Lower Back Strain Muscle strain occurs when muscles are over-stretched or torn. This is also called a pulled muscle. Strained lower back muscles cause inflammation, which leads to back spasm. These painful spasms can cause difficulty moving. Further Reading: Pulled Back Muscle and Lower Back Strain Related Articles Lower Back Stabilization Exercises for Back Pain Related Videos Lower Back Strain VideoLower back strain is caused by damage to the muscles and ligaments of the back. Learn about muscle anatomy and the symptoms of lower back strain.Back Strains and Sprains VideoA muscle strain or a muscle sprain in the back is the most common cause of back pain. In most people, this pain will last a short time, a few days to a couple of weeks.Causes of Lower Back Pain VideoChronic pain in the lower back may be caused by the discs or the joints of the spine.