Anatomy of a Shoe

By David Sharnoff

Shoes are an essential piece of equipment for your players. Here’s what you and your staff need to know to best service your customers.

Achilles Notch

A cut out area at the top center of the heel counter that cradles the Achilles tendon.

Heel Counter

Cups the heel and, if firm on compression, should stabilize the heel as the foot contacts the ground.

Upper

Made of leather, synthetic leather, nylon mesh or new high tech material, the upper is either glued to the outside of the shoe or pulled over the midsole and attached to the outsole in a “unibody” design. May also have support beams integrated into the lacing system.

Cupsole

Part of the outsole that extends up into the shoe’s upper. It can be a partial, three-quarters, or full cupsole design, each providing greater degrees of stability to the shoe’s upper.

Last

Between the insole and the midsole, there are three types: Board last, which looks like cardboard and provides a firmer/stiffer ride; Strobel or California last, which looks like a woven material with stitching exposed along the edge and provides a softer ride; and Combination last, which is a combination of the features above.

Midsole

The meat-and-potatoes of the shoe, made of either EVA or PU (polyurethane). EVA is lighter and provides more comfort; PU is heavier and provides more support. Air pockets in the rearfoot and/or forefoot areas of the midsole provide a more comfortable ride.

Insole

Also called the “sock liner,” it’s made of EVA (ethyl vinyl acetate) or poron material. Many consumers don’t realize the insole is removable and can be replaced with over-the-counter insoles to customize the fit.

Lacing System

Straight lacing is most typical, but it doesn’t provide the chance to personalize the fit. Variable lacing allows players to adjust fit to their liking. Hidden lacing behaves like straight lacing; Integrated lacing threads through support pieces for a more secure fit; Speed lacing offers loops rather than traditional eyelets.

Laces

Flat laces are more common, but tend to unravel easier. Round, or spaghetti, laces are designed not to unravel as easily.

Toe Box

Encapsulates the toes and is often reinforced to protect the forefoot and extend wear.

Outsole

The bottom of the shoe, made of synthetic rubber, PU or EVA. It may have a herringbone, nubby or pillar design.

Cradle System

Found in the midpoint of a shoe, it’s typically made of TPU (thermoplastic urethane) that strengthens the midfoot/outsole design. It cradles the upper and is integrated with the lacing system.

Flexpoint

Simply put, it’s where the shoe bends. If it bends at the midpoint (arch) area, find another shoe. The shoe should bend closer to the toe box area and have flex grooves on the outsole to assist in this function. The deeper the cut out in the midpoint area, the greater chance for a poor flexpoint.

See all articles by David Sharnoff

About the Author

David Sharnoff is a podiatrist in Shelton, Conn.. He is a longtime advisor to the WTA Tour and a member of Tennis magazine's Technical Advisory Panel. Dr. Sharnoff also is a longtime contributor to professional journals in the field of podiatric medicine.