The study appeared earlier this year in the journal Arthritis and Rheumatism.

Arthritis is not a single disease. The MedlinePlus Medical Encyclopedia, a United States government website, says there are more than one hundred different kinds.

Arthritis produces pain, swelling and limited movement in one or more joints. It involves the breakdown of cartilage. Joints need cartilage for smooth movement and to absorb shock when you put pressure on a joint.

Arthritis can be caused by injury, infection, an autoimmune disease or just long-term use. Some forms are curable, others are not. Some autoimmune forms of arthritis, if not treated, may cause joints to become deformed.

The most common form of arthritis, osteoarthritis, is more likely to affect older people. It most commonly affects the hips, knees or fingers. Overweight people have a higher risk of osteoarthritis. Other risk factors are repeatedly putting stress on a joint or having an earlier injury.

A physical therapist can design an individualized exercise program to reduce arthritis pain and support healthy joints. Getting plenty of sleep, reducing stress and eating a diet high in vitamins and minerals can also help.

And that's the VOA Special English Health Report. I'm Bob Doughty.