Study on Trial Improvement of Japanese Footwear “Zori” from the Viewpoint of Foot Shape and Walking Function

Abstract

  Taking notice that Zori (leather sandal) representative of Japanese woman's footwears present not a few structural problems from the viewpoint of foot shape and walking function, we tried to solve these problems, leading to trial preparation of such an improved footwear as is adapted to the foot shape and walking function and has a good sense of putting-on. The results are mainly as follows.

  1) Mean values of area which was subtracted the Zori area from the foot area in each of 30 subjects revealed an areal protrusion of 15.4% of the mean foot area, indicating incompatibility between the foot and the Zori area.

  2) In view of a high correlation observed between the stature and the foot length, improved sandals were classified into M size and L size for 150-159.9cm and 160-166.9cm stature, respectively.

  3) Design of improved Zori was made as follows ; The width and the length of Zori were determined from mean values for foot shape. For positioning of Zori straps, fore strap was set between both bases of first and second toes, internal and external straps being set at the respective perpendicular locations of sphyrion and malleorus fibulare. Next, the curve of the Zori surface was made to bend along with the line of metatarsophalangeal joint and a camber of 15° was set from the above line to the tip of Zori.

  4) Comparative examination of the effect of leather sandals in terms of both brake and acceleration force of sagittal force of the ground reaction force between improved and ordinary Zori proved such a distinct increase in the above effect for the former Zori as was almost equivalent to that with bare foot, compared with a remarkable decrease for the latter Zori.