Investigation of the optimal arch design of the last for heel-heighted shoe with low, mid and high heel height

Abstract

This study aimed at evaluating the effect of arch shape of the last on the insole pressure distribution of lady shoes with 20mm, 50mm and 80mm heel height. The right foot of ten girls in barefoot standing on the shoe heel was scanned in 3D format in order to obtain the data of foot arch. Three types of last were designed: control last (CL), higher last (HL) and lower last (LL). The arch shape of CL was designed based on the foot, while the arch of HL and LL was modified by 2.5mm higher or lower than that of control last in the position of cuboids. Insole pressure variables of peak pressure (PP), contact area (CA) and pressure-time integral (PTI) at hind, mid and fore foot were analyzed by paired-T test with the significant level of 0.05. The result shows that no significant differences were observed in mid foot between comparisons of HL and CL and CL and LL in each heel height. However, HL demonstrated a significantly lower PP and PTI than CL at forefoot in the 20mm and at hind foot in the 80mm heel height respectively; while LL only demonstrated a significantly larger PP than CL under hind foot in 50mm heel height. It can be concluded as that the last with an appropriate arch support was helpful for attenuating the magnitude of pressure in forefoot and hind foot.