Final answer:
During CPR, maintaining light contact with the chest allows for complete chest recoil, ensuring effective blood circulation.
Step-by-step explanation:
Keeping the heel of the hand lightly in contact with the chest during the relaxation phase of chest compression is important because it allows for complete chest recoil. This is a critical aspect of effective CPR, as the chest needs to be allowed to fully recoil between compressions to maximize blood flow.
It ensures that the heart refills with blood between compressions, which is essential for circulating blood to the vital organs, including the brain, where neurons can die within minutes without blood flow.