Martial arts is another name for “hand to hand combat”. Practitioners of martial arts wear a uniform that is tied with a belt like the belt on the martial arts uniform in this picture.
The belt of a martial arts form is used to denote rank in many martial arts. A unique color will be assigned to the belts for each rank. A common belt color ranking system would start with white for beginners, progress through yellow, blue, brown, red, and finally black for the highest ranked members.
Legends claim the highest level members had a black belt because they had been practicing for so long that the belt had become black with ground in dirt, sweat, and grime.
The martial arts belt is based on the behavior of a group of muscles and tendons within the body that pull the waist area forwards.
The cartoon character in this picture has the type of waste being described.
The waist is so far in front of the body that it pulls the back out of it’s natural straight up and down shape,
into a V-shape.
The martial arts belt was created to train the muscles and tendons in question, because they are useful in the performance of the martial arts.
Having the student go through the motions involved in wrapping the belt around their waste, pulling it forwards to tighten it,
and knotting it in a specific way every time they trained, exercised the muscles and tendons that pull the waste forwards just like repetitive punching exercises the arms and kicking exercises the legs.
The type of knot the belt is tied in is an important part of the training. When the arms and hands move in the specific way necessary to create a knot in the belt, those exact movements are transmitted to and duplicated by the muscles and tendons involved in pulling the waist forwards.
Actually, the coloured belts were thought up by Jigoro Kano, the inventor of Judo and have nothing to do with the muscles as such, but are symbolic markers