Low back pain is one of the most frequently reported symptoms in the industrialized world. In most cases, the symptom is due to a benign non-emergent condition involving some degree of spinal degeneration. Pain that continues for more than 7–12 weeks despite conservative management is described as chronic. The estimated prevalence of nonspecific chronic low back pain in adults is 15% but increases with increasing age, to 44% at the age of 70 years (Luo et al, 2004). If chronic low back pain does not improve with conservative management, the cause must be identified before the most appropriate therapy can be determined. The sheer number of spinal structures that are potential sources of low back pain results in a broad differential diagnosis and represents a major challenge to identifying the cause of pain. A precise medical history and thorough physical examination, along with tailored laboratory testing and non-invasive imaging, are important steps toward establishing a working diagnosis. These measures should suffice to identify or to rule out underlying disease processes (fracture, malignancy, visceral or metabolic abnormality, deformity, inflammation, and infection), neurologic disorders requiring surgical intervention ( cauda equina syndrome, myelopathy), and social or psychological distress that may amplify or prolong pain (Jarvik et al, 2002).