Effect of gait on formation of thermal environment inside footwear

• The relation between the gait conditions and foot temperature distributions inside footwear was studied.
• The metabolic heat generation was found to have a basic impact on the temperature profile.
• High-temperature-elevation regions coincided with high-contact-load regions.
• The relation between the temperature elevation and contact load was clarified.
• The key aspects of a thermally comfortable design concept and applications were described.

In this study, the relationship between the gait condition and foot temperature distributions inside footwear was investigated using subject experiments. Mechanical, physical, and physiological variables such as the foot contact force, landing speed, and metabolic heat generation were also measured. Gait motion measurements showed that a large contact force was concentrated in the small area of the heel at the initial contact and later at the forefoot. A faster gait produced a larger contact force, higher landing velocity, higher skin temperature, and larger metabolism during gait. The temperature at the bottom of the foot increased, and the temperature on the upper side decreased. The metabolic heat generation had a basic impact on the temperature profile, and skin temperatures tended to increase gradually. In addition, high-temperature-elevation regions such as the big toe and heel coincided with regions with high-contact loads, which suggested a relationship between the temperature elevation and contact load.