2 new studies suggest that modern running shoes could increase the risk of injuries to runners.

One study involved 68 healthy young women and men who ran at least 24 kilometers a week. The runners were observed on a treadmill machine. Sometimes they wore running shoes. Other times they ran barefoot.

Researchers from the JKM Technologies Company in Virginia, the University of Virginia and the University of Colorado did the study.
They found that running shoes create more stress that could damage knees, hips and ankle joints than running barefoot. They observed that the effect was even greater than the effect reported earlier for walking in high heels.

The study appeared in the official scientific journal of the American Academy of Physical Medicine.

The other study appeared in the journal Nature. It compared runners in the United States and Kenya. The researchers were from Harvard University in Massachusetts, Moi University in Kenya and the University of Glasgow in Scotland.