sesshoumaru
Mar-21-06, 07:44 PM
I was surfing the threads earlier today and I saw the "Physics of Tricking 101" post, and I thought...what a great idea! However, it didn't get off to a great start so I'm a let it die!
This thread will pick up where "Physics of Tricking 101" left off (which is the beginning); not to be confused with the breakdown of simple things such as "jumping", but with an actual scientific post...so let's get to it!
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Pendulum Motion + Center of Gravity = Folha Secca/Gainer
Pendulum Motion is described as the motion of a weight hanging from a fixed point in space by a string, which can swing freely from side-to-side. After observing this...you'll also notice that the path of the weight is similar to that of an arc, and that the distance between the weight and the fixed point does not change.
This is the same motion that is the primary force which makes Folha Secca's & Gainers work! The weight relates to the foot, the string is the leg in motion, and the hip is the fixed point.
If the body is rigid (all points within the body remain the same distance from each other), then kicking the "string" leg should shift the body's weight into the end of the object that's in motion (the foot). As this happens the center of gravity (which is located at the center of mass) get's displaced. Once it shifts over the base (the planted foot), then the body starts to rotate in the same direction the leg was kicked. Since the pendulum follows a circular motion, then the body will follow it as well.
Rotation doesn't technically start until the center of gravity is compromised. This happens when the center of mass (which is located at a persons navel), extends over the base of which the rigid body stands on. In short, once your navel hangs over the front of your toes or the back of the heel, then you must take a step in the appropriate direction to retain your equilibrium. If this does not occur, then you will fall.
The center of gravity is integral to the technique of gainers because gravity only effects the what's below the center of mass. That's why your upper body doesn't get tired from standing up for a long time...it is your legs that do work. Since this is true, we use our upper body to generate more upward momentum, so our legs only have to do half the work!
When the kick is intitiated and the center of gravity is breached, then rotation is acheived. It would be the sole work of your legs to get you upside down; but once upside down, equilibrium will be acheived again, and it will take another force to get you back to your feet. This is when the upper body comes into play. When you rotate until you're upside-down, the upper body falls victim to gravity and the lower body does no work. Luckily a strong kick from the start would remedy this, but the arms would alieviate alot of stress on the legs if they were used. So the kick of the leg get's your lower body up and over, but the swing of the arms get your upper body to swoop under as your legs come overhead. If done properly, a complete 360 rotation about the fixed point (being the hip) should be acheived!
I'd put little diagrams in there, but I can't figure out how! :eh:
This thread will pick up where "Physics of Tricking 101" left off (which is the beginning); not to be confused with the breakdown of simple things such as "jumping", but with an actual scientific post...so let's get to it!
--------------------------------------------------------------------------
Pendulum Motion + Center of Gravity = Folha Secca/Gainer
Pendulum Motion is described as the motion of a weight hanging from a fixed point in space by a string, which can swing freely from side-to-side. After observing this...you'll also notice that the path of the weight is similar to that of an arc, and that the distance between the weight and the fixed point does not change.
This is the same motion that is the primary force which makes Folha Secca's & Gainers work! The weight relates to the foot, the string is the leg in motion, and the hip is the fixed point.
If the body is rigid (all points within the body remain the same distance from each other), then kicking the "string" leg should shift the body's weight into the end of the object that's in motion (the foot). As this happens the center of gravity (which is located at the center of mass) get's displaced. Once it shifts over the base (the planted foot), then the body starts to rotate in the same direction the leg was kicked. Since the pendulum follows a circular motion, then the body will follow it as well.
Rotation doesn't technically start until the center of gravity is compromised. This happens when the center of mass (which is located at a persons navel), extends over the base of which the rigid body stands on. In short, once your navel hangs over the front of your toes or the back of the heel, then you must take a step in the appropriate direction to retain your equilibrium. If this does not occur, then you will fall.
The center of gravity is integral to the technique of gainers because gravity only effects the what's below the center of mass. That's why your upper body doesn't get tired from standing up for a long time...it is your legs that do work. Since this is true, we use our upper body to generate more upward momentum, so our legs only have to do half the work!
When the kick is intitiated and the center of gravity is breached, then rotation is acheived. It would be the sole work of your legs to get you upside down; but once upside down, equilibrium will be acheived again, and it will take another force to get you back to your feet. This is when the upper body comes into play. When you rotate until you're upside-down, the upper body falls victim to gravity and the lower body does no work. Luckily a strong kick from the start would remedy this, but the arms would alieviate alot of stress on the legs if they were used. So the kick of the leg get's your lower body up and over, but the swing of the arms get your upper body to swoop under as your legs come overhead. If done properly, a complete 360 rotation about the fixed point (being the hip) should be acheived!
I'd put little diagrams in there, but I can't figure out how! :eh: