(Many, many more details about this topic can be found here.)
Many marathony dancers used to dance in open embrace originally or have learned from teachers who still do or did so in the past. That is totally fine and we often also use open embrace in our classes out of pedagogical reasons. But, as we want to dance in a close embrace at a Milonga, we teach a posture, that will work out no matter which distance you choose. Please be aware, that many teachers who used to dance in open embrace don‘t. Although they might dance close embrace nowadays, they might not have updated their concept of a posture but stick to the original idea of the leader standing very upright, with the bodyweight distributed over the whole foot. Kind of an ideal everyday posture, like a perfectly upright beanpole. It might look like this:
But if you use this posture in close embrace, you will "force" your partner to either lean on you or stick out her butt in order to create a chest contact and still have enough space for the feet. Because only few teachers nowadays encourage dancing „apilado“ (off axis, leaning) and most women feel uncomfortable weighing on their partners, many followers will instinctively choose option two. It allows them to keep their gravity centre above their feet. This posture might look like this:
When dancing with a partner in a close embrace, it might not look quite as crass and some even find it sexy. But I can tell you: it is not healthy. Dancing with a constant backbend compresses the vertebrae, uses a lot of muscular tension, inhibits natural dissociation and does actually interrupt the flow of the leading signals from top to down. If a communicative signal is supposed to „run through“ the axis, should it not remain unbroken?
Let us not speak about the long-terms downsides of such a posture. Many yoga teachers nowadays abstain from encouraging their students to aim for hyper-flexibility because they know about the risks of such a practise. So please keep in mind: You (or your lovely partner) will not be young forever, but you might still want to dance Tango without hurting.
(Please don‘t tell me, that I stick out my butt as well. What you see are the natural curves of my spine and well... the rest of my body. The only way to get rid of those would be to go on a stricter diet.)
So, in my opinion, these are your options of dancing without forcing yourself or your partner into an unhealthy posture or dancing off-axis:
Look at the following video of Gustavo Naveira and Giselle Anne. Both of them stand very upright most of the time and open the embrace, when they need more space for their feet and legs. In any case, Giselle Anne does not have to stick out her behind. (Nevertheless: don‘t do all the stuff that they are dancing at a Milonga, please.)
2. Adapt your posture to allow for both partners to keep their spine upright. If you still don‘t know how, please work with specialised teachers.
Check out a dancing video that we made for our DVD. I have chosen it, because you can often see us from the side and the light allows for a good visibility. You can also watch an initially faulty posture changing to the better: Check out the first couple of seconds when we go into the embrace. In the beginning, Detlef is standing with his body weight a little bit too much towards his heels. His mistake! In order to create a connection, I then break my axis and lean my upper body towards him. I should not have done that, but maintained my posture and therefore show him how to position himself, as I tell our students. My mistake!
Fortunately (whilst already being in the embrace) Detlef also shifts his weight to the front of his feet and all of a sudden, my posture is good again. Both of our axes remain upright throughout most of the dance and we‘ve got enough space for our feet. (We don‘t claim to be perfect though.)
Look at the following video by Tete - in particular the moment when he and Sylvia go into the embrace. By the way: Tete was a famous dancer and teacher who, like most Milongueros of that era answered „Tango de Salón“ when someone asked him, what style he danced. But that is yet another story...
Edit:
Please note that I don't want to put all the blame on the leaders. There are many, many things that followers can do to put themselves into a disadvantageous position or to hurt the leaders. This post concentrates one one particular feature of the leader's posture and the consequences for the followers, because I have experienced this situation to a larger extent and I believe it to be a typical problem of recent developments.
If you want to work on the details of your posture and connection, I encourage you to buy our book+DVD. ;-)