Overweight children are more likely than their normal-weight peers to suffer fractures, muscle and bone pain and other orthopedic complications, a new study shows.

These problems may be part of a vicious cycle that discourages overweight kids from being active and boosts their risk of gaining even more excess weight, Dr. Jack A. Yanovski of the National Institutes of Health in Bethesda, Maryland and colleagues conclude.

While overweight and obese adults are known to be at increased risk of arthritis and joint cartilage breakdown, it isn’t clear how common such problems are in healthy but overweight children, Yanovski and his team note in their report in the June issue of Pediatrics.

To investigate, the researchers reviewed medical charts from 227 overweight and 128 non-overweight children.

The overweight children were four and a half times more likely to have experienced some type of skeletal fracture than the non-overweight kids, and four times more likely to suffer from bone or muscle pain, the researchers found. The most common type of musculoskeletal pain, knee pain, was documented in the charts 6.6 percent of overweight children, compared to 2.3 percent of normal-weight kids.

When a subgroup of the study participants were asked directly about musculoskeletal pain, 21.4 percent of overweight children said they suffered from knee pain, compared to 16.7 percent of non-overweight kids. Overweight children also reported more impairment of mobility than their non-overweight peers.

Yanovski and his colleagues used X-rays to examine lower extremity alignment in another subgroup of children. More than 11 percent of the overweight children showed abnormal alignment, compared to less than 3 percent of the normal weight children. The researchers hypothesize that this misalignment could contribute to musculoskeletal discomfort.

While overweight people generally have denser bones and thus be at lower risk of fracture, the researchers note, this may be offset by the greater force that results when an overweight child falls or braces him or herself against an outstretched arm.

“Significantly overweight children and adolescents should be encouraged to engage in alternative modes of physical activity, such as bicycle riding or swimming, that potentially could alleviate the severity of lower extremity joint loading and discomfort,” the researchers conclude.

SOURCE: Pediatrics, June 2006.