Influence of foot pain on walking ability of diabetic patients.

A connection method is proceeded by: placing a covered electric wire (18) on a terminal (17); applying an ultrasonic vibration in a state of pressing the covered electric wire (18) against the terminal (17) so as to melt and remove a covering portion (26); arranging a plurality of core wires on the terminal (17) in parallel; and pressing the arranged core wires (25) against the terminal (17) so that the core wires (25) and the terminal (17) conductively contact with each other.