Final answer:
Rescuers need to allow chest recoil during CPR to enable the heart to refill with blood between compressions. Proper hand placement and force are also essential to prevent injury.
Step-by-step explanation:
Something that rescuers need to allow while performing chest compressions during CPR (cardiopulmonary resuscitation) is sufficient chest recoil. Chest recoil is critical because it allows the heart to refill with blood between compressions. When performing CPR, rescuers should compress the chest at least 5 cm deep at a rate of 100 compressions per minute, as this manual compression helps to push blood through the pulmonary and systemic circuits. The current emphasis in CPR is on high-quality chest compressions over artificial respiration. It is important for rescuers to be properly trained in CPR, as incorrect hand placement or excessive force can result in injury to the patient such as a broken sternum, broken ribs, or damage to organs.