Qun Xia

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Quantitative data on the range of in vivo vertebral motion is critical to enhance our understanding of spinal pathology and to improve the current surgical treatment methods for spinal diseases. Little data have been reported on the range of lumbar vertebral motion during functional body activities. In this study, we measured in vivo 6 degrees-of-freedom(More)
The study design included an in vivo laboratory study. The objective of the study is to quantify the kinematics of the lumbar spinous processes in asymptomatic patients during un-restricted functional body movements with physiological weight bearing. Limited data has been reported on the motion patterns of the posterior spine elements. This information is(More)
STUDY DESIGN Controlled laboratory study. OBJECTIVE To measure the range of motion of lumbar facet (zygapophyseal) joints in vivo during various functional weight-bearing positions of the upper body. SUMMARY OF BACKGROUND DATA Determination of normal in vivo motion of the lumbar facet joints remains elusive despite numerous in vitro studies, animal(More)
BACKGROUND CONTEXT Lumbar degenerative spondylolisthesis (DS), typically characterized by the forward slippage of the superior vertebra of a lumbar motion segment, is a common spinal pathological condition in elderly individuals. Significant deformation and volume changes of the spinal canal can occur because of the vertebral slippage, but few data have(More)
Lumbar vertebrae are complicated in structure and function. The purpose of this study was to investigate the in-vivo motion characteristics of different portions of the lumbar vertebrae during functional activities. Motion of L2, L3 and L4 was reproduced using a combined dual fluoroscopic and MR imaging technique during flexion-extension and left-right(More)
OBJECTIVE Although some studies have reported on the kinematics of the lumbar segments with degenerative spondylolisthesis (DS), few data have been reported on the in vivo 6 degree-of-freedom kinematics of different anatomical structures of the diseased levels under physiological loading conditions. This research is to study the in vivo motion(More)
OBJECTIVE To observe the in vivo three-dimensional (3-D) transient motion characteristics of the subaxial cervical spine in healthy adults. METHODS Seventeen healthy volunteers without cervical spine related diseases were recruited for this study, including 8 males and 9 females with a mean age of 26 years (range, 23-41 years). The vertebral segment(More)
OBJECTIVE To observe the in vivo vertebral motion of adjacent segments in patients with degenerative spondylolisthesis (DS) during functional weight-bearing activities. METHODS A total of 15 symptomatic L4 DS patients (mean age 54.4 years) and 15 asymptomatic volunteers (mean age 53.4 years) were recruited. The vertebral segment motion of each subject was(More)
BACKGROUND Accurate knowledge of the spinal structural functions is critical to understand the biomechanical factors that affect spinal pathology. Many studies have investigated the human vertebral motion both in vitro and in vivo. However, determination of in vivo motion of the vertebrae under physiologic loading conditions remains a challenge in(More)
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