Crunching Too High The ab crunch is a subtle movement that lifts the shoulder blades a few inches off the floor. Jerking the shoulders up adds momentum and reduces the effectiveness of the exercise. Bring your shoulders 1 or 2 inches off the floor imagining you are bringing your ribs https://bookmarkbirth.com/story18012800/5-t%C3%A9cnicas-simples-para-abdominal-solo