The purpose of this Clinical Study is to investigate the effect of electrical stimulation for chronic low back pain.

Inclusion Criteria:

1. Age ≥ 18 years, ≤65 years
2. Chronic Low Back Pain with a first occurrence >90 days prior to enrolment, and the last relatively pain-free time >90 days prior to enrolment.
3. Continuing low back pain despite >90 days of medical management
4. Oswestry Disability Index score ≥25% and ≤60% at the time of enrolment
5. Able to understand and sign the Informed Consent form.
6. Ability to comply with the instructions for use and to operate the ReActiv8, and to comply with this Clinical Investigation Plan.
7. Suitable for ReActiv8 surgery as determined by the implanting physician prior to inclusion.
8. Prior week average Low Back Pain NRS of ≥6.0 and ≤9.0 on a 11 point NRS scale (0-10) at the Baseline Visit

Exclusion Criteria:

1. BMI > 35

2. Back Pain characteristics:

   1. Any surgical correction procedure for scoliosis at any time, or a current clinical diagnosis of scoliosis.
   2. Lumbar spine stenosis, as defined by an anterior-posterior diameter of the spinal canal of <10mm in subjects with lower extremity pain
   3. Neurological deficit possibly associated with the back pain (e.g. foot drop).
   4. Back pain due to pelvic or visceral reasons (e.g.: endometriosis or fibroids) or infection (e.g.: post herpetic neuralgia).
   5. Back pain due to inflammation or damage to the spinal cord or adjacent structures (e.g. arachnoiditis or syringomyelia)

3. Any current indication for back surgery according to local institutional guidelines, or has indication for back surgery but cannot undergo surgery for other reasons.

4. Leg pain described as being worse than back pain, or radiculopathy (neuropathic pain) below the knee.

5. Source of pain is the sacroiliac joint as determined by the Investigator.

6. Drug use

7. Surgical and other procedures exclusions

8. Any prior diagnosis of lumbar vertebral compression fracture, lumbar pars fracture, or lumbar annular tear with disc protrusion

9. Planned surgery.

10. Co-morbid chronic pain conditions

11. Other clinical conditions

12. Psycho-social exclusions

13. Protocol Compliance Exclusions

14. General exclusions