Why do Martial Artists wear the dojo crest on the left?

You will be hard pressed to find a lot of documentation on the traditions of correctly wearing patches on a Gi. Several reasons for that.... In the first few years of the current style of Gi being used, patches were rarely if ever worn. That is a more recent development. The Gi is correctly worn with the left flap on the outside. This is likely a habit that came from the earlier hand formations seen in many styles. In Chinese styles you often see the left open hand placed on top of the right clenched fist. This is because the right fist represents a persons trained ability to fight. (Most people are right handed so the right was chosen for that). The left open hand represents our preference for peace. The left hand covering the right symbolizes that we are trained to fight but we restrain our fighting nature. The Gi follows that with the left flap over the right. The OBI (belt) is correctly worn wrapped twice around the waste then tied in a square knot, so that the knot hole faces towards the right side of your body. This too for the same reasons.

So it is only logical to me that we would wear our assoc, style, or dojo patch on the left flap of the GI and placed so that it is over our heart. There are no traditions that I'm aware of allowing multiple patches to be worn. But having started in the 1960's I often saw either no patches on Gi or usually only one patch over the heart. Over the years different schools started adding patches . If you go to martial arts events such as seminars, or tournaments, you often see people wearing Gi covered with patches not only all over the Gi top but on the pants too. To me this is all wrong. The old masters were not showoffs and were quiet humble men. today the multiple patches make it seem like people are boasting or acting like they are in a carnival rather than a martial art. Personally I don't want to ever be known as one of those guys that wears lots of patches or colored GI. I'd rather be not remembered or remembered for my abilities.

Hope this helps!

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In Kajukenbo, the patch that indicates your Branch ( it sort of indicates how you are trained to move goes over your heart on the left side of the gi ), the Hawaiian flag is on your upper left tricep, the crescent patch ( we call this the "Rocker", don't ask, Kajukenbo has weird terminology, goes on your right tricep ), and when you reach Black Belt, you get the Black Belt patch that goes underneath your "Rocker" patch. I have no idea why, this is what I have been taught.

The strange thing about Kajukenbo is that variations of the standard protocol is allowed, so a particular school may choose to wear those patches any way they want to and the other Kajukenbo schools are supposed to respect that.

in China the bow means a sign of respect and humility done by martial artist for two reasons master to student ,the other is to all martial artist to show respect and show all martial arts are one.. its means you respect the person as your friend in martial arts and share your skills... this also is done in shaolin temple you do it I=every time you enter a martial arts school or the shaolin temple... but this is been passed to japan since some styles in japan have come from China... I don't know about patches and I never have had one when I had a Gi ... I practice Chinese ,atrial arts now and all you shirts always have the school name and a picture of any thing to do with Chinese martial arts or Chinese art... this is to show your school and respect to the school...