Yahoo Sports reports that German shoe company Puma filed with a U.S. district court a complaint for trademark infringement, patent infringement, and unfair competition against Brooks. Puma claims that it owns the “Nitro” trademark for shoes and that Brooks is infringing on its “Nitro” trademark by using the word “Nitro” in its shoe advertisements. Puma also avers that Brooks is copying one of its patented shoe designs, which even includes the phrase “Nitrogen-injected.” In a statement, Brooks said that it is not guilty of infringement and that Puma is abusing trademark law by trying to prevent its competitors from using the word “nitro” in describing nitro-infused shoes.