dr-wieland-kinz-lecture-062923-fit-treatise-1782After a short welcome and introduction by the moderator, Franziska Kuntze from POLOLO, Dr. Wieland Kinz addressed the question of whether it makes sense to wear barefoot shoes and referred to his decades of experience with inter¬national scientific studies – the measurement of children’s feet and shoes. Basically, this discussion goes back a long way – because as early as 1782, there was a first scientific study that led to the realisation that the feet become longer when walking, which is why shoes should be longer than the feet.

A sketch from that time shows the superimposed outlines of a shoe sole and a foot, which made it clear that the shape of the shoe and the shape of the foot do not fit together, i.e. the foot has “far too little space in the shoe”.

Barefoot shoes are characterised by small big toe angle and flexibility of the sole

Dr. Kinz then jumped to 2014, when the “Nike free” shoe was launched, which had already felt like a barefoot shoe – however, it was still “too tight” in the toe area. He showed a picture of the clearly pronounced angle of the big toe.

The development of so-called barefoot shoes continued and finally led, for example, to the “FiveFingers” models from vibram with a straight cut in the big toe area. He made it clear that shoes that are indistinguishable right and left run counter to the natural shape of the foot. So-called barefoot shoes could best be defined by the angle of the big toe (as small as possible) and the flexibility of the sole (as pronounced as possible).

dr-wieland-kinz-lecture-062923-japan-big-toe-angelMethodical studies in Asia had led to astonishing findings: In 1958, for example, measurements were taken on a large scale of barefoot walkers in China, who were still very common at the time – this led to the conclusion that shoe wearers were 17 times more likely to have hallux valgus than barefoot walkers.

Experiences from Japan also underline this finding: Until 1972, not a single surgical correction of a hallux valgus is said to have been necessary there – but then increasingly as a result of the production of closed shoes that began in 1960.

While the production of the traditional open “Japanes Wooden Clogs” and matching socks declined massively from 1960 onwards, the number of closed leather shoes produced increased in the opposite direction.

Then, with a time lag of twelve years, an onset and increase in operations to correct hallux valgus could be observed. Not only shoes with a pronounced big toe angle are therefore problematic for health, but also socks – these should be anatomically correct and “bolt upright”.

Feet in socks – what to watch out for?

On the subject of socks, he also noted that when measuring children’s feet, he found that feet in socks turned out smaller and narrower: First the feet were measured in socks and then barefoot. He had expected that feet in socks would be longer and wider, or at least the same length as bare feet, because of the material. To his surprise, however, it was the other way round: with socks, the feet were shorter and narrower than barefoot.

Dr. Kinz therefore noted two aspects about socks in his lecture:

  • a) The toe: Most socks are pointed or trapezoidal at the front. This does not make ergonomic sense and
  • b) The sizing system: Most socks are supposed to fit over four to five sizes – usually they are much too short. Socks should therefore be chosen with these aspects in mind.


Avoiding malpositions – wearing suitable shoes or going barefoot

dr-wieland-kinz-vortrag-290623-hallux-vagus-behandlungHe was concerned about the search in the National Library of Medicine for methods to correct hallux valgus, because the focus there was on surgical correction (a good 3,800 publications), while conservative methods are apparently still considered to be of secondary importance (only around 170 publications).

Dr. Kinz’ pointed conclusion for conservative treatment: “Put on shoes that fit or go barefoot!” Walking barefoot (if the surface and temperature allow it) is simply better than wearing constricting footwear.

Dr. Kinz then presented a video interview with the barefoot shoe expert Alexander Tok, the operator of the “Barfuß im PottCast” (Barefoot Podcast). He explained that, in contrast to southern German-speaking regions, it is now common in North Rhine-Westphalia, according to his experience, to have barefoot shoes in the range of regular shoe shops – also for sports. The demand for barefoot shoes for adults and children is increasing.
He described the advantage of barefoot shoes with the preventive or regenerative effect: In the ideal case, wearing barefoot shoes can prevent malpositions or even correct them to a certain extent. Sustainability is also gaining in importance on the part of customers. Finally, he gave the tip to keep the assortment “small” (clear) and to offer different breadths and widths of different manufacturers as well as good advice – this also includes the honest statement that there may not be a suitable shoe available at the moment.

At the end of his presentation, Dr. Kinz mentioned that his standard work is currently being revised: “Kinderfüße – Kinderschuhe. Alles Wissenswerte rund um kleine Füße und Schuhe” (“Children’s Feet – Children’s Shoes. Everything worth knowing about small feet and shoes”), 4th revised edition 2023. The expected publication date is autumn 2023 (ISBN 3-00-005879-6). Summarising this new edition and the lecture, he stated that shoes and socks that do not correspond to the shape of the child’s foot in the toe area are pointless or even harmful: “That means: as straight as possible at the big toe and so wide that the toes are not constricted!”

Discussion round with astonishing findings, e.g. on correct measurement of the inside shoe length

In the discussion, Franziska Kuntze mentioned that parents often came to the POLOLO ShowRoom and were disappointed about the materials used by some other suppliers (e.g. polyester instead a wool lining, which does not keep warm and is not breathable). She thus underlined Alexander Tok’s statement that sustainability is gaining importance on the customer side (see also frequent appearance of children’s shoes in the RAPEX list: “Rapid Exchange of Information System”). However, there still seems to be some irritation among customers with regard to ergonomics and aesthetics.

dr-wieland-kinz-vortrag-290623-schabloneAt the end, the problem of the correct measurement was discussed. Dr. Kinz had asked to cut out a 20 cm strip of cardboard (representing a correspondingly long foot) – this should now be measured with a suitable measuring device in order to derive a recommendation for the shoe purchase. Two serious challenges emerged:

A shoe size recommendation based on a measurement is not very helpful, because in almost half of all cases it is wrong – there is hardly any manufacturer with the correct shoe size. It is much more important to determine the exact inside length of the shoe and, taking into account an allowance of at least 12 mm, to compare it with the respective foot length (determined, for example, using a cardboard template).

The measurement of the insole cannot always be relied upon, as it often does not match the inside length of the shoe (probably for cost reasons) – sometimes manufacturers even offer an insole for four shoe sizes. Franziska Kuntze commented that POLOLO had very good experience with this procedure in its own ShowRoom – but at POLOLO the insoles are also all adapted to the sizes.



At the end of the discussion

Dr. Wieland Kinz emphasised that

  1. the softer a shoe is, the better the foot is trained,
  2. socks that are too short also endanger foot health
  3. and that small children also need an extra 12 mm (like adults) because their feet are still much softer and more deformable.

Franziska Kuntze pointed out that

  1. real and untreated raw fibres such as organic wool or organic cotton are much more breathable and better for the foot climate as well as the Ecological Footprint than polyester,
  2. vegan alternatives are becoming more and more important for young parents when buying shoes, and
  3. vegetable-tanned leathers are chrome-free.


We thank all participants and especially Dr. Wieland Kinz for the interesting seminar!

Franziska Kuntze & POLOLO Team



images 1-5: Dr. Wieland Kinz / image 6: Primeri GmbH

Further Information:


How small children’s feet develop / What should you parents keep in mind when buying shoes for your little ones?