There are two basic ways an athlete will perform over bar mechanics, also known as the backbend, in the high jump. There are high jumpers that drive with their head and others who drive with their arm. Either drive technique works for high jumpers, but they do need to be coached differently.
Athletes that drive to the mat with their head need to look at the opposite corner of the high jump mat while in the air. A bad habit of these athletes is that they choose to look at the bar while in the air. By looking at the bar in midair, it makes the athlete's chin come to their chest which makes the athlete’s butt and hips drop on the bar. These jumpers need to focus on not “snapping” by keeping their eyes on the opposite corner of the high jump mat.
Athletes that drive to the mat using their arm need to ensure that they are staying away from the bar during takeoff. Arm drivers have a bad habit of hitting the bar off with their elbow or shoulder due to improper takeoff placement away from the bar. This is because they want to use that arm to drive themselves over the bar. These jumpers need to focus on staying away from the bar and driving their arms up towards the sky first and then allowing the arm to drive towards the mat.