Recent studies show that despite the rise of Ugg boots and their generic imitations in the fashion industry, the comfy sheepskin-lined footwear prove to ruin the wearer’s feet over a long period of time.

Health experts in the United Kingdom, such as Dr. Ian Drysdale of the British College of Osteopathic Medicine, told the Daily Mirror newspaper that Ugg-style boots cause pain within the foot, ankle, hip and eventually the back.

“Their feet are sliding around inside,” Drysdale said. “With each step, the force falls toward the inside of the foot and the feet splay.”

Ultimately, the design of the Ugg boot flattens the arch of your foot, causing joint and muscle pain.

Ugg Australia informed the Mirror that Ugg boots are “comfort” rather than “performance footwear” and that cheaper “knockoffs” lack more of the reinforced heels or insoles in the designer brand.

Dr. Robin Ross, a podiatrist of the New York State Podiatric Association, told the New York Daily News that many women wear their Ugg-style boots every day, escalating the problem even more.

“If someone plans on going on a long hike or standing on their feet all day, [Uggs] are not good, whether it’s the brand or an imitation,” Ross said.

Ugg boots were introduced worldwide by celebrity trendsetters such as Cameron Diaz and Katie Holmes in the mid-2000s.