To be hit by a elbow, also known as the "chicken wing slap". Harder to deliver, as it requires your opponent to be behind you, but more effective than a punch, since your wrist would twist slightly as your fist connected, reducing the overall force exerted. A elbow can be delivered quicker, so it hurts more, often with a quick jolt of your shoulders.
Chicken winging somebody in front of you is not advised.
After this chollo slapped my head against a paper-thin aluminin locker, I chicken winged him off my back and stomped his teeth in.