Multipoint determination of pressure-volume curves in human intervertebral discs
Article Abstract:
The human intervertebral disk may biomechanically act like a hydraulic system in which internal disk pressure changes dramatically with even the smallest change in volume. Initial internal pressure was measured in the nucleus pulposus of 12 intervertebral disks from human cadavers. Saline solution was then injected continuously into the nucleus pulposa and pressure values were recorded. Then, to simulate pressures the human back is normally exposed to in changing positions and carrying things, the procedure was repeated using five disks that were clamped and loaded with 9.1 kilogram weights. Contrary to expectations, pressure increased linearly with volume, not exponentially. If however, the pressure-volume relation is calculated using the entire volume of of the nucleus pulposa and not just the volume of the saline injected, pressure rises exponentially with volume.
Publication Name: Annals of the Rheumatic Diseases
Subject: Health
ISSN: 0003-4967
Year: 1993
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Human lumbar apophyseal joint damage and intervertebral disc degeneration
Article Abstract:
Joint damage involving the bony projections of the lumbar spine may precede degeneration of discs between vertebrae, but both may worsen with age. Autopsies of the upper lumbar vertebrae of 31 people revealed that lumbar joints showed more signs of early cartilage damage than knee, hip, or ankle joints. Even the spines of young people showed evidence of damage. Lumbar joint cartilage was damaged in the absence of disc damage. Areas where cartilage is soft were more likely to be damaged, perhaps because of inadequate weight loading or because collagenous joint capsule fibers insert close to these areas. Physical exercise to condition the lumbar joint cartilage may prevent or lessen the damage caused by a sedentary lifestyle.
Publication Name: Annals of the Rheumatic Diseases
Subject: Health
ISSN: 0003-4967
Year: 1995
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Effect of sustained loading on the water content of intervertebral discs: implications for disc metabolism
Article Abstract:
Weight-bearing activities appear to significantly affect the fluid levels in the discs between the spinal bones which in turn may affect bone formation. Researchers simulated a day's weight-bearing activities on 10 spinal sections from five corpses and then evaluated the fluid levels in weight-bearing and non-weight-bearing disc samples. Mean fluid levels decreased by 18% corresponding to a significant decrease in overall body height. Most of the fluid loss occurred in the inner regions of the samples.
Publication Name: Annals of the Rheumatic Diseases
Subject: Health
ISSN: 0003-4967
Year: 1996
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