Footwear science is BIG TIME. It's amazing the magnitude of people, time and money that are involved these days. The more I looked into it the more confused I became as to how footwear has not been more true to the natural foot.
Recently it has become more clear why the tragic trajectory. I've heard a footwear company tout the huge amount of footstrike data they had to work with and promote that their footwear doesn't inhibit the natural movement of the foot. Yet, their footwear is not foot-shaped and has a completely rigid, thick sole with an arch. In addition I was asked, "Ah Jess, why do you care about your little toe?" said in the tone of, "it doesn't REALLY matter." It was then that I knew, this person DOES NOT KNOW WHAT THE FOOT'S NATURAL MOTION IS. Does not know about ALL that the foot is designed to do ...and designed to do FOR THE REST OF THE BODY. This isn't just anyone, this is a long time successful veteran in the industry.
Call me crazy, but I'd rather my little toe, be extending out from my body helping me balance than need a cane to do it for me later. Look at the neuroscience more and take into account the 100,000+ mechanoreceptors on the entire bottom of the foot designed to receive messages upon ground contact and send them to the brain about how to move the body. Shut down that communication and your brain's ability to move your body fluidly, efficiently and safely...decreases big time.
Or on the flip side, a very normal, shoe-shaped foot. Yikes.
There's a big gap.
First, if you haven't already, see the blog: Anatomical? More like abnormal.
The majority (and that's being conservative) of feet in shoe-wearing societies are not anatomically correct. Which leads me to my next revelation:
Today's research uses faulty footstrike data.
To make my point clear, I have to thank one of the major shoe manufacturers for posting a video telling of how one of it's very successful and current shoe models came to be, thanks to their research. The video concludes with the quote: "[This shoe] allows the foot to be the foot." Please Meet Fred if you haven't already and tell me whether you think he would think this particular shoe, the shape of whose sole is seen in a screenshot from the video below, would let him function properly:
Using screenshots from the video and a reenactment of a similar movement with my own foot, I will point out a few things about the "test foot" used. I also want to be clear, my foot is not functioning 100% naturally, but it's getting close, and is still a helpful example of what's possible.
Here is the foot they're using:
This foot is what I will call "shoe-shaped" which means to some degree: immobile, unstable and weak. The big toe is pushed inward and the four little toes are each deformed to some degree. This has a direct impact on quite a few things. Here are two:
The width and breadth of the body's base of support
These toes, which would naturally be the widest part of the foot, are not. Toes are designed to exert pressures EQUAL to that of the ball of the foot. This means that in a foot whose toes are functioning to their max, the base of support the body has to push from every step would be significantly greater than in the foot above.
The foot's ability to communicate to the brain
Better toe function serves to improve how the foot receives information upon ground contact which the brain uses to send signals to stablilizer muscles such as those in the core and the hip. These muscles, as Gray Cook states HERE, are REFLEX engaged. We can't consicously decide to turn them on. They respond to input from the mechanoreceptors in the feet and the hands for example. Inhibiting information from the foot limits the brain's ability to send appropriate signals to the stabilizer muscles. Without their stability, the body's prime movers (think gluteus maximus for hip extension) have a less stable base to move from which means injury potential can be severely increased and power output severly decreased. From safety to world-record breaking performance...this is SERIOUSLY SIGNIFICANT.
The second thing that stands out about this foot is it's narrowness. It is skinny. Where's the beef??
Nearly all of the of the foot's tendons attach at the toes. When a joint (there are many in the toes) goes through its full range of motion, the tendons lengthen and many muscles get worked. Not using the toes through their full range of motion means not fully using (loading) the majority of the muscles of the foot. Just like any other body part, this results in atrophy and consequent weakness.
They even say in the video:
"If we want to have a muscle to increase in its strength, it needs to go through it's full range of motion."
I don't know what anatomy books they are using, but their footwear certainly does not allow for the foot's full range of motion, though they promote that it does, and even show the "science" to support it.
The following images and descriptions compare the test foot to my foot in similar points of the movement.
Preparing to hit the ground
The test foot's toes are scrunched and unable to dorsiflex much if at all. Notice the width and breadth of my toes and the dorsiflexion occuring at the ball of the foot which prepares the foot for natural ground contact allowing it to immediately stabilize powerfully through the ball of the foot.
Speaking of SPLAY. Notice the width of the contact area in contact with the ground. In the test foot, the toes are narrow, which limits the base of support. On the right my foot is widest at the toes. Simple science says: the wider the base of support, more stability you have and more strength you can express.
Full plant, prior to toe-off
The point at which the toes are are still on the ground, with joints at maximum dorsiflexion before toe-off. The test foot contact area is narrow, smaller. Toes are designed to be strong and stable on the ground so the body can pivot where it wants to go on the WIDEST base possible before the toes lift off. THIS is where SPLAY is most powerful. The test foot is again very narrow here.
At this point the ball of the foot comes off the ground while the very ends of the toes are briefly still in contact with the ground providing the last bit of stability as the body moves forward with momentum. The test foot has very little to go off of, you could say.
It may be even easier to visualize the natural foot's function in the following few photos I've found of perpetually barefoot kids at play. Look at their feet in similar phases of landing and launching:
There could be incredible value using scientific research when it comes to the feet and footwear, however up until now, due to the use of faulty foot strike data, much of it has failed the foot. One only has to look at the footwear options available today to see the evidence.