Biomechanical Effects of Using a Passive Exoskeleton for the Upper Limb in Industrial Manufacturing Activities: A Pilot Study.

This study investigates the biomechanical impact of a passive Arm-Support Exoskeleton (ASE) on workers in wool textile processing. Eight workers, equipped with surface electrodes for electromyography (EMG) recording, performed three industrial tasks, with and without the exoskeleton. All tasks were performed in an upright stance involving repetitive upper limbs actions and overhead work, each presenting different physical demands in terms of cycle duration, load handling and percentage of cycle time with shoulder flexion over 80°. The use of ASE consistently lowered muscle activity in the anterior and medial deltoid compared to the free condition (reduction in signal Root Mean Square (RMS) -21.6% and -13.6%, respectively), while no difference was found for the Erector Spinae Longissimus (ESL) muscle. All workers reported complete satisfaction with the ASE effectiveness as rated on Quebec User Evaluation of Satisfaction with Assistive Technology (QUEST), and 62% of the subjects rated the usability score as very high (>80 System Usability Scale (SUS)). The reduction in shoulder flexor muscle activity during the performance of industrial tasks is not correlated to the level of ergonomic risk involved. This preliminary study affirms the potential adoption of ASE as support for repetitive activities in wool textile processing, emphasizing its efficacy in reducing shoulder muscle activity. Positive worker acceptance and intention to use ASE supports its broader adoption as a preventive tool in the occupational sector.

Looped Elastic Resistance during Squats: How Do Band Position and Stiffness Affect Hip Myoelectric Activity?

Looped elastic bands around the thigh are commonly used during squats and result in increased hip activation. Due to the closed kinetic chain nature of the squat exercise, one may expect that placing the elastic band on distal segments, close to the floor contact, may not result in the same increase in hip muscle activation as that achieved with a looped band around the thigh. We analyzed the effects of band position (thigh, lower leg, and forefoot) and band stiffness on the myoelectric activity of the tensor fascia latae, gluteus medius, gluteus maximus, biceps femoris, vastus medialis, and vastus lateralis during squats in 35 healthy subjects (18 men and 17 women). The greatest myoelectric activity of hip muscles was observed when the stiffest band was positioned around the forefeet with an increase in 24% for the tensor fascia latae, 83% for the gluteus medius, and 68% for the gluteus maximus compared to free (without resistance band) squatting. Contrary to previous thinking, the use of elastic bands around the forefeet during squats can elicit increased myoelectric activity of hip muscles, with a magnitude often greater than when the band is placed around the thigh segments.

Diferencias de actividad electromiográfica abdominal en el entrenamiento del core / Differences of abdominal electromiographic activity in core training

Resumen Introducción: La musculatura del core involucra a todos los grupos musculares ubicados en la zona media del cuerpo. La metodología clínica de elección para el registro y análisis de su actividad bioeléctrica es la electromiografía superficial (sEMG), metodología clínica para el registro y posterior análisis de las actividades bioeléctricas del músculo esquelético. Objetivo: El objetivo de esta investigación es determinar si existen diferencias de actividad electromiográfica en la musculatura del recto abdominal y oblicuo externo entre practicantes de musculación y practicantes de calistenia. Metodología: El estudio es de tipo comparativo, de diseño no experimental, transversal de enfoque cuantitativo en una muestra de 20 sujetos; 10 practicantes de calistenia y 10 que entrenan con ejercicios de musculación clásicos. Resultados: Los ejercicios que tuvieron mayor respuesta electromiográfica fueron abdominal en suspensión y abdominal inclinado. Conclusiones: La calistenia es una alternativa viable para la activación muscular a nivel del Core.

Abstract Introduction: The Core musculature involves all the muscle groups located in the middle area of the body whose activity can be measured using superficial electromyography (sEMG), a clinical methodology for recording and subsequent analysis of skeletal muscle bioelectric activities. Objectives: The objective of this research is to determine if there are differences in electromyographic activity in the muscles of the rectus abdominis and external oblique between bodybuilding practitioners and calisthenics practitioners. Methodology: A comparative study, non-experimental design, cross-sectional with a quantitative approach in a sample of 20 subjects; 10 calisthenics practitioners and 10 who train with classic bodybuilding exercises. Results: The exercises with the greatest electromyographic response were abdominal in suspension and abdominal incline. Conclusions: Calisthenics is a viable alternative for muscle activation at the Core level.

The immediate effect of whole-body vibration on rectus abdominis muscle activity and cutaneous temperature: A randomized controlled trial.

OBJECTIVES: To compare acute effects of isometric abdominal exercises performed with or without vibration on the electromyographic activity and cutaneous temperature in the abdominal region of physically active individuals. METHODS: A randomized controlled crossover clinical trial was undertaken in thirty volunteers who completed one unique session of two different protocols of interventions apart from a week from each other, in a two-week study protocol. The subjects were randomly divided in to two groups of 15 volunteers; both were assigned to perform board exercise (30 s on the front, right and left lateral boards, with a rest interval of 2 min). The first group performed it on a vibrating platform at a frequency of 30 Hz for the first week, while the remaining participants executed the same exercise without stimulates vibration. In the second week the protocol was inverted. The outcome were surface electromyography (EMG) data for the rectus abdominis muscle (RAM) and cutaneous temperature (CT) of the abdominal region. Normality was accepted, and Student's t-tests were used to compare the measurements for dependents variables (P < 0.05). RESULTS: There were no differences in RAM activation and CT between protocols with or without vibration (P > 0.05). CT increased (P = 0.001) after both the exercises with and without vibration. CONCLUSION: The results suggest that there were no effects in cutaneous temperature or muscle activation through the use of vibration associated with isometric abdominal exercises.

Revisión sistemática sobre la estructura interna y externa del press de banca / Systematic review of the internal and external structure of the bench press

Objetivo: Se realizó una revisión de la literatura con el objetivo de agrupar el conocimiento actual sobre el análisis de la estructura interna (actividad muscular), y estructura externa (cinemática) en el ejercicio de press de banca para una mejor comprensión del ejercicio. Métodos: Se realizó una búsqueda en la base de datos PUBMED, sobre artículos que realizaran una investigación en la actividad muscular y cinemática del ejercicio de press de banca. Se obtuvieron un total de 40 artículos. Una vez analizados, se aplicaron los criterios de inclusión y exclusión, finalmente 8 artículos fueron incluidos. Resultados: Los músculos: pectoral mayor, deltoides anterior y tríceps braquial se han estudiado como los motores primarios del ejercicio, observando la respuesta de la actividad muscular en cuanto a cambios de intensidad, estímulos externos, orden de ejercicios y subfases del movimiento. Sobresalen el pectoral y tríceps como músculos que presentan una mayor actividad durante el ejercicio. En la mayoría de los estudios, un aumento de la intensidad conlleva a la aparición de la denominada “sticking región”, donde aparece una disminución de los parámetros cinemáticos durante el levantamiento de la barra, acompañado por una activación limitada del pectoral y el deltoides anterior. Conclusiones: Hay un mayor conocimiento de la estructura interna, realizada metodológicamente de distintas formas por lo que es necesaria la unificación de los procedimientos para mejorar el conocimiento del press de banca. Sin embargo, hay muy poca información sobre aspectos cinemáticos del movimiento y su estudio, así como sobre las relaciones entre estos parámetros y la actividad muscular con el objetico de obtener la relación causa efecto entre la actividad muscular y el movimiento que esta produce.(AU)

Objective: A review of the literature was carried out with the aim of grouping the current knowledge on the analysis of the internal structure (muscle activity) and external structure (kinematic) studied together in the bench press exercise for a proper understanding of the phenomenon. Methods: A search was made in the PUBMED database of articles that carried out an investigation on the muscle activity and kinematic of the bench press exercise. A total of 40 articles were obtained. Once analyzed, the inclusion and exclusion criteria were applied, a total of 8 articles were included. Results: The pectoralis major, anterior deltoids, and triceps brachii muscles have been studied as the primary movers of exercise, observing the response of muscle activity in terms of changes in intensity, external stimuli, order of exercises, and subphases of movement. The pectoral and triceps stand out as muscles that present greater activity during exercise. In most studies, an increase in intensity leads to the appearance of the so-called sticking region, where a decrease in kinematic parameters appears during the lifting of the bar, accompanied by limited activation of the pectoral and anterior deltoid. Conclusions: There is a greater knowledge of the internal structure, carried out methodologically in different ways, so it is necessary to unify the procedures to improve knowledge of the phenomenon. However, there is no much studies focus on kinematic knowledge of movement and its study, as well as establish the relationships between these parameters and muscle activity in order to obtain the cause-effect relationship between muscle activity and the movement it produces.(AU)

Classifier Level Fusion of Accelerometer and sEMG Signals for Automatic Fitness Activity Diarization.

The human activity diarization using wearable technologies is one of the most important supporting techniques for ambient assisted living, sport and fitness activities, healthcare of elderly people. The activity diarization is performed in two steps: the acquisition of body signals and the classification of activities being performed. This paper presents a technique for data fusion at classifier level of accelerometer and sEMG signals acquired by using a low-cost wearable wireless system for monitoring the human activity when performing sport and fitness activities, as well as in healthcare applications. To demonstrate the capability of the system of diarizing the user's activities, data recorded from a few subjects were used to train and test the automatic classifier for recognizing the type of exercise being performed.

Análise eletromiográfica de músculos da coluna vertebral durante a marcha em diferentes formas de carregar o bebê / Electromyographic analysis of the spinal muscles during the gait in different ways to carry a baby

Introdução: A forma de carregar o bebê pode causar desequilíbrios em músculos relacionados à coluna vertebral. Objetivos: Investigar a atividade elétrica dos músculos trapézio fibras descendentes e eretores lombares durante a marcha na simulação de carregar um bebê. Métodos: 20 voluntárias, destras e saudáveis participaram das coletas durante a marcha em esteira na simulação do ato de carregar o bebê em diferentes formas: 1) posição horizontal; 2) posição vertical; 3) suporte tipo "canguru" e 4) suporte tipo "sling". Os resultados eletromiográficos foram analisados pela análise da intensidade do sinal eletromiográfico dos músculos trapézio fibras descendentes e eretores espinhais lombares bilateralmente. Resultados: A ANOVA de dois fatores indicou que a forma de carregar (F(4,59)=17,1 p<0,001) e lado (F(1, 59)=89,6 p<0,001) afetaram a intensidade da atividade do músculo eretor espinhal e também a forma de carregar (F(4, 59)=6,4 p<0,001) e lado (F(1, 59)=59,9 p<0,001) do músculo trapézio fibras descendentes. Conclusões: O suporte canguru gerou menor ativação em músculos espinhais durante a quando comparado a outras situações.

Introduction: The way to carry the baby may cause imbalances in muscles related to the spine. Objectives: To investigate the electrical activity of the muscles trapezius descending fibers and lumbar erector during the simulation of carrying a baby. Methods: 20 volunteers right-handed and healthy participate of the study during walking on a treadmill to simulate the act of carrying the baby in different ways: 1) horizontal position; 2) vertical position; 3) Support Type "kangaroo" and 4) Support Type "sling". The EMG results were analyzed by analysis of the intensity of the electromyographic signal of the muscles trapezius fibers descendants and spinal lumbar erector bilaterally. Results: A two-way ANOVA indicated that the way of loading (F(4, 59)=17.1 p <0,001) and next (F(1, 59)=89.6 p <0.001) affected the intensity of the activity spinal erector muscles and also the way of loading (F(4, 59)=6.4 p <0.001) and next (F(1, 59)=59.9 p <0.001) of the trapezius muscle fibers descendants. Conclusions: Kangaroo support generated less activation in spinal muscles during when compared to other situations.

Abordagem diagnóstica da dermatomiosite / Diagnostic approach to dermatomiositis

O Instituto Lauro de Souza Lima (ILSL) é um centro de referência dermatológica e a dermatomiosite é uma doença frequente em seu ambulatório. A dermatomiosite é identificada por suas lesões de pele específicas e pela presença de miopatia inflamatória. Sua incidência é baixa. A confirmação diagnóstica é realizada através da análise da apresentação dermatológica, dosagem sérica de enzimas musculares, eletroneuromiografia e biópsias de pele e músculo. Objetivo: analisar a incidência, características clínicas e procedimentos diagnósticos realizados bem como o tempo para o diagnóstico, levando em conta a sua efetividade. Método: estudo retrospectivo dos prontuários de pacientes diagnosticados com dermatomiosite de janeiro de 2000 a abril de 2013 no ILSL. Conclusão: aconselha-se que se dê prioridade ao atendimento de pacientes com os sintomas neurológicos mais sugestivos, tais como: fraqueza muscular e disfagia associadas a lesões de pele, tendo em vista a possibilidade de dermatomiosite.

As the Instituto Lauro de Souza Lima is a Dermatology Reference Center, dermatomyositis is prevalent in its outpatient clinic. Dermatomyositis is identified by its specific skin lesions and inflammatory myopathy and has low incidence. Diagnostic confirmation is made by the dermatological presentation, serum muscle enzymes, electroneuromyography and skin and muscle biopsies. Objective: to analyze the incidence, clinical features, diagnostic procedures and time to diagnosis of dermatomyositis patients, according to the algorithm rationality and effectiveness Methods: it is a retrospective surveillance of Instituto Lauro de Souza Lima (ILSL) patients from January 2000 until April 2013. Conclusion: in a dermatology outpatient department it is advisable to prioritize dermatological cases with neurological symptoms suggestive of dysphagia and muscular weakness with skin lesions, referring for neurological examination due to the possibility of derrmatomyositis.

Síndrome de médula anclada en el adulto / Tethered cord syndrome in adults

El síndrome de médula anclada es provocado por una fijación anormal de la médula secundaria a disrafismo espinal. Es una afección poco frecuente, de diagnóstico tardío en el adulto, puede confundirse con otras afecciones. Se caracteriza por manifestaciones neurológicas deficitarias sensitivas y motoras de miembros inferiores, deformidades ortopédicas en los pies y estigmas cutáneos. La realización de estudios electrofisiológicos es de vital importancia en estos casos para demostrar el grado de intensidad de la afectación nerviosa, así como su topografía. Las imágenes de resonancia magnética confirman este diagnóstico. Presentamos tres casos en los cuales la sintomatología aparece en la adultez temprana y se tiene un diagnóstico presuntivo diferente al de médula anclada. A todos estos casos se les realizó estudio de conducción nerviosa periférica, potenciales evocados somatosensoriales y electromiografía de miembros inferiores, así como estudios imagenológicos. Los estudios electrofisiológicos demostraron afección moderada a severa de las estructuras nerviosas evaluadas y las imágenes de resonancia magnética confirmaron el diagnóstico de médula espinal anclada.

Tethered cord syndrome is due to pathologic fixation of the spinal cord in the spinal canal. It's an uncommondisease, it's diagnosis is very late in adults and can simulate other affections. It presents neurological manifestations,orthopedics deformities in legs and skin manifestation. Neurophysiologycal studies are very important in those cases to demonstrate the intensity of nerve affection and exactly topography. The image studies, in special magnetic resonance image confirm this disease.We show three cases with tethered cord syndrome that appears in young ages and others presumptive diagnosis are planted at the beginning of clinical picture. Nerve conduction study, Somatosensory evoked potentials and Electromiography of lower members and Magnetic Resonance Images were done to those patients. Electrophysiologycal studies have showed moderate to severe abnormalities of the nerve structures and Magnetic Resonance Images confirmed tethered cord syndrome.

Estudio radiográfico y electromiográfico de los músculos masetero y temporal anterior en individuos con maloclusión tipo II, 1 de angle y controles / Radiographic and electromiographic study of masseter and temporal anterior muscles in subjects with angle II, I malloclusion and controls

El objetivo de este estudio fue comparar la actividad electromiográfica (EMG) de los músculos Masetero (Ms) y Temporal anterior (Ta) de sujetos portadores de maloclusión Angle II, 1 y controles. Se seleccionaron 19 sujetos estudiantes universitarios con características antropométricas similares (edad, peso, talla e IMC). Clínica y radiográficamente se dividieron en dos grupos: Grupo Control (GC) individuos portadores de neutroclusión y Grupo Disto (GD) con individuos portadores de maloclusión Tipo II, 1 de Angle. Se les realizó una electromiografía de superficie (EMG) de acuerdo a la técnica de Ferrario et al. (1993) y se analizaron los datos a partir de Root Mean Square (RMS). A partir de este registro se analizaron la amplitud media de voltaje (mV), la relación Ms/Ta y la distribución de las clases de voltaje, determinadas por los potenciales de acción de unidades motoras (PAUM). De la telerradiografía se analizaron los siguientes datos: ANB, SNA, SNB según Steiner (1992), relación molar, ángulo alfa de inclinación del Ms y brazo de palanca de acuerdo al modelo de Throkcmorton et al. (1980). Se utilizó Test "t" Student para evaluar significancia estadística (p<0,05) entre los grupos. La amplitud de voltaje fue mayor en el GD para todos los músculos estudiados (p<0,05). La relación Ms/Ta fue mayor en el GC. El ángulo alfa fue mayor en GD, también el brazo de palanca. La distribución de PAUM fue mayor en GC (79,0 por ciento), que en GD (57,8 por ciento) (p<0,05). GD presenta mayor amplitud de voltaje que GC, probablemente por presentar menos aferencias inhibitorias periodontales. También GD presenta una menor variedad de PAUM lo que implica que tiene menos reserva funcional que GC.

The of this study is compare the electromiographic activity (EMG) of the Masseter (Ms) and Temporal Anterior (Ta) muscles in subjects with malocclusion Angle II, I and controls. This study involving 19 young adults with similar anthropometric characteristics (Age, weight, hight, BMI). We evaluate clinical and radiographicaly this subject and divided it in to groups: Control Group CG with neutrocclusion and Distal Group (DG) with Angle II, I malocclusion. The both groups was submit a surface EMG according to Ferrario et al. (1993). We used the root mean square (RMS) math operation to calculate the mean voltage amplitude for each muscle. Furthermore we calculate the ratio Ms/Ta and the distribution of voltage class determinate for motor units actions potentials (MUAP). The Rx examination included SNA, SNB and ANB angles according to Steiner (1992), alfa angle and lever arm of Ms according the Throckmorton et al. (1980) mandibular model. The Stundent "t" Test was used to determine whether there were significant differences (p<0.05) between CG and DG parameters. The voltage amplitude was more higher in DG than CG. The ratio Ms/Ta showed protagonism of Ms in CG. The alfa angle and lever arm of Ms were more greater in DG than CG. DG presents a poor number of voltage class (57.8 percent) respect to CG (79.0 percent). DG presents a greater voltage amplitude in relation to CG, probably because the feedback inhibitory periodontal tissue plays an important role. Moreover DG presents a low voltage classes distribution of MUAP that suggest that have minus functional reserve.

Microneurografia e pletismografia de oclusão venosa na insuficiência cardíaca: correlação com prognóstico / Microneurografía y pletismografía de oclusión venosa en la insuficiencia cardiaca: correlación con pronóstico / Microneurography and venous occlusion plethysmography in heart failure: correlation with prognosis

FUNDAMENTO: Microneurografia e pletismografia de oclusão venosa podem ser considerados métodos de avaliação da atividade simpática. OBJETIVO: Avaliar a intensidade da atividade simpática através da microneurografia e da pletismografia de oclusão venosa em pacientes com insuficiência cardíaca, e correlacionar essa intensidade com prognóstico. MÉTODOS: 52 pacientes com insuficiência cardíaca (FE <45 por cento ao ecocardiograma), sendo 12 em CFII e quarenta em CFIV. Após compensação avaliou-se a atividade nervosa simpática muscular (ANSM) no nervo peronero (microneurografia), e o fluxo sanguíneo muscular (FSM) no antebraço (pletismografia de oclusão venosa). Após seguimento de 18 meses os pacientes foram divididos em três grupos: 12 em CFII, 19 em CFIV que não morreram e 21 em CFIV que morreram. A intensidade da atividade da simpática foi comparada nos três diferentes grupos. RESULTADOS: CFII apresentaram menor ANSM (Atividade Nervosa Simpática Muscular) (p=0,026) e maior FSM (p=0,045) que os CFIV que não morreram. CFIV que morreram apresentaram maior ANSM (p<0.001) e menor FSM (p=0,002) que os CFIV que não morreram. Curva ROC: valor de corte >53,5 impulsos/min para ANSM (S=90,55. E=73,68 por cento) e <1,81 ml/mn/100gr para FSM (S=90,4 por cento. E=73,7 por cento). Curva Kaplan-Meier: sobrevida maior com ANSM <53,5 impulsos/min (p<0,001), e ou FSM >1,81 ml/min/100gr (P<0,001). Análise de regressão logística: quanto maior a ANSM e menor o FSM, maior é a probabilidade de morte. CONCLUSÃO: A intensidade da ANSM e do FSM podem ser considerados marcadores prognósticos na insuficiência cardíaca avançada.

BACKGROUND: Microneurography and venous occlusion plethysmography can be considered methods of assessment of the sympathetic activity. OBJECTIVE: To evaluate the intensity of the sympathetic activity through microneurography and venous occlusion plethysmography in patients with heart failure (HF) and correlate this intensity with prognosis. METHODS: 52 patients with HF (ejection fraction < 45 percent at the echocardiogram): 12 with FCII and 40 with FCIV. After compensation, the muscular sympathetic nervous activity (MSNA) in the peroneal nerve (microneurography) and the muscular blood flow (MBF) in the forearm were evaluated (venous occlusion plethysmography). After an 18-month follow-up, the patients were divided in 3 groups: 12 with FCII, 19 with FCIV that did not die and 21 with FCIV that died. The intensity of the sympathetic activity was compared in the three different groups. RESULTS: Patients with FCII presented lower MSNA (p=0.026) and higher MBF (p=0.045) than the ones with FCIV that did not die. The patients with FCIV that died presented higher MSNA (p<0.001) and lower MBF (p=0.002) than the patients with FCIV that did not die. ROC curve: cutoff >53.5 impulses/min for MSNA (S=90.55. E=73.68 percent) and < 1.81 ml/min/100gr for MBF (S=90.4 percent. E=73.7 percent). Kaplan-Meier curve: higher survival with MSNA < 53.5 impulses/min (p<0.001), and/or MBF >1.81 ml/min/100gr (P<0.001). Logistic regression analysis: the higher the MSNA and the lower the MBF, the higher is the probability of death. CONCLUSION: The intensity of the MSNA and the MBF can be considered prognostic markers in advanced HF.

FUNDAMENTO: Microneurografía y pletismografía de oclusión venosa se pueden considerar como métodos de evaluación de la actividad simpática. OBJETIVO: Evaluar la intensidad de la actividad simpática a través de la microneurografía y de la pletismografía de oclusión venosa en pacientes con insuficiencia cardiaca, y correlacionar esa intensidad con pronóstico. MÉTODOS: Un total de 52 pacientes con insuficiencia cardiaca (FE <45 por ciento al ecocardiograma), 12 de ellos en clase funcional II (CFII) y 40 en clase funcional IV (CFIV). Tras la compensación, se evaluaron la actividad nerviosa simpática muscular (ANSM) en el nervio peronero (microneurografía), y el flujo sanguíneo muscular (FSM) en el antebrazo (pletismografía de oclusión venosa). Tras el seguimiento de 18 meses, se dividieron a los pacientes en tres grupos: 12 individuos en CFII, 19 en CFIV que no murieron y 21 en CFIV que murieron. La intensidad de la actividad simpática se la comparó en los tres diferentes grupos. RESULTADOS: Los pacientes en CFII presentaron menor actividad nerviosa simpática muscular (p=0,026) y mayor FSM (p=0,045) que los en CFIV que no murieron. Los individuos en CFIV que murieron presentaron mayor ANSM (p<0.001) y menor FSM (p=0,002) que los en CFIV que no murieron. Curva ROC: valor de corte >53,5 impulsos/min para ANSM (S=90,55. E=73,68 por ciento) y <1,81 ml/mn/100gr para FSM (S=90,4 por ciento. E=73,7 por ciento). Curva Kaplan-Meier: sobrevida mayor con ANSM <53,5 impulsos/min (p<0,001), y/ó FSM >1,81 ml/min/100gr (P<0,001). Análisis de regresión logística: cuanto mayor sea la ANSM y menor el FSM, mayor será la probabilidad de muerte. CONCLUSIONES: La intensidad de la ANSM y del FSM puede considerarse como marcadores pronósticos en la insuficiencia cardiaca avanzada.