Insoles for Barefoot Shoes, Everything You Need to Know

Note: This article was originally written in German by Stride Soles Head of Design Dominik Walter and edited for English by Dr. Zac Cartun, MD.

Key Points

• Stride complements barefoot shoes with a minimalist insole that simulates natural ground stimuli, keeps the foot musculature active, and improves the foot climate. 
• This combination is above all interesting for people who primarily wear barefoot shoes on hard, unnatural surfaces and desire stimulation and a more active perception of the ground.
• Users who spend a great deal of time on hard floors can also benefit from a minimalist complement when comfort, flexibility, and sensory stimulation come together.
• The point is not “insole versus barefoot shoe,” but rather “minimalist insole as a complement to the barefoot shoe.”
  

We humans are a masterpiece of evolution.

Over tens of thousands of years, our body was perfectly adapted to one thing: walking barefoot on natural, uneven ground. Whether forest floor, sand, or meadow – every step stimulated the millions of receptors on the sole of our foot. 

The sole of the foot constantly supplied sensory information that supported balance, posture, and movement control. This permanent stimulus was the body’s own protective mechanism: It automatically ensured training, muscle building, good blood circulation, stability and – through the reflex zones – presumably even the activation of our internal organs.

The foot had to constantly adapt to changing surfaces.

The modern forced situation for the foot and organism

And today? Within only a few decades we have almost completely exchanged this natural ground for hard asphalt, concrete, and sterile floors. Even worse: Our feet are stuck in shoes that follow fashion constraints instead of the biomechanics of the body. We have deprived our feet of the stimuli. 

With the trend of barefoot shoes, foot health moves into the center of perception. The idea is simple: The cage for our feet, in the form of stable and heavily cushioned shoes, should disappear, while the protective function should remain. The idea is convincing: To give the foot back its natural freedom. This happens mainly through three factors:

1. Toe freedom

Modern barefoot shoes have a wide toe box. Through this, the big toe, which takes over an important biomechanical function during the push-off phase while walking and for stabilization of the foot during the stance phase, is unrestricted in its movement (see: Figure 1).

Figure 1: Normal toe box vs. toe box in barefoot shoes

2. No heel-to-toe drop

Heel-to-toe drop refers to the height difference between heel and forefoot. Through so-called wedge heels, from the modern sneaker to the business shoe, a large proportion of shoes have a heel-to-toe drop. This often lies between 5–15 mm. The opposite is referred to as zero heel or zero-drop (see: Figure 2). This is often justified by relieving the Achilles tendon. In reality, however, a drop is unnatural and places stress on the knee and hip.

Figure 2: Heel-to-toe drop vs. Zero-Drop

3. Thin outsoles

The outsoles in barefoot shoes are often extremely thin and elastic. The idea here is to pass the stimuli of the ground directly on to the feet, so that they adapt themselves to the changing surfaces through muscular tension, instead of leaving this to soft cushioned soles. Mindfulness is intended to be increased by making stones, sand, wood, asphalt, or earth more clearly noticeable [Source]. One example is the Kjavik One in the following Figure 3.

Figure 3: Kjavik One with thin outsole

Barefoot shoes and insoles – do they fit together?

Many people first think of a contradiction when it comes to barefoot shoes and insoles. Barefoot shoes stand for freedom, flexibility, and a natural walking feeling, while classic insoles are often associated with guidance and passive support.

Stride Soles approach differs fundamentally from this passive approach: A minimalist insole does not have to replace the foot, but can specifically complement its function.[Pubmed2]

Simulating nature – the neuro-orthopedic principle

At Stride Soles we are not satisfied with simply supporting the foot passively. Our goal is to simulate nature. Our insole construction promotes targeted stimulation of the receptors on the sole of the foot. We bring the stimuli of natural ground back into the shoe in order to activate the musculature instead of shutting it down. How do we do this? By taking into consideration the Golgi tendon apparatus and the myofascial chains.

Golgi tendon apparatus

The role of the Golgi tendon apparatus and the myofascial chains in insole care is in fact of fundamental importance for a holistic understanding of body mechanics.

The Golgi tendon apparatus is a sensory organ that is located at the connection points of muscles and tendons. It plays a key role in proprioception because it sends information about muscle tension and muscle length to the central nervous system. This information is crucial for the coordination and control of muscle activity.

When stimulating insoles are used, they directly influence the Golgi tendon apparatus. Through targeted pressure and stimulation, this apparatus is activated, which leads to an adjustment in muscle tension. This adjustment is not limited only to the foot, but affects the entire muscular apparatus. Improved muscle control and coordination at the foot can therefore lead to a more efficient and healthier movement pattern throughout the entire body.

Myofascial chains

Myofascial chains refer to the network of muscles and fascia (connective tissue) that extends throughout the entire body. These chains transfer forces and movements from one part of the body to another and provide holistic movement integration. [Goethe University]

Insoles that specifically stimulate the foot influence these myofascial chains. A change in the position or function of the foot therefore has far-reaching effects on the entire body. This can express itself in improved posture, more efficient movement, and a reduction of pain in various regions of the body, such as the back or the knees.

The active stimulation through the insoles therefore not only leads to a local adaptation in the foot area, but initiates a chain reaction throughout the whole body via the myofascial chains. This holistic approach pursues the goal of improving body awareness.

In summary, it can be said that our insoles, through the activation of the Golgi tendon apparatus and the influence on the myofascial chains, not only provide localized support of the foot, but unfold a comprehensive, body-wide effect. This approach promotes a sustainable improvement of body mechanics and well-being.

Blind diagnosis after 8–10 weeks

What enables us to control this highly complex effect with pinpoint accuracy? A treasure of data from several hundred thousand dynamic measurements that we have collected for more than 35 years, through users of our system from more than 60 countries worldwide. But the actual proof of success lies in our unique control system:

After eight to ten weeks—the time that, according to our experience, the organism needs to adapt and respond neurologically—we ask every customer to return for a follow-up examination. And here we take a radical path: We do not ask the customer how he is doing. We measure first.

Based on the new barefoot dynamic measurement, we determine the remaining deficits and problem points completely neutrally and based on facts. We describe the patient’s weak points and pain points solely on the basis of the data—and only afterward does the patient describe to us his subjective perception. If the measurement results agree with the subjectively reported complaints, this increases the objectifiability of our treatment. An example of the before-and-after measurement is shown in the following Figure 4.

Figure 4: Success measurement of Stride insole treatment

Where barefoot shoes reach their limits

Barefoot shoes simulate barefoot walking—but in everyday life often on asphalt, concrete, or tiles. That is not the same as walking barefoot on natural, uneven ground.

Hard, uniform surfaces change the load distribution and can challenge the natural work of the foot differently than forest floor or other varied surfaces.

That is exactly why the real question arises: How can a more natural surface be brought into the shoe without losing the advantages of the barefoot shoe?

Figure 5: Barefoot shoes with Stride Balance insole

Stride as a complement

The idea is not to guide the foot rigidly or support it passively, but to stimulate it and keep it active. In this way, the approach clearly differs from classic supporting insoles.

The open, rough structure is intended to simulate natural unevenness and offer the foot a surface to which it can react.

In this way, barefoot shoes are not replaced, but complemented—especially for people who wear them on artificially hard, smooth surfaces.

Material and construction

The 4-mm base made from the elastic pedFLX elastic white material [insoles3D] is intended to compensate for hard asphalt and concrete surfaces without covering up the basic characteristics of a barefoot shoe: passing the stimuli from the ground on to the foot. Flexible 3D-printed insoles have already been used in studies to individually influence pressure distribution and comfort. 

The Stride barefoot insole is highly flexible without being “doughy.” The material composition is selected so that a tough-elastic surface is created, and the insoles always return to their original shape.

The open structure can additionally improve air exchange and thereby support the foot climate. From user reports it can be gathered that the surface provides a pleasant wearing feeling; some even report a feeling of increased blood circulation.

Through the flat profiling of the Stride it is ensured that the muscle bellies remain exposed and are not hindered during their work. At the same time, sufficient effectiveness is present to reduce excessive impact loading from artificial surfaces on the feet, knees, hips, and back, while at the same time providing impulses to which the foot reacts. The goal is to simulate a natural surface inside the shoe.

Conclusion

Barefoot shoes and classic supporting insoles often contradict each other. However, Stride Balance follows a different principle: stimulate instead of support, activate instead of fix, natural stimuli instead of rigid guidance.

In this way, the combination of a barefoot shoe and a minimalist insole can be a meaningful solution for natural movement on hard and artificial surfaces.