Effect of Two Osteopathic Techniques on Thickness of Paravertebral Muscles of the Lumbar Spine

Inclusion Criteria: * At least one episode of low back pain over the last three months; confirmation of lumbar spine dysfunction by an experienced osteopath; age between 18 and 40 years; do not have performed physical stress activities over the last 24 hours; do not be physically active (physical activity for at least three times a week); fulfill the orientations to the follow-up assessment. Exclusion Criteria: * History of surgery, fracture or fixation on the lumbar spine and/or the pelvis; being pregnant; signs of radiculopathy; disc herniation at the lumbar spine; degenerative process at the lumbar spine; have received any kind of manipulative treatments over the past four weeks;