Amitabh Gupta, Brad Fernihough, Glen Bailey, Petra Bombeck
Slide Three
This is an antero-lateral view, which shows the attachment of psoas with greater attachment from the bodies of the lumbar vertebrae than the discs. This would therefore suggest a compressive loading of the vertebrae with contraction of psoas, potentially adding to lumbar stability. Compression of IV discs will take place rather than shear, as there is little attachment to the discs.
Due to the greater angle at L5-S1, psoas will naturally produce a greater shearing force than a compressive force at his level. This will be even more pronounced in those with exaggerated lordosis, which is one of the common traits among the dance population, reported clinically.
This may influence the pathogenesis of spondylolysis and spondylolisthesis due to an overactive or mechanically advantaged psoas.
