The influence of resistance exercise with emphasis on specific contractions (concentric vs. eccentric) on muscle strength and post-exercise autonomic modulation: a randomized clinical trial

Contextualização:Ações concêntricas apresentam maior estresse cardiovascular quando comparadas às excêntricas. Entretanto, não se sabe a influência desses tipos de ações no comportamento da modulação autonômica cardíaca durante o processo de recuperação pós-esforço.Objetivo:Comparar o efeito de um treinamento resistido para o grupo extensor do joelho realizado com ênfase concêntrica vs excêntrica sobre a força muscular e a recuperação pós-exercício considerando índices de variabilidade de frequência cardíaca (VFC) em jovens saudáveis.Método:Cento e cinco homens, com idades entre 18 e 30 anos, foram randomizados em quatro grupos: controle concêntrico (CCONC), controle excêntrico (CEXC), treinamento concêntrico (TCONC) e treinamento excêntrico (TEXC). Os grupos CCONC e CEXC realizaram uma sessão de exercício reduzido (ER) para o grupo extensor do joelho [três séries de uma repetição a 100% de uma repetição máxima (1RM)], e os grupos TCONC e TEXC realizaram dez sessões de treinamento. A VFC foi analisada no momento basal e na recuperação após as sessões (T1, T2, T3 e T4).Resultados:Observou-se aumento da força muscular para o grupo TEXC. Em relação à modulação autonômica cardíaca, observou-se, em comparação ao momento basal, aumento dos índices SDNN e SD2 no momento T1 nos grupos CCONC e CEXC e aumento dos índices RMSSD, SD1 e AF (ms2) nos momentos T1, T2 e T4 no grupo TEXC.Conclusões:Conclui-se que o treinamento resistido realizado com ênfase em contrações excêntricas promoveu ganho de força e aumento da modulação vagal cardíaca durante o processo de recuperação em relação à condição basal.

Influência de calços na orientação postural de indivíduos com escoliose idiopática

INTRODUCTION: The relationship between the orientation of the segments and the adjustments that can be triggered by shoe lift and insoles in scoliotic patients during maintenance of standing position is unclear. OBJECTIVE: To verify static changes and those associated with unilateral manipulations of shoe lift in the postural orientation in people with idiopathic scoliosis. MATERIALS AND METHODS: Experimental group composed of ten patients with idiopathic scoliosis with double curve (less 10°) and control group with ten participants without scoliosis (aging from 13 to 24 years). Participants were videotaped in upright stance, standing with no, low (1 cm), and high (3 cm) shoe lift, which were placed under right and left shoe. In each condition, the participant maintain upright stance for 15 seconds and reflective markers were affixed on specific anatomical places. Postural angles were obtained: high thoracic; medium thoracic; thoracolumbar; and lumbar, as well segmental angles: shoulder; scapula; pelvis; and knee. RESULTS: In the no shoe lift condition, differences were observed between groups for high and medium thoracic angles and for shoulder. With low and high shoe lift under the right foot, difference was observed between shoe lift heights for high thoracic, for pelvis and knee angles. With low and high shoe lift under the left foot, differences between groups were observed for thoracolumbar angle and between shoe lift heights for pelvis and knee angles. CONCLUSIONS: The shoe lift promotes reorientation in the lower regions of the spine and segments of pelvis and knee. It might be suggested that in the scoliosis with double curves, manipulation in the basis of support changes the alignment of the trunk that might promote structural reorganization and the search of new adjustments among segments in individuals with idiopathic scoliosis.

Indicadores biomecânicos do risco de quedas em marcha com duplas tarefas e a influência do treinamento de equilíbrio com haste vibratória: diferenças entre idosos caidores e não caidores

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise cinemática das articulações dos membros torácicos e pélvicos de ovinos hígidos

Pós-graduação em Medicina Veterinária - FMVZ

Estabilidade da fixação antirrotacional lateral com parafuso associada à técnica de avanço de tuberosidade da tíbia

Pós-graduação em Cirurgia Veterinária - FCAV

Classificação do grau de comprometimento motor e do índice de massa corpórea em crianças com paralisia cerebral

Children with cerebral palsy due to movement and posture disorders might have an injured nutritional state. This study's objective was to classify the body mass index of children with cerebral palsy and verify its relation with the injury level of gross motor function. Twenty children, male and female sex, with cerebral palsy with ages between 2 and 14 years participated in the study. They were chosen from a rehabilitation center with physiotherapy, occupational and speech therapy accompaniment. Children were classified according to the gross motor function classification scale. The anthropometric measures of each child weight, heel-knee length, estimated stature and body mass index were gauged. The body mass index was classified according to the Center for Disease Control and Prevention's body mass index percentile calculator for children and teenagers. The obtained data didn't show any relation between the gross motor function and body mass index. The reduced number of participants and the fact of all children be accompanied in dysphagia clinics and, when necessary, nutrition clinics, might have influenced these results.

Avaliação do uso de fantomas antropomórficos na análise experimental dos fatores que afetam o contraste de imagens radiográficas

This experimental study aimed the evaluation of the use of anthropomorphic phantoms in the analysis of the influence of the acquisition parameters in the contrast of radiographic images. The analyzed factors were the variation of the peak kilovoltage (kVp) and the product of the filament circuit by the time of exposition (mAs). The influence of these factors was verified for different anthropomorphic phantoms: foot, knee and chest. The image contrast behavior with the simulators was compared to values obtained with the use of an aluminum ladder being the behavior of this reference for analysis and discussion. To assure the reproducibility of images, quality control tests were made and evaluation of procedure conditions before the experiments. The results obtained are shown in a scale of images where it was possible to evaluate the impact in the darkness of images. Regions with different compositions were analyzed which were different in image, this way the values of optical density and contrast are represented as charts and graphics. We conclude that the use of anthropomorphic phantoms in the evaluation of the influence of tension of the tube and time of exposition in the contrast of the radiographic images is not indicated for a quantitative analysis through optical density, once they present incompatible results with the data as reference as the aluminum ladder even so these simulators present a great property in qualitative analysis regarding the differentiation of structures and subjective evaluations

Comportamento de indivíduos com doença de Parkinson no levantar da cadeira e no início da marcha: relações com o envelhecimento

Large motor dysfunctions are observed in older adults with the age advance. Parkinson’s disease (PD) patients have motor deficits to perform daily living activities. To raise from a chair, a daily task necessary to live independently, requires both large muscle recruitment and large joint range of motion to achieve the vertical position safely. Normally, we initiate gait after raise from a chair. The aim of this study was to analyze the PD patients’ behavior when rising from a chair and initiating gait and to compare it according to the age advance. In order to do that, 23 PD patients (66.61±7.64 years old) were distributed in three age groups: Young group, between 51 and 60 years of age (n=7); intermediary group, between 61 and 70 years of age (n=7); and elderly group, over 70 years of age (n=9). There were no statistical differences among groups either for the disease evolution stage or for it compromising. The task was to stand from a chair and to initiate gait forward in three attempts. The dependent variables were: spatial and temporal (first step length and duration, and stride length, duration and velocity) and angular (flexion and extension of head, shoulder, hip, knee, and ankle). The motion of standing from a chair was divided in two phases. The data was statistically treated by means of Analyses of Variance with group as the only factor. The Scheffé’s post hoc test was used to localize differences among groups and the significance level was adjusted to p≤0.017. There were statistical differences for stride...(Complete abstract click electronic access below)

Taxa de desenvolvimento de força em diferentes contrações musculares

O objetivo deste estudo foi comparar a taxa de desenvolvimento de força (TDF) nas contrações isométrica e isocinéticas concêntrica a 60°.s-1 e 180°.s-1. Quatorze indivíduos do gênero masculino (idade = 23,1±2,8 anos; estatura = 174±31,3 cm e; massa corporal = 81±12 kg) participaram deste estudo. Na primeira visita foi realizada uma familiarização ao equipamento isocinético. Posteriormente, os indivíduos realizaram em ordem randômica 5 contrações isocinéticas máximas para os extensores do joelho em 60°.s-1 e 180°.s-1 para determinar o torque máximo concêntrico (TMC) e 2 contrações isométricas máximas de 3 s para determinar o torque máximo isométrico (TMI). O TMI (301,4±56,0 N.m) foi maior do que o TMC a 60°.s-1 (239,8±42,2 N.m) e 180°.s-1 (175,0±32,5 N.m). O TMC a 60°.s-1 foi maior do que o TMC a 180°.s-1. Para os intervalos de 0-30ms e 0-50ms, a TDF na condição isométrica (1196,6±464,6 e 1326,5±514,2 N.m.s-1, respectivamente) foi similar à TDF a 60°.s- 1 (1035,4±446,2 e 1134,3±448,4 N.m.s-1) e maior do que a 180°.s-1 (656,7±246,6 e 475,2±197,9 N.m.s-1), sendo ainda que a TDF na contração concêntrica rápida foi menor do que na lenta. No intervalo 0-100ms, a TDF da contração isométrica (1248,8±417,4 N.m.s-1) foi significantemente maior que a obtida na contração isocinética rápida (909,2±283,4 N.m.s- 1). A TDF obtida na contração isocinética lenta (1005,4±247,7 N.m.s-1) foi similar à obtida na contração isométrica e na concêntrica isocinética rápida. No intervalo 0-150ms, a TDF isométrica (1084,2±332,1 N.m.s-1) foi maior do que as concêntricas (60°.s-1 e 180°.s-1) (834,8±184,2 e 767,6±201,8 N.m.s-1, respectivamente), não existindo diferenças entre estas duas últimas. Conclui-se que a TDF é...(Resumo completo, clicar acesso eletrônico abaixo)

Avaliação das medidas articulares de membros pélvicos em ovinos

The aim of this study was to determine the angle of motion values for hindlimbs in clinically healthy adult Santa Ines sheep using a standard goniometer. Twenty female Santa Ines sheep weighing 32–45 kg (mean30.4, SD=3.7), and aged from three to six years old were used. A standard transparent plastic goniometer was used to measure passive maximum flexion, maximum extension, and range of motion (ROM) of the shoulder, elbow, carpal, hip, stifle, and tarsal joints, in the right and left limbs. The goniometric measurements were done with the sheep awake and in a standing position. The measurements were made in triplicate by two independent investigators. In all evaluated joints there was no significant difference between the means of both sides. No significant difference was observed between measurements performed by the two investigators. The mean (± SD) values of the measurements (degrees) were: 129 ± 4 (ROM) for tarsal joint; 46 ± 4 (flexion), 146 ± 6 (extension), and 100 ± 4 (ROM) for stifle joint; 54 ± 3 (flexion), 143 ± 7 (extension), and 89 ± 5 (ROM) for hip joint. The data obtained is useful to provide objective information of the joints. More studies are necessary using other breeds

Efeito agudo de diferentes volumes de alongamento estático na contração voluntária máxima de idosas

Several studies have shown that different stretching routines can lead to decreases on acute neuromuscular system performance. Although the deficit in muscle strength mediated by different methods of stretching has been systematically observed, few studies have investigated the possible existence of a dose-response relationship between the amount of stretching and muscle strength deficit in older adults. In this context, the objective of this study was to investigate the acute effect of two different stretching volumes on isometric force-time curve (Cf-t) in elderly women. The study included 13 older women (64.08 ± 4.27 years, 69.98 ± 10.56 kg, 157.90 ± 8.66 cm, 28.25 ± 4.22 kg/m²). The participants visited the laboratory for five consecutive days, among which the first two were used for familiarization. During the other three days the participants underwent experimental conditions: control (C) stretch 30 seconds (AE30) and stretch 60 seconds (AE60). For the AE30 and AE60 conditions, three series of passive static stretching were performed, with duration of 30 and 60 seconds, respectively. The experimental conditions were performed with an interval of at least 24 hours between them and the order of execution was randomized. The recording of isometric Cf-t of the knee extensor muscles was performed in extensor chair connected to a force transducer. Measurements were recorded immediately after each experimental condition, for five seconds. For statistical analysis, descriptive procedures were used and ANOVA one way to check possible changes on the Maximal Voluntary Contraction (CVM) and Peak Rate of Force Development (TDFP) among the three conditions (p <0.05). The ANOVA showed no statistically significant difference for CVM and TDFP, between the three conditions. It can be concluded that different volumes of static stretching, three sets ...(Complete abstract click electronic access below)

Efeitos de uma partida sobre o pico de torque funcional e convencional nos músculos isquiotibiais e quadríceps de jogadores de futebol de salão com e sem desequilíbrio muscular

Introdução – Uma das causas mais prováveis de lesões esportivas está relacionada aos desequilíbrios musculares e a fadiga muscular, que é evidenciada no decorrer de um jogo de futebol, principalmente no final do jogo. Esta pode ser avaliada através da comparação da força de contração máxima antes e após o exercício. A fadiga produzida durante o jogo diminui a força muscular concêntrica e excêntrica de flexores e extensores do joelho podendo aumentar a incidência de lesões. Objetivo - Avaliar o efeito de uma partida sobre o pico de torque funcional e convencional nos músculos isquiotibiais e quadríceps de jogadores de futebol de salão com e sem desequilíbrio muscular. Método – Oito jogadores de futebol de salão do gênero masculino, com idade entre 18 e 24 anos, fizeram três visitas ao laboratório: 1ª foram realizadas a antropometria e adaptação aos equipamentos; 2ª teste máximo no dinamômetro isocinético para determinar a razão do pico de torque funcional e convencional nos músculos isquiotibiais e quadríceps; 3ª idem ao 2ª, após a partida de futebol de salão. Análise estatística – através das médias ± DP dos dados obtidos foi utilizado o teste t para amostras dependentes e o Mann Whitney para comparação do pico de torque antes e após a partida de futebol de salão e para comparação da relação flexor/extensor pré e pós- esforço, respectivamente. Em ambos os testes foram adotado um nível de significância de p < 0,05. Resultados - Não foram encontradas diferenças significantes entre os grupos de atletas com desequilíbrio muscular na perna dominante (GD) e grupo equilíbrio (GE) e para os extensores e flexores do GD e GE nas condições Con60. Através do Mann Whitney foram encontradas diferenças...(Resumo completo, clicar acesso eletrônico abaixo)

Modelagem em 3D de uma patela humana e análise de esforços utilizando o método dos elementos finitos

Throughout the history of medicine surgeons realized the importance of the patella to the functioning of the knee. The main function of the patella is to increase the mechanical efficiency of the quadriceps tendon and knee extensor mechanism. It was found that 50% to 80% of the fractures without deviation of the patella have the transversal pattern, possibly due to excessive tensile forces applied to the extensor mechanism. The purpose of this study is to analyze the loads to which a patella is submitted during a normal extension movement of knee. This analysis will be done by modeling a 3D patella and subsequent load simulation as, described in medical literature, using the finite element method

Influência do alongamento prévio no pico de torque e na taxa de força em exercício de contração isométrica

The objective of this study was to investigate the influence of previous active static stretch on the isometric peak torque (PT) and rate of force development (RFD) measured from different time intervals from the beginning of muscle contraction. Participated of this study 15 male individuals, apparently healthy, with ages between 18 and 25 years, without regular physical activity practice. The individuals were submitted in different days to the following tests: 1) Familiarization session to the isokinetic dynamometer; 2) Two maximal isometric concentric contractions for knee extensors in isokinetic dynamometer to determine PT and RFD (Control), and; 3) Two active static stretching exercises for the dominant leg extensors (10 x 30 s for each exercise, with 20 s of rest). After the stretching, the isokinetic test was repeated (Post-Stretching). The conditions 2 and 3 were performed in random order. The RFD was considered as the mean slope of the moment-time curve at time intervals of 0-30, 0-50 and 0-100ms relative to the beginning of muscle contraction. It was verified significant reduction for both maximal RFD and PT after the stretching (p < 0.05). At intervals of 0- 30ms, 0-50ms and 0-100ms, the RFD at the conditions with stretching was similar to the RFD without stretching (p > 0.05). At intervals of 0-150ms and 0-200ms, the RFD obtained at the contraction without stretching was significantly higher that that obtained at the contraction with stretching (p < 0.05). It can be concluded that the static stretching, performed with duration of 600 s diminish isometric PT, maximal RFD and RFD measured at late phase (> 100 ms) of muscle contraction.

Efeitos do treinamento isocinético e isométrico sobre a taxa de desenvolvimento de força máxima

The objective of the present study was to compare the effects of a high speed isokinetic training (180°.s-1) and an isometric training (75°) on the maximum rate of force development (RFDmax) measured in the isokinetic and isometric modes. Twenty seven male non active subjects participated of this study (Mean + SD = body mass 78.6 + 14.1 kg; stature 175.1 + 8.9 cm; age 22.6 + 3.8 years). They were randomly divided into three groups: Control (GC); Isokinetic training (GISOC) and; Isometric training (GISOM). The subjects were submitted in different days to the following pre training protocols: 1) Familiarization to the isokinetic dynamometer tests; 2) Five maximum concentric isokinetic contractions of the knee extensors (180°.s-1) to access the maximum concentric torque (TMC) and the concentric RFDmax; 3) Two maximum isometric contractions of the knee extensors (75°) to access the maximum isometric torque (TMI) and the isometric RFDmax. The same tests were repeated after the training period, but without the familiarization session. Eighteen training sessions were performed (3 times per week). The GISOC performed the entire training whit concentric isokinetic contractions whit the speed of 180°.s-1. The GISOM performed the entire training whit isometric contractions whit the angle between the thigh end the leg being 75° (0° = full knee extension). TMI, TMC, concentric RFDmax, isometric RFDmax values of the GC was not different between pre and post training. GISOM increased only the TMI and the GSIOC increased the TMC, concentric RFDmax and isometric RFDmax. Furthermore, the GISOC had a higher percentage increase of the isometric RFDmax than the isokinetic RFDmax. Based on these results, it is possible to conclude that the increase in maximum strength corresponded to the training specificity theory, unlike to the RFDmax. Thus the use of isometric contraction ...(Complete abstract click electronic access below)