Adidas has filed a patent infringement suit against Skechers. The company claims that Skechers’ Mega Flex design is stolen from the design of Adidas’ Springblade shoe. Both shoes feature a series of blade-like structures that run underneath the sole of the shoe. The design provides a “high energy return” to runners, according to the suit, and “sense of buoyancy, even when you’re walking”.

“We will not stand by and allow others to blatantly copy our products and infringe on our valuable intellectual property,” Adidas said in a statement. “We are the leader in footwear innovation, design, and engineering, creating high-performance shoes for athletes. This pattern of unlawful behaviour and freeloading in the industry is outrageous and must end. We will take every legal measure possible to protect and defend our innovations.”

Nike has also filed a patent infringement suit against Skechers earlier this year. Skechers have seen significant growth in recent years and sales for 2015 totalled $3.1 billion, a 32 percent increase on the previous year. Skechers said it does not comment on pending litigation.