American Style Smooth Ballroom dances and some elements of International Style Ballroom dances at the Silver and above levels employ an action called "Continuity Movement". Simply stated, "Continuity Movement" refers to the continuous passing of the feet from one step to the next without closing, enabling the fluid movement of the partnership. "Outside Partner Dance Position" is the key element in accommodating this fluid movement. CBM is the movement action that facilitates "Outside Partner Dance Position".
The following is a detailed technical description of the terms stated above and may be a little hard to follow. After each technical description, I will give a non-technical example (**) of what it means.
"Outside Partner Dance Position" is achieved by moving the foot of the forward travelling partner on a track outside of their partner's supporting foot using CBM and ending in CBMP. ** The dancer, in Closed Dance Position standing on his/her left foot, steps forward with his/her right foot outside to the left of their partner. The only part of the right leg that is outside of the partner is from the knee down. The right foot ends up in front of his/her left foot and the partner's shoulders remain parallel to each other.
CBM - Contra Body Movement is technically defined as turning the left side of the body towards the right moving leg on a forward step, or turning the right side of the body towards the left moving leg on a backward step. The body and the legs move at the same time and the moving foot ends up in CBMP. ** Stand on your left foot and hold your right foot forward. Now rotate your left leg to the right keeping the right leg in the same position. It will feel like your legs cross and your right hip rotates backward. Now point your right foot behind you. As you move your right foot from behind you to in front of you, rotate your left supporting leg at the same time. This rotation should place your right foot in front of your left. This will give you the feeling of CBM.
CBMP - Contra Body Movement Position is a "foot position" achieved by placing the moving foot slightly across and in front of the supporting foot (moving forward) or placing the moving foot slightly across and behind the supporting foot (moving backwards) using CBM. ** With the weight on the left foot, place the right foot in front of the left (moving forward). With the weight on the right foot, place the left foot behind the left (moving backwards).
Now that we know technically about CBM and CBMP, how does this accommodate Continuity Movement? Let's try to understand this from a very general partnership and movement standpoint.
Example: We have a doorway only as wide as a single dancer and we want to walk through this doorway in partnership. The logical way would be to just walk through the doorway in "Closed Dance Position". This works, but our movement would be limited because of our partner directly ahead of us. It is difficult to achieve Continuity Movement from this position. What if we simply turned sideways so both partners could move through together? This doesn't give us Continuity Movement either because we would be stepping sideways which is even more awkward. What if we did a little of both? What if we moved diagonally through the door as a partnership? This would allow the partnership to be maintained and at the same time accommodate a free Continuity Movement of the legs outside of our partner. The dancers are in the standard "Closed Dance Position", which means by definition, "Offset to the left" and having a "Left Side Lead". CBM creates a little more "Left Side Lead" and the ability to gracefully step outside your partner with Continuity Movement.
Contra Body Movement is a key element for achieving higher levels of dancing. CBM is also utilized in Latin and Rhythm dancing as well, but for different purposes. It may seem a little complex, but it is well worth your time and effort to learn. It is the gateway to the really good stuff!!! Your dancing will be greatly rewarded.