Creating the body memory of an "uplifted" sternum.
In the video clip here, I show how an "uplifted" sternum can help us in the walk, giving us more balance and freeing the legs.
There are many images that can help us in our alignment:

• Think your head is a helium balloon floating upwards and the spine hangs on it like a thread.
• Think of your head and shoulders to be a cloth hanger - where the shoulders are hanging freely while the head is pointing upwards.
• Think of a fountain that streams upwards from the feet through your middle line and spraying out from a point over your head. This creates a movement upwards on our center line, while the outer areas (shoulders etc.) are released like the water that is flowing down from the highest point of the fountain. 
• Another way to help us lifting up our sternum rather than having it collapse is to use one arm to guide us forward and upwards as if we had a invisible cord fixed to our sternum and pointing upwards to a place in the far distance. We can use this as an exercise while practicing the Tango walk without a partner. This exercise creates a body memory of an "uplifted" sternum, which later - while dancing with a partner -  will be of great help. 

​Attention: Make sure that you are not leaning forward when your arm goes forward and up. The head should continue to "float" upwards like a balloon. 

Add on: There is much more to say about the "correct" way of walking in Tango. The above text and the video are only a short "blip" shedding light onto a certain aspect of the walk. For instance one thing which I still want to say here is that during walking there is no up and down bouncing of the head. That means that the "lifting" of the sternum is more an internal movement and does not show on the head moving up. As basic rule for the head hight: It always stays constant during the walk and only at the end of the walk - at the collection of the feet, we go back to "zero" point - which is our full height. ​
Now it's your turn to test it: Find out for yourself if lifting up the arm in a practice walk stimulates you to lift up your sternum and if so, what is the impact on your feet and legs and on the walking itself.