Advanced Foot Massage, also referred to as Foot Zone Therapy or Reflexology, is based on the premise that energy flows through the body through meridians from the brain to the feet.  Every organ and cell has a representative point on the foot, and when pressure is applied, the brain sends a signal to the corresponding part of the body to facilitate healing and restore balance.  Termporary pain is felt on areas of the foot that correspond to the affected organ or body part.  When the pain is relieved or reduced, the healing process has begun. 

(Source:  www.massagetherapy.com/glossary/index.php)