A combination of "gross structural model of the foot", finite element analysis, internal deformations and stress in plantar soft tissues, von Mises stress,..., could be found in G. Yarnitzky et al. / Journal of Biomechanics 39 (2006) 2673?2689 : https://www.eng.tau.ac.il/~msbm/reso...-2673-1689.pdf
One interesting conclusion (which I hope I don't extract from its context) of the authors is : "... internal deformations and stresses in the plantar pad during gait cannot be predicted from merely measuring the foot?shoe force reactions." Should we add something to the definition of foot orthotics ?
Otherwise, to be honest, I don't know how to read, understand and properly use this work as it is a lot of (unknown for me
) science inside it !