Lower back pain can be caused by many things. One of the most common causes is a strain or sprain. Here is a list of some other causes of lower back pain:

• Herniated disk: A herniated disk applies pressure to surrounding nerves and can cause pain. 
• Spinal stenosis: Spinal stenosis occurs when the spinal canal narrows and puts pressure on nearby nerves and causes pain.
• Scoliosis: Scoliosis is a spinal deformity that can cause pain in your lower back.