A blade for a turbomachine bladed wheel is disclosed. The blade includes an airfoil and a platform with at least one air injection passage. The platform including includes a groove running along the pressure side of the airfoil at least in the vicinity of a downstream portion thereof, and formed between the pressure side and a ridge formed on the platform surface at a short distance from the downstream portion of the pressure side. At least one air injection passage is arranged in the groove. Because of the presence of the groove, the air stream injected via the air injection passage(s) is kept close to the pressure side and thus provides effective cooling of the downstream portion thereof.