It is normal. The black Nike logo on the back is the brand of the shoe, and it is normal to have the logo. NIKE is headquartered in Portland, Oregon, USA. The company produces a wide range of sporting goods, such as clothing, footwear, sports equipment, etc. NIKE is a world-famous sports brand. Its original meaning in English is the Greek goddess of victory, and its Chinese translation is Nike. The Nike logo is a small hook. Nike has always regarded it as its glorious mission to inspire every athlete in the world and provide them with the best products. Nike's pioneering air cushion technology brought a revolution to the sports world. Sports shoes manufactured using this technology can protect athletes' knees well and reduce the impact on the knees when they land during strenuous exercise.