Looking For The Best Walking Shoes? Foot Specialists Share Their Criteria

Have you heard the terms functional shoe and minimal shoe? Many people ask whether these terms are interchangeable, a hot topic of debate in the foot health and gait mechanics research community. Both terms describe a shoe that allows your foot to function in its most natural position, but the difference between a functional shoe and a minimal shoe, in our view, is this: A shoe is functional if it has a wide toe box and a low heel-to-toe drop; a shoe is minimal if it has a wide toe box, zero heel-to-toe drop, and a thin and flexible sole.

 Criteria for a Shoe to Be Considered Functional

• The shoe is shaped like a foot.
• The shoe has a wide toe box.
• The shoe has a low heel-to-toe drop.
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Criteria for a Shoe to Be Considered Minimal

• The shoe has all the aforementioned criteria.
• The shoe has zero heel-to-toe drop.
• The shoe has a thin and flexible sole.

All minimal shoes are functional, but not all functional shoes are minimal. If you are wondering why these features matter and how they affect your foot health and ultimately your walking, keep reading.

Dr. Conley views a wide toe box as a nonnegotiable when selecting footwear. Wearing shoes with a wide toe box is her number one piece of advice for anyone asking which shoe features they should prioritize. The widest part of your shoe should match with the widest part of your foot’s anatomy, the forefoot area near your toes. In order to achieve this, you must select a shoe with a wide toe box. This is not a size wide shoe. The difference between a shoe that is wide in the toe area and a shoe that is size wide is the location of the width. (See Figure 8-2.)

If a shoe’s toe box is tapered (that is, not shaped like the natural foot), it doesn’t provide enough room for the toes to properly splay. In shoes with a tapered toe box, your toes are compressed and squeezed together, which alters their natural alignment and potentially compromises the function of your foot.

Think about this: If you are trying to balance, walk, or run with a rubber band wrapped around your toes, would it be easy or hard to do? When your toes are squeezed together, activities become much more difficult than when your toes are spread out, because toe splay allows your foot muscles to engage. When toes in restrictive footwear are unable to splay, the function of muscles like the abductor hallucis, the muscle that helps straighten the big toe, and the abductor digiti minimi, the muscle that helps straighten the little toe, may be compromised, as evidenced by the improved strength of these intrinsic muscles in individuals who wear minimal footwear that allows toe splay. These foot muscles play an essential role in your ability to maintain posture and balance, so you do not want to risk compromise of their critical function, which could lead to balance challenges or falls.

The average heel-to-toe drop in a walking shoe is about 8 to 12 millimeters, or between a third and a half inch, which is quite elevated compared to our natural anatomy.

Heel-to-toe drop refers to the height difference between the heel and forefoot of the shoe, as measured in millimeters. This shoe feature indicates how much higher the heel sits compared to the toes when the shoe is on level ground (the heel-to-toe ratio). Shoes with a higher heel-to-toe drop (usually 7 mm or more) raise the heel more, whereas functional shoes have a lower drop (1–6 mm) and keep the foot closer to a level position. A drop of 6 millimeters or less is recommended for more natural foot alignment. A minimal shoe puts the heel and toe at the same level (0 mm difference between heel and toe elevation). Altra Running is often credited with coining the term zero drop. The following chart shows the average heel-to-toe drop of the three categories of shoes.

Here’s the problem: The elevated heel position is not natural. Imagine having to wear a shirt that holds your arms at a 10-degree bend. You’d see right away that it looks ridiculous and could potentially cause an injury over time. Yet we accept elevated heels as normal for our feet. Why? Because it has become the societal norm and a consumer expectation.

Decades of marketing have trained us to associate higher heel-to-toe drop with fashion and attractiveness. Some people even end up feeling more comfortable in elevated shoes because over time their body has adapted: Calves have shortened, and feet have weakened. Working in Montana for over twenty years, Dr. McDowell has seen this body adaptation in an unexpected patient population: cowboys. Wearing cowboy boots for work and recreation for decades can cause adaptive shortening, and she has worked with numerous gentlemen who spent so many years in an elevated position and then had difficulty walking without boots when they retired.

Wearing a minimal shoe with zero drop builds lower leg strength. Walking in a minimal shoe asks the foot and calf to work harder, which helps train the muscles and prevents deconditioning or atrophy, which can occur when a shoe does more of the work of walking. Humans require strength in our feet and ankles to maintain balance, keep us upright, and prevent falls as we age. Wearing a lower-drop shoe allows you to exercise your lower body when you are simply walking throughout the day.

The final consideration with low- to zero-drop features in walking shoes is that they promote more normalized foot mobility and flexibility. Holding the heel more even with the forefoot, lower-drop shoes may allow for greater movement of the foot and ankle, which enables more efficient and natural walking.

If functional footwear is new to you (and to your connective tissues), there is no need to change too many factors at once. Take a staged approach in adopting these features in your walking shoes. Most major shoe manufacturers now include a drop measurement on product information pages. Several brands offer shoes with a wide toe box and a 4- to 5-millimeter heel-to-toe drop. These are great transitional shoes.