Functional exercise capacity in maximal and submaximal activities of individuals with polio sequelae.

PURPOSE: Poliomyelitis is an infectious disease that can cause total paralysis. Furthermore, poliomyelitis survivors may develop new signs and symptoms, including muscular weakness and fatigue, years after the acute phase of the disease, i.e., post-polio syndrome (PPS). Thus, the objective was to compare the functional exercise capacity during maximal and submaximal exercises among individuals with polio sequelae (without PPS diagnosis), PPS, and a control group. METHODS: Thirty individuals participated in three groups: a control group (CG, n = 10); a group of individuals with polio sequelae but without PPS diagnosis (PG, n = 10); and a PPS group (PPSG, n = 10). All participants underwent (i) a cardiopulmonary exercise test to determine their maximal oxygen uptake ([Formula: see text]) and (ii) a series of functional field tests (i.e., walking test, sit-to-stand test, and stair climbing test). RESULTS: [Formula: see text]O2max was 30% lower in PPSG than in CG and PG. Regarding functional field tests, walking and stair climbing test performances were significantly different among all groups. The PPSG sit-to-stand performance was lower than CG. CONCLUSION: The sequelae of paralytic poliomyelitis impair functional exercise capacity obtained from maximal and submaximal tests, especially in patients with PPS. Furthermore, submaximal variables appear to be more negatively impacted than maximal variables.

Muscle residual force enhancement: a brief review.

Muscle residual force enhancement has been observed in different muscle preparations for more than half a century. Nonetheless, its mechanism remains unclear; to date, there are three generally accepted hypotheses: 1) sarcomere length non-uniformity, 2) engagement of passive elements, and 3) an increased number of cross-bridges. The first hypothesis uses sarcomere non-homogeneity and instability to explain how "weak" sarcomeres would convey the higher tension generated by an enhanced overlap from "stronger" sarcomeres, allowing the whole system to produce higher forces than predicted by the force-length relationship; non-uniformity provides theoretical support for a large amount of the experimental data. The second hypothesis suggests that passive elements within the sarcomeres (i.e., titin) could gain strain upon calcium activation followed by stretch. Finally, the third hypothesis suggests that muscle stretch after activation would alter cross-bridge kinetics to increase the number of attached cross-bridges. Presently, we cannot completely rule out any of the three hypotheses. Different experimental results suggest that the mechanisms on which these three hypotheses are based could all coexist.

Lung function in post-poliomyelitis syndrome: a cross-sectional study.

OBJECTIVE: To compare lung function between patients with post-poliomyelitis syndrome and those with sequelae of paralytic poliomyelitis (without any signs or symptoms of post-poliomyelitis syndrome), as well as between patients with post-poliomyelitis syndrome and healthy controls. METHODS: Twenty-nine male participants were assigned to one of three groups: control; poliomyelitis (comprising patients who had had paralytic poliomyelitis but had not developed post-poliomyelitis syndrome); and post-poliomyelitis syndrome. Volunteers underwent lung function measurements (spirometry and respiratory muscle strength assessment). RESULTS: The results of the spirometric assessment revealed no significant differences among the groups except for an approximately 27% lower mean maximal voluntary ventilation in the post-poliomyelitis syndrome group when compared with the control group (p = 0.0127). Nevertheless, the maximal voluntary ventilation values for the post-poliomyelitis group were compared with those for the Brazilian population and were found to be normal. No significant differences were observed in respiratory muscle strength among the groups. CONCLUSIONS: With the exception of lower maximal voluntary ventilation, there was no significant lung function impairment in outpatients diagnosed with post-poliomyelitis syndrome when compared with healthy subjects and with patients with sequelae of poliomyelitis without post-poliomyelitis syndrome. This is an important clinical finding because it shows that patients with post-poliomyelitis syndrome can have preserved lung function.

Lung function in post-poliomyelitis syndrome: a cross-sectional study / Funcao pulmonar em pessoas com sindrome pos-poliomielite: um estudo transversal

OBJECTIVE: To compare lung function between patients with post-poliomyelitis syndrome and those with sequelae of paralytic poliomyelitis (without any signs or symptoms of post-poliomyelitis syndrome), as well as between patients with post-poliomyelitis syndrome and healthy controls. METHODS: Twenty-nine male participants were assigned to one of three groups: control; poliomyelitis (comprising patients who had had paralytic poliomyelitis but had not developed post-poliomyelitis syndrome); and post-poliomyelitis syndrome. Volunteers underwent lung function measurements (spirometry and respiratory muscle strength assessment). RESULTS: The results of the spirometric assessment revealed no significant differences among the groups except for an approximately 27% lower mean maximal voluntary ventilation in the post-poliomyelitis syndrome group when compared with the control group (p = 0.0127). Nevertheless, the maximal voluntary ventilation values for the post-poliomyelitis group were compared with those for the Brazilian population and were found to be normal. No significant differences were observed in respiratory muscle strength among the groups. CONCLUSIONS: With the exception of lower maximal voluntary ventilation, there was no significant lung function impairment in outpatients diagnosed with post-poliomyelitis syndrome when compared with healthy subjects and with patients with sequelae of poliomyelitis without post-poliomyelitis syndrome. This is an important clinical finding because it shows that patients with post-poliomyelitis syndrome can have preserved lung function. .

OBJETIVO: Comparar a função pulmonar de pacientes com síndrome pós-poliomielite à de pacientes com sequelas de poliomielite paralítica (sem quaisquer sinais ou sintomas de síndrome pós-poliomielite) e à de sujeitos saudáveis. MÉTODOS: Vinte e nove sujeitos do sexo masculino foram divididos em três grupos: controle, poliomielite (pacientes que sofreram de poliomielite paralítica, mas que não apresentaram síndrome pós-poliomielite) e síndrome pós-poliomielite. Os voluntários foram submetidos a avaliações da função pulmonar (espirometria e avaliação da força muscular respiratória). RESULTADOS: Os resultados da espirometria não revelaram diferenças significantes entre os grupos, à exceção da ventilação voluntária máxima, cuja média no grupo síndrome pós-poliomielite foi aproximadamente 27% mais baixa que no grupo controle (p = 0,0127). No entanto, os valores de ventilação voluntária máxima observados no grupo pós-poliomielite foram comparados aos da população brasileira e se apresentaram dentro da faixa normal. Não foram observadas diferenças significantes entre os grupos no tocante à força muscular respiratória. CONCLUSÕES: À exceção da ventilação voluntária máxima mais baixa, não houve comprometimento significante da função pulmonar em pacientes ambulatoriais com diagnóstico de síndrome pós-poliomielite quando comparados a pacientes com sequelas de poliomielite, mas sem a síndrome pós-poliomielite e a sujeitos ...

Comportamento da força em resposta ao alongamento e encurtamento muscular / Force behavior in response to muscle stretch and shortening

Alguns fenômenos relacionados à produção de força na fibra muscular não podem ser perfeitamente explicados pela teoria das pontes cruzadas; dentre eles, podemos citar o comportamento da força durante e após mudanças de comprimento muscular. Investigando a força durante estas mudanças, notou-se que o aumento e a diminuição da mesma durante o alongamento e encurtamento têm algumas características em comum com relação à forma do traçado da força: ambos apresentam duas fases (I e II), com duas mudanças de inclinação (P1 e P2). Apesar dessas similaridades, existem particularidades: quando diferentes velocidades são aplicadas, os comportamentos de P1 e P2 durante alogamento diferem ligeiramente dos seus homólogos durante o encurtamento. Distintos mecanismos moleculares tentam explicar essas particularidades: durante o alongamento P1 ocorre devido à reversão do curso de alavancagem das pontes cruzadas, ao passo que durante o encurtamento, as mesmas seguem seu curso normal. Em ambas as condições, P2 está relacionado ao ponto onde as pontes cruzadas se destacam; mas como este ponto ocorre em diferentes sentidos, resulta em diferentes estados moleculares finais. Ademais, P1 e P2 têm sido usados para se analisar o comportamento da força durante as mudanças de comprimento. Existem três mecanismos aceitos para explicar o ganho de força durante o alongamento 1) um aumento no número de pontes cruzadas; 2) um aumento na força gerada por cada ponte cruzada e 3) pontes cruzadas operando em estado de pré-curso-de-alavancagem. Já com relação à diminuição da força acredita-se que há uma perda da força média produzida por cada ponte cruzada, quando estas são “empurradas” para um estado molecular de menor tensão...

Some phenomena related to force production in muscle fibers cannot be fully explained by the crossbridge theory; among them we can cite the force behaviour during and after length changes. Investigating force during these changes, it was noted that the increase and decrease in force during stretchand shortening have some characteristics in common with respect to their force trace: both have twophases (I and II), with two changes in slope (P1 and P2). Despite these similarities, there are particularities: when different velocities are applied, P1 and P2 behaviours during stretch differ slightly from their counterpart during shortening. Distinct molecular mechanisms try to explain these particularities: during stretch, P1 occurs due to a reversal of powerstroke, where as during shortening, crossbridges follow the normal powerstroke course. In both conditions, P2 is related to the point where the cross-bridges detach; but as it happens in different directions, it results in different final molecular states. Furthermore, P1 e P2 have been used for force behaviour analyses during length changes. There are three accepted mechanisms to explain force enhancement during stretch: 1) an increase in the number of crossbridges, 2) an increase in force generated per crossbridge and 3) crossbridges operating in prepowerstroke. On the other hand, concerning force depression, it is believed there is a loss in the force produced per crossbridge, while they are "pushed" to a molecular state of lower strain...

Post-polio syndrome: renaissance of poliomyelitis?: [review] / Síndrome pós-polio: renascimento da poliomielite?: [revisão]

Poliomyelitis is an acute and infectious viral disease, transmitted primarily through oral-fecal contact or directly, person to person. Approximately 90% of the individuals infected by the polio virus do not present symptoms; however, the affected individuals can show a variety of symptoms if the virus reaches the bloodstream. In up to 2% of cases, the virus reaches the central nervous system preferably infecting and destroying the motor neurons, resulting in muscular weakness and acute flaccid paralysis. Despite the expressive reduction in the number of cases, many people live with the consequences of the acute illness, thus representing a burden to the public healthcare systems. Many of these people present new manifestations as signs and symptoms that are called post-polio syndrome. It can be defined and characterized by new neuromuscular symptoms, which occur at least 15 years after a period of clinical and functional stability in patients with previous history of symptomatic poliomyelitis. The signs and symptoms characterizing the post-polio syndrome include new muscular weakness, muscular fatigue and atrophy, pain in joints and muscles, sleep disorders, intolerance to cold, respiratory and swallowing difficulties, and recent weight gain. Therefore, the aim of this review is to present the physiological changes caused by the new manifestation of symptoms in individuals with poliomyelitis.

A poliomielite é uma doença aguda e infecciosa causada por vírus, cuja transmissão ocorre primariamente pela via oral-fecal ou por transmissão direta, de pessoa a pessoa. Aproximadamente 90% dos infectados pelo vírus da poliomielite não apresentam sintomas, entretanto, os indivíduos afetados podem exibir uma variedade de sintomas se o vírus atingir a corrente sanguínea. Em até 2% dos casos, o vírus atinge o sistema nervoso central infectando e destruindo, preferencialmente, os neurônios motores, levando o indivíduo a um quadro de fraqueza muscular e paralisia flácida aguda. Apesar da expressiva diminuição do número de casos de poliomielite, muitas pessoas convivem com as consequências da doença aguda, onerando os sistemas públicos de saúde. Muitas destas pessoas apresentam uma nova manifestação de sinais e sintomas que em conjunto foram denominados de síndrome pós-poliomielite, esta pode ser definida e caracterizada por novos sintomas neuromusculares que ocorrem ao menos 15 anos após um período de estabilidade clínica e funcional ter sido atingida, em pacientes com história prévia de poliomielite sintomática. Os sinais e sintomas que caracterizam a síndrome pós-poliomielite são: a nova fraqueza muscular, a fadiga muscular, a atrofia muscular, a dor muscular e articular, distúrbios do sono, a intolerância ao frio, dificuldades respiratórias e de deglutição e o aumento recente de peso. Portanto, o objetivo desta revisão é apresentar as alterações fisiológicas decorrentes da nova manifestação de sintomas nas pessoas com poliomielite.

Epilepsia e atividade física: estudos em humanos e animais: [revisão] / Epilepsy and physical activity: human and animal studies: [revision]

A epilepsia é considerada o distúrbio neurológico crônico mais prevalente no mundo, influenciando negativamente a qualidade de vida de indivíduos com epilepsia. Apesar do efeito favorável do exercício físico sobre a saúde ser inquestionável, a realização de um programa de exercício físico por pessoas com epilepsia ainda é um assunto controverso. Estudos têm mostrado efeitos benéficos do exercício físico na frequência de crises assim como na qualidade de vida. Entretanto, indivíduos com epilepsia são frequentemente desencorajados e excluídos da participação em programas de exercício físico pelo medo que tal participação possa precipitar crises epilépticas. Sendo assim, o objetivo desse estudo foi revisar o efeito do exercício físico baseado em dados de estudos clínicos e experimentais de epilepsia.

Epilepsy is the most common chronic neurological disorder in the world that influences negatively the quality of people's life affected by this disease. Although the favorable effect of physical activity on general health is unquestionable, the appropriate physical exercise for people with epilepsy is still controversial. Studies have shown beneficial effect of physical exercise on frequency of seizures as well ason life quality. However, people with epilepsy frequently are discouraged and excluded from participation in physical exercise due to the fear that the participation in a physical exercise program can precipitate epileptic seizures. Therefore, the aim of this study was to review the effect of physical exercise based onclinical and experimental studies of epilepsy.

Periodização do treinamento de força: uma revisão crítica / Periodized strength training: a critical review

Originária da Alemanha e da antiga União das Repúblicas Socialistas Soviéticas (URSS), a teoria da periodização do treinamento se desenvolveu em meados do século XX, no chamado período científi co, baseada na teoria da Síndrome Geral da Adaptação (SGA). A literatura científi ca pertinente ao treinamento de força entende a periodização como a variação sistemática da intensidade e do volume com a fi nalidade de se desenvolver de forma efi ciente uma ou mais capacidades físicas. O presente trabalho teve por objetivo analisar o efeito da periodização sobre o treinamento de força com relação às suas adaptações específi cas e comparar os modelos mais recorrentes (fi xo, linear e ondulado). Para tanto, foi feito um levantamento bibliográfi co sobre as variáveis utilizadas para a prescrição do treinamento resistido, assim como uma revisão sistemática de artigos encontrados nas seguintes bases de dados: Pubmed e Scielo. A constatação principal da presente revisão foi que o modelo ondulado é o mais efi ciente para o aumento de força máxima e potência, seguido pelo linear e por último o fi xo, embora sejam necessárias mais investigações enfocando resistência de força e hipertrofi a muscular.

Originating from Germany and former Union of Soviet Socialist Republics (USSR), the training periodization theory was developed in the middle of the 20th Century, the so-called scientifi c period, based on the General Adaptation Syndrome theory (GAS). The scientifi c literature on strength training understands periodization as the systematic variation of intensity and volume aiming at more effi ciently developing one or more physical abilities. This paper aimed at analyzing the effect of periodization on strength training as related to its specifi c adaptations and comparing the most recurrent models (fi xed, linear, and undulating). For that, a bibliographic survey on the training variables used to prescript resistance training was carried out, as well as a systematic review of the articles found in the following databases: Pubmed and Scielo. The main fi nding of this review was that the undulated model is the most effective one for increasing maximum strength and power, followed by the linear one, and lastly by the fi xed one, although more investigation focusing on strength resistance and muscle hypertrophy is required.