Influência do arco longitudinal medial na distribuição plantar e na flexibilidade posterior / La influencia del arco longitudinal medial en la distribución plantar y la flexibilidad posterior / The influence of medium longitudinal arch on plant distribution and posterior pliability

RESUMO O objetivo deste estudo foi verificar se a formação do arco longitudinal do pé interfere na distribuição da pressão plantar e na flexibilidade dos músculos posteriores da coxa. O método de estudo foi transversal e as impressões plantares foram obtidas usando o plantígrafo e analisadas segundo o método Viladot. A distribuição plantar e a flexibilidade foram avaliadas pela baropodometria e pelo banco de Wells, respectivamente. Foi observado que crianças com pés cavos apresentam maior flexibilidade quando comparadas às que têm o pé normal (p=0,02); e também que pés cavos apresentam maior pressão, ou seja, maior sobrecarga em calcâneo quando comparados àqueles com o arco plantar normal (p=0,02 membro inferior direito e p=0,03 membro inferior esquerdo). A avaliação do arco longitudinal medial mostra que crianças com pés cavos apresentam maior flexibilidade dos músculos posteriores de membro inferior. Os pés cavos também estão associados com maior descarga de peso em região de calcâneo.

RESUMEN El objetivo de este estudio fue verificar si la formación del arco longitudinal del pie interfiere con la distribución de la presión plantar y la flexibilidad de los músculos posteriores del muslo. El método de estudio fue transversal y las huellas plantar se obtuvieron utilizando el plantigraph y se analizaron según el método de Viladot. La distribución plantar y la flexibilidad se evaluaron mediante baropodometría y el banco de Wells, respectivamente. Se observó que los niños con pies huecos tienen mayor flexibilidad en comparación con aquellos con pies normales (p=0,02); y también que los pies huecos tienen una mayor presión, es decir, una mayor sobrecarga del talón en comparación con aquellos con arco plantar normal (p=0,02 miembro inferior derecho y p=0,03 miembro inferior izquierdo). La evaluación del arco longitudinal medial muestra que los niños con pies huecos tienen una mayor flexibilidad en los músculos posteriores de la extremidad inferior. Los pies huecos también están asociados con una mayor descarga de peso en la región del talón.

ABSTRACT Objective: To evaluate whether the formation of the longitudinal arch of the foot interferes with the distribution of plantar pressure and the pliability of the posterior thigh muscles. Methodology: a cross-sectional study and the footprints were obtained using the footprinting mat and analyzed according to the Viladot method. Plantar distribution and pliability were assessed by baropodometry and Wells' bank, respectively. Results: It was observed that children with cavus feet present greater pliability when compared to those with normal feet (p=0.02). Also, the cavus feet exhibit higher pressure, that is, a greater heel overload compared to those with normal plantar arch (p=0.02 lower right limb and p=0.03 lower left limb). Conclusions: The evaluation of the medial longitudinal arch shows that children with cavus feet have greater pliability of the lower limb posterior muscles. The cavus feet are also associated with higher pressure in the calcaneal region.

Algoritmo para predecir tensiones con técnicas de inteligencia artificial en una tibia humana / Algorithm for prediction of strains in human tibia by means of artificial intelligence techniques

INTRODUCCIÓN: el desarrollo de la informática y sus herramientas influyen de forma significativa en los avances científicos tecnológicos, en la esfera de la salud. La simulación de problemas reales mediante redes neuronales, relaciona intrínseco, la medicina y la informática, por utilizar estas redes modelos basados en el funcionamiento de neuronas humanas. Si a esta potente herramienta unimos un método numérico de cálculo, que permita servir de fuente de datos a la red neuronal, se podrán modelar tejidos y partes del cuerpo humano. Una de las ramas de mayor implementación, podría ser la ortopedia, debido en lo fundamental, a la similitud que tiene el cuerpo humano y su estructura ósea, con las propiedades de los materiales de ingeniería, la cual es un área clave en la aplicación del Método de los Elementos Finitos. OBJETIVO: crear un algoritmo que permita dar solución al problema de remodelación ósea de una tibia humana bajo diferentes valores de cargas mecánicas. MÉTODOS: se empleó el Método de los Elementos Finitos. Se usó el software profesional ABAQUS/CAE para el cálculo de tensiones y deformaciones y una red neuronal para el procesamiento de los valores obtenidos. La red neuronal fue establecida; se aplicó el software MATLAB R2013a. RESULTADOS: se logró un modelo de red neuronal que posibilita predecir las cargas que una determinada zona de la tibia puede soportar. CONCLUSIONES: mediante el uso de las técnicas de inteligencia artificial y con el empleo del método de los elementos finitos, fue posible obtener un modelo que pronosticò las magnitudes de tensiones, que una región de la tibia humana podría soportar, en dependencia de los valores de densidades óseas presente en dicha región.

INTRODUCTION: the development of information sciences and their influence in a significant way the scientific and technological advances in the field of health care. The simulation of real-life problems through neuronal networks intrinsically relates medicine and informatics since these networks use models based on human neuron functioning. If we add to this potent tool a numerical calculation method that allows the neuronal network to serve as a data source, then tissues and parts of the body could be modeled. One of the branches with more implementation in this regard could be orthopedics due to the similarities of the human body and its osseous structures with the properties of the engineering materials and this is a key area in the application of finite element method. OBJECTIVE: to create an algorithm that may solve the problems of osseous remodeling of a human tibia under different mechanical load values. METHODS: the Finite Element Method was used together with the professional software ABAQUS/CAE for estimation of strains and deformations and a neuronal network to process the obtained values. The neuronal network was set and then the software MATLAB R2013a was applied. RESULTS: a neuronal network model that makes it possible to predict the loads that certain area of the tibia may stand. CONCLUSIONS: through the artificial intelligence techniques and the use of the finite element the strain magnitude that may be supported by a human tibia area depending on the osseous density values present in this area.method, it was possible to obtain a model that predicts the strain magnitude that may be supported by a human tibia area depending on the osseous density values present in this area.

Electromagnetic stimulation as coadjuvant in the healing of diaphyseal femoral fractures: a randomized controlled trial / Estimulación electromagnética como coadyuvante en el tratamiento de fracturas diafisarias de fémur: Ensayo clínico aleatorio

Introduction: There is controversy in medical literature regarding the use of electromagnetic fields to promote bone healing. Methods: After designing and building devices capable of generating an electromagnetic field for this study, their safety was confirmed and the electromagnetic therapy was randomly allocated and compared to placebo in patients with fracture of the femoral diaphysis. Treatment began six weeks after the fracture and it was administered once a day, during 1 h, for eight consecutive weeks. Twenty devices were built, 10 of which were placebo-devices. Between June 2008 and October 2009, 64 patients were randomized in two different hospitals and were followed for 24 weeks. The mean age was 30 years (18-59) and 81% were males. Results: Healing observed at week 12 was 75% vs. 58% (p= 0.1); at week 18, it was 94% vs. 80% (p= 0.15); and at week 24, it was 94% vs. 87% (p= 0.43) for the device group and the placebo group, respectively. Discussion: This study suggests that an electromagnetic field stimulus can promote earlier bone healing compared to placebo in femoral diaphyseal fractures. Faster bone healing translates into sooner weight bearing, which - in turn - permits quicker return to normal daily activities.

Introducción: El uso de estimulación electromagnética como coadyuvante en la consolidación de fracturas es controversial en la literatura médica. Métodos: Para este estudio, se diseñó y construyó un dispositivo capaz de generar un campo electromagnético. Tras confirmar su seguridad se asignaron pacientes aleatoriamente con fractura diafisaria de fémur a recibir terapia electromagnética o placebo. La estimulación inició a las seis semanas de la fractura, 1 h diaria, por ocho semanas consecutivas. Se construyeron 20 dispositivos, 10 reales y 10 dispositivos-placebo. Entre junio 2008 y octubre 2009, ingresaron 64 pacientes al estudio de dos instituciones y fueron seguidos durante 24 semanas. El promedio de edad de los pacientes fue de 30 años (rango 18-59) y 81% eran de sexo masculino. Resultados: La consolidación observada para el grupo con el dispositivo y el grupo placebo fue: en la semana 12, 75% vs. 58% (p =0.1); en la semana 18, 94% vs. 80% (p =0.15) y en la semana 24, 94% vs. 87% (p =0.43). Discusión: Este estudio muestra una tendencia a la consolidación más temprana al estar expuesto a un campo electromagnético frente a placebo. Una consolidación más temprana permite un apoyo precoz y, así, más rápida reincorporación al trabajo y a las actividades cotidianas.

Preliminary analysis of knee stress in Full Extension Landing

OBJECTIVE: This study provides an experimental and finite element analysis of knee-joint structure during extended-knee landing based on the extracted impact force, and it numerically identifies the contact pressure, stress distribution and possibility of bone-to-bone contact when a subject lands from a safe height. METHODS: The impact time and loads were measured via inverse dynamic analysis of free landing without knee flexion from three different heights (25, 50 and 75 cm), using five subjects with an average body mass index of 18.8. Three-dimensional data were developed from computed tomography scans and were reprocessed with modeling software before being imported and analyzed by finite element analysis software. The whole leg was considered to be a fixed middle-hinged structure, while impact loads were applied to the femur in an upward direction. RESULTS: Straight landing exerted an enormous amount of pressure on the knee joint as a result of the body's inability to utilize the lower extremity muscles, thereby maximizing the threat of injury when the load exceeds the height-safety threshold. CONCLUSIONS: The researchers conclude that extended-knee landing results in serious deformation of the meniscus and cartilage and increases the risk of bone-to-bone contact and serious knee injury when the load exceeds the threshold safety height. This risk is considerably greater than the risk of injury associated with walking downhill or flexion landing activities. .

30o inclination in handles of plastic boxes can reduce postural and muscular workload during handling

BACKGROUND: The handling of materials, which occurs in the industrial sector, is associated with lesions on the lumbar spine and in the upper limbs. Inserting handles in industrial boxes is a way to reduce work-related risks. Although the position and angle of the handles are significant factors in comfort and safety during handling, these factors have rarely been studied objectively. OBJECTIVE: To compare the handling of a commercial box and prototypes with handles and to evaluate the effects on upper limb posture, muscle electrical activity, and perceived acceptability using different grips while handling materials from different heights. METHOD: Thirty-seven healthy volunteers evaluated the handles of prototypes that allowed for changes in position (top and bottom) and angle (0°, 15°, and 30°). Wrist, elbow, and shoulder movements were evaluated using electrogoniometry and inclinometry. The muscle electrical activity in the wrist extensors, biceps brachii, and the upper portion of the trapezius was measured using a portable electromyographer. The recorded data on muscle movements and electrical activity were synchronized. Subjective evaluations of acceptability were evaluated using a visual analog scale. RESULTS AND CONCLUSIONS: The prototypes with handles at a 30° angle produced the highest acceptability ratings, more neutral wrist positions, lower levels of electromyographic activity for the upper trapezius, and lower elevation angles for the arms. The different measurement methods were complementary in evaluating the upper limbs during handling. .

Función del diafragma durante la colocación de cargas sobre el abdomen en sujetos normales / Study of diaphragmatic muscle function during abdominal weight in normal subjects

Los efectos de las cargas en el abdomen con el objeto de producir entrenamiento del diafragma, no han sido suficientemente evaluados. Estudiamos la función del diafragma durante la colocación de cargas sobre el abdomen y con cambios en el patrón respiratorio. Se estudiaron 6 voluntarios normales. Se obtuvo flujo en la boca, presión gástrica (Pga), presión esofágica (Pes), movimiento torácico (TX) y abdominal (AB), presión inspiratoria máxima (PImax) y presión transdiafragmática media (Pdi) y máxima (Pdimax). Se calculó la relación Pdi/Pdimax y el índice tensión-tiempo del diafragma (TTdi). Etapas: patrón normal (PN), patrón abdominal (PA) y carga de 1, 2, 4 y 6 kg con PN y PA. El PA fue facilitado por las cargas sobre el abdomen. Solo con 6 kg (PN y PA) la Pga a capacidad residual funcional aumentó significativamente (p 0.001). La Pdi siguió a las variaciones de la Pga y aumentó con todos los PA (p < 0.001). Con PA y carga el índice TTdi alcanzó un valor de 0.05 ± 0.02 (p < 0.001). Las cargas no aumentaron este índice más de lo que hizo el PA solo. Nuestros hallazgos sugieren que las cargas sobre el abdomen aumentan la propiocepción relacionada con los movimientos respiratorios y descenso del diafragma. Las cargas producen cambios leves en la mecánica del diafragma (en sujetos normales, 1/3 de la carga necesaria para desarrollar fatiga). En sujetos normales estos cambios parecen ser insuficientes para producir entrenamiento de los músculos respiratorios.

The effects of the abdominal weight with the intention of producing training of the diaphragm, have not been sufficiently evaluated. We studied the function of the diaphragm during the abdominal weight training and during associated changes in the respiratory pattern. Six normal volunteers were studied. Flow at the mouth at functional residual capacity (FRC) was obtained as well as gastric pressure (Pga), esophageal pressure (Pes), thoracic and abdominal movements, maximal inspiratory pressure and mean and maximal transdiaphragmatic pressure (Pdi and Pdi max). Pdi/Pdimax and the diaphragm tension-time index (TTdi) were calculated. Studied steps: normal pattern (NP), abdominal pattern (AP) and weight of 1, 2, 4 and 6 kg with NP and AP as well. We found 1) The AP was facilitated by the abdominal weight, 2) Only with 6 kg (NP and AP) the Pga at FRC increased significantly (p 0.001), 3) the Pdi followed the variations of the Pga and increased with all the AP (p < 0.001), 4) The index TTdi load reached a value of 0.05 ± 0.02 (p < 0.001). The charges did not increase this rate more than did the AP alone. Our findings suggest abdominal weight increases propioception related to the respiratory movements and descent of the diaphragm. The loads on the abdomen produce minor changes in mechanics of the diaphragm (1/3 of the load required to develop fatigue in normal subjects). Al least in normal subjects these changes appear to be insufficient to produce respiratory muscle training.

Comparison of MRI T2 Relaxation Changes of Knee Articular Cartilage before and after Running between Young and Old Amateur Athletes

OBJECTIVE: To compare changes in T2 relaxation on magnetic resonance (MR) images of knee articular cartilage in younger and older amateur athletes before and after running. MATERIALS AND METHODS: By using a 3.0-T MR imager, quantitative T2 maps of weight-bearing femoral and tibial articular cartilages in 10 younger and 10 older amateur athletes were acquired before, immediately after, and 2 hours after 30 minutes of running. Changes in global cartilage T2 signals of the medial and lateral condyles of the femur and tibia and regional cartilage T2 signals in the medial condyles of femoral and tibia in response to exercise were compared between the two age groups. RESULTS: Changes in global cartilage T2 values after running did not differ significantly between the age groups. In terms of the depth variation, relatively higher T2 values in the older group than in the younger group were observed mainly in the superficial layers of the femoral and tibial cartilage (p < 0.05). CONCLUSION: Age-related cartilage changes may occur mainly in the superficial layer of cartilage where collagen matrix degeneration is primarily initiated. However, no trend is observed regarding a global T2 changes between the younger and older age groups in response to exercise.

Altered Cellular Kinetics in Growth Plate according to Alterations in Weight Bearing

PURPOSE: To examine the effects of change in weight bearing on the growth plate metabolism, a simulated animal model of weightlessness was introduced and the chondrocytes' cellular kinetics was evaluated. MATERIALS AND METHODS: Unloading condition on the hind-limb of Sprague-Dawley rats was created by fixing a tail and lifting the hind-limb. Six rats aged 6 weeks old were assigned to each group of unloading, reloading, and control groups of unloading or reloading. Unloading was maintained for three weeks, and then reloading was applied for another one week thereafter. Histomorphometry for the assessment of vertical length of the growth plate, 5-bromo-2'-deoxyuridin immunohistochemistry for cellular kinetics, and biotin nick end labeling transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assay for chondrocytes apoptosis in the growth plate were performed. RESULTS: The vertical length of the growth plate and the proliferative potential of chondrocytes were decreased in the unloading group compared to those of control groups. Inter-group differences were more significant in the proliferative and hypertrophic zones. Reloading increased the length of growth plate and proliferative potential of chondrocytes. However, apoptotic changes in the growth plate were not affected by the alterations of weight bearing. CONCLUSION: Alterations in the weight bearing induced changes in the chondrocytic proliferative potential of the growth plate, however, had no effects on the apoptosis. This may explain why non-weight bearing in various clinical situations hampers normal longitudinal bone growth. Further studies on the factors for reversibility of chondrocytic proliferation upon variable mechanical stresses are needed.

Electromyographic preactivation pattern of the gluteus medius during weight-bearing functional tasks in women with and without anterior knee pain / Padrão de pré-ativação eletromiográfica do glúteo médio durante atividades funcionais com descarga de peso em mulheres com e sem dor anterior do joelho

BACKGROUND: Proximal factors have been proposed to influence the biomechanics of the patellofemoral joint. A delayed or diminished gluteus medius (GM) activation, before the foot contact on the ground during functional activities could lead to excessive femur adduction and internal rotation and be associated with anterior knee pain (AKP). There are few studies on this topic and the results were inconclusive, therefore, it is necessary to investigate the GM preactivation pattern during functional activities. OBJECTIVE: To compare the GM electromyographic (EMG) preactivation pattern during walking, descending stairs and in single leg jump task in women with and without AKP. METHODS: Nine women clinically diagnosed with AKP and ten control subjects with no history of knee injury participated in this study. We evaluated GM EMG linear envelope before the foot contact on the ground during walking and GM onset time and EMG linear envelope during descending stairs as well as in a single leg vertical jump. Mann-Whitney U tests were used to determine the between-group differences in GM EMG preactivation pattern. RESULTS: No between-group differences were observed in GM linear envelope during walking (P=0.41), GM onset time and linear envelope during descending stairs (P=0.17 and P=0.15) and single leg jump (P=0.81 and P=0.33). CONCLUSIONS: Women with AKP did not demonstrated altered GM preactivation pattern during functional weight bearing activities. Our results did not support the hypothesis that poor GM preactivation pattern could be associated with AKP.

CONTEXTUALIZAÇÃO: Tem sido proposto que fatores proximais influenciam a biomecânica da articulação fêmoro-patelar. Um atraso ou diminuição da ativação do glúteo médio (GM) antes do contato do pé no solo, durante atividades funcionais, poderia levar a adução e rotação interna excessiva do fêmur e provocar a dor anterior do joelho (DAJ). Existem poucos estudos sobre o assunto, e os resultados não foram conclusivos; assim, há necessidade de estudar a pré-ativação do GM durante atividades funcionais. OBJETIVO: Comparar o padrão de pré-ativação eletromiográfica (EMG) do GM durante a caminhada, descida de degraus e salto unipodal entre mulheres com e sem DAJ. MÉTODOS: Nove mulheres com diagnóstico clínico de DAJ e dez mulheres sem história de lesão no joelho participaram do estudo. Avaliou-se a envoltória linear do sinal EMG do GM antes do contato do pé no solo, durante caminhada; o tempo de ativação do GM e a envoltória linear do sinal EMG durante descida de degraus e salto unipodal. Utilizou-se o teste Mann-Whitney para determinar a diferença intergrupos no padrão de pré-ativação EMG do GM. RESULTADOS: Não se encontrou nenhuma diferença intergrupos na envoltória linear do GM durante caminhada (P=0.41), no tempo de ativação e na envoltória linear, durante descida de degraus (P=0.17 e P=0.15) e salto unipodal (P=0.81 e P=0.33). CONCLUSÕES: Mulheres com DAJ não apresentaram alterações significativas no padrão de pré-ativação do GM durante atividades funcionais. Os presentes resultados não sustentam a hipótese de que o pobre padrão de pré-ativação do GM esteja envolvido na DAJ.

Análise do uso de suporte parcial de peso corporal em esteira e em piso fixo durante o andar de crianças com paralisia cerebral / Analysis of partial body weight support during treadmill and overground walking of children with cerebral palsy

OBJETIVO: Analisar características espaço-temporais e ângulos articulares de crianças com paralisia cerebral andando sem o uso de suporte parcial de peso corporal (SPPC) em piso fixo e com 0 por cento e 30 por cento de SPPC em piso fixo e em esteira. MÉTODOS: Seis crianças com paralisia cerebral hemiplégica espástica (7,70±1,04 anos) foram filmadas andando com velocidade confortável sem o uso de SPPC, com 0 por cento e 30 por cento de SPPC em piso fixo e com 0 por cento e 30 por cento de SPPC em esteira. Marcadores refletivos foram afixados nos principais pontos anatômicos dos dois hemicorpos para registro das coordenadas "x", "y", "z". RESULTADOS: As crianças andaram mais rapidamente e com passadas mais longas e mais rápidas, com duração dos períodos de apoio simples e balanço maiores e apoio duplo menor no piso fixo do que na esteira, independentemente do uso do SPPC. O quadril foi a única articulação que apresentou diferenças entre os hemicorpos e entre as condições, sendo que o hemicorpo plégico apresentou menor amplitude de movimento (ADM) que o hemicorpo não plégico, e a ADM foi maior na condição sem o uso de SPPC do que com 30 por cento de SPPC em piso fixo. CONCLUSÃO: Crianças com paralisia cerebral hemiplégica espástica são capazes de andar em piso fixo e esteira com diferentes porcentagens de SPPC, sendo que seus desempenhos foram melhores no piso fixo, independentemente do uso de SPPC, do que na esteira.

OBJECTIVE: To analyze the spatial-temporal characteristics and joint angles during overground walking without body weight support (BWS) and with 0 percent and 30 percent BWS, and during treadmill walking with the same BWS in children with cerebral palsy. METHODS: Six children with hemiplegic and spastic cerebral palsy (7.70 ± 1.04 years old) were videotaped during overground walking at a comfortable speed with no BWS, with 0 percent and 30 percent BWS, and during treadmill walking with 0 percent and 30 percent BWS. Reflective markers were placed over main bony landmarks in both body sides to register the coordinates "x", "y", "z". RESULTS: During overground walking, children walked faster and presented longer and faster strides, longer duration of single-stance and swing periods, and shorter duration of double-stance period, than treadmill walking, regardless of BWS use. The hip was the only joint that presented a difference between body sides and experimental conditions; i.e. range of motion (ROM) was reduced in the plegic side when compared to the nonplegic side, and during overground walking without BWS when compared to 30 percent BWS. CONCLUSION: Children with hemiplegic and spastic cerebral palsy were able to walk overground and on a treadmill with different percentages of BWS, and their performance was superior during overground walking, regardless of BWS use.

The finite element modeling of human pelvis and its application in medicolegal expertise / 法医学杂志

OBJECTIVE@#To develop a novel three dimensional finite element(FE) model of the human pelvis and investigate the biomechanics of the pelvic injury and explore the applications of FE approach in forensic medicine.@*METHODS@#The FE model of pelvis including bilateral iliac bones, sacrum, bilateral femurs, joint cartilages and ligaments was developed with Mimics 13.1 based on the CT images. The CT value of material properties were assigned. A static pressure of 600 N was applied at the upper surface of the sacrum endplate downwards along the vertical axis of sacral bone to validate the model. To simulate the side impacts, the lateral forces of 1, 2, 3, 4 and 5 kN were applied to the trochanter surface of right femur, respectively. The von Mises stress contours, displacement contours and stress distribution curves were subsequently calculated.@*RESULTS@#An integrated FE model of pelvis including the joint cartilages and ligaments was successfully established. The model geometry coincided well with the CT images. The stress distributions of pelvis in erect position mainly located near the sacroiliac joints and the greater sciatic notches. Stress concentration was found on the superior and inferior pubis ramus, hip and sacroiliac joints on both sides under side impacts.@*CONCLUSION@#The established FE model has accurate and reliable biomechanical features. The FE model can be used to simulate injury and provide intuitive and accurate evidence for medicolegal expertise.

Desenvolvimento de instrumentação para aplicação e avaliação do treinamento locomotor com suporte parcial de peso / Development of instrumentation for application and assessment of locomotor training with partial body weight support

O treino locomotor com suporte parcial de peso (TLSP) é um método para reabilitação da marcha que consiste em suspender o indivíduo sobre uma esteira enquanto seus membros inferiores são movimentados passivamente. Para aplicar o TLSP de forma apropriada, é preciso que a descarga de peso sobre membros inferiores seja controlada e monitorada. O objetivo deste trabalho foi desenvolver um sistema de suporte de peso (SSP) capaz de medir descarga de peso sobre membros inferiores e superiores. Além disso, instrumentação para medição do ângulo do joelho, contato do pé e eletromiografia foi desenvolvida para avaliação do treino. O SSP foi construído com um sistema de polias, cabo de aço, guincho manual, uma célula de carga fixa ao cabo e duas outras em apoios para as mãos adaptados a uma esteira elétrica. Eletrogoniômetros e footswitches foram construídos para o sistema de medição, e uma plataforma de aquisição de sinais foi desenvolvida em ambiente LabVIEW®. As células de carga e os eletrogoniômetros foram calibrados e testados. Um ensaio piloto foi realizado com um indivíduo saudável a uma velocidade de 1,5 km/h com descarga de 60% do peso corporal sobre membros inferiores. O SSP desenvolvido apresentou erro menor que 1,5% e forneceu medidas das descargas de peso sobre membros superiores e inferiores. Ele permitiu analisar assimetria sobre membros superiores, o que pode ser importante na reabilitação neurológica. O spadrões cinemáticos e eletromiográficos fornecidos pelo sistema de medida foram semelhantes aos mostrados na literatura. A patente do sistema foi requerida junto ao INPI sob o protocolo n° 0000280904043771.

The locomotor training with partial weight support (LTPWS) is a method for gait rehabilitation which consists in suspending the individual over a treadmill while its lower limbs are passively moved mimicking the gait cycle. In order to properly apply LTPWS, the weight load over lower limbs must be controlled and monitored. The main aim of this work was to develop a partial weight support system (WSS) able to measure lower and upper limb loading. Also, instrumentation for measuring knee angle, foot contact and EMG data was developed for training assessment. The WSS was constructed with a pulley system, a steel cable, a manual winch, aload cell fixed at the cable and two other load cells fixed to handrails built on an electrical treadmill. For the measuring system, electrogoniometers and footswitches were constructed and a signal acquisition platform was developed on LabVIEW® environment. The load cells and electrogoniometers were calibrated and tested. A pilot test with a healthy individual was carried out at a speed of 1.5 km/h with a load of 60% of the body weight, over lower limbs. The developed WSS exhibited an error below 1.5% and was able to measure upper and lower limb weight load. It allows analyzing upper limbs loading and lateral unbalance, what might be important for neural rehabilitation. The measuring system was able to provide kinematic and electromyographic patterns similar to those shown in the literature under similar conditions. A patent request was submitted to the INPI under protocol nº 0000280904043771.

Comparación de las características mecánicas estáticas del fémur aislado de perro, con y sin la colocación de una placa de ortopedia fabricada en polipropileno / Compare the mechanical statistical characteristics of dog femur isolet, with or without placing to an orthopedic píate made of polypropylene

Los objetivos generales fueron: evaluar resistencia a la compresión del fémur derecho aislado y del fémur izquierdo osteotomizado transversalmente fijado con una placa ortopédica fabricada en polipropileno, y comparar las características mecánicas estáticas entre ambos. Este trabajo se realizó mediante la confección de un modelo experimental de carga constituido por un fémur de mamífero (perro) en condiciones aisladas. Se utilizaron los huesos fémur de 13 perros mestizos, adultos jóvenes, de talla mediana a grande. Para los pruebas se utilizó una máquina servohidráulica para ensayos estáticos y dinámicos Amsler Wolpert. Se utilizó para el tratamiento de los datos, el test estadístico de diferencias de medias para muestras pareadas dependientes. Como resultado del análisis de las curvas se obtuvo que: el fémur derecho soportó antes de la falla, entre 4,02 a 8,47 KN de carga (= 6,66 KN) con una deformación de 2,02 a 5,09 mm (= 3,66 mm). En tanto el conjunto fémur izquierdo + placa ortopédica soportó antes de la falla, entre 3,05 a 5,61 KN de carga (= 4,49 KN) con una deformación de 2 a 4.5 mm (= 3 mm). Como conclusión, es posible afirmar que hay diferencias en la resistencia a la carga compresiva entre el fémur derecho y su contralateral izquierdo + placa ortopédica.

The general aims were: to evaluate the resistance to compression of the right femur isolated and that of the left femur transversally osteotomized fixed to an orthopedic plate made of polypropylene and to compare the mechanical statistical characteristics between both. This work was carried out by performing an experimental charge pattern made of a mammal femur (dog) under isolated conditions. Femur bones of 13 hybrid young adult dogs of medium to large size were used. A servohydric engine was used for the Amsler Wolpert static and dynamic essays. The mean difference statistical test for depending paired samples was used for the evaluation of data. As a result of the curves analysis it was obtained that: before failure the right femur underwent a charge of 4.02 to 8.47 KN (= 6.66 KN) with a deformation of 2.02 to 5.09 mm (= 3.66mm) while the charge that the left femur + orthopedic plate underwent before de failure was of 3.05 to 5.61 KN ( = 4.49KN) with a deformation of 2 to 4.5 mm ( = 3mm). As a conclusion it might be stated that there are differences in the resistance to the compressive charge between right femur and its left contra lateral + the orthopedic plate.

Estudio biomecánico de resistencia en fémur porcino y predictibilidad de zona de fractura / Biomechanical study of porcine femur resistance and predictability of fracture zone

During everyday activities, bones are submitted to the action of different strengths. While walking, the femur must support loads up to 3 times the body weight. It is for this that the need of knowing the mechanical behavior of the femur submitted to different loads and the place where the fracture would occur is born. This study analyzes, through experimental testing, the maximum resistance of the porcine femur, mechanically comparable to the human femur, submitted to different strengths, to obtain the location of fracture and compare the results obtained with computational simulation and with information described for human femur.

Durante actividades de la vida diaria, los huesos se ven sometidos a la acción de diferentes fuerzas. En la marcha, el fémur debe soportar cargas de hasta 3 veces el peso corporal. Es por esto que nace la inquietud de conocer el comportamiento mecánico del fémur sometido a distintos tipos de cargas, y el lugar de falla donde se produciría una fractura. Este estudio analiza, mediante ensayo experimental, la resistencia máxima del fémur porcino, mecánicamente comparable al fémur humano, frente a distintas cargas, para obtener así el sitio de fractura y luego comparar los resultados obtenidos con simulación computacional y con datos descritos para el fémur humano.

School backpack. How much load do Saudi school boys carry on their shoulders?

To investigate the percentage of body weight represented by school backpacks, to determine the dimensions of school packs, and to identify the methods of carrying book bags by elementary school boys. A cross-sectional study, using a multistage random sampling technique, was conducted during the Spring of 2005. Six elementary schools from Riyadh were included involving 702 Saudi boys in grade 1-6. Measures included body mass, height, biacromial and bi-iliac breadths, triceps and subscapular skinfolds, calculated fat percentage, school bag weight and dimensions. Students were also asked to respond to questions related to how they travel to and from school, how they carry the bag, and if they have pain due to bag carriage. Body fat percentage increased from 14.2% in the first graders to 24.6% in the sixth graders. The increase in body dimensions, however, was less than the increase in the fat percentage. School bag averaged 3.2 kg in absolute weight and 10.7% relative to student's body mass. Nearly 50% of the sample carried backpacks weighing more than 10% of their weight. Bag surface area averaged 1.05 m2 while the ratio of bag surface area to student's trunk area ranged from 129% in the first graders to 81% in the sixth graders. Approximately 29% of the students walk to and from school. More than 65% of the sample carried their bags over one or 2 shoulders, 20% used single strap bags carried by one hand and 14.5% had bags with wheels. Over one third of the students reported experiencing bodily pain due to bag carriage. A considerable proportion of Saudi school boys carried an overloaded and oversized backpacks. Moreover, one third of the sample experienced bodily pain related to school bags. It is recommended that school bags be limited to no more than 5-10% of student's body weight

Effects of shoe lift on weight bearing in stroke patients.

OBJECTIVES: To determine the effect of shoe lift, cueing and cueing with shoe lift on weight bearing in paretic leg of stroke hemiparetic patients and compare the effect between each condition. DESIGN: Cross-sectional experimental study. SETTING: Department of Rehabilitation Medicine and Department of Ear Nose and Throat, Faculty of Medicine, King Chulalongkorn Memorial Hospital, Chulalongkorn University. SUBJECT: Ten hemiparetic patients as a result of unilateral stroke. MATERIAL AND METHOD: Weight symmetry of each patient was measured by posturography during quiet stance and in conditions of compelled weight shift. Each patient was started with quiet standing, standing with shoe lift under the sound leg; cueing and cueing with shoe lift under the sound leg respectively. Weight symmetry scores were recorded for comparing the weight distribution between each foot. RESULTS: There were 10 hemiparetic patients. Seven were male. The average age was 53.4 +/- 8.45 years. There were 5 right hemiparesis and 5 left hemiparesis. The average onset was 12.3 +/- 15.73 months. In the right hemiparetic patients, weight bearing in the paretic leg was significantly improved when cueing with shoe lift compared with quiet standing and with shoe lift (Backward p = 0.012, Forward p = 0.011 and Backward p = 0.001, Forward p = 0.036 respectively). In the left hemiparetic patients, weight bearing in the paretic leg was significantly improved when cueing compared with quiet standing (Backward p = 0.046), and when using the shoe lift (Backward p = 0.016). Cueing with shoe lift could significantly improve weight bearing in the paretic leg when compared with shoe lift alone (Backward p = 0.015). Shoe lift alone could improve weight bearing in the paretic leg of the right and left hemiparetic patients but was not statistically significant (p > 0.05). CONCLUSION: Cueing with shoe lift under the sound leg can significantly improve weight bearing of the paretic leg of the right and left stroke hemiparetic patients.

Physicochemical and structural analysis of three regions of the deep digital flexor tendon of pigs

Few studies have discussed the relationship between the molecular organization and the physicochemical and biomechanical properties of pig tendons. In this work, we examined the extracellular matrix of the deep digital flexor tendon of pigs, which was subjected to tensional (proximal region) and compressive (distal and terminal regions) forces. The three regions of the tendon were used for swelling tests and their glycosaminoglycan content was determined. Longitudinal sections of the tendon were stained and observed using polarized light microscopy. The distal and terminal regions were swole more in water than the proximal region. After staining with toluidine blue the metachromasy was more intense in the distal and terminal regions, indicating an accumulation of proteoglycans in these regions. Analysis of the glycosaminoglycans by agarose gel electrophoresis showed that dermatan sulfate was present in all regions, whereas chondroitin sulfate occurred only in the regions of compression. The shape of the fibroblasts changed along the tendon: rounded cells occurred in regions under compression, while in the region under tension, elongated cells predominated. The organization and distribution of the collagen bundles were different for each region. Birefringence analysis revealed a more regular crimp pattern in the region under tension than in the regions under compressive forces. The elastic fibers also showed a different distribution in each region. These results indicate that the regional differences in the structure and composition of the deep digital flexor tendon of pigs are related to the biomechanical properties of the tendon.

Avaliação isocinética da musculatura envolvida na flexão e extensão do tronco: efeito do método Pilates® / Isokinetic evaluation of the musculature involved in trunk flexion and extension: Pilates® method effect

O desequilíbrio entre a função dos músculos extensores e flexores do tronco é um forte indício para o desenvolvimento de distúrbios da coluna lombar. O objetivo do presente trabalho foi avaliar o efeito do método Pilates® sobre a função de extensores e flexores do tronco. Para tanto, foram selecionadas 20 pessoas (16 mulheres com idade média de 34,06 ± 7,21; quatro homens com idade média de 33,5 ± 6,68 anos) com habilidade para executar os exercícios do nível intermediário-avançado, que completaram 25 sessões durante 12 semanas. Os voluntários foram submetidos ao teste isocinético de avaliação da flexão e extensão do tronco no início e ao final do período de treinamento. A função dos extensores do tronco apresentou aumento em todos parâmetros analisados (pico de torque _ 25 por cento, p = 0,0004; trabalho total - 28 por cento, p = 0,0002; potência - 30 por cento, p = 0,0002; quantidade total de trabalho - 21 por cento, p = 0,002) em relação ao período pré-treinamento. Com relação aos músculos flexores, foi detectado discreto aumento para trabalho total (10 por cento, p = 0,0003) e para quantidade total de trabalho (10 por cento, p = 0,002). Analisando a razão flexor:extensor, em todos os parâmetros, foi detectada redução significativa em relação aos índices obtidos no pré-treinamento (pico de torque - 24 por cento, p = 0,0001; trabalho total - 23 por cento, p = 0,002; potência - 25 por cento, p = 0,01; quantidade total de trabalho - 14 por cento, p = 0,04). O método Pilates® (nível intermediário-avançado) mostrou-se uma eficiente ferramenta para o fortalecimento da musculatura extensora do tronco, atenuando o desequilíbrio entre a função dos músculos envolvidos na extensão e flexão do tronco.

Déficit bilateral nos movimentos de flexão e extensão de perna e flexão do cotovelo / Bilateral deficit in leg flexion and extension and elbow flexion movements

Os exercícios resistidos (ER) podem ser realizados de forma uni e bilateral. O objetivo foi comparar a carga máxima (CM) na flexão e extensão de perna e flexão de cotovelo isoladamente e entre a soma desses dois resultados com aquele desenvolvido simultaneamente pelas duas pernas e dois braços, respectivamente. Foram submetidos 60 indivíduos ao exercício de flexão e extensão de perna e a flexão de cotovelo ao teste de 1RM. Os resultados para os movimentos de flexão e extensão de perna e flexão de cotovelo esquerdos e direitos na CM - 31,6 (± 7,9), 32,0 (± 8,0), 20,2 (± 9,2), 20,2 (± 9,8), 29,3 (± 13,9) e 29,8 (± 14,1) kg, respectivamente - mostraram-se similares (p > 0,05) e fortemente associados (r = 0,96, 0,96 e 0,98). Comparando a soma dos valores unilaterais com os da execução bilateral, a CM apresentou uma diferença significativa para os movimentos de extensão de perna (p = 0,04) e flexão de cotovelo (p = 0,03); o mesmo não foi observado no movimento de flexão de perna (p = 0,75). Esse resultado pode ser explicado pelo menor incremento de carga - dois quilos e meio - neste último movimento em relação aos dois movimentos anteriores - cinco quilos. Apesar de a maioria dos sujeitos ser destra, não houve diferenças unilaterais na CM, embora nem todos fossem treinados. A soma dos resultados unilaterais foi maior em 9,8 por cento e 4,0 por cento para os movimentos de extensão da perna e flexão de cotovelo, respectivamente, daquele obtido bilateralmente, mostrando, provavelmente, uma limitação central na coordenação motora de um movimento complexo feito em máxima velocidade e com carga elevada. No entanto, no movimento de flexão de perna, a soma dos resultados unilaterais foi inferior à dos bilaterais (-0,6 por cento), apresentando uma possível aprendizagem do movimento e adaptação ao treinamento com pesos a partir de 12 semanas.