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)

Relação entre a disparidade de força entre membros inferiores e estabilidade postural em atletas de voleibol

Volleyball is a sport in which the laterality dominant limb shows superior strength and coordination because of its preferential use. Asymmetrical tendencies during the landing after the jump when striking or blocking actions are predominant for most part of game (ARRUDA; EDUARDO, 2008). Adaptations include imbalance of forces in static and dynamic motions at the knee joint, which increases risk for injury. Also, asymmetries in balance control during jumping and landing associate with a general postural instability that can be observed during static balance tasks. The purpose of this study was to investigate relationship between unequal lower limb strength (muscle imbalance) and postural stability levels in volleyball athletes and non-athletes. Nine female volleyball athletes and 10 active non-athletes participated in this study. Four encouters with participants were scheduled: three encounters in the bodybuilding gymnasium to collect anthropometric measures (weight, height for BMI, thigh circumference, which provided an initial diagnosis about asymmetry), and to perform the isometric strength test (i.e., leg press using a load cell and a force transducer to calculate uni an bilateral strength). The last encounter was in the laboratory where a balance test on a force platform was administered under five test conditions, with three repetitions each: baseline (natural standing position), one-leg standing, right side, with full vision (D_CV), and blindfolded (D_SV), one-leg standing, left side, with full vision (E_CV), and blindfolded (E_SV). The stability levels were evaluated using the path length parameters which was based on the total displacement of the center of pressure (DTCP). . Both groups shows asymmetric strength levels between legs, with better performance for the right leg. An ANOVA three way using the DTCP for the CV condition, legs (D x E), trials (3) with repeated measures for the first two factors and with a between (three)...

A influência do alongamento prévio no pico de torque e na taxa de desenvolvimento de força

The objective of this study was to investigate the influence of previous active static stretch on the peak torque (PT) and rate of force development (TDF) during isokinetic concentric contractions at 60 and 180.s-1 in active individuals. Twelve active subjects with ages between 18 and 30 years participated of this study. The individuals were submitted in different days to the following tests: 1) Familiarization session to the isokinetic dynamometer; 2) Five maximal isokinetic concentric contractions for knee extensors at each angular velocity (60 and 180.s-1) to determine PT and TDF (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. There was no significant modification after the stretch exercises on the PT, angle and time at which the PT was attained, at 60 and 180º.s-1. In the same way, there was no significant modification on the TDF and angle at which the maximal TDF was attained in both angular speeds. In other way, the time to attain maximal TDF (TTDF) at 180º.s-1 was significantly lower after the stretching (Pre - 98.3 ± 27.5 ms and Post - 86.6 ± 30.2 ms). There was significant modification on the torque (60 and 180º.s-1) and time (60º.s-1) at different delta of angle variations, obtained at 60º.s-1 at Control and Post-Stretching conditions. However, there was significant reduction of time after the stretching exercises on delta of angle variations of 90-88º (Pre - 46.6 ± 6.5 ms and Post - 44.1 ± 5.1 ms), 88-85º (Pre - 65.8 ± 7.9 ms and Post - 63.3 ± 4.9 ms) and 85-80º (Pre - 93.3 ± 7.7 ms and Post - 90.0 ± 4.2 ms) at 180º.s-1. With base on these data, it is possible to conclude that PT and TDF do not modify after static stretching, irrespectively on the speed...(Complete abstract click electronic access below)

Equilíbrio muscular e pico de torque após jogo de futsal

Indoor soccer is a modality of sport similar to football, which is accompanying an increasing of the number of participants. With the growth of this sport, increased as well the number of injuries, which has been requiring greater attention and care from the health professionals. AIMS: To investigate the functional balance before and after an indoor soccer game and analyze the maximum force before and after the game, in order to verify if there is a great loss of muscle strength of knee flexors and extensors during the game. METHODS: The study included seven amateur soccer players. The isokinetic evaluation was made using the Biodex 3 isokinetic dynamometer at velocities of 60°/s and 180°/s with five repetitions at each velocity for each leg. Further, the study analyzed the peak torque of each leg at each speed of the extensor muscles and flexor concentric and eccentric. RESULTS: Compared to the peak torque before and after the game, there were no significant differences. At 60°/s in the non-dominant leg, peak torque decreased after the game of the extensor concentric and eccentric. In the dominant leg there was a decrease of peak torque in eccentric flexion at 60°/s and concentric flexion to 180°/s. Comparing the peak torque between dominance, there was any significant differences in speed. However, in eccentric flexion at 60°/s before the match there was a significant difference. The peak torque of the dominant leg showed better results than the non-dominant leg. Regarding the functional balance there was no statistically significant differences between the muscles involved. CONCLUSION: From the results achieved, it is possible to conclude that the peak torque of flexor eccentric decreases depending on the length of the exercise. This muscle is stronger in the dominant leg, comparing to the non-dominant leg

Análise de parâmetros cinéticos em mulheres com Síndrome da Dor Femoropatelar no gesto de subida de escada

Pós-graduação em Fisioterapia - FCT

Estudo comparativo da utilização de PRP (Plasma Rico em Plaquetas) autólogo na cicatrização de feridas metacarpianas em equinos: aspectos macroscópicos, histopatológicos, imunoistoquímicos e morfométricos

Pós-graduação em Medicina Veterinária - FMVZ

Estudo do efeito de diferentes protocolos fisioterapêuticos no tratamento da osteoartrite de joelho

Pós-graduação em Saúde Coletiva - FMB

Desenvolvimento de parafuso de interferência bioabsorvível para cirurgia de joelho em PLDL (poli ácido lático) e compósito PLDL + βTCP (beta trifosfato de cálcio)

Pós-graduação em Engenharia Mecânica - FEB

Fatores indutores e supressores da eritropoiese em caninos doentes renais crônicos

Pós-graduação em Cirurgia Veterinária - FCAV

Reação postural de pacientes com doença de Parkinson e idosos sadios no teste de retropulsão instrumentado

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação a longo prazo da técnica de avanço da tuberosidade tibial modificada em cães

Pós-graduação em Cirurgia Veterinária - FCAV

Treinamento com vibração do corpo todo resulta em ganho de força muscular e mobilidade funcional em indivíduos com doença de Parkinson

Pós-graduação em Desenvolvimento Humano e Tecnologias - IBRC

Presença de fatores de risco dependentes ou não de esforço físico em praticantes de corrida de rua

In order to reduce the sedentarism and to improve population's health condition, many physical activity incentive programs have been stimulated. As a result, many people have adhered to street racing, but their health condition is almost always ignored. The aim of this study was to evaluate street racers' health condition, identifying the presence of cardiovascular risk factors as well as problems associated to street racing. The study case was composed by 111 racers from the town of Bauru (94 men and 17 women) aged in average 39±13 years old, who were evaluated in 4 street race competitions. The subjects answered to an anamnesis with questions about their socioeconomic status, medicine use, cardiovascular risk, physical exercise practices, and issues related to racing and injury. Weight (kg) and height (m) were measured to calculate the body mass index (BMI, kg/m²) as well as systolic and diastolic blood pressure (BP), heart rate (HR), abdominal circumference (AC), and flexibility. It could be observed that the majority of racers were Caucasian, married and belonged to social classes over C. The prevalent age was between 18 and 35 years old (42%). Among the participants, 38.7% have already undergone some kind of surgery and 13% declared having some health problem. The questionnaire pointed out that 36% had low and moderate cardiovascular risk. It could be noticed from the AC that 10% of men and 18% of women had high cardiac risk. Among the tested, 43.2% (24.3% altered and 18.9% borderline) showed high BP on the day of the test, but only 2.7% had self-declared hypertensive. In relation to injury, 36% had already had lesions of some kind, 27.5% of which had occurred in the last 8 months. 66.6% had derived from training or racing competitions and the knee was the mostly affected body part. Only 43% had professional orientation by a physical education teacher during their training and the main reasons for them to begin racing practice were...

Avaliação do perfil antropométrico e de força de jovens jogadores de polo-aquático

The present study aimed to analyze the performance of 'boost' among water polo athletes. Twelve athletes (13,9  1,08 years, 169,0  6,0 cm and 59,5  13,5 kg of bodyweight) were under went to anthropometric assessment, body composition and maximum concentric strength of lower limbs. The jump test in the water was done by 'boost' and scaled to jump height. According to the results of strength (Leg Press 45: 157,08  43,30 kg Leg Extension: 72,08  12,86 kg), anthropometry (arm circumf.: 26,04  3,25 cm, thigh circumf.: 50,47  7,65 cm, sholder circumf.: 95,97  8,00 cm, elbow diam.: 4,74  0,51 cm, wrist diam.: 3,21  0,34 cm, knee diam.: 7,89  0,58 cm, biacromial diam.: 37,49  3,81 cm and bi-iliac diam.: 25,43  4,34 cm) and body composition (BMI: 20,74  4,00 kg / m² and% fat: 8,45  4,28), only stature showed a linear correlation (r= 0,595) to the values of vertical jump (height: 47,80  4,35 cm) performance. This anthropometric variable was one able to influence the height of performance by modifying it self, perhaps by maturity. However maturity may be an implicity feature of performance, since force is a concerned effect of the growth. Otherwise technique could play a mains role to the performance of the 'boost'. It can be conclude that possibly is advantageous for water polo athlete be higher and more mature for the realization of 'boost', and the training directed for the technique, but is necessary muscle fitness for the holder

Effects of high and low volume of strength training on muscle strength, muscle volume and lipid profile in postmenopausal women

Changes in lipid profile are considered a risk factor for cardiovascular disease (CVD), especially in postmenopausal woman who have been associated with age-related loss of muscle mass. The beneficial role of aerobic exercise in the prevention of CVD has been well documented. However, the effect of strength training has not been established. The purpose of this study was to determine the changes of lipoprotein levels after 12 weeks of different volumes of strength training and its correlation with strength and muscle volume in postmenopausal women. The participants were randomized into three groups: low volume (LVST; n = 12, 1 set) and high volume of strength training (HVST; n = 11, 3 sets), or control group (n = 12). Training groups performed 12 weeks of supervised strength exercises, 15 maximum repetitions, five times a week, 20 minutes for LVST and 40 minutes for HVST for each training session. Measurements included body composition, strength and muscle volume, as well as blood analysis (glucose, total cholesterol, triglycerides, low-density lipoprotein, and high-density lipoprotein) pre- and post-training. The HVST and LVST improved the one-repetition maximum knee extension strength (p < 0.001), maximal dynamic strength (p < 0.001), and muscle volume (p = 0.048). Post-training triglyceride was lower in HVST when compared to LVST and the control group (p = 0.047). Even though they present the same neuromuscular and morphological adaptations in postmenopausal women, the HVST is more effective than LVST in improving the lipid profile of postmenopausal woman, and can be considered as an ideal program of intervention to reverse changes in lipid metabolism commonly found in this group. Copyright (C) 2014, The Society of Chinese Scholars on Exercise Physiology and Fitness. Published by Elsevier (Singapore) Pte Ltd. All rights reserved.