using a cluster sampling method, a group of menopausal women from three geographic areas in tehran were asked to participate in the study. demographic data was obtained using a questionnaire. subjects were than referred to perform bone mass densitometry (bmd). the relationship between various variables (i.e. age of menarche, number of years of endogenous estrogen exposure, ... ) with mineral de...

Bone microarchitecture and mineralization were determined at three-dimensional synchrotron radiation micro computed tomography in two inbred mice strains. Distal metaphysis of the left femur was imaged in three dimensions at 6.65 microm, whereas the right femur was analyzed with histomorphometry. Three-dimensional quantitative parameters of trabecular and cortical bone architecture were compute...

purpose: given that weight and body mass index (bmi) are considered as modifiable factors in osteoporosis, the present study aimed to examine the relationship of weight and bmi with bone mineral density (bmd) and bone mineral content (bmc) at the femur and lumbar vertebrae in perimenopausal women. methods: in this descriptive-correlational study, we measured the bone density of the femur and lu...

UNLABELLED Quantitative information about bone tissue-level loading is essential for understanding bone mechanical behavior. We made microfinite element models of a healthy and osteoporotic human femur and found that tissue-level strains in the osteoporotic femoral head were 70% higher on average and less uniformly distributed than those in the healthy one. INTRODUCTION Bone tissue stresses a...

Avascular necrosis of the femoral head (ANFH) is a pathologic process that results from interruption of blood supply to the femur bone resulting in the death of bone cells and collapse of the femoral head. Nontraumatic ANFH continuesto be a significant challenge to orthopedic surgeons. While the exact mechanisms remain elusive, many new insights have emerged from research in the last decade tha...

This study explores how curvature in the quokka femur may help to reduce bending strain during locomotion. The quokka is a small wallaby, but the curvature of the femur and the muscles active during stance phase are similar to most quadrupedal mammals. Our hypothesis is that the action of hip extensor and ankle plantarflexor muscles during stance phase place cranial bending strains that act to ...

Both stiffness and strength of bones are thought to be controlled by the "bone mechanostat". Its natural stimuli would be the strains of bone tissue (sensed by osteocytes) that are induced by both gravitational forces (body weight) and contraction of regional muscles. Body weight and muscle mass increase with age. Biomechanical performance of load-bearing bones must adapt to these growth-induce...

BACKGROUND Questions regarding the distribution of stress in the proximal human femur have never been adequately resolved. Traditionally, by considering the femur in isolation, it has been believed that the effect of body weight on the projecting neck and head places the superior aspect of the neck in tension. A minority view has proposed that this region is in compression because of muscular f...

Postmenopausal osteoporosis is a degenerative disease caused by lack of estrogen whereby bone degeneration exceeds bone formation, resulting in loss of bone mass. Various drugs have been utilized in an attempt to ameliorate bone strength in such patients. The aim of the present study was to compare the effects of vitamin K or teriparatide alone and combined on bone metabolism and biomechanics i...