Here is some information for all ages who are learning about boarding sports for the first time. In all the types of boarding Sports you’re either “Regular” or “Goofy” foot.
Regular and goofy
Regular stance, regular foot or reg is standing with the left foot in front while skateboarding, surfing, snowboarding, waveboarding, wakeboarding or wakeskating. This stance is called regular because it is found more commonly amongst participants of these sports. The opposite of regular stance, i.e. leading with the right foot, is called goofy foot. Although a rider who practices more than one board sport typically favors the same foot, it is not unheard of for a rider to ride goofy in one sport and regular in another.
Testing for footedness:
Several informal tests exist to determine whether someone is goofy or regular-footed. Often the subject is directed to imagine sliding across an icy pond and asked which foot he would prefer in front. Sometimes the subject is pushed gently from behind to see which foot he will put forward to balance himself. Another test includes seeing which foot one puts out in front to climb steps. Footedness is an intuitive feeling; a beginner who tries both stances over a period of time will eventually know which one is right for them.
Other varieties of footedness:
When a rider rides in other than his preferred stance, he is said to ride switch stance. “Riding switch” adds to the degree of difficulty of any move and hence often to its aesthetic value. This is so particularly in trick-orientated boardsports. Many experts manage to gain some amount of ambidexterity in their stance but this is not easy.
In skateboarding, if the foot in the middle of the board moves to the nose and the foot on the tail moves to the middle in the preferred stance, it is called “nollie stance”. This is usually done to perform tricks while nollie-ing, not to ride. While doing this going backwards with tail in front it is called “fakie stance”. When a rider pushes with the front foot, it is called “pushing mongo”. This is an uncommon way to ride and is often mocked because the way the hip swings open lacks style.
To minimize the dissonance between switch and regular stance, a snowboarder may adopt a “duck stance”, which orientates each foot outward so a front foot will always be facing forward.
“Switch stance” in freestyle skiing is riding backward (facing top of hill).
In BMX, being goofy does not depend on whether you ride right or left foot forward. If a rider is regular and rides with their right foot forward, they will favor turning anti-clockwise in the air and grinding on the right. If a rider is regular and rides with their left foot forward, they will favor turning clockwise in the air and grinding on the left. You can be either a goofy grinder (e.g. you have your right foot forward and prefer to grind on the left), a goofy spinner (e.g. you have your right foot forward and prefer to turn clockwise), or both.
Goofy BMX riders are in the minority but there are a similar number of people who ride left foot forward to those who ride right foot forward.
excerpt from wikipedia.