This is performed the same way as the good morning.
This is one of the best exercises to develop your low back, glutes and hamstrings. To perform a good morning begin by placing the bar on your back in about the same position as you would a squat. The first thing to move during a good morning should be your hips. With a very slight bend in your knees, push your hips back and begin the descent. You should maintain a good arch in your lower back and keep your head up. Continue until your low back is about parallel to the floor and raise back up. You can use a wide, medium or close stance when doing a good morning.
The difference is the use of a Buffalo Bar. This bar has a slight bend in it making it more comfortable on the upper back and places less stress on the shoulders.