"That has a definite impact over time," Laudicina said. Sitting up straight — Forest Gump-style with both feet planted on the floor — and simply standing up straight will save many people from unwanted aches and pains.
Women who happen to be pregnant have a tough and painful time of it.
First, the more the fetus grows, the more it pulls on the mother's back. A recent scientific paper showed that women's spines have evolved to curve during pregnancy to help balance. But pregnant women still feel lower back pain from the extra muscle strength it takes to keep themselves upright.
The change in body mass distribution also puts women at risk for hip, ankle and calf pain.
Then, enter the hormones. In order to push the baby out, it helps if the joints in the pelvis can flex and move a bit, Paulos said. To accommodate this need, the body releases joint-relaxing hormones.
"But they don't discriminate," Paulos said. "When you're pregnant, all your ligaments in your joints relax."
As a result, pregnant women's kneecaps can start to wobble and hurt. So may their spines. The best thing to do, Paulos said, is to be fit before pregnancy and stay fit during pregnancy.
"As far as the orthopaedic aspects of being heavy, carrying extra strength to carry the extra weight will reduce pain," Paulos said.
Children have an easier time losing weight than adults, but their years with extra pounds may cause a long-lasting burden of pain.
About 19 percent of children age 6-11 are overweight, according to the National Center for Health Statistics. For these growing kids, growing pains can get worse.
Children's bones grow at specific areas of very thick lining called growth centers, which sometimes cause pains for kids.
"As the bones grow, they do cause a little inflammation and pain," Paulos said. "But if you are heavy as a kid, it separates the growth center from the rest of the bone and it can cause pain and inflammation.
"Bad alignment and heavy weight can affect the growth centers of growing children," he said, adding that disease and rickets can have the same effect.
The problem of overweight children is growing, along with adult obesity in America. Sixteen percent of children and teenagers are overweight — triple what the proportion was in 1980.
In January, the surgeon general put out a call to fight childhood obesity and overweight problems. In addition to bone pain, overweight children face a higher life risk for type 2 diabetes, heart disease and a 70 percent chance of becoming overweight or obese as adults.
People may first associate the bow-legged body with the side-to-side swagger of a cowboy, but real bow legs, sometimes called genu varum in medicine, arise from less glamorous sources.
When bow-legged people stand with their feet together, their legs tend to bend outward from each other, leaving a round space between the knees, or below the knees. Sometimes only one leg bends while the other remains straight, giving a true bow appearance.
Infants often look bow-legged before the age of two, but the shape naturally corrects itself as the child grows and begins to walk. However, several factors, like genetics, Blunts' disease (a bone growth disorder) or rickets (caused by vitamin deficiencies) may contribute to the permanent bone curvatures that give the distinctive "bow" shape.