Focal Extracorporeal Shock Wave Therapy With Two Different Dosing Regimens for Chronic Low Back Pain

Chronic mechanical low back pain is a common musculoskeletal condition that leads to functional disability and diminished quality of life. While focal extracorporeal shock wave therapy (F-ESWT) has emerged as a non-invasive treatment option to promote tissue regeneration and modulate inflammation, clinical protocols lack precise standardization regarding energy density and session distribution.

This randomized, double-blind clinical trial aims to analyze the clinical effects of two specific dosing regimens of F-ESWT. Eligible participants from the Physical Medicine and Rehabilitation Service will be randomly allocated to either Group A or Group B. Both groups will undergo targeted applications to the lumbar region using predefined therapeutic parameters detailed in the protocol.

Clinical evaluations will be performed at baseline and during post-treatment follow-up periods. Pain intensity, functional disability, and localized mobility will be measured using validated clinical tools to define which dosing scheme optimizes short-term and mid-term patient recovery.

Inclusion criteria

• Individuals of both sexes.
• Age between 18 and 65 years.
• Clinical diagnosis of mechanical chronic low back pain (cLBP), defined as pain localized between the lower costal margin and the gluteal fold, with at least 12 weeks of evolution.
• Lumbar pain intensity of at least 5/10 on the Numeric Pain Rating Scale (NPRS).
• Predominantly mechanical pain, exacerbated by activities such as prolonged standing, trunk movements, extension, or lumbar rotation, and without clinical data of predominant radicular pain.
• Plain radiograph of the lumbar spine available as part of the baseline evaluation.
• Ability to attend all 4 treatment sessions and subsequent follow-up evaluations.
• Signed informed consent form previously approved by the Institutional Review Board / Research Ethics Committee.

Exclusion criteria

• Low back pain of probable non-mechanical origin or secondary to a specific cause that substantially modifies clinical management.
• Clinical data of predominant lumbar radiculopathy, including pain radiating below the knee with a dermatomal distribution, focal motor deficit, objective sensory alterations, or compatible reflex changes.
• Diagnosis or suspicion of cauda equina syndrome.
• History of previous lumbar spine surgery.
• Current vertebral fracture or recent history of lumbar fracture.
• Spondylolisthesis grade II or higher.
• Significant structural scoliosis or severe lumbar deformity that prevents treatment standardization.
• Suspicion or evidence of a tumor, infection, spondylodiscitis, or axial inflammatory disease.
• Severe clinically documented osteoporosis or history of vertebral fragility fracture.
• Pregnancy or lactation.
• Coagulation disorder, use of anticoagulants at therapeutic doses, or a hemorrhagic condition that increases procedure risk.
• Previous epidural infiltration, facet block, radiofrequency, or other lumbar interventional procedure within a recent period defined by the protocol.
• Current treatment with another physical rehabilitation modality or instrumental therapy directed at low back pain, if it cannot be suspended during the intervention period.
• Current use of nonsteroidal anti-inflammatory drugs (NSAIDs) that the patient cannot suspend according to the study indications.
• Concomitant neurological, rheumatological, oncological, or musculoskeletal disease that significantly interferes with pain or disability evaluation.
• Cognitive impairment, decompensated psychiatric disorder, or any condition that prevents understanding instructions, answering questionnaires, or completing follow-up.