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Biomedical subjects

B M Cyron

Publications and source records attributed to B M Cyron.

9 recordsLinked to original sources
PubMed1979

The compressive strength of lumbar vertebrae.

Values for the compressive breaking load of lumbar vertebrae at physiological strain rates show enormous scatter across the population, ranging from 0.8 kN to nearly 16 kN. Increase in strength was found at faster strain rates, but differences in compressive strength between upper and lower lumbar vertebrae were not significant. Hydraulic strengthening does not appear to contribute to the compressive strength at the strain rates studied.

Adolescent↗
PubMed1978

Spondyloysis. The role of the posterior elements in resisting the intervertebral compressive force.

Compressive tests were carried out on cadaveric lumbar intervertebral joints, before and after the neural arch was fractured. The results show that although the neural arch can play some part in resisting the intervertebral compressive force, there is no bony contact between the downward projecting tips of the inferior articular processes and the laminae of the vertebra below.

Adolescent↗
PubMed1976

Spondylolytic fractures.

A method is described whereby fractures of the neural arch similar to those in spondylolysis are produced experimentally. The forces, bending moments and displacements required to initiate the fractures are given; The mechanical aspects in the aetiology of spondylolysis are explained by a simplified two-dimensional force analysis.

Aged↗
PubMedDate not supplied

Variations in the amount and distribution of cortical bone across the partes interarticulares of L5. A predisposing factor in spondylolysis?

The possible role of the physical and mechanical properties of the neural arch as contributing factors in the etiology of spondylolysis was tested by comparing two groups of vertebral specimens obtained at necropsy. Group I specimens had been subjected to repetitive cyclic force which they withstood without fracturing. Group II specimens were randomly selected. The cross-sectional distribution of cortical and cancellous bone in the partes interarticulares were measured, and the two groups compared. The previously stressed group was found to have a greater percentage of cortical bone than the random group. The data are interpreted to suggest that thin partes interarticulares may predispose to spondylolysis through the mechanism of fatigue failure.

Adolescent↗
PubMedDate not supplied

Articular tropism and stability of the lumbar spine.

Lumbar intervertebral joints were subjected to compressive and shear forces calculated to simulate walking with a heavy pack on the back. The joints with articular tropism were found to rotate toward the side of the more oblique facet. The mechanics relating the orientation of the articular facets with joint forces and stability of the lumbar spine are discussed.

Adolescent↗