Axial rotation of the trunk has been reported as a significant risk of low back dysfunction. However, a lack of biomechanical investigation exists that explains how twisting is accomplished with simultaneous asymmetric handling between the hip joints and lumbar spine. We used a three-dimensional motion analysis to measure movements of the bilateral hips and lumbar spine. Forty-four persons part...

1Previouslv published in Orthopadie-Technik, 1/75, 7-9. Origins of concept "Present indications are that transverse rota­ t ions of the various segments of the leg are an impor tant factor in the ease and rhy thm of walking of normal individuals. In order to improve function, reduce fatigue, and prevent more or less continual abrasion at critical points of the s tump of the amputee , provision ...

We study the problem of thermal convection in a laterally heated horizontal cylinder rotating about its axis. A cylinder of aspect ratio Γ=H/2R=2 containing a small Prandtl number fluid (σ=0.01) representative of molten metals and molten semiconductors at high temperature is considered. We focus on a slow rotation regime (Ω<8), where the effects of rotation and buoyancy forces are comparable. T...

BACKGROUND Axial vertebral rotation (AVR) is one of the important parameters to evaluate the severity and predict the progression of scoliosis. However, the AVR measurements on radiographs may underestimate its actual value. This pilot study investigated a new three-dimensional (3D) ultrasound method to measure AVR. METHODS Three cadaveric vertebrae T7, L1, and L3 were scanned with a 3D medic...

BACKGROUND This study was performed to evaluate three-dimensional positional change of the condyle using three-dimensional computed tomography (3D-CT) following unilateral sagittal split ramus osteotomy (USSRO) in patients with mandibular prognathism. METHODS This study examined two patients exhibiting skeletal class III malocclusion with facial asymmetry who underwent USSRO for a mandibular ...

We performed a biomechanical study on human cadaver spines to determine the effect of three different interbody cage designs, with and without posterior instrumentation, on the three-dimensional flexibility of the spine. Six lumbar functional spinal units for each cage type were subjected to multidirectional flexibility testing in four different configurations: intact, with interbody cages from...

AIM Facetectomy is a leading surgical method for stenosis treatment. The objective of this study was to investigate biomechanical effect of graded facetectomy on the lumbar spine using an asymmetrical finite element model. MATERIAL AND METHODS A validated 3-dimensional asymmetrical finite element model of lumbar L1-L5 was developed based on computerized tomography (CT) scans. All components w...

The objective of this study were to: (i) describe the typical three-dimensional (3D) angular kinematics of the lumbar spine and pelvis during running and; (ii) assess whether the movements of the lumbar spine and pelvis during running are coordinated. A cohort of 20 non-injured male runners who usually ran >20 km/week were voluntarily recruited. All trials were conducted on a treadmill at a run...