Knee osteoarthritis and aging: evaluation of the different muscles of thigh / Artrosis de rodilla y envejecimiento: investigación de los diferentes músculos del muslo / Osteoartrite de joelho e envelhecimento: investigação de diferentes músculos da coxa

ABSTRACT Introduction: Osteoarthritis (OA) is a chronic inflammatory degenerative disease, characterized by progressive degeneration of the articular cartilage, affecting mostly the knee joint. The elderly population is the most affected, intensifying the aging process. The concentration of intramuscular adipose tissue in the thigh muscles and knee OA at different ages remains under investigation. Objective: Investigate the cross-sectional area of thigh muscles at different ages with the relationship of the presence of intramuscular fat and knee OA. Methods: 80 participants were paired into 4 groups: Young Osteoarthritis Group and Old Osteoarthritis Group, both sedentary with knee OA diagnosis II or III; Healthy Young Group and Healthy Old Group, both healthy and sedentary. The groups were paired according to gender and body mass index, submitted to physiotherapeutic evaluation, WOMAC questionnaire, knee X-ray and thigh CT scans. Morphometric analysis was performed manually with ITK-SNAP software (version 3.6), by a single evaluator. Statistical analysis used the one-way ANOVA test followed by Bonferroni post-hoc for dependent variables (p≤0.05). Results: Comparison of the cross-sectional area of the rectus femoris, vastus lateralis, semitendinosus, sartorius and gracilis muscles between the groups indicated no significant differences (p>0.05). The study of attenuation for muscle adipose tissue indicated no significant difference in the values of between the OA-Young and Aged-S groups for all the muscles evaluated. Conclusion: Young individuals with knee OA present muscle morphological characteristics similar to those found during the aging process, characterizing early aging of the thigh muscles. Level of Evidence III; Retrospective cross-sectional and observational study.

RESUMEN Introducción: La artrosis (OA) es una enfermedad inflamatoria degenerativa crónica, caracterizada por la degeneración progresiva del cartílago articular, que afecta principalmente a la articulación de la rodilla. La población anciana es la más afectada, intensificándose el proceso de envejecimiento. La concentración de tejido adiposo intramuscular en los músculos del muslo y la OA de rodilla a diferentes edades sigue siendo objeto de investigación. Objetivo: Investigar el área transversal de los músculos del muslo a diferentes edades con la relación de la presencia de grasa intramuscular y la OA de rodilla. Métodos: Se emparejó a 80 participantes en 4 grupos: Grupo de jóvenes con osteoartritis y Grupo de mayores con osteoartritis, ambos sedentarios y con diagnóstico de OA de rodilla II o III; Grupo de jóvenes sanos y Grupo de mayores sanos, ambos sanos y sedentarios. Los grupos fueron emparejados según sexo e índice de masa corporal, sometidos a evaluación fisioterapéutica, cuestionario WOMAC, exámenes radiográficos de las rodillas y tomografía computarizada del muslo. El análisis morfométrico se realizó manualmente con el software ITK-SNAP (versión 3.6), por un único evaluador. En el análisis estadístico se utilizó la prueba ANOVA unidireccional seguida del post-hoc de Bonferroni para las variables dependientes (p≤0,05). Resultados: La comparación del área transversal de los músculos recto femoral, vasto lateral, semitendinoso, sartorio y gracilis entre los grupos no indicó diferencias significativas (p>0,05). El estudio de la atenuación para el tejido adiposo muscular no indicó diferencias significativas en los valores de entre los grupos OA-Young y Aged-S para todos los músculos evaluados. Conclusión: Individuos jóvenes con OA de rodilla presentan características morfológicas musculares similares a las encontradas durante el proceso de envejecimiento, caracterizando el envejecimiento precoz de los músculos del muslo. Nivel de Evidencia III; Estudio transversal y observacional retrospectivo.

RESUMO Introdução: A osteoartrite (OA) é uma doença inflamatória crônico-degenerativa, caracterizada pela degeneração progressiva da cartilagem articular, acometendo em maior parte a articulação do joelho. A população idosa é a mais atingida, intensificando o processo de envelhecimento. A concentração de tecido adiposo intramuscular nos músculos da coxa e a OA de joelho em diferentes idades permanece em investigação. Objetivo: Investigar a área de secção transversa dos músculos da coxa em diferentes idades com a relação da presença de gordura intramuscular e OA de joelho. Métodos: 80 participantes foram pareados em 4 grupos: Grupo Osteoartrite Jovem e Grupo Osteoartrite Idoso, ambos sedentários com diagnóstico de OA de joelho II ou III; Grupo Jovem Saudável e Grupo Idoso Saudável, ambos saudáveis e sedentários. Os grupos foram pareados de acordo com sexo e índice de massa corporal, submetidos à avaliação fisioterapêutica, questionário WOMAC, exames de raio-x dos joelhos e tomografia computadorizada da coxa. A análise morfométrica foi realizada manualmente com software ITK-SNAP (versão 3.6), por um único avaliador. Análise estatística utilizou o teste ANOVA one-way seguido pelo post-hoc de Bonferroni, para variáveis dependentes (p≤0,05). Resultados: A comparação da área de secção transversa dos músculos reto femoral, vasto lateral, semitendinoso, sartório e grácil, entre os grupos, não indicou diferenças significativas (p>0,05). O estudo da atenuação para o tecido adiposo muscular não indicou diferença significativa nos valores de entre os grupos OA-Jovem e Idoso-S para todos os músculos avaliados. Conclusão: Indivíduos jovens com OA de joelho apresentam características morfológicas musculares semelhantes às encontradas durante o processo de envelhecimento, caracterizando um envelhecimento precoce dos músculos da coxa.Nível de Evidência III; Estudo retrospectivo transversal e observacional.

Height and body mass index distribution in children and adolescents with and without spina bifida

Abstract Objective Children with spina bifida (SB) are at risk for stunting and overweight. However, height and Body Mass Index (BMI) z-score distribution in children and adolescents with SB are unclear. The aim of this study was to examine height and BMI z-score distribution in Brazilian children and adolescents with and without SB. This study further aimed to examine whether height and BMI z-scores differ between individuals with and without SB. Method This study included 101 participants (SB: n= 18; non-SB: n= 83, aged 7-16 years). The World Health Organization (WHO) AnthroPlus software was used to calculate height and BMI z-scores. AnthroPlus z-score distribution graphs were used to examine individual z-scores based on the 2007 WHO normal distribution curve. Effects of the group (SB vs non-SB) on height and BMI z-scores were examined with sequential regression. Results In the WHO distribution graph analysis, height z-scores of participants with SB were slightly left-shifted compared to the WHO normal distribution curve. In the regression analysis, group (SB vs non-SB) was a significant predictor of height z-scores after controlling for sex and age (ΔR2= 0.064, p= 0.010). BMI z-scores of participants with SB were right-shifted compared to the WHO normal curve. However, there was no contribution of the group to BMI z-scores (ΔR2= 0.011, p= 0.301). Conclusions These findings suggest that Brazilian children and adolescents with SB may be at risk for reduced height and increased BMI.

Teste de fadiga de preensão manual usando contrações dinâmicas em crianças típicas / Handgrip fatigue test using dynamic contractions in typical children

Objective: To verify the development of fatigue and sex-influence on the handgrip during dynamic contractions in typical children. Methods: Cross-section study. Fifty-eight children, distributed into two groups according to sex (30 boys), aged 8 to 12 years, of both sexes, performed successive dynamic contractions with a bulb dynamometer until they reached maximum perceived effort. The values from the first, the last contractions of the fatigue test, and the measure after 30-s of the last contraction (recovery contraction) were recorded and compared using the linear regression model with mixed effects. T-Student test was used to compare the perceived effort scores and time-to-fatigue between groups. Results: The handgrip values significantly decreased, and perceived effort scores significantly increased in the final measure in relation to the initial measure of the fatigue test. After the fatigue handgrip test, 30-sec of recovery was insufficient to restore the baseline handgrip values. There were no differences between the female and male groups for all variables. Conclusion: The handgrip fatigue test using dynamic contractions showed it efficiently induces motor and perceived fatigue in children, without differences between sexes.

Objetivo: Verificar o desenvolvimento da fadiga e a influência do sexo na preensão manual durante contrações dinâmicas em crianças típicas. Métodos: Estudo transversal. Cinquenta e oito crianças, distribuídas em dois grupos de acordo com o sexo (30 meninos), com idades entre 8 e 12 anos, de ambos os sexos, realizaram sucessivas contrações dinâmicas com um dinamômetro de bulbo até atingirem o esforço máximo percebido. Os valores da primeira, da última contração do teste de fadiga e da medida após 30 segundos da última contração (contração de recuperação) foram registrados e comparados usando o modelo de regressão linear com efeitos mistos. O teste T-Student foi usado para comparar os escores de esforço percebido e o tempo até a fadiga entre os grupos. Resultados: Os valores de preensão palmar e os escores de esforço percebido diminuíram significativamente durante o teste de fadiga. Não houve diferenças entre os grupos para todas as variáveis. Conclusão: O teste de fadiga de preensão palmar utilizando contrações dinâmicas mostrou-se eficaz na indução da fadiga motora e percebida em crianças, sem diferenças entre os sexos.

Atividade física objetiva em jovens com espinha bífida: um protocolo de revisão sistemática / Objective physical activity in youth with spina bifida: a systematic review protocol

Atividade física (AF) diária associa-se a melhora do estado de saúde de jovens. Evidências indicam que crianças com espinha bífida (EB) estão em risco para inatividade física. Este artigo apresenta um protocolo de revisão sistemática que propõe avaliar níveis de AF objetiva diária em crianças e adoles-centes com EB. Este protocolo foi desenvolvido seguindo o Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols (PRISMA-P) 2015. A revisão foi registrada no International Prospective Register of Systematic Reviews (PROSPERO, CRD42022349920). Os critérios de inclu-são baseiam-se em artigos originais: 1) publicados em revistas com revisão por pares; 2) que avaliem AF objetiva diária em crianças e adolescentes com EB; e 3) que utilizem monitores para avaliação da AF (ex: acelerômetros). Palavras-chave foram baseadas no MeSH e literatura existente. As seguin-tes bases de dados serão utilizadas como fontes de informação: PubMed, Embase, SPORTDiscus, LILACS, CINAHL, Scopus, PsycINFO e Web of Science. Os seguintes dados serão extraídos: características do estudo e da amostra, variáveis de AF (protocolos de medição e pontos de corte de classificação de AF) e resultados dos níveis de AF. A qualidade dos estudos será avaliada com o Standard Quality Assessment Criteria for Evaluating Primary Research Papers from a Variety of Fields(ERA). A busca e seleção dos estudos, extração de dados e avaliação de qualidade serão realizadas por dois revisores independentes. Espera-se que a revisão forneça evidências para auxiliar na pre-venção e tratamento de inatividade física e guiar futuras pesquisas sobre AF objetiva em crianças e adolescentes com EB

Daily physical activity (PA) is associated with improvements in health status in youth. However, evidence indicates that children with spina bifida (SB) are at risk for physical inactivity. This paper documents a systematic review protocol that aims to examine daily objective PA levels in children and adolescents with SB. This protocol was developed following the Preferred Reporting Items for Systematic Review and Me-ta-Analysis Protocols (PRISMA-P) 2015. The protocol was registered on the International Prospective Register of Systematic Reviews (PROSPERO, CRD42022349920). The inclusion criteria are based on original articles: 1) published in peer-reviewed journals; 2) examining daily objective PA in children and adolescents with SB; and 3) using PA monitors to measure PA (e.g., accelerometers). Key words were de-termined based on MeSH and existing literature. The following databases will be used as sources of infor-mation: PubMed, Embase, SPORTDiscus, LILACS, CINAHL, Scopus, PsycINFO, and Web of Science. Study and sample characteristics, PA variables (measurement protocols and PA classification cut-points) and PA levels results will be extracted from the studies. The quality of studies will be assessed with the Standard Quality Assessment Criteria for Evaluating Primary Research Papers from a Variety of Fields (ERA). The search and selection of articles, and extraction of data and quality assessment will be performed by two in-dependent reviewers. It is expected that this study provides evidence to support prevention and treatment of physical inactivity and guide future research directions in objective PA in children and adolescents with SB

Validity of the VO2peak prediction model to Brazilian youth with spina bifida / Validação de um modelo preditivo do VO2pico em jovens brasileiros com espinha bífida

Objective:To validate a peak oxygen uptake (VO2peak) prediction model in Brazilian youth with spina bifida. Methods:Twenty participants with spina bifida performed a graded arm crank test to measure VO2peak. The VO2peakvalues predicted by the equation "VO2peak(mL/min) = 194 + 18 × peak workload ­110 × sex" were compared to the VO2peakvalues measured. Results:The predicted VO2peakwas not different from the measured VO2peak. A high correlation was found between both VO2peak values, and the Bland-Altman analysis did not show a significant difference, demonstrating agreement between the values. Conclusions:The VO2peak prediction model in Brazilian youth with spina bifida was validated, being an advantageous alternative to assess and follow physical fitness and prescribe exercise training intensity.

Objetivo: Validar uma equação preditiva do consumo pico de oxigênio (VO2pico) em jovens brasileiros com espinha bífida. Métodos: Vinte participantes com espinha bífida realizaram um teste ergoespirométrico de membros superiores para medir o VO2pico. Os valores de VO2pico preditos pela equação "VO2pico (mL/min) = 194 + 18 × carga pico ­ 110 × sexo" foram comparados com o VO2pico medido. Resultados: O VO2pico predito pela equação não foi diferente do VO2pico medido. Foi encontrada alta correlação entre os valores de VO2pico e, a análise Bland Altman não mostrou diferença significativa, demonstrando concordância entre os valores. Conclusão: A equação preditiva do VO2pico é válida para jovens brasileiros com espinha bífida e é uma alternativa vantajosa para obter e acompanhar o condicionamento físico e prescrever a intensidade de treinamento nesses indivíduos.

Avaliação de sintomas na distrofia muscular de Duchenne: uma estratégia de cuidado paliativo / Evaluation of symptoms in Duchenne muscular dystrophy: a palliative care strategy

A avaliação de sintomas na distrofia muscular de Duchenne (DMD) permite o adequado manejo terapêutico e o Edmonton Symptom Assessment System (ESAS) possui esta função: avaliar simultaneamente múltiplos sintomas de pacientes em cuidados paliativos (dor, cansaço, sonolência, náusea, apetite, falta de ar, depressão, ansiedade e bem-estar). Objetivo: Verificar se pacientes com DMD entendem os termos do ESAS e são capazes de graduar seus sintomas por este instrumento. Métodos: 10 pacientes com DMD foram avaliados transversalmente em relação à: compreensão dos itens do ESAS, caracterização dos sintomas (pelo ESAS e Escala de Faces) e medida da função motora. A graduação de sintomas do paciente, pelo ESAS, foi realizada também pelo avaliador. Os dados foram analisados descritivamente e por meio do coeficiente de correlação de Spearman. Resultados: Todos os pacientes compreenderam os sintomas dor, cansaço, sonolência, depressão (tristeza) e bem-estar, já os sintomas náusea, apetite, falta de ar e ansiedade não foram compreendidos por todos. A média geral de todos os sintomas avaliados pela escala ESAS foi abaixo de 5 pontos. Entre os resultados da escala ESAS e Escala de faces, houve correlação forte para os sintomas "depressão" (r= 0,64) e "ansiedade" (r= 0,65). Houve correlação perfeita (r= 1,0) entre ESAS preenchida pelo paciente e pelo avaliador para os itens "depressão" e "ansiedade" e correlação forte (r= 0,82) para "sonolência". Conclusão: Pacientes com DMD entenderam os termos do ESAS e graduaram seus sintomas por este instrumento, portanto, não há necessidade de alteração dos termos do ESAS para avaliação de pacientes com DMD

Symptom assessment, in Duchenne Muscular Dystrophy (DMD), allows an adequate treatment, and the Edmonton Symptom Assessment System (ESAS) assess it: evaluating clinical problems of patients in palliative care (pain, tiredness, drowsiness, nausea, appetite, shortness of breath, depression, anxiety, and well-being). Objective: To verify if patients with DMD understand the terms of the ESAS and if their symptoms could be assessed using this instrument. Methods: Ten patients with DMD were cross-sectional evaluated in relation to the understanding of the ESAS items, capacity to describe symptom (using the ESAS and the Faces Scale) and the Motor Function Measure. The patient's symptom by ESAS was also classified by evaluator. A descriptive and correlation (Spearman's correlation coefficient) analysis of data was performed. Results: All patients understood the symptoms of pain, tiredness, drowsiness, depression (sadness), and well-being. However, some patients did not understand the symptoms of nausea, appetite, shortness of breath. The general mean of all symptoms assessed by the ESAS was below 5 points. For the symptom 'depression' and 'anxiety', a strong correlation was found between the results of the ESAS and the Face scale (r= 0.64, and r= 0.65, respectively). Additionally, a perfect and strong correlation, respectively, was found between the ESAS completed by the patient and the evaluator for the items ''depression'," and 'anxiety' (r= 1.0)" and a 'drowsiness' (r= 0.82). Conclusion: DMD patients understood the ESAS terms and graded their symptoms using this instrument. Therefore, it is not necessary to change the ESAS terms to assess patients with DMD

Exercício excêntrico e alongamento para músculos flexores plantares aplicados durante 21 dias após imobilização não modificam o tecido não contrátil / Ejercicio excéntrico y estiramiento para músculos flexores plantares aplicados durante 21 días tras inmovilización no cambian el tejido no contráctil / Eccentric exercise and stretching for plantar flexor muscles applied during 21 days after immobilization do not modify the non-contractile tissue

RESUMO As adaptações da matriz extracelular, que está intimamente ligada à manutenção da integridade e do desempenho do sistema musculoesquelético, não estão consensualmente descritas na literatura após recarga por desuso. O objetivo deste estudo foi analisar a área de tecido conjuntivo perimisial e de secção transversa das fibras musculares nos músculos sóleo e plantar de ratas imobilizadas e posteriormente reabilitadas por protocolos de alongamento e exercício excêntrico. A expressão do tecido conjuntivo perimisial de ambos os músculos estudados não apresentou diferença significativa após o procedimento de imobilização e treinamento. O treino excêntrico aplicado por 10 dias foi suficiente para recuperar a área das fibras para o músculo plantar, enquanto a recuperação do músculo sóleo aconteceu somente após o protocolo de 21 dias.

RESUMEN No figuran descriptas de manera consensual en la literatura las adaptaciones extracelulares, ligadas al mantenimiento de la integridad y del desempeño del sistema musculoesquelético tras inmovilizaciones. En este estudio se evalúa el área del perimisio del tejido conjuntivo y de la sección transversal de las fibras musculares del sóleo y del plantar en ratas inmovilizadas y después rehabilitadas siguiendo los protocolos de estiramiento y de ejercicio excéntrico. En el área evaluada de ambos músculos no se observaron significativas diferencias tras el procedimiento de inmovilizarlos y entrenarlos. Aplicados en diez días, el entrenamiento excéntrico ha sido suficiente para recuperar el área de las fibras para el músculo plantar, mientras que el músculo sóleo ha tardado veintiuno días en recuperarse.

ABSTRACT The adaptations of the extracellular matrix, which is closely related to the maintenance of the integrity and performance of the musculoskeletal system, are not widely described in the literature after rehabilitation due to prolonged disuse. The aim of this study was to analyze the perimysial connective tissue area and the cross-sectional area of muscle fibers in soleus and plantaris muscles of immobilized female rats, later rehabilitated due to stretching and eccentric exercise protocols. The expression of the perimysial connective tissue of both studied muscles did not show significant differences after the procedure of immobilization and training. Eccentric training applied for 10 days was enough to recover the area of fibers for the plantaris muscle, while the recovery of the soleus muscle happened only after the 21-days protocol.

Efeito do uso das órteses no prolongamento da marcha de pacientes com distrofia muscular de Duchenne: revisão da literatura / Effect of using orthoses on prolonging ambulation in patients with Duchenne Muscular Dystrophy: review of literature

A capacidade de marcha em pacientes com distrofia muscular de Duchenne diminui progressivamente devido ao avanço da fraqueza e encurtamento muscular. As órteses para membros inferiores são frequentemente prescritas na tentativa de prolongar a marcha nestes pacientes. Objetivo: Realizar uma revisão da literatura a fim de verificar o efeito do uso das órteses em relação ao prolongamento do tempo de marcha. Método: Foi realizado um levantamento bibliográfico nas bases PUBMED, PEDRO e SCIELO com as palavras-chave orthoses, bracing, gait, gait loss, ambulation, Duchenne muscular dystrophy. Resultados: Nos quatorze artigos selecionados foi identificada a prescrição das órteses do tipo KAFO (também chamadas de órteses longas) e AFO, sempre associada a outra intervenção terapêutica. A maioria dos estudos relatou que o uso do dispositivo prolonga o tempo de marcha. Conclusão: O uso da órtese, independentemente do tipo, prolonga a deambulação, pois retarda o avanço de encurtamentos. Assim, sugere-se o início precoce da AFO a fim de minimizar o prejuízo funcional característico da doença.

The walking ability of patients with Duchenne muscular dystrophy gradually decreases due to advancing weakness and muscle contracture. Lower limb orthoses are often prescribed in an attempt to prolong ambulation in these patients. Objective: To perform a literature review in order to verify the relationship between using orthoses and prolonging ambulation. Method: A literature review was performed in the PUBMED, PEDRO, and SCIELO databases with the keywords orthoses, bracing, gait, gait loss, ambulation, and Duchenne muscular dystrophy. Results: In 14 selected articles the prescription of knee-ankle-foot orthoses (KAFO) (also called long orthoses) and ankle-foot orthoses (AFO) was identified, always associated with another therapeutic intervention. Most studies have reported that the use of such a device prolongs ambulation. Conclusion: The use of orthoses, regardless of type, prolongs ambulation, because it delays the progress of muscle contracture. Thus, the early use of AFO is recommended in order to minimize the functional impairment characteristic of the disease.

Men with early degrees of knee osteoarthritis present functional and morphological impairments of the quadriceps femoris muscle.

OBJECTIVE: Quadriceps muscle weakness is common in knee osteoarthritis (OA). Reasons for weakness may include atrophy, reduction in the muscle fibers number, and changes in the muscle activation. It is uncertain when these muscular changes begin to appear. Therefore, the purpose of this study was to determine whether men with early stages of knee OA already had functional and quadriceps muscle morphologic alterations. DESIGN: Forty men were divided into two groups: control group (healthy subjects) and OA group (subjects with knee OA). A biopsy of the vastus lateralis muscle was performed for morphometric analysis. Isokinetic evaluation of knee extensor torque, concentric and eccentric (90 and 180 degrees/sec), was performed simultaneously with vastus lateralis electromyographic activity evaluation. RESULTS: Significant differences were found in knee extensor torque (P < 0.05) and in normalized root mean square (P < 0.01) during the eccentric contractions (both velocities), with higher values for the control group. No differences were found during concentric contractions. The OA group presented greater values of the minimum diameter of type 1 fibers and greater proportion and relative cross-sectional area of type 2b fibers (P < 0.05). CONCLUSIONS: Men with early stages of knee OA do not present alterations of concentric strength but had decreased eccentric strength and morphologic quadriceps muscle changes, indicating neuromuscular adaptations.

Expression of receptors of advanced glycation end product (RAGE) and types I, III and IV collagen in the vastus lateralis muscle of men in early stages of knee osteoarthritis.

Alterations in the contractile and non-contractile proteins of the skeletal muscle may reduce muscle function in knee osteoarthritis (OA), and the formation and accumulation of advanced glycation end products, particularly in collagen, can influence the quality of these muscle proteins. The objective of this study was to evaluate the reactivity of types I, III and IV collagen and the expression and localization of receptor for advanced glycation end products (RAGE) in the vastus lateralis (VL) muscle in early stages of knee OA. The hypothesis was that these patients present a higher expression of RAGE and increased immunoreactivity in the collagen. Thirty-five men were divided into two groups: the control group (CG; n = 17) and the osteoarthritis group (OAG; n = 18). All participants were submitted to a biopsy of the VL. The muscle samples were analyzed by immunohistochemistry for collagen and for RAGE and laminin. The expression of RAGE was counted (intracellular, extracellular and total). Student's t-test for independent samples and Mann-Whitney U test were used for the RAGE's intergroup analysis (α ≤ 0.05). A semiquantitative analysis was performed to assess the collagen reactivity. No significant differences were observed in the intracellular, extracellular or total localization of RAGE (p > 0.05). Higher immunoreactivity was observed in the OAG for all types of collagen, with more reactivity for collagen III and IV. We concluded that in the initial stages of knee OA, no differences were observed for RAGE levels between the groups. However, the OAG's higher collagen expression may represent adaptations for reducing muscle stiffness and avoiding injury.

Change in the contractile behavior of muscle fibers in subjects with primary muscle dysfunction.

The mechanical and metabolic characteristics of skeletal muscle fibers can interfere with muscle contractile performance in healthy subjects. Few studies have investigated the degree of association between muscle function and muscle fiber morphology in patients with myopathy. A biopsy was obtained from the left biceps brachii muscle of 12 subjects with myopathic disorders. The relative cross-sectional area of type 2 fibers and their subtypes was determined by the ATPase technique. Relative torque (RT) was calculated by dividing isokinetic elbow flexion peak torque (PT) values (90 and 180° s-1) by isometric PT values. Correlations were analyzed using Spearman's coefficient (r). The relative cross-sectional area of type 2b fibers was positively correlated with RT90 (r = 0.71, P = 0.009) and RT180 (r = 0.73, P = 0.007). The relative cross-sectional area of type 2a fibers showed a moderate and negative correlation with RT180 (r = -0.62, P = 0.03) and a low correlation with RT90 (r = -0.57, P = 0.05). In contrast to healthy subjects, patients with myopathy presented changes in the contractile behavior of type 2a fibers and compensatory adaptations in type 2b fibers. The results suggest that RT in combination with morphometric parameters provides data regarding muscle function in patients with myopathic disorders and can contribute to the establishment of therapeutic exercises.

Morphological adaptation of muscle collagen and receptor of advanced glycation end product (RAGE) in osteoarthritis patients with 12 weeks of resistance training: influence of anti-inflammatory or glucosamine treatment.

The aim of this study was to investigate the effect of 12-week resistance training on morphological presence of collagen and RAGE (receptor for advanced glycation end products) in skeletal muscle of patients with knee osteoarthritis (OA). Little is known about the influence of exercise on the skeletal muscle matrix that supports joints affected by OA mainly when it is associated with medication taken by OA patients (non-steroid anti-inflammatory drugs (NSAID) and glucosamine). A biopsy was collected from the vastus lateralis muscle in all patients before and after 12-week period of training. The patients (age 55-69 years) were divided into three groups, treated with NSAID, glucosamine or placebo. In addition, the muscle samples were analysed by immunohistochemistry for collagen types, RAGE and capillaries ratio. An increment in immunoreactivity for type IV collagen after the training period was observed in 72 % of all biopsies when compared with their respective baseline samples. Reduced immunoreactivity of collagen type I was observed in all patients treated with glucosamine. A significant increase with training in the amount of RAGE was detected in the placebo group only (p < 0.05). Comparison of post-treatment states indicated significant differences between the placebo and glucosamine group data, demonstrating increased levels in the placebo group (p < 0.05). These findings suggest a basement membrane remodelling in favour of a strengthened extracellular matrix surrounding individual muscle fibres after 12 weeks of resistance training. Glucosamine with training appeared to attenuate RAGE accumulation more than was seen with NSAID or placebo in skeletal muscle of OA patients.

Characterization of fiber types in different muscles of the hindlimb in female weanling and adult Wistar rats.

We analyzed lesser diameter and distribution of fiber types in different skeletal muscles from female Wistar rats using a histoenzymology Myofibrillar Adenosine Tri-phosphatase (mATPase) method. Fragments from muscles were frozen and processed by mATPase in different pH. Adult and weanling rat soleus muscles presented a predominance of type I fibers and larger fiber diameters. In the plantar muscle in adult rats, the type IIB fibers demonstrated greater lesser diameter while in the weanling animals, types I and IIB fibers were larger. The plantar muscle of animals of both ages was composed predominantly of the type IID fibers. The type IID fibers were observed in similar amounts in the lateral gastrocnemius and the medial gastrocnemius muscles. Type IIB fibers showed predominance and presented higher size in comparison with other types in the EDL muscle. The present study shows that data on fiber type distribution and fiber lesser diameter obtained in adult animals cannot always be applied to weanling animals of the same species. Using the mATPase, despite the difficult handling, is an important tool to determine the different characteristics of the specific fibers in the skeletal muscle tissue.

Eletroestimulação seletiva mantem estrutura e função do tibial anterior desnervado de ratos / Structure and function of denervated tibialis anteriores are maintained by electrical stimulation in rats

OBJETIVO: A eletroestimulação para tratamento de músculos desnervados deve ser aplicada através do tratamento seletivo. Este estudo avaliou o efeito da eletroestimulação seletiva do músculo desnervado sobre sua estrutura e função. MÉTODOS: Foram utilizados cinqüenta ratos Wistar distribuídos em controle, desnervado estimulado e desnervado não-estimulado. Após avaliação eletrodiagnóstica de estímulo pré-desnervação, os animais sofreram desnervação proximal completa do músculo tibial anterior unilateral. Houve reavaliação semanal para adaptação dos parâmetros de tratamento seletivo, aplicado três vezes por semana. Os animais foram mortos após 7, 14, 28 e 56 dias do pós-cirúrgico. Foram realizados procedimentos histoquímicos e estudos morfológicos e morfométricos. RESULTADOS: Os animais desnervados estimulados não apresentaram contratura da articulação do tornozelo e não houve automutilações nas patas. Alterações significativas nas áreas das fibras musculares tipo IIB (desnervados estimulados aos 7 dias) e tipo IIA e híbridas (desnervados estimulados 28 e 56 dias) indicaram menor atrofia. Transição do tipos de fibras musculares foi significativa, indicando uma manutenção do padrão funcional do músculo tibial anterior nos períodos de 7 e 14 dias. CONCLUSÃO: Conclui-se que houve manutenção temporária da estrutura e função do músculo tibial anterior desnervado através da eletroestimulação seletiva.

OBJECTIVE: Electrical stimulation for treatment of denervated muscles should be implemented by selective treatment. This study evaluated the effect of selective electrical stimulation on the structure and function of denervated muscle. METHODS: Fifty Wistar mice were allocated to control, stimulated denervated and non-stimulated denervated groups. Following an electrodiagnostic evaluation, the animals underwent complete unilateral denervation of the proximal anterior tibialis muscle. Weekly re-assessment was carried out in order to adjust the parameters of the selective treatment, applied three times a week. The animals were sacrificed at 7, 14, 28 and 56 days after undergoing the surgical procedures. Histochemical procedures and morphologic and morphometric studies were carried out. RESULTS: The denervated stimulated animals did not present contracture of the ankle joint and self-mutilation was not found on the feet. Significant alterations around the type IIB (denervated stimulated at 7 days), type IIA and hybrid (denervated stimulated at 28 and 56 days) fibers showed less atrophy. The transition of muscle fibers types was significant, indicating the preservation of the functional pattern of the anterior tibialis muscle at 7 and 14 days. CONCLUSION: We found that the selective electrical stimulation was able to temporarily maintain the structure and function of the denervated anterior tibialis muscle.

Propriedades mecânicas do músculo gastrocnêmio de ratas, imobilizado e posteriormente submetido a diferentes protocolos de alongamento / Mechanical properties of gastrocnemius muscle of female rats immobilized and posteriorly submitted to different stretching protocols

O alongamento é amplamente utilizado na prática clínica da fisioterapia e no desporto, porém, as alterações mecânicas que essa técnica gera no músculo esquelético são pouco exploradas cientificamente. Este estudo avaliou as alterações mecânicas que acometem o músculo gastrocnêmio de ratas Wistar, adultas jovens, após 14 dias de imobilização e, secundariamente, submetido a alongamento manual passivo por 10 dias consecutivos, aplicado uma ou duas vezes ao dia. Foram utilizados 50 animais, sendo 10 para cada grupo: Controle (GC); Imobilizado (GI); Imobilizado e Liberado (GIL); Imobilizado e alongado uma vez ao dia (GIA1); e Imobilizado e alongado duas vezes ao dia (GIA2). O músculo gastrocnêmio foi submetido ao ensaio mecânico de tração, onde foram avaliadas as propriedades de carga e alongamento nos limites máximo e proporcional, além de rigidez e resiliência. A imobilização reduziu os valores das propriedades mecânicas de carga no limite máximo (CLM), carga no limite proporcional (CLP), alongamento no limite máximo (ALM), rigidez e resiliência, em 44,4 por cento, 34,4 por cento, 27,6 por cento, 64,4 por cento e 54 por cento, respectivamente, quando comparados com os valores do GC. A remobilização livre e o alongamento restauraram as propriedades de CLM, CLP, ALM, rigidez e resiliência do músculo, exceto para o GIA2, que foi incapaz de restabelecer a propriedade de ALM (31,3 por cento menor que GC). Concluí-se, portanto que, após 14 dias de imobilização segmentar, cargas individuais de alongamento e a livre movimentação permitem restituir as propriedades mecânicas do tecido muscular.

Stretching is widely employed in physiotherapeutic clinical practice and in sportive activities; however, the mechanical alterations of the skeletal muscle generated by this technique are poorly scientifically investigated. This study evaluated the mechanical alterations suffered by the gastrocnemius muscle of young adult female Wistar rats, submitted to14 days of immobilization followed by passive manual stretching during 10 consecutive days once or twice a day. Fifty animals were equally distributed in five groups, Control (CG); Immobilized (IG); Immobilized and liberated (ILG); Immobilized and submitted to stretching once a day (IEG1); Immobilized and submitted to stretching twice a day (IEG2). The gastrocnemius muscle was analyzed by mechanical traction assay and the properties related to load and maximal and proportional stretching evaluated in addition to stiffness and resilience. Immobilization decreased load at maximal thresholds (MTL), load at proportional thresholds (LPT), stretch at maximal thresholds (SMT), stiffness and resilience were reduced in 44.4 percent, 34.4 percent, 27.6 percent, 64.4 percent and 54 percent respectively, compared to CG values. With subsequent free remobilization and stretching, all parameters were restored except for IEG2 in which SMT remained reduced in 31.3 percent, when compared to CG. It is concluded that after 14 days of segmental immobilization, individual stretching loads and free movements contribute to regain muscle mechanical properties.

Propriedades mecânicas do gastrocnêmio eletroestimulado pós-imobilização / Mechanical properties of gastrocnemius eletrostimulated after immobilization

INTRODUÇÃO: As propriedades mecânicas (PM) consistem num instrumento de aplicabilidade clínica para profissionais de saúde que atuam no sistema músculo-esquelético. OBJETIVOS: Avaliar dois protocolos de estimulação elétrica neuromuscular (NMES) na potencialização do restabelecimento das PM no complexo músculo-tendíneo após imobilização segmentar de ratas. MATERIAIS E MÉTODOS: Foram utilizados 50 animais distribuídos em: Controle (GC, n=10); Imobilizado (GI, n=10); Imobilizado e remobilizado livre (GIL, n=10), Imobilizado e NMES uma vez ao dia (GIE1, n=10) e Imobilizado e NMES duas vezes ao dia (GIE2, n=10). A imobilização foi realizada por 14 dias. O GIL foi liberado posteriormente por 10 dias. A NMES foi aplicada pós-imobilização por 10 dias, GIE1 aplicado pela manhã (10 minutos) e, GIE2 aplicado pela manhã e à tarde (totalizando 20 minutos). Posteriormente, o músculo gastrocnêmio foi submetido ao ensaio mecânico de tração sendo as PM de rigidez, resiliência, carga e o alongamento no limite máximo avaliadas. RESULTADOS: A imobilização reduziu os valores das propriedades de carga e rigidez (p<0,05). A NMES utilizada duas vezes ao dia determinou resultados menos satisfatórios das PM avaliadas que àqueles obtidos uma vez ao dia e no grupo remobilizado (p>0,05). CONCLUSÃO: O músculo gastrocnênio tornou-se estruturalmente mais organizado frente à aplicação unitária da NMES e na remobilização.

INTRODUCTION: Mechanical properties (MP) are clinically applicable tools for healthcare professionals working on the musculoskeletal system. OBJECTIVES: The aim of this study was to evaluate two protocols of neuromuscular electric stimulation (NMES) to improve MP regeneration of the myotendinous complex after segment immobilization in female rats. MATERIALS AND METHODS: Fifty animals were equally distributed into five groups: Control (CG, n=10); Immobilized (IG, n=10); Immobilized and freely remobilized (IFG, n=10); Immobilized and NMES once /day (IEG1, n=10); Immobilized and MNES twice/day (IEG2, n=10). Immobilization was kept for 14 days, and remobilization was subsequently released for 10 days. NMES was applied for 10 days, post-immobilization, every morning for 10 minutes to IEG1 animals and every morning and afternoon (total 20 minutes) to the IEG2 group. After these procedures, the gastrocnemius muscle was submitted to the mechanical traction assay to evaluate stiffness, resilience, load and stretching at maximum limit MPs. RESULTS: Immobilization reduced the MP values concerning load and stiffness (p<0.05). Results for NMES applied twice a day were less satisfactory than the ones obtained with one application or in the remobilized group (p> 0.05). CONCLUSION: It is concluded that the gastrocnemius muscle became structurally better organized through a single NMES application and by remobilization.

Morphological effects of two protocols of passive stretch over the immobilized rat soleus muscle.

This study evaluated two different stretching protocols employed during a period of hind-limb immobilization in terms of their effects on muscle morphology. Quantitative data regarding the soleus muscle were obtained based on the clinical hypothesis that a high frequency of this exercise would improve the recovery of muscle structure. Twenty-four male Wistar rats were divided into four groups (n = 6 each): the control group (C); the immobilized group, in which the left hind limb was immobilized in order to maintain the soleus muscle in a fully shortened position for 3 weeks (I); the 'immobilized and stretched every 3 days' group, in which the left hind limb was immobilized as in the immobilized group, but with the soleus muscle stretched every 3 days for 40 min (Ist3); and the 'immobilized (as in the immobilized group) and stretched every 7 days' group (ISt7). All soleus muscles were excised 21 days after the beginning of the experiment, and were processed for (1) haematoxylin and eosin and myosin ATPase to evaluate muscle morphology and cross-sectional area and the proportions of the different fibre types, and (2) ultrastructural analysis. The cross-sectional area was found to have decreased in all fibre types (I, II and C), mainly in ISt7, when compared with the C group and ISt3 group. The proportion of the different fibre types did not show statistical difference between groups. Light and electron microscopy examination revealed signs of cell degeneration that was more intense in the group immobilized and stretched three times a week. In conclusion, sessions of passive stretching applied to the soleus during immobilization induce muscle fibre injury, suggesting that this therapeutic tool should be applied carefully to disused muscles.

The effects of aging on biceps brachii muscle fibers: a morphometrical study from biopsies and autopsies.

OBJECTIVES: In order to study the morphology and size of muscle fibers, cross sections of biceps brachii samples from autopsies, up to 9 hours after death, and biopsies of 72 subjects were compared. The subjects aged 13 to 84 years in both sexes. METHODS: The samples obtained from autopsies (n=47) were from subjects with sudden death, or who died after acute disease without evidence of neuromuscular involvement. The biopsies (n=25) were from patients with symptoms suggestive of inflammatory or metabolic myopathy, not confirmed morphologically. The lesser diameter of muscle fibers was measured using the ATPase reaction. RESULTS: Morphological analysis showed that aging changes were present from the sixth decade in autopsies, and consisted of atrophy and/or type-grouping. The statistical models adjusted for females in both autopsies and biopsies were linear straight with no variation in fiber size with increasing age. The models adjusted for males in both groups were quadratic, indicating that age influenced the size of different type fibers. In males type 2 were larger than type 1 fibers, and than fibers in females. CONCLUSIONS: These values might be useful as controls, helping interpretation of changes in fiber size in samples obtained from biopsies and autopsies.

The effects of aging on biceps brachii muscle fibers: a morphometrical study from biopsies and autopsies

OBJECTIVES: In order to study the morphology and size of muscle fibers, cross sections of biceps brachii samples from autopsies, up to 9 hours after death, and biopsies of 72 subjects were compared. The subjects aged 13 to 84 years in both sexes. METHODS: The samples obtained from autopsies (n=47) were from subjects with sudden death, or who died after acute disease without evidence of neuromuscular involvement. The biopsies (n=25) were from patients with symptoms suggestive of inflammatory or metabolic myopathy, not confirmed morphologically. The lesser diameter of muscle fibers was measured using the ATPase reaction. RESULTS: Morphological analysis showed that aging changes were present from the sixth decade in autopsies, and consisted of atrophy and/or type-grouping. The statistical models adjusted for females in both autopsies and biopsies were linear straight with no variation in fiber size with increasing age. The models adjusted for males in both groups were quadratic, indicating that age influenced the size of different type fibers. In males type 2 were larger than type 1 fibers, and than fibers in females. CONCLUSIONS: These values might be useful as controls, helping interpretation of changes in fiber size in samples obtained from biopsies and autopsies