Foot and Ankle Model for Surgical Treatment - Computational Biomechanics of the Musculoskeletal System - page 43

(b)

FIgure 3.3 ( Continued ) The model for simulation (b).

3.4 eFFeCtS oF tarSometatarSal JoInt FuSIon
In order to reveal the effect of the fixation of the TMT joints, the results of the normal and fused
joint models were compared. The contact pressures at the articulating interfaces in the midfoot and
hindfoot, von Mises stress in the five metatarsal bones, and contact pressure distribution on the
plantar foot were analyzed.

3.4.1 c ontact p reSSure of p lantar f oot and J ointS
The maximum contact pressure between plantar foot and support increased by 0.42%, 19%, and
60%, corresponding to the first peak, midstance, and the second peak. A normal arch deforms to
interact with the environment in a most effective way, protecting the segments from excessive loads.
It was found that a foot with fused joint limited arch deformation capability and was subjected to
higher plantar pressure, especially during push-off.
The first metatarsal bone was observed to be significantly dorsiflexed in flatfoot relative to
the talus bone (Blackman et al. 2009; Kido et al. 2013). The fusion resulted in a limited range
of movement of the first metatarsal bone and a stiffer arch. In order to investigate the effect of