Esteemed Almustafa, thank you for the response.
I suspected that it refers to the spinal column. However, it is written in the plural; this confused me.
Is it perhaps a typo? Or does it perhaps refer to the multidimensionality of the spinal column, because then it could make sense?
In the lecture you kindly posted, I could only find "columns" once, and then it referred to the spinal column in man and woman, thus plural. However, V.M.S.A.W speaks about columns in oneself.
Could you please clarify?
Thank you!