When the facet joints or certain other structures in the spine become injured, arthritic and degenerative the large back muscles can spasm and cause low back pain with marked limitation in motion.

An episode of lower back pain that lasts for more than two weeks can lead to muscle weakness (since using the muscles hurts, the tendency is to avoid using them). This process leads to muscle wasting and subsequent weakening, which in turn causes more back pain because the muscles of the back are less able to help hold up the spine.

A. Thoracic Spine Pain

The thoracic spine is located at the back of the chest (the thorax), mostly between the shoulder blades. It extends from the bottom of the neck to the start of the lumbar spine, roughly at the level of the waist. Therefore, thoracic spine pain usually affects the upper and middle part of the back or spine.

There are several reasons people may suffer from thoracic spinal pain. Muscle tension is among the most common causes and is often the result of poor posture. In older adults, arthritis in the thoracic facet joints can cause middle and upper back pain, as can compression fractures of the vertebrae due to osteoporosis. In younger patients, a spine segment or a rib can be out of place and cause pain.

Other causes of middle and upper back pain include herniated or degenerated discs or problems with the joints that attach the ribs to the thoracic vertebra.

B. Low Back Pain including Leg Pain

Low and lower back pain can vary from dull pain that develops gradually to sudden, sharp or persistent pain felt below the waist. Most of us at some point during life will experience low back pain that may travel downward into the buttocks and sometimes into one or both the legs. This pain can make it hard to move or stand up straight. Pain that lasts more than three months is termed chronic and needs medical attention.

The most common cause is muscle strain often related to heavy physical labor, lifting or forceful movement, bending or twisting into awkward positions, or standing in one position too long.

Sometimes back pain can be related to a disc that bulges or ruptures. If a bulging or ruptured disc press on the sciatic nerve, pain may run from the buttock down one leg. This is called sciatica.

C. Sacroiliac Joint Pain

Sacroiliac joints, also known as the SI joints are located between the iliac bones and the sacrum, connecting the spine to the hips. The two joints provide support and stability and play a major role in absorbing impact when walking and lifting.
Sacroiliac (SI) joint pain is felt in the low back and buttocks and can travel down one or both the legs. The pain is caused by damage or injury to the joint.

Under normal circumstances, sacroiliac joints should be a fairly stiff or rigid link between the pelvic bones and allow only a few degrees of movement. Sometimes, due to trauma or just extra mobility these sacroiliac joints develop too much uncontrolled motion. This allows sacroiliac joints to adopt an abnormal or stressed joint position, which may result in SIJ pain.

D. Coccyx Pain

Tailbone (coccyx) pain is centered at the very bottom of the spine, right above the buttocks. The tailbone is small, but it does have a few important jobs. It helps stabilize us when we sit. Also, many tendons, muscles, and ligaments run through the area.

Pain that occurs in or around this bony structure can be caused by trauma to the coccyx during a fall, prolonged sitting on a hard or narrow surface, degenerative joint changes, or vaginal childbirth.

Tailbone pain can feel dull and achy but typically becomes sharp during certain activities, such as sitting, rising from a seated to a standing position, leaning back while sitting or prolonged standing.