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.

Oxygen consumption and heart rate during repeated squatting exercises with or without whole-body vibration in the elderly.

Avelar, NCP, Simão, AP, Tossige-Gomes, R, Neves, CDC, Mezencio, B, Szmuchrowski, L, Coimbra, CC, and Lacerda, ACR. Oxygen consumption and heart rate during repeated squatting exercises with or without whole-body vibration in the elderly. J Strength Cond Res 25(12): 3495-3500, 2011-The aim of this study was to investigate whether vibration plus squatting would increase cardiovascular demand to the optimal exercise limits needed for the prescription of cardiovascular training. Oxygen consumption, measured breath by breath by a portable gas analysis system, and heart rate (HR), measured using an HR monitor, were evaluated in 18 elderly individuals, 15 women and 3 men with a mean age of 72 ± 6 years. These variables were measured simultaneously and at the same time points in each subject during rest and randomly during the performance of squatting exercises (8 series of 40 seconds, with 40 seconds of rest between series of performing squats in 3-second cycles with 10-60° of flexion, a total of 5 repetitions for 40 seconds) with or without vibration at a frequency of 40 Hz and amplitude of 4 mm, separated by at least 1 day. Associating whole-body vibration with squatting exercise resulted in an additional increase of around 20% in oxygen consumption and 7.5% in the HR recorded during exercise. However, during squatting exercise with vibration, the increase achieved in oxygen consumption was limited to around 2 metabolic equivalents, and mean HR represented around 56% of the predicted maximum HR for age. The results of this study show that, despite the fact that vibration increased oxygen consumption and HR during the performance of squatting exercise, the minimum standards of intensity for the prescription of physical exercise with the specific objective of improving cardiorespiratory fitness were not achieved. Therefore, a protocol such as that used in the study does not meet the threshold for cardiovascular training prescription.

Análise da translação anterior da tíbia, pico de torque e atividade eletromiográfica do quadríceps e isquiotibiais em indivíduos com lesão do ligamento cruzado anterior em cadeia cinética aberta / Analysis of anterior tibial translation, peak torque, and quadriceps and hamstrings coactivation in individuals with anterior cruciate ligament injuries performing isometric open kinetic chain exercises

Os objetivos deste estudo foram avaliar a translação anterior da tíbia (TAT), pico de torque isométrico e atividade eletromiográfica de indivíduos com lesão do ligamento cruzado anterior (LCA) realizando contrações isométricas em cadeia cinética aberta no ângulo de 30° de flexão do joelho. Foram avaliados 20 voluntários do sexo masculino (31.1 ± 7.45 anos) com ruptura completa do LCA e 20 indivíduos controle (22.2 ± 3.15 anos). Eletromiografia de superfície, artrômetro KT 1000 e um Dinamômetro isocinético foram utilizados para avaliar a atividade EMG do Quadríceps e Isquiotibiais, TAT passiva e ativa e pico de torque isométrico respectivamente durante três contrações isométricas voluntária máxima a 30 ° de flexão do joelho. Os resultados demonstraram que a TAT passiva e ativa é significativamente maior em joelhos com lesão do LCA comparado ao joelho contralateral, lado dominante e não dominante do grupo controle, porém os valores da TAT ativa foram menores do que a passiva. Não houve diferenças estatisticamente significativas entre os grupos na atividade EMG do quadríceps e isquiotibiais e no pico de torque isométrico produzido durante o tarefa motora requisitada. Os resultados deste estudo demonstram que indivíduos com lesão do LCA e indivíduos controle se comportam de maneira similar em relação a pico de torque isométrico e controle motor embora a artrocinemática da articulação tibiofemural mostrou-se diferente em joelhos lesados.

The aim of this study was to evaluated the anterior tibial translation (ATT), isometric peak torque and EMG activity in individuals with acl rupture performing isometric contraction in open kinetic chain in angle that provoke substantial ATT. It was evaluated 20 male subjects (31.1± 7.45 years) with acl total rupture and 20 control subjects (22.2 ± 3.15 years). Electromyography, arthrometric kt 1000 and isokinetic dynamometry was used to evaluate the quadriceps and hamstrings EMG activity, passive and active ATT and isometric peak torque respectively during three maximum isometric voluntary contractions at 30 degrees of knee flexion. The results demonstrated that the passive and active ATT is significant greater in knees with acl rupture compared with the contralateral knees, dominant and non dominant knees of the control group. However the active ATT values were greater than the passive ATT. There is no statistic significant differences between groups concerning quadriceps and hamstring EMG activity and in the peak torque produced during the motor task requested. The results of this study demonstrated that individuals with acl rupture had similar behavior compared with normal knees in relation to isometric peak torque and motor control despite the different arthrokinematics of the tibiofemural joint observed in injured knees.