New injection could offer quick relief for acute back pain

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Adult (≥ 18 years); * Non-specific low back pain (≤ 5 days); * Pain score (VAS) ≥ 5 (during mobilization); * Inability to walk easily (failure of the "Get Up and Go" test in less than 20 seconds). Exclusion Criteria: * Low back pain of known specific origin: spine surgery, spine trauma, discal hernia, facet joint, radicular (sciatica, cruralgia, meralgia paresthetica), muscle pain, cancer-related or rheumatological disease; * Referred or chronic pain; * Patients with opioids (acute or chronic pain and/or misuse); * Contraindication to regional anaesthesia; * Contraindication to ropivacaine, dexamethasone, sodium chloride, NSAID, paracetamol, tramadol; * Known hypersensitivity to ropivacaine, dexamethasone, other amide-type local anesthetics, or any of the excipients; * Addiction to drugs, alcohol or medication; * Patients with anticoagulants for a curative use (not preventive); * Patients with cancer or risk of bone metastasis or; severe osteoporosis; * Acute inflammatory diseases (e.g., rheumatoid arthritis, ankylosing spondylitis…); * Patient with severe hypotension or uncontrolled hypertension or; Heart Block (uncorrected second- or third-degree heart block without a pacemaker) or; severe bradycardia; * Patients with severe liver or renal disease or peptic ulcer disease; * Presence of infection or sepsis at the injection site; * Patients with uncontrolled bacterial, viral, or protozoan infections or; systemic fungal infections or; active untreated tuberculosis or; active ocular herpes simplex infections; * Patients with uncontrolled diabetes mellitus; * Patients with glaucoma or history of severe glaucoma; * Patients with severe psychiatric conditions; * Subject unable to read or/and write (inability to complete a self-administered questionnaire); * Unavailability for follow up during 6 months; * Participation in another clinical trial involving an investigational medicinal product or medical device within 4 weeks preceding the screening date; * Pregnancy in progress or planned during the study period or breastfeeding women (Art. L1121-5 of the French Public Health Code); * Women of childbearing potential (WOCBP) without a negative of highly sensitive pregnancy test before inclusion or not using a highly effective method of contraception; * Patients protected by law (Art. L1121-6 and L1121-8 of the French Public Health Code): Individuals deprived of their liberty by judicial or administrative decision, minors, adults under law protection or unable to express their consent or patient under guardianship or curatorship; * Patients not covered by a French social security scheme or not benefiting from such a scheme; * Absence of signed informed consent form before inclusion from the patient; * Patient already included in the study.