Inclusion Criteria:  The inclusion criteria for individuals without a history of low back pain.  Between the ages of 18 and 40 No previous history of low back pain in lifetime.  The inclusion criteria for patients with CLBP individuals.  Between the ages of 18 and 40. Having low back pain over 3 months or a recurrent pattern of LBP at least two episodes that interfered with activities of daily living and/or required treatment. This information will be obtained by interview during subjective examination.  Exclusion Criteria:  History of seizure for either the subject or any family member Implanted pacemaker Clinical signs of systemic disease Definitive neurologic signs including pain, weakness or numbness in the lower extremity Previous spinal surgery Diagnosed osteoporosis, severe spinal stenosis, and/or inflammatory joint disease Any lower extremity condition that would potentially alter trunk movement Vestibular dysfunction Extreme psychosocial involvement Body mass index (BMI) greater than 30 kg/m2 Active treatment of another medical illness that would preclude participation in any aspect of the study Menstruation or pregnancy (for female subject) Diagnosed herniated nucleus pulposus (HNP) Contraindications for TMS and tDCS including open wound, infection, lesions, arteriosclerosis, history of haemophilia or demand-type pacemaker Acute cerebral hemorrhage Medications that can interfere the effect of tDCS including sodium channel blocker, calcium channel blocker, NMDA receptor antagonist