Lumbosacral weight bearing & impacts of lumbar/sacral anomalies
The sacrum weight transmission factors: The direction of the trabecular bone indicates the route of load transmission in the sacrum. From the various parts of the sacrum (body, facets, alae and laminae) distinct sets of trabeculae extend towards the auricular surface. L5-S1 weight transmission Weight transmitted from the fifth lumbar vertebrae to the sacrum is distributed in 3 separate components i.e. (a) Anteriorly- through vertebral bodies (b) Intermediately- through transverse elements (c) Posteriorly- through lumbosacral facet joints The posterior components of the fifth lumbar vertebra share greater proportion of load in comparison with the posterior elements of the upper lumbar vertebral levels. The forces acting on the body and articular facets, at the upper end of the sacrum, are ultimately transmitted through the two auricular surfaces with an appreciable part of the load passing directly from the transverse process of the fifth lumbar vertebra to the ala of the sacrum through...