[Tango-L] On Axis, Off Axis

[Jay Rabe]

Some points of observation/analysis on Evan's thread of maintaining axis in 
close-embrace...

As always, the simple expression "on-axis" can be interpreted in a lot of 
different ways.

If I stand flat-footed, with my center of mass directly over the center of 
my foot. I am clearly on-axis, in the most literal sense. If I lean forward, 
putting my center of mass above the ball of my foot. I am still on my axis, 
in the sense of fully supporting my own weight, but now my chest has moved 
about 4" forward (a maximum of 1/2 the length of my foot, per Even's 
analysis of center of mass not extending beyond the edge of the 
"foot-print"). Mechanically, moving my chest forward is equivalent to moving 
my feet back. If my follower does the same, the consequence is that now 
there is more space between our feet, and we can dance without knocking 
knees. Note that, in this position (call this "position-1"), it is not 
necessary that either dancer be exerting any forward pressure on their 
partner.

Teaching this concept (weight on balls of feet) can be challenging. One 
device used by a lot of instructors is to have the dancers apply forward 
pressure to their partner. Alex uses the expression "2 pounds of force." In 
order to apply forward pressure, a person must push with their feet, which 
has the consequence of putting their center of mass/force over the balls of 
their feet. One note: It is highly important that the force vector be in a 
direction parallel to the ground, that is, directly forward into their 
partner, with no downward component. In this position (call this 
"position-2"), let's say that the individual dancers are still "on their 
axis" in the strictest sense of being able to maintain their position 
without falling if their partner steps back.

Now consider the extreme ("position-3"), in which the dancers put so much 
forward pressure on their partner that, if one were to step back, the other 
would fall (I've heard the term "apilado" used to describe this type of 
embrace). But even with this much force, per Even's analysis, the PAIR is 
still "on axis" (but now it's a shared axis), because they can, as a couple 
in an embrace, stand motionless without falling, because the leader fully 
receives and returns (balances) the force back to the follower.

Note there is a continuum of possibilities between positions 2 & 3 in the 
amount of force given & received. IMO it isn't so important how much 
pressure is given. The important things are: no downward force; weight on 
balls of feet (= space between the feet); and energy directed into their 
partner for a good "tango connection."

One interesting thing about position 3 is that the extra force sent by one 
and fully balanced by the other seems to create a coiled-spring-like effect, 
storing energy, so that when I do a lead, it is possible to release that 
energy into very fast/large/dramatic moves.

Finally, all of these principles apply to open embrace as well as close 
embrace. In close embrace, the forward force is applied with the chest, 
while in open embrace it is applied with the points of contact in the 
hands/arms.

     J
     www.TangoMoments.com