The purpose of this study was to determine energy cost and mechanical efficiency of walking wearing the Japanese style wooden clogs (JSWC). Six subjects walked with JSWC on a treadmill for 4 min at 0.83, 1.11, 1.39, 1.67, and 1.94 m・s^-1 in order to identify the relation between net energy cost (net Ė, cal・kg^-1・min^-1) and velocity (V, m・s^-1). Also, apparent efficiency was calculated by walking with JSWC in 3 subjects on a treadmill at 0.83-1.11 m・s^-1 against a horizontal impeding force. A quadratic regression equation between net Ė and V of walking with JSWC was derived as follows;

net Ė = 53.50 V² - 75.92 V+51.59 (R=1.000, p<0.01)

On the other hand, apparent efficiency of walking with JSWC was 29.6-30.6% in 3 subjects and individual difference was not significant. Energy cost of walking with JSWC was greater, especially at fast pace, than that which has previously reported in walking without JSWC. Furthermore, lower apparent efficiency was observed in this study comparing with that accepted for load-walking. It is concluded that JSWC as a Japanese traditional footwear can enhance metabolic requirement during walking.