 We will use quadripolar electrodes preferably on the right hand and foot. The electrodes are cut in 1 cm strips and attached to the hand and foot with a minimum distance of 3 cm between them wrist and ankle flexure and immediately before the base of the fingers and toes. The anatomical criterion for positioning the electrodes was chosen based on the fact that the study focuses on human beings during their growth process, which can double or triple the birth weight during the study period. The newborns are measured before feeding, in prone position, wearing dry disposable diapers. The arms are kept away from the trunk and the legs should not touch each other. The infant should be comfortable and quiet, and the measurements should be recorded when the variation is no greater than 1 point. The difference in the resistance values obtained between the distal positions right hand and right foot, right hand and left foot, left hand and left foot, and left hand and right foot is not significant, and the electrodes can thus be used in these positions. 