One of the most critical but ignored aspects of run form is the shank angle: the angle between the shank and a line dawn perpendicular to the ground at the point of impact. This angle determines the braking (and breaking) forces associated with every step you take as you run and the amount of propulsive force you apply to the ground—as well as the timing of that force. The runner with a large shank angle usually hits the ground with a straight leg, with the landing foot well