A Prospective, Randomized, Controlled, Single Centre Trial to Assess the Efficacy and Safety of Radial Extracorporeal Shock Wave Therapy in Patients With Chronic Non-specific Low Back Pain

Non-specific low back pain is defined as low back pain not attributable to a recognizable, known specific pathology (e.g., infection, tumour, osteoporosis, fracture, structural deformity, inflammatory disorder, radicular syndrome, or cauda equina syndrome). It is second only to the common cold as the most common affliction of mankind and is among the leading complaints bringing patients to physicians' offices. The reported point prevalence of non-specific low back pain is as high as 33 percent, its one-year prevalence as high as 73 percent and its lifetime prevalence exceeds 70% in most industrialized countries, with an annual incidence of 15% to 20% in the United States of America. In physically active adults not seeking medical attention, the annual incidence of clinically significant non-specific low back pain with functional impairment is approximately 10 to 15 percent. In China, non-specific low back pain has become one of the leading causes of disability-adjusted life-years (DALYs) in 2010. Some authors reported the prevalence of non-specific low back pain as 41% in Chinese adolescents.

Management for patients with non-specific low back pain is challenged by the problems that most back pain has no recognizable cause (>85%), an underlying systemic disease is rare, and most episodes of back pain are unpreventable.

Acute non-specific low back pain (lasting three to six weeks) usually resolves in several weeks, although recurrences are common and low-grade symptoms are often present years after an initial episode. Risk factors for the development of disabling chronic or persistent non-specific low back pain (variously defined as lasting more than three months or more than six months) include preexisting psychological distress, disputed compensation issues, other types of chronic pain, and job dissatisfaction.

The goals of management for patients with non-specific low back pain are to decrease the pain, restore mobility, hasten recovery so the patient can resume normal daily activities as soon as possible, (iv) prevent development of a chronic recurrent condition, and restore and preserve physical and financial independence and comfort.

Unfortunately, few if any treatments have been proven effective for non-specific low back pain in meta-analyses, including limited bed rest, physical activity and exercise, back schools, traction, massage, chiropractic, radiofrequency denervation, paracetamol, opioids and, ultimately, surgery (in cases of cauda equina syndrome, infections, tumors and fractures compressing the spinal cord, mechanical instability of the back, and, perhaps, intractable pain with a positive straight-leg-raising test and no response to conservative therapy). Earlier studies demonstrated that muscle relaxants are effective in the management of non-specific low back pain, but the adverse effects require that they be used with caution. Accordingly, the aforementioned guideline by the American College of Physicians is only based on low- and moderate-quality evidence.