The purpose of this study is to investigate the effects of a treatment involving the application of lidocaine injected on the low back area for pain control. The study will compare this form of treatment with other options such as physical exercises or pain killer medication, different measurements are going to be used to quantify the response to each of these treatments.

This trial was conducted in the Department of Rehabilitation, Hospital das Clinicas, University, of Sao Paulo Medical School, one of the largest rehabilitation centers in Brazil. The trial was initiated in January of 2007 and close to enrollment in January of 2013. Investigators included patients with a diagnosis of chronic nonspecific low back pain who were referred from various clinics in São Paulo that were linked to this rehabilitation center. Thus, patients were referred primarily by physiatrists, general practitioners, neurologists, orthopedic surgeons, and physiotherapists.

Participants were randomized to receive: (i) paraspinal lidocaine injection (LID-INJ) and standard treatment, (ii) sham lidocaine injection (SH-INJ) and standard treatment, or (iii) standard treatment only (STD-TTR). Randomization was performed using a computerized random number generator.

Assessments The evaluations were performed by an independent and blinded appraiser before treatment, after 1 week, and 3 months after the end of the applications. Baseline assessments consisted of a demographic and baseline clinical assessment [gender, age, occupation, duration of pain (months), pain intensity, associated diseases, and usual occupation] and a physical examination [measurements of weight and height to calculate body mass index (BMI)].

Primary Outcome Measure The primary outcome measure was the visual analog scale (VAS) score for pain. The VAS comprised a 10-cm ruler from 0 to 10, with 0 corresponding to no pain and 10 corresponding to maximum pain. Patients were asked to rate their average pain in the preceding 24 hs.

Secondary Outcome Measures Investigators also measured low back pain using the Brazilian Roland-Morris tool, which consisted of a specific questionnaire to assess function in patients with low back pain and has been validated in Brazil. Scores range from 0 to 24, wherein higher scores reflect greater disability due to low back pain.

Inclusion criteria:

• Age between 20 to 60 years;
• Clinical symptoms of vertebral pain that is unresponsive to symptomatic treatment with anti-inflammatory drugs for 3 months;
• Moderate to severe pain: visual analog scale (VAS) > 4;
• Diagnosis of chronic nonspecific low back pain;
• MiniMental test (MEEM) between 24 and 30;
• Availability to comply with the visits;
• Agree with signing the Informed Consent Form

Exclusion criteria:

• Severe psychiatric disease that requires psychiatric care;
• Neurological disorders (lumbosciatic pain);
• Concurrent fibromyalgia, per the 1990 diagnostic criteria of the American Academy of Rheumatology
• Concurrent rheumatic disease
• History of allergy to lidocaine (used for paraspinal blocks)
• Labor problems
• History of surgery on the lumbar spine
• No availability to visit the clinic for treatment and evaluations.