Patients with chronic low back pain are enrolled and divided into group A (atelocollagen) and group B (control) through randomization after obtaining informed consent.
Investigators record tender points for the multifidus, erector spinae, and quadratus lumborum muscles by physical examination.
Investigators evaluate each muscle using ultrasound according to the assignment of each group, and apply atelocollagen mixture (atelocollagen 3 mL + 1% lidocaine 3 mL) or local anesthetics only (normal saline 3 mL + 1% lidocaine 3 mL) to each muscle on both sides.
The subject of the study performs a total of 3 injections at intervals of 2 weeks, and each measurement variable is collected by visiting 4 weeks and 12 weeks after the last injection.
Changing medications or additive interventions are not allowed before 4 weeks after last injection. Only acetaminophen is allowed as a rescue drug.
