Don't squat while wearing skinny jeans. That's the warning health officials say should come with the tight, slinky jeans modern women love to wear. Squatting can cut the blood supply to muscles and constrict a nerve behind the knee which cuts off feeling from the knees down.

The latest warning follows problems experienced by an Australian woman who lost feeling in her feet and ankles after helping a friend move. She wore skinny jeans while squatting frequently to fill boxes. The 35-year-old woman collapsed, unable to walk, and her calves were so swollen her jeans had to be cut off. The woman was hospitalized, placed on an IV drip, and it was four days before she could walk unaided. Fortunately, she recovered fully.

Experts worry that many young women are exposing themselves to the condition that's called compartment syndrome. When non-stretchy tight jeans put pressure on the back of the leg, fibula and tibial nerves are compressed, causing numbness. Blood supply is reduced and muscles swell, sometimes causing permanent damage.

Something as simple as bending down to the level of a small child could compress the nerve and cause numbness. Wearing high heels raises the risk since the pelvis is tilted and increases pressure against the tight jeans, which adds to the risk of nerve damage.

"There's no need to ditch the skinny jeans just yet, simply avoid staying in the same position for too long and keep moving throughout the day," Priya Dasoju, professor adviser at the Chartered Society of Physiotherapy, told the BBC. "If you do suffer any prolonged pain you should of course seek help, but no one should be alarmed by this warning or change the cut of their jeans."

Some experts suggest swapping non-stretchy jeans for jeggings or for jeans with lycra.
The Australian case was described in The Journal of Neurology, Neurosurgery and Psychiatry.