Hamstring and quadriceps muscles are essential for the performance of athletes in various sport branches. Hamstring muscles control running activities and stabilize the knee during turns or tackles, while quadriceps muscles play an important role in jumping and kicking. Although hamstring and quadriceps muscle strength in athletes can be accurately measured using isokinetic dynamometry, practic...

background: osteoarthritis is one of the most common diseases in synovial joints. dueto high loading forces during weight-bearing activities, the knee joint is prone to degenerative processes. this study aimed to compare the flexibility of muscles around the knee joint in patients with knee osteoarthritis with those of healthy individuals. methods: twenty-three women with bilateral knee osteoar...

BACKGROUND The purpose of this study was to elucidate relationships between quadriceps and hamstrings voluntary muscle fatigue and upper motor lesion impairments in cerebral palsy in order to gain a better understanding of their contribution to the observed fatigue resistance. METHODS Seventeen ambulatory subjects with cerebral palsy (mean age: 17.0, SD=4.8 years) were recruited. Quantitative...

Background In chronic obstructive pulmonary disease (COPD), weakness and muscle mass loss of the quadriceps muscle has been demonstrated to predict survival and mortality rates of patients. Tumor necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK), as a member of the TNF superfamily, has recently been identified as a key regulator of skeletal muscle wasting and metabolic dysfunction. S...

background delayed onset muscle soreness (doms) is the sensation of stiffness and pain in the muscles that occurs 24-48 hours after unaccustomed or strenuous exercise. objectives the aim of this study was to examine and compare the effect of vibration training (vt) on delayed onset muscle soreness. materials and methods twenty healthy non-athletic volunteers (female, age 20-30 years, body mass ...

Chronic obstructive pulmonary disease (COPD) and other chronic diseases such as heart failure are accompanied by skeletal muscle alterations that further enhance morbidity and mortality in affected individuals. Several studies have highlighted important structural and biochemical modifications in limb and respiratory muscles in COPD. Reviewing the similarities and differences between the two mo...

BACKGROUND The loss of skeletal muscle mass with aging has been attributed to a decline in muscle fiber number and muscle fiber size. OBJECTIVE To define to what extent differences in leg muscle cross-sectional area (CSA) between young and elderly men are attributed to differences in muscle fiber size. METHODS Quadriceps muscle CSA and type I and type II muscle fiber size were measured in h...

BACKGROUND AND PURPOSE Electrical stimulation has been used to assess skeletal muscle resistance to fatigue. The purpose of this study was to test the hypothesis that 12 weeks of intense endurance exercise training on a bicycle ergometer would reduce the percentage of decline in quadriceps femoris muscle torque during an electrically elicited fatigue test. SUBJECTS AND METHODS Eleven nondisab...

In patients with osteoarthritis of the knees, quadriceps muscle dysfunction is an early and common clinical feature and an important determinant of disability. In the current study, changes in quadriceps muscle strength and voluntary quadriceps muscle activation after high tibial osteotomies for primary osteoarthritis of the knee in 19 patients were investigated. Quadriceps muscle function was ...

BACKGROUND Published data regarding the structure of the quadriceps tendon are diverse. Dissection of the quadriceps muscle group revealed that beside the rectus femoris, vastus lateralis, vastus intermedius and vastus medialis a fifth muscle component- named the tensor vastus intermedius consistently fused into quadriceps tendon. It can be hypothesized that all these elements of the extensor a...