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fracture
Mar 18, 2006, 6:21 PM
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Registered: Jun 13, 2003
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The first chapter of SCC (along with many subsequent chapters) talks a lot about your base of support, and represents it visually in two-dimensional drawings.
However, it mentions that these drawings actually represent a three-dimensional space. I'm having a little bit of trouble understanding how this space would look, though I can understand it a little in some simple cases.
One simple example might be when you are hanging straight down from two positive jugs without your feet on, which would normally be stable balance. I think the three dimensional space that represents your BoS goes straight down forming a rectangular prism. However, I don't know how to tell how far down it goes---probably this is a function of how positive the hand holds are?
What about more complex cases like a drop-knee position with only one hand on the rock? Two dimensionally the space SCC shows for this is a triangle. Is the three dimensional space in this case a triangular prism, or a tetrahedron, or something more complex than that?
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fluxus
Mar 19, 2006, 6:11 AM
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Registered: Apr 3, 2003
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In reply to: One simple example might be when you are hanging straight down from two positive jugs without your feet on, which would normally be stable balance. I think the three dimensional space that represents your BoS goes straight down forming a rectangular prism. However, I don't know how to tell how far down it goes---probably this is a function of how positive the hand holds are?
In terms of the shape of the base, that's a fine way to think about it. To ask how far down it goes; that's something of a confusing way to think about it. Many bases can be imagined out infinately but that does not matter because our bodies have a finite size. Think of standing on the floor with you feet shoulder width apart (ill. on page 6). imagine this base in 3D, passing up through your body, there is no upward limit to the base but what matters in where the body is. The same goes for hanging from the jugs(fig. 3 on page 15).
In reply to: What about more complex cases like a drop-knee position with only one hand on the rock? Two dimensionally the space SCC shows for this is a triangle. Is the three dimensional space in this case a triangular prism, or a tetrahedron, or something more complex than that?
Again you are on the right track, thinking of it as a triangular volume is fine. Look at it this way, the size, orientation, and shape of the holds, determine the volume of the base in the third dimension. Slopers provide an easy example, lets say you are in a gym with both hands matched on a big nasty sloper and your feet on small holds. the base will be a triangle with a little depth in the third dimension. In this case the limit of the third dimension is going to be defined by how far the hold stands from the wall surface. You will feel the limit of the base in the third dimension by slowly moving your hips away from the wall. You may only move an inch or two before you can't hold on, and you fall. Look at the pictures on page 31,32,33 these might help.
Now, imagine the same situation but with HUGE foot holds, your feet are on jugs that stick way out from the wall. In this case the foot holds are going to define how large the base is in the third dimension, because they provide a base that is perpendicular to the line of gravity, if you are on a vertical wall.
If you think about what directions the hold can resist force in it should become clear. For example, incut jugs can resist forces that are perpendicular to the climbing surface, this means that the base will have a lot of depth. Tiny flat edges, or crazy slopers can not resist a force that comes anywhere where near to perpendicular to the climbing surface so the base will have much less depth.
I know its a difficult concept, balance in climbing is odd and complex. So it can be difficult to conceptualize. It sounds like you've got it though.
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fracture
Mar 20, 2006, 3:57 PM
Post #3 of 3
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Registered: Jun 13, 2003
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Thanks fluxus, that helped. I think I understand it now.
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