The multifidus muscles run up and down along the back of the spine, and are important for keeping the spine straight and stable during many common movements such as sitting, walking and lifting. A problem with these muscles is often found in someone with chronic low back pain, because the back pain causes the person to use the back muscles improperly in trying to avoid the pain. The problem with the multifidus muscles continues even after the pain goes away, and is probably an important reason why the pain comes back. Teaching people with chronic low back pain how to use these muscles is recommended as part of a recovery program.