Horizontal zones were added to the Zone Theory by which contributor?

• A. Dr. Shelby Riley
• B. Dwight Byers
• C. Eunice Ingham
• D. Dr. William Fitzgerald

Answer: (A)

Horizontal zones extend the original Zone Theory by adding a cross-sectional layer that divides each vertical zone into horizontal bands across the body’s map. Shelby Riley introduced this refinement to better reflect how reflex relationships can run across regions, not just along a single longitudinal axis. By adding these horizontal divisions, practitioners can connect reflex points that correspond to different body areas within the same plane, enhancing precision in locating effects on the feet and hands. The earlier contributors laid the groundwork—Dr. William Fitzgerald established the ten vertical zones, Eunice Ingham popularized and mapped the reflex points, and Dwight Byers helped spread the practice—while Riley’s contribution specifically names the horizontal dimension added to the theory.