Any improvement in biomechanics would have a lot of positive consequences as the field has a lot of subfields. One example is soft body dynamics. Research in th

Any improvement in biomechanics would have a lot of positive consequences as the field has a lot of subfields. One example is soft body dynamics. Research in this area is very active as computational power increases more accurate and complex finite element simulations of soft tissues are possible. While the classical model used in the paper, from Delp et al., already contains pivot points, it lacks other important info. For instance, the tendon slack length parameter currently includes both the length of the free tendon and the length of the aponeurotic tendon. In reality most musculotendons consist of at least one tendon on each side. AFAIK, no functional representation is available that divides the tendon length into separate lengths for the origin and insertion of each unit, and also into its two constituents, free and aponeurotic. And as has been shown, deformation effects for muscles and tendon are indeed different as they they have different material properties. Regarding the cross-sectional areas, these are available, just not within the classical models. If there is a need to incorporate cross-sectional area into a model than the main issue is measure. Most models in biomechanics are created by taking external measurements of subjects in vivo, but I guess it won't take long before models go beyond piecewise line segments. Or soft body simulation get cheap enough to reach the same level of accuracy present in these trial-and-tested models.