Fifty-five patients, with a history of common low back pain, have participated to the study. The subjects have been randomly distributed in two experimental groups and one control group. The gender, age, weight and height characteristics of the three groups (Visual Imagery Group, VIG; Kinesthetic Imagery Group, KIG; and Control Group, CG) are presented in Table 1. The patients presented no history of neurological or psychiatric disease, and gave their informed written consent.