Frequent walking barefoot, combined with various exercises, leads to strengthening the foot muscles. Also, by performing a variety of foot kicks, like in karate or tae kwon do, exercising basic front kick (mae-geri, ap-chagi), side kick (yoko-geri, yop-chagi) or front hook kick (mawashi-geri, dolyo-chagi) as well as other ones, the exerciser develops the feet muscles.
Each of these different kicks requires the practitioner to set the foot in the exact position, regarding the impact surface, i.e. the surface of the foot, by which the trainer will strike a particular foot kick.
For example, for the aforementioned strikes, the names of the foot surface striking the opponent during their performance are: chusok (apkumchi), sokuto (balkal) and haisoku (baldung). Whilst performing each of these strikes, the practitioner must place the foot in a precisely defined way, i.e. in an adequate position.
Thus, practitioners strengthen and develop the feet muscles that help to eliminate flat foot deformation. Only a few foot strikes have been mentioned as examples though, of course, martial arts have much more exercises in themselves with a large number of different kicks .
It is very important that your toes and feet are in the correct position to achieve good treatment results.
Although useful, walking barefoot in a gym with flat floor or on the mat (tatami), will be too soft for the practitioners' feet. Only when barefoot practitioners come out in the yard of their club (martial school or centre) they will feel the difference and activation, i.e. tightening of certain foot muscles that help to eliminate the flatform deformation.
Many instructors of different martial arts practise exercise in the nature, insisting that the practitioners are barefoot.
That's why you can often see lots of practitioners of various martial arts practicing barefoot in a nearby park, at a nearby car park, along the banks of the river or on the seashore, in a forest or on a mountain, many of them doing it in the summer months by the sea on a sandy beach but also on the snow in the winter.