When I look at what I would consider an ideal shoe I base it on what's ideal to complement natural foot function. The null hypothesis is that the foot is designed to work on its own without the need for modern bracing, cushioning and motion control technology. I may deviate slightly from this to compensate for a specific structure or strength issue. The goal is progressive rehabilitation toward the ideal: to get the walker or runner in the least amount of shoe that's safe for them while they work on the functional corrections. This is my definition of minimalism.

1. Level or minimal heel-to-toe drop and close to the ground
Our arches are designed to be supported at the ends--that means heel, ball and toes in a level and balanced contact. This facilitates stability and balance in mid-stance, and complements a proper posture. A shoe should also minimize "toe-spring" (upward curve at toes), which places toes in extension and contributes to extension deformities such as hammer toes.

2. Flexible last
Your foot naturally bends in all directions, as should your shoe. Most shoes are stiff in the middle and stiff where your toes bend at the ball of the foot.

3. Wide toe box
When the big toe is compressed out of alignment, the front end of the arch doesn't work. In shoes with a narrow toe box, the big toe isn't allowed to aid in balance, stability and propulsion.

4. Not too soft or too thick
The thinner and firmer the shoe, the more ground feel (proprioception) it provides. The increased ground feel allows your body to adjust to the forces of running in a more efficient way and is optimal for learning natural running form and technique. Without a firm message to the nervous system, your body doesn't know which muscles to use, how hard to turn them on and how long to keep them on. To get a clear message in thick/soft shoes we're forced to strike the ground harder and drive the foot onto a firm surface to give us the feedback we require.