Biomaterial Database

Diurnal changes in spinal mechanics and their clinical significance. 1990

M A Adams, and P Dolan, and W C Hutton, and R W Porter

Comparative Orthopaedic Research Unit, University of Bristol, England.

Diurnal changes in the loads acting on the spine affect the water content and height of the intervertebral discs. We have reviewed the effects of these changes on spinal mechanics, and their possible clinical significance. Cadaveric lumbar spines subjected to periods of creep loading show a disc height change similar to the physiological change. As a result intervertebral discs bulge more, become stiffer in compression and more flexible in bending. Disc tissue becomes more elastic as its water content falls, and its affinity for water increases. Disc prolapse becomes more difficult. The neural arch and associated ligaments resist an increasing proportion of the compressive and bending stresses acting on the spine. Observations on living people show that these changes are not fully compensated for by modified muscle activity. We conclude that different spinal structures are more heavily loaded at different times of the day. Therefore, the time of onset of symptoms and signs, and any diurnal variation in their severity, may help us understand more about the pathophysiology of low back pain and sciatica.

UI	MeSH Term	Description	Entries
D007403	Intervertebral Disc	Any of the 23 plates of fibrocartilage found between the bodies of adjacent VERTEBRAE.	Disk, Intervertebral,Intervertebral Disk,Disc, Intervertebral,Discs, Intervertebral,Disks, Intervertebral,Intervertebral Discs,Intervertebral Disks
D007405	Intervertebral Disc Displacement	An INTERVERTEBRAL DISC in which the NUCLEUS PULPOSUS has protruded through surrounding ANNULUS FIBROSUS. This occurs most frequently in the lower lumbar region.	Disc Herniation,Disc Protrusion,Disc, Herniated,Disk Herniation,Disk Protrusion,Disk, Herniated,Intervertebral Disc Herniation,Intervertebral Disc Protrusion,Intervertebral Disk Displacement,Intervertebral Disk Herniation,Intervertebral Disk Protrusion,Prolapsed Disk,Protruded Disc,Protruded Disk,Slipped Disk,Disk Prolapse,Herniated Disc,Herniated Disk,Prolapsed Disc,Slipped Disc,Disc Displacement, Intervertebral,Disc Herniations,Disc Protrusion, Intervertebral,Disc Protrusions,Disc Protrusions, Intervertebral,Disc, Prolapsed,Disc, Protruded,Disc, Slipped,Discs, Protruded,Disk Displacement, Intervertebral,Disk Herniations,Disk Prolapses,Disk Protrusion, Intervertebral,Disk Protrusions,Disk, Prolapsed,Disk, Protruded,Disk, Slipped,Herniated Discs,Herniated Disks,Herniation, Disc,Herniation, Disk,Herniation, Intervertebral Disc,Herniation, Intervertebral Disk,Intervertebral Disc Displacements,Intervertebral Disc Herniations,Intervertebral Disc Protrusions,Intervertebral Disk Displacements,Intervertebral Disk Herniations,Intervertebral Disk Protrusions,Prolapse, Disk,Prolapsed Discs,Prolapsed Disks,Prolapses, Disk,Protruded Discs,Protruded Disks,Protrusion, Disc,Protrusion, Disk,Protrusion, Intervertebral Disc,Protrusion, Intervertebral Disk,Protrusions, Intervertebral Disk,Slipped Discs,Slipped Disks
D009068	Movement	The act, process, or result of passing from one place or position to another. It differs from LOCOMOTION in that locomotion is restricted to the passing of the whole body from one place to another, while movement encompasses both locomotion but also a change of the position of the whole body or any of its parts. Movement may be used with reference to humans, vertebrate and invertebrate animals, and microorganisms. Differentiate also from MOTOR ACTIVITY, movement associated with behavior.	Movements
D011187	Posture	The position or physical attitude of the body.	Postures
D002940	Circadian Rhythm	The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs or environmental and physiological stimuli.	Diurnal Rhythm,Nyctohemeral Rhythm,Twenty-Four Hour Rhythm,Nycthemeral Rhythm,Circadian Rhythms,Diurnal Rhythms,Nycthemeral Rhythms,Nyctohemeral Rhythms,Rhythm, Circadian,Rhythm, Diurnal,Rhythm, Nycthemeral,Rhythm, Nyctohemeral,Rhythm, Twenty-Four Hour,Rhythms, Circadian,Rhythms, Diurnal,Rhythms, Nycthemeral,Rhythms, Nyctohemeral,Rhythms, Twenty-Four Hour,Twenty Four Hour Rhythm,Twenty-Four Hour Rhythms
D004548	Elasticity	Resistance and recovery from distortion of shape.
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D001416	Back Pain	Acute or chronic pain located in the posterior regions of the THORAX; LUMBOSACRAL REGION; or the adjacent regions.	Backache,Back Ache,Back Pain with Radiation,Back Pain without Radiation,Vertebrogenic Pain Syndrome,Ache, Back,Aches, Back,Back Aches,Back Pains,Backaches,Pain Syndrome, Vertebrogenic,Pain Syndromes, Vertebrogenic,Pain, Back,Pains, Back,Syndrome, Vertebrogenic Pain,Syndromes, Vertebrogenic Pain,Vertebrogenic Pain Syndromes
D001696	Biomechanical Phenomena	The properties, processes, and behavior of biological systems under the action of mechanical forces.	Biomechanics,Kinematics,Biomechanic Phenomena,Mechanobiological Phenomena,Biomechanic,Biomechanic Phenomenas,Phenomena, Biomechanic,Phenomena, Biomechanical,Phenomena, Mechanobiological,Phenomenas, Biomechanic
D013131	Spine	The spinal or vertebral column.	Spinal Column,Vertebrae,Vertebral Column,Vertebra,Column, Spinal,Column, Vertebral,Columns, Spinal,Columns, Vertebral,Spinal Columns,Vertebral Columns