1. Super-skinny jeans: Skinny jeans can compress nerves in the groin and legs, reducing blood flow to the lower legs. This can lead to muscle damage, swelling, and numbness. While these symptoms might sound a bit extreme, they recently caused a 35-year-old woman who squatted repeatedly while wearing skinny jeans to spend four days in the hospital, according to a freaky case study published in the Journal of Neurology, Neurosurgery, and Psychiatry.