Karl Birkenstock invented the firm footbed in the 1960's. He discovered that a mixture of cork granules blended with natural rubber is firm enough to support arches while malleable enough to gradually conform. The formula also proved to be lightweight, durable, and environmentally sustainable.
Karl shaped his footbeds for fussgesundheit (good-foot-health) with a neutral heel, prominent arch supports and room for toes to reach out naturally.
See also Soft Footbed.
