et du CoM Conceptiond d'une plateforme de force couplée à un capteur Kinect

National audienceLe contrôle de l'équilibre postural est naturel et essentiel pour une bonne qualité de vie. Sa mesure et l'origine de sa déficience sont importantes pour permettre un diagnostic et éventuellement des préconisations d'équipements de compensation. Les outils de mesure actuels-plateformes de force et logiciels associés pour la mesure du Centre de Pression (CoP)-sont onéreux et ne permettent pas une étude approfondie de la stratégie de contrôle postural des patients par les thérapeutes. Pour envisager l'utilisation de matériel plus adapté, et également à bas coût et transportable, nous proposons une approche permettant de vérifier si le capteur Kinect de Microsoft peut être une solution à la situation présente. Le travail proposé ici a comme objectif de concevoir, fabriquer et valider un nouvel outil pour mesurer simultanément le CoP et le Centre de Masse (CoM). Ceci permettrait de confronter ces valeurs en vue de valider l'utilisation du capteur Kinect (mesure aisée du CoM) pour l'évaluation de l'équilibre postural

Sistema de aquisição de baixo custo para um dinamômetro biomédico

Objective: to create a purchasing system for optimizing a low cost device fabrication itself. Method: For this purpose was designed a system which is powered by a 12V battery center. The full bridge of "Wheatstone" is powered by the central battery set to 9V. Results: The sign of the strain has a range of 0 to 30 mV which is amplified filtered by a signal conditioner own manufacturing using an LM 324. The electrical signal then passes to vary from 0 to5V which will be processed in an analog input of PIC microcontroller. Tests for the registration and interpretation of data are through software MyOpenLab. Conclusion: The work is in progress and initial results suggest that the system will be able to measure muscular strength accurately and cost-effective.Objetivo: criar um Sistema de Aquisição de baixo custo, otimizando um dispositivo de fabricação própria. Método: Para tanto, foi idealizado um sistema dedicado, o qual é alimentado por uma bateria central de 12V. A ponte completa de “Wheatstone” é alimentada pela bateria central, regulada em 9V. Resultados: O sinal dos extensômetros apresenta uma variação de 0 a 30 mV, o qual é amplificado e filtrado por um Condicionador de Sinais de fabricação própria, usando um LM 324. O sinal elétrico então passa a variar de 0 a 5V, que serão tratados em uma entrada analógica de um Microcontrolador PIC. Os testes para registro e interpretação dos dados ocorrem através do software MyOpenLab. Conclusão: O trabalho está em andamento e os primeiros resultados sugerem que o sistema será capaz de mensurar a força muscular de forma precisa e com custo reduzido