How I interpret Medial Column Supinatus:

At Carnegie Stage 13, the lower limb bud becomes visible

At Stage 17, the soles of the future foot are cephalad (facing upwards)

At Stage 18, the soles have structurally rotated so that they facing one another

At Stage 23 both feet are in Supinatus

At approximately day 60 Pf, the heel and medial column supinatus begin to unwind, at this stage, you see the Talipes Equinovaurs structure. If the ontogenetic torsional unwinding (OTU) ends at this stage, the child is born with a Clubfoot Deformity.

At approximately day 64 Pf, the heel supinatus has significantly unwound, but the medial column supinatus remains. If the OTU ends at this stage the child is born with a PreClinical Clubfoot Deformity.

At approximately day 68 Pf, the heel supinatus has totally unwound, leaving only the medial column supinatus. If the OTU ends tat this stage, the child is born with a Primus Metatarsus Supinatus (Rothbarts foot) deformity

At approximately day 75 Pf, the medial column supinatus has totally unwound. The child is born with a Plantargrade foot (no medial column supinatus).

I have correlated medial column supinatus with structural foot pathology (e.g., Hallux Valgus Deformity). The higher the medial column supinatus values (and associated mean rotation values), the higher the probability that the individual will develop foot pathology.

I equate high rotation values with Gravity Drive (abnormal) Pronation.