Contextualization: Trigger points are muscle nodules found in muscles. We can observe five different types of trigger point, in clinical practice two of them stand out, the active trigger point; Which is painful; And latent; Asymptomatic; Both of which are sensitive to palpation. Once the individual present these muscle nodules can develop pain and motor dysfunction. Studies indicate that the prevalence of trigger points is 95% of individuals with chronic musculoskeletal pain, but this prevalence is not yet clear in individuals with low back pain.

Objective: To compare the pain and function levels of patients with acute and chronic low back pain who, when asymptomatic, had trigger points compared to the pain and function levels of patients with acute and chronic low back pain who, when asymptomatic, had no trigger points.

Study design: Cohort study, two arms, blind evaluator, prospectively enrolled at baseline.

Location: This research will be conducted in the physiotherapy department at the Rehabilitation Center of the Brotherhood of Santa Casa de Misericórdia de São Paulo (ISCMSP).

Patients: 400 asymptomatic individuals Follow-up: Asymptomatic individuals will be assessed at baseline and over 3 years. You will be asked to contact the research department within 6 weeks of low back pain (acute) and after 12 weeks of low back pain (chronic). Participants will be allocated to two groups, trigger point group (n = 200) and group without trigger point (n = 200).

Outcomes: The pain intensity, function level and trigger point pain intensity outcomes will be evaluated at the baseline, within 6 weeks for the patient to present pain in the lumbar (acute) and after 12 weeks the pain persists (chronic)

Inclusion Criteria:

• Men and women;
• Age between 18 - 40 years;
• Asymptomatic;
• There is no treatment for lumbar spine, hip or knee.

Exclusion Criteria:

• Anterior lumbar spine surgeries;
• Severe spinal diseases (fracture, tumor, ankylosing spondylitis);
• Root conditions (herniated disc, spondylolisthesis);
• Congenital malformation;
• Pregnant women.