Analysis finds no link between physical activity and knee osteoarthritis

The condition happens when the cartilage between joints wears away

A new study says humans might have something in common with salamanders.

A new analysis by researchers throughout the United States and United Kingdom found no link between the amount and duration of physical activity and your risk of developing knee osteoarthritis.

Osteoarthritis is more commonly known as wear-and-tear arthritis. This condition results when the cartilage between joints wears away, causing the bones of the joints to rub more closely against one another without the benefit of cartilage shock absorption.

The rubbing results in pain, swelling, stiffness, decreased ability to move and, sometimes, the formation of bone spurs, according to WebMD.

Although osteoarthritis is found in young people, it mostly occurs in those over age 45. Woman are more likely to be affected than men.

According to the Arthritis Foundation, more than 27 million people in the U.S. have osteoarthritis, with the knee being one of the most commonly affected areas.

The new analysis included six global community-based studies, including 5,065 participants with and without knee osteoarthritis who were followed for five to 12 years.

“Knowing that the amount of physical activity and time spent doing it is not associated with the development of knee osteoarthritis is important evidence for both clinicians and the public who may need to consider this when prescribing physical activity for health,” said co–lead author Thomas Perry, BSc, Ph.D., of the University of Oxford, in the U.K.

Next, it will be important to understand the role of injury and specific types of activity within this association, noted co–lead author Lucy S. Gates, Ph.D., of the University of Southampton, and co–senior author Maria Sanchez-Santos, of the University of Oxford.

Almost everyone will eventually develop some degree of osteoarthritis, according to WebMD, because the most common cause is age. However, several factors increase the risk of developing significant arthritis at an earlier age.

  • Age: The ability of cartilage to heal decreases as a person gets older.
  • Weight: Weight increases pressure on all the joints, especially the knees. Every pound of weight you gain adds 3 to 4 pounds of extra pressure on your knees.
  • Heredity: This includes genetic mutations that might make a person more likely to develop osteoarthritis of the knee. It may also be due to inherited abnormalities in the shape of the bones that surround the knee joint.
  • Gender: Women ages 55 and older are more likely than men to develop osteoarthritis of the knee.
  • Other illnesses: People with rheumatoid arthritis, the second most common type of arthritis, are also more likely to develop osteoarthritis. People with certain metabolic disorders, such as iron overload or excess growth hormone, also run a higher risk of osteoarthritis.

You can read the full analysis in the journal Arthritis & Rheumatology.

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