Clinical Trial Examining the Short and Long-term Effect of Myofascial Trigger Points Injection in Low Back Pain Patients

Inclusion Criteria: * CLBP of non-malignant origin, with or without accompanying leg pain, including patients with history of previous back surgery or trauma * MPS as evident by at least one active MTP, located medial or lateral to the posterior iliac crest involving the gluteus maximus or medius, quadratus lumborum and erector spinae muscles * While not precluding the participation in the study, MTP in other areas will not make patients eligible * Pain lasting for at least six months Exclusion Criteria: * Any current motor weakness, but not sensory loss or abnormal reflexes in the lower limbs * Any injection or nerve block in the low back in the last 6 months * Local or systemic infection * Bleeding disorder or the use of anticoagulation medications * Known allergy to local anesthetics * Poor understanding of written and spoken English or French