André Gustavo Pereira de Andrade

Functional Performance and Inflammatory Cytokines After Squat Exercises and Whole-Body Vibration in Elderly Individuals With Knee Osteoarthritis

OBJECTIVE To investigate the effects of squat exercises combined with whole-body vibration on the plasma concentration of inflammatory markers and the functional performance of elderly individuals with knee osteoarthritis (OA). DESIGN Clinical, prospective, randomized, single-blinded study. SETTING Exercise physiology laboratory. PARTICIPANTS Elderly subjects with knee OA (N=32) were divided into 3 groups: (1) squat exercises on a vibratory platform (platform group, n=11); (2) squat exercises without vibration (squat group, n=10); and (3) the control group (n=11). INTERVENTIONS The structured program of squat exercises in the platform and squat groups was conducted 3 times per week, on alternate days, for 12 weeks. MAIN OUTCOME MEASURES Plasma soluble tumor necrosis factor-α receptors 1 (sTNFR1) and 2 (sTNFR2) were measured using immunoassays (the enzyme-linked immunosorbent assay method). The Western Ontario and McMaster Universities Osteoarthritis Index questionnaire was used to evaluate self-reported physical function, pain, and stiffness. The 6-minute walk test, the Berg Balance Scale, and gait speed were used to evaluate physical function. RESULTS In the platform group, there were significant reductions in the plasma concentrations of the inflammatory markers sTNFR1 and sTNFR2 (P<.001 and P<.05, respectively) and self-reported pain (P<.05) compared with the control group, and there was an increase in balance (P<.05) and speed and distance walked (P<.05 and P<.001, respectively). In addition, the platform group walked faster than the squat group (P<.01). CONCLUSIONS The results suggest that whole-body vibration training improves self-perception of pain, balance, gait quality, and inflammatory markers in elderly subjects with knee OA.

Analysis of lower limb asymmetries by isokinetic and vertical jump tests in soccer players.

Abstract Menzel, H-J, Chagas, MH, Szmuchrowski, LA, Araujo, SRS, de Andrade, AGP, and Resende de Jesus-Moraleida, F. Analysis of lower limb asymmetries by isokinetic and vertical jump tests in soccer players. J Strength Cond Res 27(5): 1370–1377, 2013—Assessment of lower extremity bilateral asymmetries in soccer players is important for both injury prevention and performance. The purpose of this investigation was to compare isokinetic knee extensor assessment of asymmetry with a more specific countermovement jump (CMJ). Forty-six Brazilian male professional soccer players participated in this study. The maximal power, maximal force and impulse were determined during CMJ and the total work and peak torque at 60, 180, and 300°·s−1 during isokinetic leg extension, separately for each leg. Factor analysis was performed for all investigated variables, and the diagnostic concordance between different criteria was analyzed by McNemar’s &khgr;2 test. The factor analysis showed that the isokinetic and CMJ tests were widely independent methods for the assessment of bilateral differences. Concordance of the diagnostic information could only be found between the maximal force during CMJ and the total work and peak torque at 180 and 300°·s−1 during isokinetic leg extension. Impulse and maximal power during CMJ on a double force platform appear to be appropriate additional variables for the identification of bilateral differences. Therefore, it might be pertinent to perform, in addition to isokinetic assessment, a vertical jump test on a force platform to assure widespread and reliable diagnostic information.

Acute effect of constant torque and angle stretching on range of motion, muscle passive properties, and stretch discomfort perception.

Abstract Cabido, CET, Bergamini, JC, Andrade, AGP, Lima, FV, Menzel, HJ, and Chagas, MH. Acute effect of constant torque and angle stretching on range of motion, muscle passive properties, and stretch discomfort perception. J Strength Cond Res 28(4): 1050–1057, 2014—The aim of the present study was to compare the acute effects of constant torque (CT) and constant angle (CA) stretching exercises on the maximum range of motion (ROMmax), passive stiffness (PS), and ROM corresponding to the first sensation of tightness in the posterior thigh (FSTROM). Twenty-three sedentary men (age, 19–33 years) went through 1 familiarization session and afterward proceeded randomly to both CA and CT treatment stretching conditions, on separate days. An isokinetic dynamometer was used to analyze hamstring muscles during passive knee extension. The subjects performed 4 stretches of 30 seconds each with a 15-second interval between them. In the CA stretching, the subject reached a certain ROM (95% of ROMmax), and the angle was kept constant. However, in the CT stretching exercise, the volunteer reached a certain resistance torque (corresponding to 95% of ROMmax) and it was kept constant. The results showed an increase in ROMmax for both CA and CT (p < 0.001), but the increase was greater for CT than for CA (CA vs. CT in poststretching, p = 0.002). Although the PS decreased for both CA and CT (p < 0.001), the decrease was greater for CT than for CA (CA vs. CT in poststretching, p = 0.002). The FSTROM increased for both CA and CT, but the increase for CT was greater than that for CA (CA vs. CT in poststretching, p = 0.003). The greater increase in ROMmax for the CT stretch may be explained by greater changes in the biomechanical properties of the muscle-tendon unit and stretch tolerance, as indicated by the results of PS and FSTROM.

Brain Temperature in Spontaneously Hypertensive Rats during Physical Exercise in Temperate and Warm Environments

This study aimed to evaluate brain temperature (Tbrain) changes in spontaneously hypertensive rats (SHRs) subjected to two different physical exercise protocols in temperate or warm environments. We also investigated whether hypertension affects the kinetics of exercise-induced increases in Tbrain relative to the kinetics of abdominal temperature (Tabd) increases. Male 16-week-old normotensive Wistar rats (NWRs) and SHRs were implanted with an abdominal temperature sensor and a guide cannula in the frontal cortex to enable the insertion of a thermistor to measure Tbrain. Next, the animals were subjected to incremental-speed (initial speed of 10 m/min; speed was increased by 1 m/min every 3 min) or constant-speed (60% of the maximum speed) treadmill running until they were fatigued in a temperate (25°C) or warm (32°C) environment. Tbrain, Tabd and tail skin temperature were measured every min throughout the exercise trials. During incremental and constant exercise at 25°C and 32°C, the SHR group exhibited greater increases in Tbrain and Tabd relative to the NWR group. Irrespective of the environment, the heat loss threshold was attained at higher temperatures (either Tbrain or Tabd) in the SHRs. Moreover, the brain-abdominal temperature differential was lower at 32°C in the SHRs than in the NWRs during treadmill running. Overall, we conclude that SHRs exhibit enhanced brain hyperthermia during exercise and that hypertension influences the kinetics of the Tbrain relative to the Tabd increases, particularly during exercise in a warm environment.

Inflammatory Mediators and Pain in the First Year After Acute Episode of Low-Back Pain in Elderly Women: Longitudinal Data from Back Complaints in the Elders—Brazil

Objective The aims of this study were to determine the course of plasma levels of inflammatory mediators (interleukin 6 [IL-6], tumor necrosis factor &agr; [TNF-&agr;], soluble TNF receptor 1 [sTNF-R1]) and the severity of low-back pain (LBP) over 6 to 12 months after an acute episode of LBP in elderly women and to establish an association between inflammatory mediators and LBP recovery. Design This was a longitudinal study of a subsample (155 elderly women with acute LBP, aged ≥65 years) of the international Back Complaints in the Elders cohort study. Plasma levels of IL-6, TNF-&agr;, and sTNF-R1 were measured using enzyme-linked immunosorbent assays and pain severity using the numerical pain scale. Results There was a decrease in the severity of LBP (P = 0.033) and in the levels of IL-6 and TNF-&agr; (P < 0.001) and an increase in sTNF-R1 (P < 0.001) in the first year after an acute episode of LBP. The probability of occurrence of pain relief at the 12-month follow-up was 2.22 times higher in elderly women who had low levels of IL-6 (<1.58 pg/mL) at baseline. Conclusions Our findings showed a relationship between inflammation and LBP by establishing that low IL-6 plasma levels preceded outcome (LBP recovery), supporting the concept that proinflammatory cytokines promote pain.

Validação das propriedades psicométricas do RESTQ-Coach na versão brasileira

The purpose of this study was to validate a Brazilian version of the The Recovery, Stress Questionnaire for Coaches (RESTQ-Coach), herein named Questionario de Estresse e Recuperacao para Treinadores Esportivos (RESTQ-Coach-versao brasileira). The RESTQ is an assessment tool for Brazilian sport coaches. Also, using Confirmatory Factor Analysis (CFA) and Exploratory Factor Analysis (EFA), the purpose of this study was to verify the adequacy of the theoretical model by Kallus e Kellmann (1993). A sample comprised of 424 coaches, average age of 37.06 (±9.20) years, was divided into eleven different sports modalities, consisting of five team sports and six individual sports. The results of the AFC shows that the original model of the questionnaire proposed by Kallus e Kellmann (1993) is inadequate for this sample, and that the AFE was identified as the best solution to a factorial validation of the instrument, which is composed of six factors. This solution disclosed general internal consistency values of α = .85. Values of the global adjustment indicators of the Brazilian model for six AFE factors were: χ2 = 9.660,239 e gl = 2695, p=0,001; CFI= 0,96; TLI= 0,95; RMSEA 0,07, expressing their quality. We concluded that Kallus e Kellmann (1993) model was not corroborated by the AFC for this Brazilian sample. The best factorial solution to the RESTQ-Coach Brazilian version is composed by six constructs.

Relação entre força muscular de membros inferiores e capacidade de aceleração em jogadores de futebol

The aim of this study was to analyze bilateral differences in lower limb strength and running velocity with right and left turns in soccer players. Nineteen junior athletes with a mean age of 18.58 ± 0.77 years participated in this study. Running velocity was analyzed by 15 m sprint test with and without 90o turns using photocells. In order to identify lateral differences of muscular strength characteristics, squat jumps with one leg were performed on a force plate. The significance level was p < 0.05. Except for the time dependent variables of the squat jump, retest-reliability coefficients were higher than 0.85. In order to identify correlations between lateral differences of strength parameters and lateral differences in the sprint test, contingency coefficients were calculated. The only significant correlation (p = 0.05) was found between bilateral differences of maximal force and the dominant leg. The results suggest that there is no relationship between muscular strength of the lower limbs and acceleration performance of soccer players.

The level of performance stabilization influences motor adaptation on an isometric force control task

This study compared the effects of two levels of performance stabilization on the adaptation to unpredictable perturbations in an isometric control force task with the goal of controlling 40% of the maximum force. The experiment consisted of pre-exposure and exposure phases. In the pre-exposure two levels of performance stabilization were manipulated: a stabilization group (SG) performed three trials in a row while maintaining 40% of the maximum force for three seconds and an absolute error less than or equal to 5% (i.e., the criteria of performance), and a superstabilization group (SSG) performed six blocks of the same criteria. During the exposure phase, the task was the same as that in the pre-exposure phase; however, it was inserted 9 trials of perturbations when the task goal changed to 60% of the maximum force. We measured the %RMSE, RMS from the biceps and triceps brachii and co-contraction. In the pre-exposure phase, both groups showed similar performance and muscle activity. When exposed to the perturbations, SSG performance more quickly returned to the previous level of accuracy, showed lower muscle activation and demonstrated a greater muscle co-contraction than did SG. The results give support to the adaptive process model on motor learning.

Task difficulty and inertial properties of hand-held tools: an assessment of their concurrent effects on precision aiming

Aiming hand-held tools at targets in space entails adjustments in the dynamical organization of aiming patterns according to the required precision. We asked whether and how these adjustments are modified by the tools mass distribution. Twelve participants performed reciprocal aiming movements with a 50-cm long wooden probe. Kinematic patterns of probe movements were used as a window into the behavioral dynamic underlying performance of a reciprocal aiming task. We crossed three levels of task difficulty (IDs 2.8, 4.5 and 6.1) with two types of probe varying in their mass distribution (proximal vs distal loading). Movement duration was affected by task difficulty and probe loading (shorter for larger targets and proximal probe loading). Progressive deviations from a sinusoidal movement pattern were observed as task difficulty increased. Such deviations were more pronounced with proximal probe loading. Results point to a higher degree of non-linearity in aiming dynamics when the probe was loaded proximally, which might reflect employment of additional perceptual-motor processes to control the position of its less stable tip at the vicinity of the targets. More generally, the effects of probe loading on aiming pattern and dynamics suggest that perceptual-motor processes responding to task level constraints are sensitive to, and not independent from, biomechanical, end-effector constraints.

Bandwidth Knowledge of Results on the Learning of the Saloon Dart Throwing Task

The effects of two different bandwidths of information of Knowledge of Results (KR) were investigated. 54 university students participated. The experiment consisted of an acquisition phase with practice of throwing a saloon dart as accurately as possible at a target lying on the floor 2.5 meters away until a specific area of the target was hit three trials in a row. Narrow bandwidth and Wide bandwidth groups received KR when performance was outside the bandwidth. A Control group received KR after every trial. A transfer test was run 10 min. later with 10 more trials and the target 3.0 m away, with no KR. Analyses showed that narrow KR bandwidth was associated with better learning of real world tasks.