Inclusion Criteria:
* Patients seeking care for chronic low back pain, defined as having occurred and recurred over regular or irregular periods or intervals of time, persisting over at least the last 3 months;
* Fluent in Portuguese;
* Pain intensity (self reported) of at least 50 mm measured by a 0-100 VAS pain scale;
* Pain of benign musculoskeletal origin wherein the etiology is tendinopathies, synovitis, bursitis, strain, and sprain, of traumatic or non-traumatic origin, as determined by the outcome assessor based on any one or combination of the following: (i) Prior diagnosis by a qualified licensed medical professional current within the last 2 years evidenced through source documentation; (ii) Previous records review, such as x-ray, MRI, CT scans, etc., where available, that indicate muscle or ligament injury and the absence of radiculopathies, fractures, tumors, and infectious diseases;
* Patient willing and able to maintain the individualized pain regimen (it will be determined in the first phase of the study and it will comprise what the patient can use or cannot use to manage any low back pain that may arise throughout the course of study duration).
Exclusion Criteria:
* Pain intensity (self reported) of less than 50 mm measured by a 0-100 VAS scale;
* Acute low back pain, defined as having persisted less than half the time over less than the last 3 months;
* Pain is not episodic, such that it has either been continually present without respite over the past 3 months and/or there has not been recurrent episodes within the past 3 months;
* Pain is of other than, or in addition to, benign musculoskeletal origin;
* Prior surgical intervention to the intended treatment area that in the opinion of the outcome assessor may affect the study treatment and or outcomes assessment;
* Neurologic deficit(s) that in the opinion of the outcome assessor may affect the study treatment and or outcomes assessment;
* Peripheral nerve disease;
* Secondary orthopedic problem(s) that in the opinion of the outcome assessor may affect the study treatment and or outcomes assessment;
* Local corticosteroid and/or botulinum toxin (Botox®) injection for pain relief in or around the intended treatment area within 30 days prior to study enrollment;
* Treatments such as chiropractic care, and acupuncture targeting the intended treatment area(s) within 30 days prior to study enrollment;
* Current, active chronic pain disease, such as chronic fatigue syndrome, fibromyalgia, endometriosis, inflammatory bowel disease, interstitial cystitis diabetic neuropathic pain;
* Current cancer or treatment for cancer in the past 6 months;
* Significant heart conditions including chronic heart failure (CHF) and implantable heart devices such as a pacemaker;
* Active infection, wound, or other external trauma to the areas to be treated with the PBMT;
* Medical, physical, or other contraindications for, or sensitivity to, light therapy;
* Pregnancy, breast feeding, or planning pregnancy prior to the end of study participation;
* Female subject of childbearing age who is unwilling to engage in effective medical contraceptive use while sexually active during the study procedure administration phase;
* Serious mental health illness such as dementia or schizophrenia; psychiatric hospitalization in the past two years;
* Developmental disability or cognitive impairment that in the opinion of the outcome assessor would preclude adequate comprehension of the informed consent form and/or ability to record the study outcome assessments.
