Sprains and strains account for most acute back pain.
Sprains are caused by overstretching or tearing ligaments, and strains are tears in tendon or muscle. Both can occur from twisting or lifting something improperly, lifting something too heavy, or overstretching. Such movements may also trigger spasms in back muscles, which can also be painful.
Sprains and strains usually improve within 6-8 weeks.
Muscles can become irritated because of repetitive use of movements and postures that strain the muscles and their associated tendons.
Chronic injury can make muscles stiff and/or weak, can upset the balance between muscles, and can lead to loss of muscle control, all of which cause pain.
Identifying the movement or posture that is straining the muscles as well as stretching and strengthening the muscles are necessary to relieve pain.
As we age our spines age with us.
Due to normal wear and tear, discs narrow and bulge (known as disc degeneration), facet joints develop arthritis, and the curves of the spine can change, sometimes resulting in scoliosis. These changes are all part of the normal aging process, and usually do not lead to pain (insert epidemiologic info on MRI scans ageing discs, scoliosis).
For reasons we don’t fully understand though, in some people degenerated discs, facet arthritis, and scoliosis can become inflamed and painful. In those cases it is important to strengthen the muscles of the spine, which will better support painful structures, relieving pressure and inflammation.