Abstract
Foot shape data were collected from 937 elderly subjects 70 years of age or above to identify the features of normal and hallux valgus foot shapes. This paper reports the results of analysis of the data obtained from 489 of those subjects. The INFOOT (I-Ware Laboratory Co., Ltd.), three-dimensional scanner, was used to measure the foot shapes. The data points obtained by scanning the foot surface shapes were used to develop homologous shape models. The distance between the shapes was calculated to determine the difference among the models. The calculated distances were then analyzed using the multi-dimensional scaling method to identify the shape features. It was revealed that among the elderly there was hallux valgus with normal arch and varus of the calcaneus in addition to lower arch and valgus of the calcaneus. There were no gender differences found in the hallux valgus types, while females had lower arches than males. These results suggest that there are two types of hallux valgus in terms of shapes, each of which is likely to have different a mechanism of deformity.
