Objective Data on Daily Activity in Patients Treated with SCS: the Intellis Study

Inclusion Criteria: * Refractory chronic pain in low-back and/or legs that persists for at least 6 months following the most recent spinal surgery * 18-70 years of age. Patients \>70 years will not be included due to the reduction in general activity level that is usually seen in older patient cohorts. * Mean pain intensity should be 5 or higher measured on a Visual Analogue Scale (VAS). * Patient has been informed of the study procedures and has given written informed consent. Exclusion Criteria: * Expected inability of patients to receive or properly operate the spinal cord stimulation system * History of coagulation disorders, lupus erythematosus, rheumatoid arthritis * Addiction to drugs, alcohol (5E/day) and/or medication * Evidence of an active disruptive psychiatric disorder or other known condition significant enough to impact perception of pain, compliance to intervention and/or ability to evaluate treatment outcome as determined by investigator * Active malignancy * Life expectancy \< 1 year * Local infection or other skin disorder at site of incision * Pregnancy