Background: Heavy backpacks are often used by soldiers and firefighters. Weight carrying could reduce the speed and efficiency in task completion by altering the foot sole sensitivity and postural control.Methods: In fifteen healthy subjects

we measured the changes in sensitivity to vibrations applied to the foot sole when standing upright or walking after load carrying（30% body weight）. The participants were asked to judge different vibration amplitudes applied on the 2 nd or 5 th metatarsal head and the heel at two frequencies（25 and 150 Hz） to determine the vibration threshold and the global perceptual representation（Ψ）of the vibration amplitude（Φ）given by the Stevens power function（Ψ=k×Φ

n

）. Any increase in negative k value indicated a reduction in sensitivity to the lowest loads. Pedobarographic measurements

with computation of the center of pressure（COP） and its deviations

were performed during weight carrying.Results: The 25-Hz vibration threshold significantly increased after weight carrying when standing upright or walking.After standing with the added loads

the absolute negative k value increased for the 25 Hz frequency. After walking with the added loads

the k coefficient increased for the two vibration frequencies. Weight carrying significantly increased both the CoP surface and CoP lateral deviation.Conclusions: Our data show that weight carrying reduces the sensory pathways from the foot sole and accentuates the center of pressure deviations.