Abstract The aim of this study was to evaluate maximum voluntary contraction through surface electromyography in stabilizer shoulder muscles, as well as the clinical evaluation of shoulder injury in the pre, post, and detraining stages of specific training in child swimmers. Twelve competitive swimmers volunteered for this study. Anthropometric measurements, clinical examination, electromyography (with Delsys® data acquisition system), and pain intensity levels were performed. Clinical examination and EMG data were compared using repeated-measures ANOVA with Bonferroni correction pre, post, and after detraining. The intervention program lasted for 12 weeks. The pain group presented higher pain intensity values compared to the post-intervention program. Most of the tests presented lower values at the detraining compared to the baseline. After the intervention, pain levels significantly decreased in five tests. Muscle strengthening work is highly recommended because it improves the swimmer’s shoulder performance, reducing injuries and decreasing pain intensity after 12 weeks of intervention.

Abstract Background: Walking is an economic activity, the more efficient the mechanical contribution, the less metabolic energy is necessary to keep walking. Patients with chronic heart failure and heart transplant present peripheral musculoskeletal disorders, dyspnea, and fatigue in their activities. Objective: In this scenario, the present study sought to verify the correlations between metabolic and electromyographic variables in chronic heart failure, heart transplant patients, and healthy controls. Methods: Regression and correlation between cost of transport and electromyographic cost, as well as correlation between oxygen consumption and muscle coactivation in patients and controls at five different walking speeds have been performed, with alpha = 0.05. Results: Strong correlation values (r controls: 0.99; chronic heart failure: 0.92; heart transplant: 0.88) indicate a linear relationship between the cost of transport and electromyographic cost. Oxygen consumption was significantly correlated to muscle activation in all groups. Conclusion: These results suggested that dynamic muscle coactivation was an important factor, especially for CHF and HT. These data support the idea that peripheral muscle limitations play an important role in people with CHF and HT. These findings indicate a strong relation between metabolic and electromyographic variables. For chronic heart failure and heart transplant patients, it can help to explain some difficulties in daily activities and aid in physical rehabilitation.

Abstract Regulated and systematized physical activity is considered to have health benefits in different areas for the older adult, like: body composition, cardiovascular system, metabolic and endocrine level, muscle strength, bones, joints and flexibility. Purpose. Evaluate and compare the spinal angles between two groups of elderly people: active and sedentary, using the flexicurve method. Methods. Participated 30 elderly people, of which they were divided into two groups: 15 active and 15 sedentary (they did not present differences for anthropometric characteristics), between 65 and 74 years old. To measure the angles of the vertebral column (cervical, thoracic and lumbar) the flexicurve and the Biomec Flex software v.3.0 are used. Results. Significant difference was obtained between groups in the measurement of the cervical spine, where only active older adults presented measurements within normal parameters, and sedentary older adults presented cervical hyperlordosis. The lumbar spine measurements presented curvature rectification values for both groups (according to the reference values of the literature). Conclusion. The curvature of the cervical spine was affected in sedentary older adults in the present study, compared to the curvature of the spine in active older adults. Furthermore, the rectification of the curvature of the lumbar spine and the changes due to this posture should be considered in the planning of physical exercise in this population.

Resumen Se considera que la actividad física regulada y sistematizada conlleva beneficios para la salud en diferentes ámbitos para el adulto mayor, ya sean: composición corporal, sistema cardiovascular, nivel metabólico y endócrino, fuerza muscular, huesos, articulaciones y flexibilidad. Objetivo. Evaluar y comparar los ángulos de la columna entre dos grupos de adultos mayores: activos y sedentarios, utilizando el método de flexicurva. Métodos. Para este estudio participaron 30 adultos mayores, de los cuales se dividieron en dos grupos: 15 activos y 15 sedentarios (no presentaron diferencias cuanto a características antropométricas), entre 65 y 74 años. Para medir los ángulos de la columna vertebral (cervical, torácica y lumbar) se utiliza la flexicurva y el software Biomec Flex v.3.0. Resultados. Se obtuvo como resultado una diferencia significativa entre grupos en la medida de la columna cervical, donde solo los adultos mayores activos presentan medidas dentro de los parámetros normales, y los sedentarios presentaron hiperlordosis cervical. Las medidas de la columna lumbar presentaron valores de rectificación de la curvatura para ambos grupos (de acuerdo con los valores de referencia de la literatura). Conclusión. La curvatura de la columna cervical se mostró afectada en adultos mayores sedentarios del presente estudio, en comparación la curvatura de la columna de los adultos mayores activos. Además la rectificación de la curvatura de la columna lumbar y los cambios debido a esta postura deben ser considerados en la planificación de ejercicio físico en esta población.

Abstract Autonomy and independency are reduced by the ageing. Physical activity improves muscle strength, flexibility, and self-select walking speed. Objectives: To compare the results of physical characteristics, functional tests and walking tests between sedentary and active lifestyle elderly groups. Methodology: two elderly groups were assessed, both with 13 participants. The level of activity was self-reported, through five functional tests and two walking tests. Results: the active group presented greater abdominal circumference and waist-hip index. No differences were found for the functional and gait tests between the two groups. Differences intra-group were found with different equations: the Enright & Sherrill equation, 1998 and Troosters, Gosselink & Decramer, 1999 for the two groups; for the Enright equation, 2003 for the sedentary group. Conclusions: Only two physical parameters showed difference between the groups. The intensity of physical activity should be systematic and monitored to achieve the results and benefits of an active lifestyle.

Resumen El envejecimiento disminuye la autonomía e independencia de los adultos mayores. La fuerza muscular, flexibilidad y marcha son mejoradas con actividad física. Objetivos: comparar los resultados de las características físicas, los tests funcionales y tests de marcha entre grupos de adultos mayores activos y sedentarios; Metodogía: se evaluaron dos grupos, cada uno con 13 individuos, de adultos mayores activos y sedentarios - el nivel de actividad física fue autoreportado - mediante cinco tests funcionales y dos tests de marcha. Resultados: el grupo de activos presentó mayor circunferencia abdominal e índice cintura-cadera. No fueron encontradas diferencias para los tests funcionales y de marcha entre los dos grupos. Con diferentes ecuaciones fueron encontradas diferencias intra grupo: la ecuación de Enright & Sherrill, 1998 y Troosters, Gosselink & Decramer, 1999 para los dos grupos; para la ecuación de Enright, 2003 para el grupo de sedentarios. Conclusiones: Solamente hubo diferencia entre grupos para dos variables físicas. Se sugiere que la intensidad de la actividad física debe ser sistematizada y monitoreada para que sea posible alcanzar los resultados y beneficios de una vida activa.

Durante exercícios realizados em máquinas de musculação, a força de atrito (FA) entre seus componentes mecânicos pode influenciar na magnitude da sobrecarga oferecida pela máquina para o praticante do exercício. No entanto, pouco se sabe sobre como medir esse atrito e qual seu real efeito. Assim, os objetivos deste estudo foram (i) descrever uma técnica para medição da FA em máquinas de musculação, e (ii) exemplificar a técnica quantificando a FA de uma máquina de musculação durante exercício em diferentes velocidades e cargas. Foram utilizados diagramas de corpo livre, equações da mecânica clássica além da medição dos ângulos articulares com eletrogoniômetro, e da força aplicada ao cabo de aço com célula de carga, para estimar a força de atrito. Para testar a metodologia, um indivíduo realizou repetições do exercício variando cargas e velocidade de execução. As cargas avaliadas foram 3kg, 6 kg e 9 kg; e as velocidades foram 30º/s, 60º/se 120º/s. A FA, expressa em percentual da carga, mostrou-se crescente com o incremento de velocidade e decrescente com o aumento da carga. Resultados em torno 40% obtidos para a menor carga e maior velocidade sugerem que a força de atrito deve ser um fator levado em consideração na escolha e manutenção de equipamentos de musculação.

During exercises performed in weight training machines, the friction force (FF) between its mechanical components can influence the magnitude of the overload offered by the machine on force of the exercise. However, little is known about how to measure this friction and what its real effect. Thus the objectives of this study were (i) describe a technique for measuring FF in weight training machines, and (ii) exemplify the technique, by quantifying the FF of the weight training machine at different exercise speeds and loads. For this, a subject performed repetitions of the exercise in different loads and speeds. The loads evaluated were 3 kg, 6 kg and 9 kg; and the speeds were 30°/s, 60°/s and 120°/s. The FF, normalized by selected load, increased significantly with the increasing of the speed and decreased with increasing of the load. Results for friction force around 40% found for highest speed and lowest load show that take the FF in count it's an important factor to consider during muscle equipment choice and maintaining.

CONTEXTUALIZAÇÃO: A análise da mecânica externa dos exercícios de Pilates e da biomecânica das articulações pode subsidiar a prescrição de exercícios na reabilitação. OBJETIVOS: Avaliar o comportamento do torque de resistência (ΓR) do exercício de extensão de quadril (EQ) realizado no Cadillac; realizar uma análise biomecânica a partir do comportamento do ΓR e das distâncias perpendiculares médias ponderadas (DPMPs) para estimar a força muscular resultante (FM R) dos extensores e flexores e propor critérios mecânicos para progressão do exercício de EQ realizado no Cadillac. MÉTODOS: Catorze praticantes de Pilates realizaram EQ no aparelho Cadillac em quatro situações em ordem aleatorizada - usando duas molas (vermelha e azul) fixadas em duas posições (alta e baixa). As posições angulares foram coletadas por meio de eletrogoniometria. Para o cálculo do ΓR, torque muscular (ΓM) e da FM R foram usados diagramas de corpo livre e equações de movimento. Os valores de DPMP dos músculos flexores e extensores do quadril foram quantificados usando dados da literatura. RESULTADOS: O ΓR e a FM R apresentaram comportamentos semelhantes em todas as situações, entretanto os valores máximos de ΓR não ocorrem na mesma posição articular que a FM R máxima. A DPMP dos flexores de quadril apresentou um comportamento crescente-decrescente, com máximo próximo aos 55º de flexão, enquanto os extensores de quadril apresentaram comportamento semelhante, com máximo próximo aos 25º de flexão. CONCLUSÃO: A análise biomecânica do exercício e a avaliação das características mecânicas associadas à articulação do quadril podem ser usadas como critérios objetivos de prescrição e progressão do exercício de EQ no Pilates.

BACKGROUND: The understanding of the external mechanics of Pilates exercises and the biomechanics of the joints may guide the prescription of rehabilitation exercises. OBJECTIVES: To evaluate the resistance torque (ΓR) during hip extension (HE) exercises performed on the Pilates Cadillac. To perform a biomechanic analysis of the ΓR and the weighted mean moment arm (WMMA) in order to calculate the resultant muscle force (FM R) of the hip extensors and flexors. To present a mechanical criteria for progression of HE exercise on the Pilates Cadillac. METHODS: Fourteen participants performed HE exercises on the Cadillac in four randomly assigned situations - using two springs (blue and red), which were attached in two positions (high and low). Angular positions were measured using an electrogoniometer. In order to calculate ΓR, the muscle torque (ΓM) and FM R, free-body diagrams and movement equations were used. The WMMA of the hip extensors and flexors were estimated from the literature. RESULTS: The ΓR and FM R presented a similar behavior during all situations; however, the maximum ΓR values did not occur at the same joint position as the FM R maximum values. The WMMA of the hip flexors presented an increased- decreased behavior with greatest values around 55º of flexion, while the hip extensors presented a similar behavior with greatest values around 25º of flexion. CONCLUSION: Biomechanic analysis of HE exercises and the evaluation of mechanical features in relation to the hip joint may be used as an objective criteria for the prescription and progression of HE exercise in Pilates.