Additional size number
Additional size number is an extra space in a shoe - the difference between the shoe length (or width) and the foot itself. Sufficient over-dimension gives the foot room to function correctly. Extra space of about 4-5 mm should be present in every shoe for a full unwinding of the stride. When buying new shoes for children, an additional room number of about 10-12 mm is recommended for optimal foot growth. Adults usually opt for an oversize of 5-6 mm for closed walking shoes, 7-10 mm for sports shoes, and only 2-3 mm for open-toed sandals.
Anatomically shaped toe box
A toe area of a shoe that respects the natural shape of the foot. It is broad enough, and the longest point in the shoe is at the big toe and second toe, not in the center of the middle toe as in most regular shoes, which then deform the foot.
Caoutchouc (Natural rubber)
Caoutchouc is a flexible rubber material of natural or synthetic origin.
Shoes that do not meet some barefoot parameters - lower sole flexibility, slight heel elevation, or less than ideal toe box shape - are seen as a compromise. Compared to regular shoes, they are still closer to barefoot footwear.
The big toe is said to be dominant if it is significantly longer than other toes. Feet with a dominant toe need an ideally shaped toe box that respects the shape of the foot and does not push the big toe towards the center of the shoe.
Fin shaped toes
The term fin or fan-shaped foot is a foot with a wide toe area but a narrow heel. For such feet, shoes with sufficient toe room and the possibility of tightening around the heel/ankle are needed.
The insole is an insert in the shoe, sometimes, it is a part of the shoe, and other times it is glued or removable. The function is to increase comfort, flatten minor irregularities from the shoe construction, insulate the shoe, and wick sweat away from the foot. Anatomically shaped insoles also have a corrective function, although, in barefoot shoes, you won’t find insoles with arch support or a raised heel.
Leather (Shoemaker's leather)
Shoemaker’s leather is already processed animal hide.
The principle of the membrane is to take moisture in the form of the steam out of the shoe but not to let water in. The membrane increases the water resistance of the shoe and maintains the breathability needed to wick away sweat. However, shoes with a membrane are not fully waterproof.
Nubuck is similar to suede (velour). It is top-grain leather that has been sanded on the grain side, producing a velvet-like surface.
Pre-walking booties / Soft soles
Pre-walking booties or Soft soles are „shoes“ without rubber soles, usually all-leather or textile. They are as flexible as possible and do not restrict children’s movement. We recommend them for crawling children, beginners who combine crawling and first steps, and as slippers for older children. They are non-slip, thermally insulating, and protect the foot from abrasion and injuries.
Proprioception is the ability of the nervous system to detect changes occurring in the muscles and inside the body through movement and muscle activity. Proprioception is necessary for correct movement coordination, registering changes in the body position, muscle tone, the progress of certain reflexes, etc. From the proprioceptors, stimuli are conducted and reconnected in the spinal cord and further to the nervous system.
The reinforced place in the shoe behind the heel is called the high or raised heel. Its purpose is to keep the foot in the correct position. Barefoot shoes don't normally have a reinforced heel so that the ankle fully works, strengthens, and properly holds the whole body on its own, not through passive external support in the form of a raised heel.
Rubber is an elastic material obtained by vulcanization of natural or synthetic rubber (caoutchouc) - a chemical treatment for increased elasticity.
The rubber outsole is a protective element on the front of the shoe (toe) that reduces the risk of excessive abrasion, especially in children's shoes. It can be caused by tripping while walking, kicking various objects, riding a bicycle, etc. The rubber outsole is usually made of rubber or other durable man-made material.
Sole is synonymous with outsole.
The valgus ankle is an incorrect position of the heel bone, which is deviated towards the outside of the foot. Slight valgosity up to 15° is natural for children up to three years of age (up to 5° for children up to six years of age). Valgosity is associated with increased ligament laxity. However, risk factors also include improper psychomotor development of the child, inappropriate footwear, overweight, low child activity level, and lack of sensory stimuli coming to the foot.
Velour is textile similar to suede (leather that has been treated on the reverse side). The reverse side becomes the front and is characterized by fine hairs. Velour is less abrasive/scratchy but more difficult to clean than smooth leather.
We refer to closed, non-perforated boots as all-year boots. They are versatile and can be worn all year round. However, they aren't designed for extreme conditions - cold/hot weather. The shoes are most useful on warm winter days, in cooler spring and autumn.
Zero drop refers to a flat sole with no heel rise. The foot is then in its natural position and holds the whole body correctly. There is no shifting of the center of gravity or certain joints and ligaments overloading, etc.