Heel skin stiffness effect on the hind foot biomechanics during heel strike

Abstract

The nonlinear parameter of the heel skin has been successfully predicted from in vivo indentation tests based on a subject-specific FE model. Skin properties' sensitivity tests clearly showed that the stiffness of the heel skin could have a direct effect on the biomechanics of the hind foot. The results suggest that individuals with a pathologically stiffened heel skin could exert an increase in the heel pressure, which may potentially lead to skin breakdown or ulcer.

Biomechanical analysis of suture locations of the distal plantar fascia in partial foot

“…However, the predicted peak pressure was higher than the measurement. This difference might be from a single heel pad layer without considering the effect of the multilayer skin [30]. Also, the higher planter pressure in FE prediction was caused by the resolution ratio of the Fscan sensors that reported an average pressure for an area of about 25 mm², while the FE analysis provided solutions of nodal contact pressure rather than an average pressure calculated from per element surface area.…”

Viscoelasticity in Foot-Ground Interaction

“…In order to investigate the force-deformation behaviour of the heel pad in in vitro, in situ and in vivo conditions, several mathematical models have been developed and utilised [36,40,42,53,65,[68][69][70][71][72][73][74]. Additionally, a number of FE analyses were used to quantify the mechanical behaviour of the heel pad [45,52,[75][76][77][78][79][80].…”

“…Two main in vivo material testing techniques have been used to inform inverse FE analyses: indentation [45,52,[75][76][77][78] and compression [79,80]. In both cases, the plantar soft tissue is compressed between a rigid loading surface and a bony prominence but in the case of indentation, the loading surface is significantly smaller than the plantar surface of the foot.…”

“…In both cases, the plantar soft tissue is compressed between a rigid loading surface and a bony prominence but in the case of indentation, the loading surface is significantly smaller than the plantar surface of the foot. In both cases, the applied force is measured using a load sensor and tissue deformation is either inferred from the displacement of the loading surface [75,92] or directly measured using medical imaging techniques such as ultrasound [45,52] or MRI [80]. These measurements enable the calculation of an indentation/compression force-deformation graph that describes the macroscopic mechanical response to loading of the tissue.…”

Investigation on the load-displacement curves of a human healthy heel pad: In vivo compression data compared to numerical results

“…Finite element modeling of the soft tissues of the foot would pave the way for understanding stress-related injuries (e.g. plantar fasciitis and diabetic ulceration [22,23]), as well as improve orthotics and footwear design, considering the stress induced in the plantar region (e.g. distribution of the plantar pressure [15,[24][25][26]).…”