Foot cushioning mechanisms – what do we gain by wearing barefoot shoes?

The human foot is a unique structure in the animal world. The bipedal mode of walking triggered a series of adaptations that led to its current shape. Key features that distinguish us from apes include the long big toe and the lack of opposability. The presence of the longitudinal arch of the foot is also unique to humans. Despite these differences, humans and apes share similarities such as walking on the whole foot and the stiffening of the midfoot. The unique features of the human foot, including the springing of the longitudinal arch and short toes, are likely adaptations for long-distance running [1].

Heel-to-toe walking, forefoot running

A characteristic feature of human walking is the initiation of foot contact with the ground by the heel. The heel bone has a structure that allows it to dissipate forces during impact. A distinctive feature for humans is the large, developed heel tuberosity and the lateral process of the heel tuberosity – it is believed that this bony prominence increases the surface area of the heel to help disperse force during walking. Additionally, beneath the heel is adipose tissue with a characteristic lobular structure, which further enhances cushioning. Heel walking is more energy-efficient for bipedal walking. However, in running, the forces acting on the foot during contact with the ground are approximately two to four times higher than those experienced during barefoot walking [2]. This can be noticed by anyone who runs without shoes – the feet naturally start landing on the middle or front part of the foot because the heels simply start to hurt.

The foot – our shock absorber

As the foot adapted to bipedal locomotion, it underwent a series of adaptations. Loose bones needed to be stabilized by ligaments and appropriate muscle activation. Efficient foot rolling requires the stabilization of the tarsal joints (between the heel bone and the midfoot). This is achieved through the longitudinal arch, which is built from 9 midfoot bones: the calcaneus, talus, navicular, cuneiforms, and the first 3 metatarsal bones. It is stabilized by ligaments, muscles, and most superficially by the plantar fascia. This complex extends from the heel to the base of the toes. Thanks to this arrangement, when the big toe extends upwards, tension in the plantar fascia occurs, which is called the windlass mechanism [3].

The windlass mechanism

The extension of the big toe causes tension in the tissues, which pulls the heel towards the heads of the metatarsal bones, effectively raising the longitudinal arch and stiffening the midfoot during the push-off phase. This effect, described by Hicks, is compared to a windlass because the plantar fascia wraps around the first metatarsal head just like a drum on a winch. This tension pulls the calcaneus, shortening the height of the arch, and thus stiffening the foot to enable effective propulsion.

What do the foot’s shock-absorbing mechanisms have to do with minimalist shoes?

The shock-absorbing mechanisms described above can be activated primarily when we are barefoot. At that point, nothing limits the mobility and function of the foot. However, when wearing shoes with a stiff sole, the muscular and ligament structures stop being responsible for transferring loads and are replaced by the cushioning materials of the footwear. Additionally, in most classic shoes, the toes are often narrowed, which restricts the proper positioning of the big toe, thereby limiting its optimal function (and let’s note how important its role is in the windlass mechanism). Compressed toes at the front of the shoe prevent the engagement of the short foot muscles responsible for shock absorption. As a result of years of foot stiffening, the muscles weaken and stretch — which can lead to pain, foot deformities (such as flat-footed valgus), or the occurrence of neuralgia.

So, what happens in minimalist shoes? By design, they aim to imitate barefoot walking as closely as possible. They feature a very thin and flexible sole, a wide toe box that fits the toes, and no cushioning. If we have been walking in such shoes since birth, our feet have the daily opportunity to train their muscles, which don’t atrophy and can control the foot’s alignment independently. However, if we have spent many years walking in "classic" shoes with stiff, cushioned soles, transitioning to minimalist shoes may come with the risk of injury. A sudden shift, without strengthening the foot, stretching tight muscles, and allowing the sole to adapt to new stimuli, may lead to injury and frustration. When buying your first pair of minimalist shoes, it’s worth being patient, as the destructive effects of previously worn shoes may require time and effort to restore the foot’s natural shock-absorbing function. But it’s worth dedicating this time, as it’s an investment in all our joints.

Foot cushioning in barefoot shoes

If we take the challenge of training the foot so that the muscles can maintain its stability, this brings a series of benefits—counteracting the negative effects of wearing tight and stiff shoes. Strengthening the foot muscles corrects improper foot alignment (such as heel valgus and the lowering of the longitudinal arch), which automatically leads to proper knee alignment (in the case of flat-footed valgus, knock knees may also occur). Improper knee alignment can cause faster wear, muscle overloading, and it also affects the hip joints, generating overloads there. Some existing body disorders have their primary cause in the feet, and correcting their alignment improves the functioning of the higher joints.

From the point of view of cushioning and the sole—whether it's a heel or any other setting where the heel is higher than the toes—automatically changes the entire body's alignment, spinal curvature, and center of gravity. This shifts the center of gravity forward, causing improper muscle tension distribution (muscle balance between the front and the back of the body is disturbed). Walking barefoot or on a flat sole ensures neutral alignment of the pelvis and spine.

The aspect of stimuli coming from the sole of the foot is also important—there are nerve endings from all over the body. Alternating pressure on different reflex points on the foot can positively influence the entire body, including internal organs.

Can minimalist shoes be used sporadically?

There are times when, for various reasons, we don’t want or can’t give up classic shoes with a stiff sole and cushioning. This doesn’t mean that it’s not worth dedicating time to occasional barefoot walking or using shoes that imitate it. Runners can significantly improve their running technique and enhance performance if they incorporate barefoot running or running in minimalist shoes into their training routines. Similarly, people training for team sports, by strengthening their feet, can reduce the risk of injuries, such as sprained ankles [5].

How to start walking in barefoot shoes?

Switching to walking in minimalist shoes involves some necessary work (correcting foot deformities, stretching tight muscles, strengthening weakened ones). A sudden transfer may carry the risk of injury, especially if we have spent many years wearing shoes that weaken and deform the feet. However, the benefits for the entire body are so significant that it’s worth considering the change. If someone is struggling with foot problems, deformities, or pain in the feet or higher joints, it’s advisable to consult a physical therapist specializing in foot therapy. They will be able to assess the deformities, release tight tissues, and select exercises to ensure that walking in minimalist shoes becomes a pleasure and brings beneficial effects for the entire body.

Literature:

Holowka N. B., Lieberman D. E., Rethinking the evolution of the human foot: insights from experimental research, Journal of Experimental Biology 2018, 221.
Gill C. M., Taneja A. K., Bredella M. A., Torriani M., DeSilva J.M., Osteogenic relationship between the lateral plantar process and the peroneal tubercle in the human calcaneus, J Anat. 2014, 224(2), pp. 173–179.
Welte L., Kelly L. A., Lichtwark G. A., Rainbow M. J., Influence of the windlass mechanism on arch-spring mechanics during dynamic foot arch deformation, Royal Society, 2018.
Kelly L. A., Lichtwark G., Cresswell A. G., Active regulation of longitudinal arch compression and recoil during walking and running, J R Soc Interface. 2015, 12(102).
Hryvniak D., Dicharry J., Wilder R., Barefoot running survey: Evidence from the field, Journal of Sport and Health Science 2014, 3, pp. 131-136.