Load measuring parts 50 and 52 are provided with reaction sensors 50a, 50b, 52a and 52b to measure loads at two positions, the tiptoe and the heel, on each sole of right and left feet of a wearing person 12. The remote computer is accessed by a CPU in the managed computer system as though it were a local IDE controller attached to a local IDE device. In the event it is determined that the erase operation performed on the NAND Flash memory chip is unsuccessful, the number of bits stored by the cell is reduced from the first number of bits to a second number of bits; the second number of bits is strictly less than the first number of bits.