The Birkenstock Men’s Women’s Madrid Birko-Flor Sandals are designed with a single-strap and the upper is made from the skin-friendly, hard-wearing synthetic material Birko-Flor. Anatomically shaped cork footbed Birko-Flor upper Suede footbed lining Deep heel cup EVA outsole Interior and exterior longitudinal arch supports Transverse arch support 1 strap with an individually adjustable metal pin buckle Deep heel cup The very deep moulding in the heel area supports the foot tissue and holds the heel bone firmly in its natural position. It provides the foot with nearly as much support when it is in a Sandals as when it is in a closed shoe. Heel mould The heel mould activates the calf muscles, stabilises the back of the foot and improves gait and coordination. Interior and exterior longitudinal arch supports The arch supports that run alongside the sides of the footbed surround the tarsal bones inside and out. This feature gives the foot the stability it needs when taking a step. Transverse arch support The support that runs through the middle of the footbed stabilises the metatarsal bone. In this way, the transverse arch support helps ensure that the foot has a naturally straight and solid stance. Toe grip There are raised indentations at the front of the footbed near the toes. Thanks to the toe grip, the toes remain loose and spread out in their natural position. The indentations also support the natural rolling motion of the toes. Footbed edge The footbed is drawn up especially high at the front. As a result, the high footbed edge protects the toes during the rolling motion of the foot.