Feet are for walking and running, not (anymore) for grasping.

Blog 05 Feet are for walking and running and not (anymore) for grasping. Introduction

To this day, surgeons and anatomists have not fully understood the functional mechanisms of the human foot.
The term "arch" is to be regarded as technically unsuitable for the longitudinal structure of the foot; an arch construction requires a foundation, and this is not present.
Previous concepts include the following:
(I) The skeleton of the foot below the talus is considered a continuous "footplate" or "lamina pedis," and it is believed that this structure is capable of longitudinal pronation or supination, internal and external rotation movements, and creates "closed-packed" and "loose-packed" positions (MacConaill 1945 and MacConaill, Basmajian 1969).

(II) It has often been suggested that movements in the intrinsic intertarsal joints are rotations around definitive axes (Hicks 1953, Van Langelaan 1983, Benink 1985, Lundberg et al 1989).

(III) The importance of the axes of the calcaneo-cuboid and talo-navicular joints, which can be "in and out of axis," defining mobility and stability in the subtalar joint line (Elftman 1960, Mann 1993). 
From the lecture by Mr. David Stainsby, MD International Symposium for Foot Surgery Munich 2012.

We find many simplifications in the "screwing" of the foot. It causes the foot to be soft upon landing and to "screw" and become rigid shortly after landing. This allows for a powerful push-off with minimal soft tissue (plantar fascia) strain. The activity of the tibialis posterior shortly after landing seems to me to be an important indicator for this model. The forefoot continues in pronation, while the rearfoot returns to supination.

2 to 3 million years of evolution have transformed our feet from grasping organs into efficient walking and running organs. It is possible that evolution is still ongoing and optimization is not yet complete; about 40 years ago, there was an opinion that our little toe was disappearing because we no longer really needed it.
In this context, the current trend of barefoot walking and running is very interesting. Incidentally, we had something similar 25 years ago:  a big hype with barefoot shoes, most of which disappeared after a short time. This is because barefoot walking, while very healthy, is no longer mastered by most of us. 60 years of running shoes with increasing cushioning and consequently increasing support and guidance have not done our foundation any good. Degenerated feet are the result, and barefoot walking is no longer possible for many. It is not without a certain irony that, with this development, many of us are dependent on these supportive, guiding, and cushioning "health shoes."
The term "health shoe," however, is very misleading. While these shoes help people suffering from pain in their daily mobility, they do not solve the problem in any way.
And degenerated feet will not automatically become healthy again just by walking barefoot. Practice has shown that they need to be specifically trained.

How do I best train my feet?
To answer this question, we need to know what the demands on our feet are.

Walking and running are pre-programmed movement sequences.

The "heel strike" is not always the same; on a hard surface, for example, the supination angle (the sole of the foot is directed inwards) is greater than on soft ground.
Increased supination before and during landing on hard ground increases the total pronation movement.  This allows the landing to be actively dampened for longer and thus more effectively.

Supination angle:

 Franz Amann 2007

Apparently, the ground conditions are visually analyzed, and the landing is prepared accordingly.

Leg and trunk muscles are already active before landing
(walking understanding K. Götz- Neumann 4th edition Fig. 2.76).
The preparation for landing therefore seems to be much more important from a muscular perspective than the push-off. Walking and running are "anticipatory" and not "reactive."

Proprioceptive.
Proprioceptive training improves perception and reaction time; these abilities are important but should not be overemphasized. Any adaptation through the perception of the foot, during walking and especially during running, only serves the next step.
The eventual adjustment of the current step always comes too late. Only with very slow, tentative walking can the gathered information serve the current step.

Classical foot exercises are useful to some extent, but should also not be overemphasized. Our feet are no longer grasping organs; evolution has transformed former grasping organs into walking and running organs, and it is possible that this development is not even complete yet. The prerequisites in terms of mobility and functionality must be created. Subsequently, the training must be functional. The coordination between the rearfoot and forefoot is elementary.

After landing, the forefoot must continue in pronation, and at the same time, the rearfoot must actively move into supination.
This ability forms the main focus of foot training.

© Jan Swager van Dok