The Effect of ESWT Added to Conservative Treatment on Pain, Disability, and Ultrasonographic Outcomes in Chronic Low Back Pain

Chronic low back pain (CLBP) is a major public health concern worldwide, leading to reduced quality of life and significant work loss. It is defined as pain lasting more than 12 weeks between the lumbar and sacral spinal segments. The global prevalence of CLBP ranges from 13.1% to 20.3%, and the number of affected individuals has increased from 370 million in 1990 to 570 million in 2017. Core muscles, including the multifidus, erector spinae, transversus abdominis, psoas major, and quadratus lumborum, play a key role in spinal stabilization. In patients with CLBP, dysfunction and loss of synergy among these muscles can compromise spinal balance. Prolonged poor posture can reduce the strength and endurance of the lumbar erector spinae, multifidus, and transversus abdominis, leading patients to compensate by overusing the erector spinae, rectus abdominis, and oblique abdominal muscles. This compensation is considered one of the primary contributors to chronic low back pain. These deep core muscles can be objectively evaluated using ultrasonography (USG), a non-invasive, inexpensive, and accessible imaging method. Strain elastography, a quantitative ultrasonographic technique, is increasingly used to assess tissue stiffness and monitor structural changes in muscle over time. Conventional treatments for CLBP include pharmacotherapy, exercise, and physical therapy. In recent years, extracorporeal shock wave therapy (ESWT) has emerged as a non-invasive, easily applicable, and low-risk treatment method. ESWT is widely used in various musculoskeletal conditions such as lateral epicondylitis, patellar tendinopathy, and calcific tendinitis of the shoulder. Studies have shown that ESWT provides pain relief and functional improvement in patients with CLBP through its angiogenic, anti-inflammatory, analgesic, and tissue-regenerative effects. Several studies have demonstrated the positive impact of ESWT on pain reduction and functional recovery in CLBP. A recent meta-analysis