Efeito agudo do alongamento de diferentes grupos musculares no desempenho muscular de idosas

Among the numerous possibilities of physical exercise, it has been recommended that stretching routines should be incorporated into training programs focused on the elderly population, and that these routines should be preferentially performed on the same strength or aerobic training session. However, studies have shown that muscle strength production can be acutely impaired if it is preceded by static stretching exercises (AE). Although there seems to be a relationship between the number of stretched muscles and strength response, no studies were found examining such relationship in the same study, simultaneously. Thus, the objective of this study is to analyze the acute effect of stretching of different muscle groups on strength performance in older women. Nineteen physically active older women participated in the study (67.8 ± 5.3 years, 68.9 ± 12.4 kg, 157.2 ± 6.4 cm)-usar ponto final em inglês e não vírgula. The participants visited the lab for six consecutive days, three of which were intended to familiarization. Over the next three days, all the participants performed the experimental conditions: control; quadriceps stretching alone and complete stretching, involving the major extensors muscle groups of knees and hips. Both the two stretching conditions were realized with three series of 30s (total volume of 90 seconds for each exercise). All experimental conditions was be performed with an interval of at least 24 hours and order of execution was be randomized. The force transducer was connected to a leg press apparatus, where the isometric force time curve and electromyographic activity of the vastus medial and vastus lateralis were recorded. Measurements were registered immediately after each experimental condition, during five seconds. Statistical analysis comprised descriptive procedures and the One way ANOVA test for repeated measures (p<0.05). No statistically significant differences between the control and the two...

Hemodynamic response in one session of strength exercise with and without electrostimulation in heart failure patients: a randomized controlled trial

Background: Studies have investigated the influence of neuromuscular electrostimulation on the exercise/muscle capacity of patients with heart failure (HF), but the hemodynamic overload has never been investigated. The aim of our study was to evaluate the heart rate (HR), systolic and diastolic blood pressures in one session of strength exercises with and without neuromuscular electrostimulation (quadriceps) in HF patients and in healthy subjects. Methods: Ten (50% male) HF patients and healthy subjects performed three sets of eight repetitions with and without neuromuscular electrostimulation randomly, with one week between sessions. Throughout, electromyography was performed to guarantee the electrostimulation was effective. The hemodynamic variables were measured at rest, again immediately after the end of each set of exercises, and during the recovery period. Results: Systolic and diastolic blood pressures did not change during each set of exercises among either the HF patients or the controls. Without electrostimulation: among the controls, the HR corresponding to the first (85 ± 13 bpm, p = 0.002), second (84 ± 10 bpm, p < 0.001), third (89 ± 17, p < 0.001) sets and recuperation (83 ± 16 bpm, p = 0.012) were different compared to the resting HR (77 bpm). Moreover, the recuperation was different to the third set (0.018). Among HF patients, the HR corresponding to the first (84 ± 9 bpm, p = 0.041) and third (84 ± 10 bpm, p = 0.036) sets were different compared to the resting HR (80 ± 7 bpm), but this increase of 4 bpm is clinically irrelevant to HF. With electrostimulation: among the controls, the HR corresponding to the third set (84 ± 9 bpm) was different compared to the resting HR (80 ± 7 bmp, p = 0.016). Among HF patients, there were no statistical differences between the sets. The procedure was well tolerated and no subjects reported muscle pain after 24 hours. Conclusions: One session of strength exercises with and without neuromuscular electrostimulation does not promote a hemodynamic overload in HF patients. (Cardiol J 2011; 18, 1: 39-46)

Exploratory study of electromyographic behavior of the vastus medialis and vastus lateralis at neuromuscular fatigue onset

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparação do efeito do período de recuperação da fadiga muscular no andar entre adultos jovens e idosos

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

Proporção tecidual da perna de caprinos jovens em função do grupo racial, peso de abate e sexo

To evaluate the effect of breed group, slaughter weight and sex on tissue proportion of the leg and muscle, bone and fat ratio in confined kids, seventy-four goats of both sex were used and divided among breed groups: Alpine (A), ½ Nubian + ½ Alpine (½ ANA), ½ Boer + ½ Alpine (½ BA), ¾ Boer + ¼ Alpine (¾ BA) and ½ Nubian + ¼ Alpine + ¼ Boer, (Three cross - TC), at three slaughter weights (25, 30 and 35 kg). Leg represented 31.01% of half carcass, where 62.29% was total muscle, 21.45% total bone and 8.35% total fat. Alpine animals had higher bone weight than other groups. Male kids had higher muscle and bone proportion, whereas females had higher subcutaneous and intramuscular fat in leg. The percentage of total weight of the muscle, five muscles, adductor muscle, quadriceps muscle and femur were higher in the slaughter weights of 25 and 30 kg.

Effects of strength and power training on neuromuscular variables in older adults

The purpose of this study was to compare the neuromuscular adaptations produced by strength-training (ST) and power-training (PT) regimens in older individuals. Participants were balanced by quadriceps cross-sectional area (CSA) and leg-press 1-repetition maximum and randomly assigned to an ST group (n = 14; 63.6 +/- 4.0 yr, 79.7 +/- 17.2 kg, and 163.9 +/- 9.8 cm), a PT group (n = 16; 64.9 +/- 3.9 yr. 63.9 +/- 11.9 kg, and 157.4 +/- 7.7 cm), or a control group (n = 13; 63.0 +/- 4.0 yr, 67.2 +/- 10.8 kg, and 159.8 +/- 6.8 cm). ST and PT were equally effective in increasing (a) maximum dynamic and isometric strength (p < .05), (b) increasing quadriceps muscle CSA (p < .05), and (c) decreasing electrical mechanical delay of the vastus lateralis muscle (p < .05). There were no significant changes in neuromuscular activation after training. The novel finding of the current study is that PT seems to be an attractive alternative to regular ST to maintain and improve muscle mass.

Do muscle strengthening exercises improve performance in the 6-minute walk test in postmenopausal women?

Background: Walking speed seems to be related to aerobic capacity, lower limb strength, and functional mobility, however it is not clear whether there is a direct relationship between improvement in muscle strength and gait performance in early postmenopausal women. Objective: To evaluate the effect of muscle strengthening exercises on the performance of the 6-minute walk test in women within 5 years of menopause. Methods: The women were randomized into control group (n=31), which performed no exercise, and exercise group (n=27), which performed muscle strengthening exercises. The exercises were performed twice a week for 3 months. The exercise protocol consisted of warm-up, stretching, and strengthening of the quadriceps, hamstring, calf, tibialis anterior, gluteus maximus, and abdominal muscles, followed by relaxation. Muscular strength training started with 60% of 1MR (2 series of 10-15 repetitions), reaching 85% until the end of the 3-month period (4 series of 6 repetitions each). Results: The between-group comparisons pre- and post-intervention did not show any difference in distance walked, heart rate or blood pressure (p>0.05), but showed differences in muscle strength post-intervention, with the exercise group showing greater strength (p<0.05). In the within-group comparison, there were differences in final heart rate and quadriceps and hamstring strength pre- and post-intervention in the exercise group (p<0.05). Conclusion: The results suggest that muscle strengthening of the lower limbs did not improve performance in the 6-minute walk test in this population of postmenopausal women. Trial registration ACTRN12609001053213.

Transcriptional response to GAA deficiency (Pompe disease) in infantile-onset patients

Pompe disease is a genetic disorder resulting from a deficiency of lysosomal acid alpha-glucosidase (GAA) that manifests as a clinical spectrum with regard to symptom severity and rate of progression. In this study, we used microarrays to examine gene expression from the muscle of two cohorts of infantile-onset Pompe patients to identify transcriptional differences that may contribute to the disease phenotype. We found strong similarities among the gene expression profiles generated from biceps and quadriceps, and identified a number of signaling pathways altered in both cohorts. We also found that infantile-onset Pompe patient muscle had a gene expression pattern characteristic of immature or regenerating muscle, and exhibited many transcriptional markers of inflammation, despite having few overt signs of inflammatory infiltrate. Further, we identified genes exhibiting correlation between expression at baseline and response to therapy. This combined dataset can serve as a foundation for biological discovery and biomarker development to improve the treatment of Pompe disease. (C) 2012 Elsevier Inc. All rights reserved.

Strength Training with Blood Flow Restriction Diminishes Myostatin Gene Expression

LAURENTINO, G. C., C. UGRINOWITSCH, H. ROSCHEL, M. S. AOKI, A. G. SOARES, M. NEVES JR, A. Y. AIHARA, A. DA ROCHA CORREA FERNANDES, and V. TRICOLI. Strength Training with Blood Flow Restriction Diminishes Myostatin Gene Expression. Med. Sci. Sports Exerc., Vol. 44, No. 3, pp. 406-412, 2012. Purpose: The aim of the study was to determine whether the similar muscle strength and hypertrophy responses observed after either low-intensity resistance exercise associated with moderate blood flow restriction or high-intensity resistance exercise are associated with similar changes in messenger RNA (mRNA) expression of selected genes involved in myostatin (MSTN) signaling. Methods: Twenty-nine physically active male subjects were divided into three groups: low-intensity (20% one-repetition maximum (1RM)) resistance training (LI) (n = 10), low-intensity resistance exercise associated with moderate blood flow restriction (LIR) (n = 10), and high-intensity (80% 1RM) resistance exercise (HI) (n = 9). All of the groups underwent an 8-wk training program. Maximal dynamic knee extension strength (1RM), quadriceps cross-sectional area (CSA), MSTN, follistatin-like related genes (follistatin (FLST), follistatin-like 3 (FLST-3)), activin IIb, growth and differentiation factor-associated serum protein 1 (GASP-1), and MAD-related protein (SMAD-7) mRNA gene expression were assessed before and after training. Results: Knee extension 1RM significantly increased in all groups (LI = 20.7%, LIR = 40.1%, and HI = 36.2%). CSA increased in both the LIR and HI groups (6.3% and 6.1%, respectively). MSTN mRNA expression decreased in the LIR and HI groups (45% and 41%, respectively). There were no significant changes in activin IIb (P > 0.05). FLST and FLST-3 mRNA expression increased in all groups from pre- to posttest (P < 0.001). FLST-3 expression was significantly greater in the HI when compared with the LIR and LI groups at posttest (P = 0.024 and P = 0.018, respectively). GASP-1 and SMAD-7 gene expression significantly increased in both the LIR and HI groups. Conclusions: We concluded that LIR was able to induce gains in 1RM and quadriceps CSA similar to those observed after traditional HI. These responses may be related to the concomitant decrease in MSTN and increase in FLST isoforms, GASP-1, and SMAD-7 mRNA gene expression.

Lean and Fat Mass Loss in Obese Patients Before and After Roux-en-Y Gastric Bypass: A New Application for Ultrasound Technique

This study aims to evaluate the thickness of the femoral quadriceps and biceps brachii and brachialis muscles bilaterally and the adjacent subcutaneous fat in patients undergoing gastric bypass Roux-en-Y before and after surgery, using ultrasound as the diagnostic method of choice. We studied 12 patients undergoing this surgical method preoperatively and during the first, third, and sixth postoperative months. During these periods, patients were evaluated by ultrasound to determine the thickness of subcutaneous adipose tissue and muscle of the upper and lower limbs. Postoperatively, these patients showed a reduction in the thickness of the upper and lower extremities muscle and adipose tissue as compared to their preoperative values. There was a significant difference in the loss of muscle thickness in all postoperative months and in the thickness of fatty tissue in the sixth month after surgery, compared to the preoperative muscle and fatty tissue thickness. Ultrasound can be considered as the diagnostic method of choice when assessment of the fat and lean body mass is required in morbidly obese patients before and after bariatric surgery.

Multivariate analysis in the maximum strength performance

This study performed an exploratory analysis of the anthropometrical and morphological muscle variables related to the one-repetition maximum (1RM) performance. In addition, the capacity of these variables to predict the force production was analyzed. 50 active males were submitted to the experimental procedures: vastus lateralis muscle biopsy, quadriceps magnetic resonance imaging, body mass assessment and 1RM test in the leg-press exercise. K-means cluster analysis was performed after obtaining the body mass, sum of the left and right quadriceps muscle cross-sectional area (Sigma CSA), percentage of the type II fibers and the 1RM performance. The number of clusters was defined a priori and then were labeled as high strength performance (HSP1RM) group and low strength performance (LSP1RM) group. Stepwise multiple regressions were performed by means of body mass, Sigma CSA, percentage of the type II fibers and clusters as predictors' variables and 1RM performance as response variable. The clusters mean +/- SD were: 292.8 +/- 52.1 kg, 84.7 +/- 17.9 kg, 19249.7 +/- 1645.5 mm(2) and 50.8 +/- 7.2% for the HSP1RM and 254.0 +/- 51.1 kg, 69.2 +/- 8.1 kg, 15483.1 +/- 1 104.8 mm(2) and 51.7 +/- 6.2 %, for the LSP1RM in the 1RM, body mass, Sigma CSA and muscle fiber type II percentage, respectively. The most important variable in the clusters division was the Sigma CSA. In addition, the Sigma CSA and muscle fiber type II percentage explained the variance in the 1RM performance (Adj R-2 = 0.35, p = 0.0001) for all participants and for the LSP1RM (Adj R-2 = 0.25, p = 0.002). For the HSP1RM, only the Sigma CSA was entered in the model and showed the highest capacity to explain the variance in the 1RM performance (Adj R-2 = 0.38, p = 0.01). As a conclusion, the muscle CSA was the most relevant variable to predict force production in individuals with no strength training background.

Muscle Atrophy and Functional Deficits of Knee Extensors and Flexors in People With Chronic Stroke

Background. Further clarification is needed with regard to the degree of atrophy in individual muscle groups and its possible relationship to joint torque deficit poststroke. Objective. The purpose of this study was to investigate quadriceps and hamstring muscle volume and strength deficits of the knee extensors and flexors in people with chronic hemiparesis compared with a control group. Design. This was a cross-sectional study. Methods. Thirteen individuals with hemiparesis due to chronic stroke (hemiparetic group) and 13 individuals who were healthy (control group) participated in this study. Motor function, quadriceps and hamstring muscle volume, and maximal concentric and eccentric contractions of the knee extensors and flexors were assessed. Results. Only the quadriceps muscle of the paretic limb showed reduced muscle volume (24%) compared with the contralateral (nonparetic) limb. There were no differences in muscle volume between the hemiparetic and control groups. The peak torque of the paretic-limb knee extensors and flexors was reduced in both contraction modes and velocities compared with the nonparetic limb (36%-67%) and with the control group (49%-75%). The nonparetic limb also showed decreased extensor and flexor peak torque compared with the control group (17%-23%). Power showed similar deficits in strength (12%-78%). There were significant correlations between motor function and strength deficits (.54-.67). Limitations. Magnetic resonance imaging coil length did not allow measurement of the proximal region of the thigh. Conclusions. There were different responses between quadriceps and hamstring muscle volumes in the paretic limb that had quadriceps muscle atrophy only. However, both paretic and nonparetic limbs showed knee extensor and flexor torque and power reduction.

Physical Activity In Daily Life In Brazilian COPD Patients During and After Exacerbation

Background: Although hospitalization is recognized as an important cause of reduction in physical activity in daily life (PADL) in COPD, there is only one study evaluating this effect, and it was performed in European COPD patients who have a lower PADL than that of South American COPD patients. Objectives: To investigate the effect of hospitalization due to acute exacerbation of PADL in Brazilian COPD patients and to evaluate the factors that determines the physical activity levels during hospitalization and after discharge. Methods: PADL was quantified using a 3-axis accelerometer on the 3rd day of hospitalization and 1 month after discharge in Brazilian COPD patients who were hospitalized due to disease exacerbation. Six-minute walking distance (6MWD), lower limb strength and pulmonary function were also evaluated. Results: A total of 20 patients completed the study. During hospitalization, patients spent most of the time (87%) lying down or sitting; however, 1 month after they were walking >40 min/day. In addition, patients with prior hospitalization had a lower level of physical activity compared to those without a previous history of hospitalization. The time spent walking during hospitalization was significantly explained by the quadriceps strength (r(2) = 0.29; p < 0.05), while 1 month after, the time spent walking was only significantly explained by the 6MWD (r(2) = 0.51; p = 0.02). Conclusions: Brazilian COPD patients are inactive during hospitalization but become active 1 month after discharge. Previously hospitalized are more inactive both during and after exacerbation. The quadriceps strength and 6MWD explain the physical activity levels during hospitalization and at home, respectively.

Isokinetic muscle strength and knee function associated with double femoral pin fixation and fixation with interference screw in anterior cruciate ligament reconstruction

Intensive scheduling in sports requires athletes to resume physical activity shortly after injury. The purpose of this study was to investigate early isokinetic muscle strength and knee function on bone-patellar tendon-bone (BPTB) ACL reconstruction with double femoral pin fixation or interference screw technique. A prospective study was conducted from 2008 to 2009, with 48 athletes who received femoral BPTB fixation with interference screw (n = 26) or double pin (n = 22). Clinical (IKDC objective score and hop test) and isokinetic muscle strength (peak torque (PT), PT/body weight and flexion/extension rate (F/E) in 60 and 240A degrees/s) were analyzed at 6 months of follow-up. Analysis at baseline showed no differences between groups before surgery related to age, gender, associated injury, Tegner or Lysholm score; thus showing that groups were similar. During follow-up, however, there were significant differences between the two groups in some of the isokinetic muscle strength: PT/BW 60A degrees/s (Double Pin = 200% +/- A 13% vs. Interference Screw = 253% +/- A 16%*, *P = 0.01); F/E 60A degrees/s (Double Pin = 89% +/- A 29%* vs. Interference Screw = 74% +/- A 12%, *P = 0.04). No statistical differences between groups were observed on IKDC objective score, hop test and complications. The significant muscle strength outcome of the interference screw group found in this study gives initial evidence that this fixation technique is useful for athletes that may need accelerated rehabilitation. Early return to sports ability signaled by isokinetic muscle strength is of clinical relevance as it is one of the main goals for athletes' rehabilitation. III.

Postural control parameters in elderly female fallers and non-fallers diagnosed or not with knee osteoarthritis

Objectives: To compare stabilometric parameters of elderly female fallers and non-fallers associated or not with knee osteoarthritis (OA). Methods: Fifty-six elderly female fallers and non-fallers diagnosed or not with unilateral or bilateral knee OA were divided into the following groups: FOA (n = 10), elderly female falters with knee OA; FNOA (n = 11), elderly female fallers without knee OA; NFOA (n = 14), elderly female non-fallers with knee OA; and NFNOA (n = 21), elderly female non-fallers without knee OA. For analyzing semi-static balance on a force platform with the elderly females standing, the following parameters were assessed in four conditions: center of pressure (COP), anterior-posterior and mediolateral displacements (APD and MLD, respectively); and COP anterior-posterior and mediolateral displacement velocities (APV and MLV, respectively). The following conditions were assessed: 1) standing on a firm wooden surface with eyes open (WSEO); 2) standing on a firm wooden surface with eyes closed (WSEC); 3) standing on a foam surface with eyes open (FSEO); 4) standing on a foam surface with eyes closed (FSEC). Results: The elderly females with knee OA showed greater APD in all four conditions assessed (P < 0.05), while the elderly female fallers showed greater MLD (P < 0.05). No difference between the groups was observed for APV and MLV (P > 0.05). Conclusions: Knee OA per se increases APD of the COP, while the history of falls, regardless of the presence of knee OA, hinders postural control in the ML direction.