As people age, bone strength and muscle elasticity and tone tend to decrease. The discs begin to lose fluid and flexibility, which decreased their ability to cushion the vertebrae.
Pain can occur when the spine has a sprain, strain or spasm in one of the muscles or ligaments in the back If the spine becomes overly strained or compressed, a disc may rupture or bulge outward. This rupture may put pressure on one of the nerves rooted to the spinal cord. When these nerve roots become compressed or irritated, back pain results.
Lower back pain may reflect nerve or muscle irritation or bone lesions. Most low back pain follows injury or trauma to the back, but pain may also be caused by degenerative conditions such as arthritis or disc disease, osteoporosis or other bone diseases or congenital abnormalities to tin the spine. Obesity, smoke, weight gain during pregnancy, stress and poor physical condition may contribute to LBP. Additionally, scar tissue created when the injured back heals itself does not have the strength or flexibility of normal tissue. Buildup of scar tissue from repeated injuries eventually weakens the back and can lead to more serious injury.
Occasionally, low back pain may indicate a more serious medical problem. Pain accompanied by fever or loss of bowel or bladder control, pain when coughing and progressive weakness in the legs may indicate a pinched nerve or other serious condition. People with diabetes may have severe back pain or pain radiating down the leg related to neuropathy. People with these symptoms should contact a doctor immediately to help prevent permanent damage.
Who develops lower back pain?
Nearly everyone has low back pain at some point; men and women are equally affected. It occurs most often between ages 30 and 50, due in part to the aging process but also as a result of sedentary life styles with too little exercise. The risk of experiencing LBP from disc disease or spinal degeneration increased with age.
LBP unrelated to injury or other known cause is unusual in pre-teen children. However, a backpack overload with schoolbooks and supplies can quickly strain the back and cause muscle fatigue. To avoid back strain, children carrying backpacks should bend both knees when lifting heavy packs, visit their locker or desk between classes to lighten loads or replace books, or purchase a backpack on wheels.