ocr: Be sure to count out loud. In a stressful situation your mind will race, and it will be easy to press too fast. Direction of Force By compressing the chest 1 1/2-2,you . are increasing the pressure inside the chest cavity, forcing the blood through the heart. Sternum Allow the chest to expand between Heart. compressions, but do not take your Spine hands off the chest as you will lose Lung. your position. The most common complication of CPR is broken ribs. Careful hand placement will decrease the likelihood of breaking them.