more tibial torsion = a change in progression angle.
How does tibial torsion impact the development of the foot progression angle?
Stratifying the data by Foot Progression Angle (FPA) revealed there were significant differences in tibial torsion among the groups and provided evidence that tibial torsion influences the direction and magnitude of the FPA. Offsetting torsions between the tibia and femur were more common in people with higher and lower FPA and had clearer patterns where the tibia tended to follow the direction of the FPA.
So, got that? The foot progression angle follows the tibial torsion...
Why do we care?
the greater the “kickstand” angle to the foot, the more we progress through the mid foot (rather than from the lateral aspect of the heel, up the lateral column, across the transverse metatarsal arch and through the 1st ray). This causes more mid foot pronation and more medial knee fall, resulting in gait inefficiency and often times in our experiences, increased knee pain.
Gait Posture. 2016 Sep;49:426-30. doi: 10.1016/j.gaitpost.2016.08.004. Epub 2016 Aug 3.
The rotational profile: A study of lower limb axial torsion, hip rotation, and the foot progression angle in healthy adults.