Abstract
The purpose of this study is to weigh the students' backpacks of middle school in daily use and to analyse their physiological responses and subjective senses when carrying backpack in order to promote healthy and comfort school life of girl middle school students. Two female students were subjects who answered the questionnaires on two types of backpack and their metabolism, perspiration and the changes of skin temperature were measured in constant environment chamber, $25{\pm}1$ and $49{\pm}10$% RH. They walked on the treadmill carrying the backpack with the increment of backpack weight, 2 kg, 4 kg to 6 kg. When the backpack increases to 6 kg, the discomfort parameters and responses increases rapidly. Comparing with general type, improved type of backpack showed good results in physiological responses, but not in subjective senses, such as the ease of movement, pain, or total preference, specially in 2 kg and 4 kg. The girl students prefer the general type of backpack which is of fashion and small, when it weighs light such as 2 kg or 4 kg, while they prefer the improved bag which is functional when it is heavy as 6 kg. The longer wearing time of the medium weight, for example, 4 kg without feeling or recognition of any discomfort due to fashion style, might cause the students' posture and health weaker or more vulnerable to the problems.
