This document provides an overview of evaluating low back pain. It discusses that most disc herniations occur at L5-S1 and 30% of asymptomatic people have disc protrusions. While MRIs often show spinal abnormalities, these findings do not always correlate with symptoms. The most common cause of low back pain is muscle imbalance leading to spasm. The document outlines approaches to evaluating patients with low back pain, including taking a history, performing physical exams, and assessing for red flags indicating serious underlying issues. Common lumbar spine conditions are described.