Vigorous physical activity in children likely to stave off knee osteoarthritis in later life

Young children need to be highly physically active if they are to stave off degenerative joint disease, specifically osteoarthritis of the knee, suggest researchers in the British Journal of Sports Medicine.

Assessing all the evidence, the researchers from the Monash University and the University of Tasmania in Australia, show that physical activity in young children is associated with the healthy development of cartilage, the firm rubbery tissue that cushions joint bones.

Loss of cartilage is a cardinal sign of the painful joint disease osteoarthritis.

The authors point to previous research, which shows that the amount of exercise taken has a significant impact on the volume of joint cartilage: children who had not been active in the preceding fortnight had up to 25% less cartilage than even mildly active children.

Another study indicates that when monitored over the long term, a high level of activity increased cartilage volume in the knee by up to 15% a year in boys and up to 10% a year in girls. And animal research suggests that withholding exercise in early life may prevent normal development of joint cartilage.

The authors suggest that exercise promotes cartilage volume in the same way that it increases bone density. Although bone density is largely determined by genes, exercise is important during growth to ensure that peak bone density is reached, so reducing the risk of osteoporosis (brittle bones) in later life. Greater cartilage volume can probably stave off osteoarthritis, they suggest.

“The current evidence supports a prescription of vigorous physical activity for optimum joint development in children,” they conclude.