Spinal roots follow a path from the chord to the periphery. At various levels of the spinal column, the nerve roots may become compressed, causing pain at a distant site, called referred pain. Thoracic pain, common in people with osteoporosis and diabetes, typically affects the chest and middle back. The spine is comprised of 24 individual bones called vertebrae. Ligaments are the bands of tissue which hold the bones together and provide stability.
Joints are the place where two bones meet and are held together by the ligaments.
Muscles attach to bones by tendons, and nerves branch out from the spinal chord on each side of the vertebrae. Disks, which have a gelatin-like center, act as cushions and shock absorbers between vertebrae. The source of back pain may originate in the nerves themselves, in the muscles, disks or joints of adjacent vertebrae rubbing against each other, according to Gaughan. Muscle spasms cause pain because the spasm decreases the space between nerve roots. Bone spurs bony outgrowths on vertebrae can cause pain and stiffness.