Risk Factors:

In most known cases, pain begins with an injury, after lifting a heavy object, or after making a sudden movement. Not all people have back pain after such injuries, however. In the majority of back pain cases, the causes are unknown.

Aging

Intervertebral disks begin deteriorating and growing thinner by age 30. One-third of adults over 20 show signs of herniated disks (although only 3% of these disks cause symptoms). As people continue to age and the disks lose moisture and shrink, the risk for spinal stenosis increases. The incidence of low back pain and sciatica increases in women at the time of menopause as they lose bone density. In older adults, osteoporosis and osteoarthritis are also common. However, the risk for low back pain does not mount steadily with increasing age, which suggests that at a certain point, the conditions causing low back pain plateau.

High-Risk Occupations

Jobs that involve lifting, bending, and twisting into awkward positions, as well as those that cause whole-body vibration (such as long-distance truck driving), place workers at particular risk for low back pain. The longer a person continues such work, the higher their risk. Some workers wear back support belts, but evidence strongly suggests that they are useful only for people who currently have low back pain. The belts offer little added support for the back and do not prevent back injuries.

A number of companies are developing programs to protect against back injuries. However, studies have been mixed on the outcome of company interventions. Employers and workers should make every effort to create a safe working environment. Office workers should have chairs, desks, and equipment that support the back or help maintain good posture.

Low back pain accounts for significant losses in workdays and dollars. According to the Bureau of Labor Statistics, back pain was responsible for around 60% of cases of people missing work due to pain involving the upper body. A 2004 study analyzed health care expenses in the United States. The analysis found back pain cost over $90 billion, of which $26 billion was spent directly on treating the back pain.

Osteoporosis is a condition characterized by progressive loss of bone density, thinning of bone tissue, and increased vulnerability to fractures. Osteoporosis may result from disease, dietary or hormonal deficiency, or advanced age. Regular exercise and vitamin and mineral supplements can reduce and even reverse loss of bone density.

Medical Conditions in Children

Persistent low back pain in children is more likely to have a serious cause that requires treatment than back pain in adults.

Stress fractures (spondylolysis) in the spine are a common cause of back pain in young athletes. Sometimes a fracture may not show up for a week or two after an injury. Spondylolysis can cause spondylolisthesis, a condition in which the spine becomes unstable and the vertebrae slip over each other.

Hyperlordosis is an inborn exaggerated inward curve in the lumbar area. Scoliosis, an abnormal curvature of the spine in children, does not usually cause back pain.

Juvenile chronic arthropathy is an inherited form of arthritis. It can cause pain in the sacrum and hip joints of children and young people. It used to be grouped under juvenile rheumatoid arthritis, but is now defined as a separate problem.

Injuries can also cause back pain in children.

Pregnancy

Pregnant women are prone to back pain due to a shifting of abdominal organs, the forward redistribution of body weight, and the loosening of ligaments in the pelvic area as the body prepares for delivery. Tall women are at higher risk than short women.

Psychological and Social Factors

Psychological factors are known to play a strong influential role in three phases of low back pain:

• Some evidence suggests preexisting depression and the inability to cope may be more likely to predict the onset of pain than physical problems. A "passive" coping style (not wanting to confront problems) was strongly associated with the risk of developing disabling neck or low back pain.
• Social and psychological factors, as well as job satisfaction, all play a role in the severity of a person's perception of back pain. For example, one study compared truck drivers and bus drivers. Nearly all the truck drivers liked their work. Half of them reported low back pain but only 24% lost time at work. Bus drivers, on the other hand, reported much lower job satisfaction than truck drivers, and these workers with back pain had a significantly higher absentee rate than truck drivers in spite of less stress on their backs. Similarly, another study found that pilots, who generally reported "loving their jobs," reported far fewer back problems than their flight crews. And yet another study reported that low rank, low social support, and high stress in soldiers was associated with a higher risk for disabling back pain.
• Depression and a tendency to develop physical complaints in response to stress also increase the likelihood that acute back pain will become a chronic condition. The way a patient perceives and copes with pain at the beginning of an acute attack may actually condition the patient to either recover or develop a chronic condition. Those who over-respond to pain and fear for their long-term outlook tend to feel out of control and become discouraged, increasing their risk for long-term problems.

Studies also suggest that patients who reported prolonged emotional distress have less favorable outcomes after back surgeries. It should be strongly noted that the presence of psychological factors in no way diminishes the reality of the pain and its disabling effects. Recognizing this presence as a strong player in many cases of low back pain, however, can help determine the full range of treatment options.