To Trish. I take it that you mean by Cross Over and using the word Lock.I think you might be refering to a New York in the International Style in either the Cha or Rumba. First the term lock gets misused. It is a Latin Cross. There is no Latin Cross in a New York in either Cha or Rumba.The action is a walk checked. If it was a Spot Turn, it is a walk turning, with the whole of the foot in contact with the floor. I thought I would just put that in. Rumba. New York to the Ladies Right. Facing partner, right leg is straight left leg is extended to your side creating a nice line, the left hip must be and should be higher than the right at this point. Now step through to your right, a small step with absolutely no gap between your thighs, at the same time swivel your right foot to a foot turned out position. Both front and back foot should be turned out and legs straight. ( a bit like Daffy Duck ) You will have about 20 percent of your weight still on the right foot at this point. From here it depends on what you are intending to do next.To add a bit more advice the correct interpetation in both Cha and Rumba is to get the heel down dead on the beat. This means that the foot of the moving foot must go out faster to be able to lower on the beat. This is called having fast feet and can be counted as, and 2.If you have tapes of any of the top dancers you will know now why they look so sharp. Best of luck with your dancing.