Abstract des Autors

Besides mechanical properties the quality of ski boots is determined by their comfort characteristics. Boot climate is a major comfort measure, especially cold feet affect comfort. The purpose of the study was to determine the microclimate in ski boots during skiing. The boot climate was assessed by temperature, relative humidity and water absorption. Temperature and relative humidity were measured using 4 sensors placed on the foot above the metatarsophalangeal joints of the first and second toe, in the arch of the foot sole, on the dorsum of the foot above os cuneiforme II, and between liner and shell at the medial ankle. To determine the amount of absorbed water in liners and socks a precision balance was used. Two subjects were recorded during five skiing days. Two low and two high quality ski boots of two different boot producers were used for the tests. During all measurements the temperature inside the ski boot decreased when skiing at ambient temperature between -6.8 °C and 6.0 °C. The temperature at the toes dropped in four cases clearly below 20 °C. High relative humidity values up to 93% and high water absorption in socks and liners up to 45.5 g were observed. The results indicate that the ski boot temperature was not affected by ski boots of low quality. It is recommended to reconsider the basic construction of liners in order to improve their moisture management. One possible improvement may be to construct the liner in a way that sweat and potentially melted snow are stored as far away as possible from the foot. In this case the outer layer of the liner should have a higher water uptake than the inner layer. In addition, highly hydrophobic sock materials should be selected in order to keep the socks dry and to avoid that the feet get wet.