In this paper, robust stability properties of periodic discrete time systems are investigated. Analytic expressions are derived for the stability radius in the scalar case.

OBJECTIVES To compare musculoskeletal characteristics of the loaded and non-loaded forearm and upper leg of competitive ten-pin bowlers. METHODS 10 competitive bowlers (30.6∓6.8 yrs) had their areal bone mineral density (aBMD) and body composition measured with Dual Energy X-ray Absorptiometry (DXA). Volumetric bone mineral density (vBMD) and bone characteristics were assessed at 4% and 66% o...

Recently, 3-T magnetic resonance imaging (MRI) has been introduced for bone imaging. Through higher signal-to-noise ratios, as compared to 1.5-T MRI, it promises to be a more powerful tool for the assessment of cortical and trabecular bone measures. The goal of our study was to compare MRI-derived cortical and trabecular bone measures to quantitative computed tomography (QCT)-derived bone miner...

one mineral density measurements are useful for predicting the risk of fracture in an individual, for assessing the effect of a disease or drug on bone mass, and for monitoring the effect of therapy of osteoporosis. For the hip and spine, measurements made at the affected site discriminate better between fragility fractures and nonfracture cases than do measure ments made on other parts of the ...

BACKGROUND & AIMS Children with cerebral palsy (CP) have a high prevalence of pathologic fractures. Bone quantitative ultrasonography (QUS) has emerged as a radiation-free method for the assessment of bone quality and fracture risk. In this study, we applied QUS technique in order to investigate bone status in handicapped institutionalized children and adolescents. METHODS This cross-sectiona...

From 1979 to 1995 in our clinic, vascularized bone grafting was performed in 29 patients with large bone defects, established nonunion, congenital pseudoarthrosis, or avascular necrosis in the upper extremity. Four patients had traumatic bone defects, six had posttraumatic nonunions, two had congenital pseudoarthroses, five had amputations, nine had defects following tumor resection, and three ...

Introduction Bone mineral density (BMD) measured using dual-energy x-ray absorptiometry (DXA) is typically used to assess fracture risk. However, other factors such as bone size and the forward momentum of a fall (a function of body size) can also potentially influence fracture risk, but are understudied. This report describes the characteristics of a cohort of Caucasian pre- and postmenopausal...

The purpose of this study was to investigate the effect of 18 months of high and low levels of volleyball practice on bone acquisition. 130 prepubescent boys (mean age 11.4 ± 0.7) were divided into a high-level training group (HLG), low-level training group (LLG), and controls. Bone mineral content (BMC) and bone area at the whole body, lumbar spine L2-L4, femoral neck of the dominant leg, and ...

Osteoporosis is a common metabolic skeletal disorder characterized by decreased bone mass and deteriorated bone structure, leading to increased susceptibility to fractures. With aging population, osteoporotic fractures are of global health and socioeconomic importance. The three-dimensional microstructural information of the common osteoporosis-related fracture sites, including vertebra, femora...