In the latest study, published in the Journal of Orthopaedic Research, scientists recruited 14 healthy women and scanned their knees as they walked wearing different types of shoes.
The women were told to walk at normal speed wearing flat shoes, then one-and-a-half inch heels and finally three-and-a-half inch heels. Researchers examined the angle of the knee as the women's feet struck the ground, as well as when they came to rest. The results showed the higher the heels, the more likely it was the knees were bent when shoes touched the ground - increasing strain on the knee joint. Similar effects were seen when the women stopped walking.
The researchers said wearing killer heels or at least three-and-a-half inches made the women's knees look more like aged or damaged joints, with the effect more pronounced for overweight women.
"Wearing high-heeled shoes has been implicated as a potential contributing factor for the higher lifetime risk of osteoarthritis in women," said lead author Matthew Titchenal of Stanford University's Biomotion Lab.
"In this study, many of the changes observed with increasing heel height and weight were similar to those seen with ageing and osteoarthritis progression."
Stilettos have long been suspected of being bad for the knees.
A recent study by the College of Podiatry in London found that women risk permanent injury by wearing heels, which start causing pain just one hour and six minutes after slipping on a pair.
Walking for long periods on the balls of the feet causes aches and pains, stress fractures, trapped nerves and greater wear and tear on the joints and soft tissue.
Usually cartilage soaks up the impact from walking, running or lifting, so bones do not rub together. However, in osteoarthritis, the cartilage breaks down and as bones come into contact, the friction makes joints swollen and painful. There are no drugs to cure it and many sufferers rely on anti-inflammatory painkillers.