The cost of ignoring the pervasiveness of these disorders has been enormous. WHO estimates that at least several hundred million people already suffer from bone and joint diseases and, with the "graying" of America and the rest of the world (the number of people aged 50-plus will double by 2020), dramatic increases in the numbers of sufferers are expected.

In the U.S. alone, musculoskeletal complaints are the leading cause of chronic complaints and visits to physicians—more than 130 million patient visits and financial costs of more than $250 billion were recorded back in 1995. More to the point, more than 70 million people in this country have pain, stiffness, and (sometimes) deformity from arthritis and other musculoskeletal conditions.

There are more than 100 types of arthritis, but two major types are generally recognized: rheumatoid arthritis and osteoarthritis.

Rheumatoid arthritis is an autoimmune disease in which the synovial membrane that surrounds the joint becomes inflamed, tender and swollen. The joint area is usually red and feels warm to the touch. The joints typically affected are fingers, toes, wrists and knees. Flare-ups of RA may be triggered by viruses or stress. The cause of RA is not clearly understood.

Osteoarthritis, the most common form of arthritis, is considered by some doctors as a normal result of aging. Perhaps because of this attitude, many young seniors are in denial when they first observe symptoms that point to OA; they're more likely to decide that an enlarged, sore joint is just a temporary strain or sprain. People who were injured when very young in high-intensity sports, such as soccer or skiing, can begin to experience symptoms of OA as early as their 30s and 40s. Also, repetitive overuse of joints in certain occupations, such as carpentry or drill-press operation, can eventually lead to OA.

OA develops when the protective layer of cartilage between the bones wears down; these bones rub against one another and produce spurs or rough spots that restrict movement and cause pain. Joints may make a cracking noise when moved. Knobbiness is easily seen in the fingers, and this may be the first overt sign of the condition. However, OA tends to affect the larger, weight-bearing joints such as the hips, knees and spine. Unfortunately, OA can secretly progress for years before the victim becomes aware of it.

Major risk factors for OA are obesity, a history of trauma (for example, automobile accidents) or prior family history of the disease. In the latter case, some families may pass on the tendency for defective cartilage or slight defects in the way that joints fit together. Excess weight puts extra stress on weight-bearing joints, especially the knees. A 10­15 pound weight loss can reduce or eliminate knee pain.

There is no cure for arthritis. Treatments are usually palliative, and some can actually be preventative. Moist heat to improve blood flow or cold treatments to reduce swelling, wearing supportive braces to protect the affected joint, or medications such as anti-inflammatory drugs may be recommended. Warm baths, massage, or stretching exercises may also be helpful.

Pain, stiffness, fatigue and fear of harming themselves may prevent seniors with arthritis from exercising. Ironically, inactivity can worsen the condition. Aerobic activity can improve circulation, strengthen surrounding muscle and cartilage, and help control weight. Walking, swimming, hiking and bicycling regularly can improve flexibility and reduce pain. Pain is the major reason that seniors limit their activities, as demonstrated in a number of studies.

Combining aerobic activity with social support lessens pain and depression and increases feelings of self-sufficiency. A study done by Dr. Leena Sharma at Northwestern University also confirmed that pain was a major cause of disability in OA patients.

Eating a healthy, well-balanced diet with plenty of vegetables, fruits and whole-grain breads and cereals, accompanied by the recommended daily amounts of vitamins and minerals, will help to control weight and provide energy for work and play.

The Arthritis Foundation recommends 10 ways for seniors to protect their joints:

1—Maintain your ideal body weight. Weight puts stress on joints.

2—Exercise. Muscles keep joints from rubbing and wearing down cartilage.

3—Stand up straight. Good posture protects your neck, back, hips and knees.

4—Use your big joints. When you lift and carry, use the big joints to protect the smaller joints.

5—Pace yourself. Alternate heavy activity with periods of rest to avoid repetitive stress.

6—Listen to your body. If you're in pain, don't ignore it.

7—Don't be static. Changing positions decreases stiffness.

8—Don't be a weekend warrior. Start new activities slowly and safely.

9—Wear proper safety equipment. Use helmets, wrist and knee pads, and seat belts.

10—Ask for help. Don't try to do a job that is too big for you.

For more information, call the Arthritis Foundation at 800.283.7800 or visit www.arthritis.org. The Arthritis Foundation also offers a brochure regarding the use of glucosamine and chondroitin sulfate.