Reflection area is a focal point nerves. Each point corresponds to a particular body organ. Reflection region is actually contained in the entire body, but often practiced is part of the foot.
Massaging the area can reflect the blood circulation in the organs concerned. When asked why be so, it's hard to answer scientifically, but its effect can indeed be verified. For example, if your toes massaged the middle of our middle fingers will feel the heat. This proves that the area is a reflection of the middle finger on the middle toe.
If people obey the will of nature, walking on the rough and rocky ground with bare feet then the reflection area which is under the feet will be exposed to "massage" that moved its function. And keep in mind that all the nerve points at the bottom of the foot is not at risk for a massage.
But after changing the human condition, man is no longer walking on rough ground, but walking on a smooth road with shoes. Eventually the human foot by the shoe, so fettered impaired blood circulation and feet become cold. And worse reflexology foot area to be restrained so it can not function anymore.