The human foot is designed to walk on grassy or muddy surfaces not on hard concrete or marble. Walking barefoot on such hard artificial surfaces jolts our body and jars the spine. Heels on shoes provide cushioning to the body. The heel requires more cushioning than the rest of the foot because it bears the brunt of the impact with the ground.
In addition to cushioning the foot, the heel also ensures durability of the shoe. A shoe without a heel would soon wear out in the heel region. You can do it because your shoes cushion your feet from injury.
Picture Credit : Google