Low back pain and lower extremity pain often get put into one category, but the causes, and therefore the treatments, can be different. Lower extremity pain, when it radiates from the low back, is usually the result of pressure on a nerve. The pain is often in the distribution which the nerve supplies. Low back pain is often related to the mechanics of the spine. Muscle strain, arthritis, trauma, osteoporosis, and fracture are often causes. Often, disease processes which cause lower extremity pain can also cause low back pain, and vice versa.