Get to know your back

If low back pain is keeping you from enjoying your favorite activities, sports, or work, learning a bit about the back can help you find relief.

(Illustration courtesy of the National Institute of Arthritis and Musculoskeletal and Skin Diseases)

While nearly everyone will experience low back pain sometime during their lifetime, it occurs most often in both women and men between ages 30 and 50. The causes are many including: normal aging, couch-potato lifestyles with too little exercise, sometimes too much exercise, or unusual exertion, such as shoveling snow.

The risk of experiencing low back pain from disc disease or spinal degeneration increases with age. If your low-back pain continues with no improvement for more than 72 hours call for a doctor’s examination.

Anatomy

The back is a complex structure of bones, muscles, and other tissues that supports the body’s trunk from the neck to the pelvis. The spinal column supports the upper body’s weight and houses and protects the spinal cord which is the main nervous system structure that carries the signals that control the body’s movements and convey its sensations.

The spinal column is composed of more than 30 bones, called vertebrae, stacked on top of one another. Each of these bones forms a circular casing that surrounds and protects the spinal cord. The spinal cord descends from the base of the brain and extends in the adult to just below the rib cage. Small nerves enter and exit from the spinal cord through spaces between the vertebrae carrying signals from organs, muscles and other tissues to and from the brain.

The spaces between the vertebrae are maintained by round, spongy pads of cartilage called intervertebral discs that allow for flexibility in the lower back and act much like shock absorbers throughout the spinal column to cushion the bones as the body moves. Bands of tissue called ligaments and tendons hold the vertebrae in place and attach the back muscles to the spinal column.

Starting at the base of the neck, the spine has four regions:
• Seven cervical or neck vertebrae are labeled C1–C7
• The next 12 thoracic or upper back vertebrae are labeled T1–T12
• Five lumbar vertebrae named L1–L5 make up the lower back
• Sacrum and coccyx, a group of bones fused together at the base of the spine.

The lumbar region of the back, where most back pain is felt, supports the weight of the upper body.