Referred pain is usually felt in the low back area and tends to radiate into the groin, buttock and upper thigh. The pain often moves around, and rarely radiates below the knee. This type of low back pain is not as common as axial low back pain or radicular pain (sciatica). Referred pain is analogous to the pain that radiates down the left arm during a heart attack. It is the result of the extensive network of interconnecting sensory nerves that supply many of the tissues of the low back, pelvis and thigh. An injury to any of these structures can cause pain to radiate ? or be ?referred? - to any of the other structures. It is important to understand that this type of pain is not due to ?pinched nerves?.