BACKGROUND Reductions in quadriceps strength and peak aerobic capacity (VO2) in patients with chronic obstructive pulmonary disease (COPD) have been studied in relatively small samples over a short period. Moreover, results were not corrected for confounding variables, such as lean muscle mass, gender, and gas transfer capacity of the lungs. OBJECTIVES To compare quadriceps muscle strength an...

BACKGROUND Whether passive measures of isokinetic muscle strength deficits and knee laxity are related to the dynamic function of the anterior cruciate ligament-deficient knee remains unclear. HYPOTHESES Arthrometer measurements are not predictive of peak external knee flexion moment (net quadriceps muscle moment), isokinetic quadriceps muscle strength correlates with peak external knee flexi...

BACKGROUND Quadriceps muscle weakness is common in chronic obstructive pulmonary disease (COPD) but is not observed in a small hand muscle (adductor pollicis). Although this could be explained by reduced activity in the quadriceps, the observation could also be explained by anatomical location of the muscle or fibre type composition. However, the abdominal muscles are of a similar anatomical an...

BACKGROUND Quadriceps muscle dysfunction is well confirmed in chronic obstructive pulmonary disease (COPD) and reported to be related to a higher risk of mortality. Factors contributing to quadriceps dysfunction have been postulated, while not one alone could fully explain it and there are few reports on it in China. This study was aimed to investigate the severity of quadriceps dysfunction in ...

BACKGROUND While total knee arthroplasty reduces pain and provides a functional range of motion of the knee, quadriceps weakness and reduced functional capacity typically are still present one year after surgery. The purpose of the present investigation was to determine the role of failure of voluntary muscle activation and muscle atrophy in the early loss of quadriceps strength after surgery. ...

INTRODUCTION Yin Yang 1 (YY1) is a transcriptional repressor that inhibits muscle gene expression and myogenesis. YY1 has not previously been investigated in the skeletal muscle of patients with COPD. The aims of this study were to investigate YY1 expression and localisation in the quadriceps muscle of COPD patients compared to healthy age-matched controls, and examine the relationship between ...

OBJECTIVE Lower-limb muscle strength is reduced in many people with diabetes. In this study, we examined whether quadriceps muscle strength is reduced in relation to insulin resistance in well-functioning ambulatory nondiabetic individuals. RESEARCH DESIGN AND METHODS Participants (age >or=70 years) underwent dual-energy X-ray absorptiometry (DEXA) scanning to ascertain muscle and fat mass, t...

Muscle contraction causes an increase in activity of 5'-AMP-activated protein kinase (AMPK). This study was designed to determine whether chronic chemical activation of AMPK will increase mitochondrial enzymes, GLUT-4, and hexokinase in different types of skeletal muscle of resting rats. In acute studies, rats were subcutaneously injected with either 5-aminoimidazole-4-carboxamide-1-beta-D-ribo...