In a quickstep is there and body position change when doing a chasse follow by a lock

"In a quickstep is there and body position change when doing a chasse follow by a lock"

"Body position" is something that has many dimensions, and undergoes nearly continuous change in at least some of its details.

That said, most big, visible, changes in the body occur "within" figures. Ideally the boundaries between figures are seamless, one figure transitioning seamlessly into the next, meaning the boundary is really only present in the description of the dancing but not in the dancing itself.

Looking inside the chasse, depending on which of the many chasses is being danced there likely will be some differences between the starting and ending body position.

The lock would in this case start and end in the same type of body position, however there is a small difference between the way the body is held in the outside partner postitions at the start and end, vs the locked position in the middle.

And of course the rise and fall, not to mention the very actions of taking a step, have small but important impacts on the usage of the body core - generally at the level which can be felt by your partner, but not seen by an outside party.

Quite a lot to dig out of that answer if you are a beginner.
A clear lead is important, a good wide firm frame is needed as a follower will position her body and move her feet depending on your body position.

For the progressive chasse, start back right BDC, you will side-close-side facing the wall, the final side (L) pointing DW, your body turning to join it facing DW ready to step right outside the lady's right side with your right foot, the lady going back left. If you are now doing a natural figure, your body will turn clockwise and the lady can move her right foot into the space on her right side to suit.
If you are going to do a lock, your left foot step will be fwd and to your left (your body remaining facing DW), the lady matching it with her right going back. Here her problems start, her right foot is now in the way of her left foot, the options are to loop it round the right or cross in front of the right in a lock.
If you do the lock step alone, right crossing in behind your left you will note that your body turns a little to face the wall position, this fractional movement, coupled with a gentle hint of a lift gives the lady confidence that she should lock her left in front of her right with weight, ready for a quick back step on her right.
A clear lead, as early as possible will let the lady comfortably follow you.
(As you can tell, I am not a teacher, so I have my asbestos underwear on ready for the flaming!)

Anon,

Sorry, can you explain the lady's HTH above?
I would have thought all backward steps are TH "peeling" the foot except the two lock steps up on the toes?

I guess that the question refers to progressive chasse followed by fwd lock-step.
If that's the case, the progressive chasse starts with CBM followed by slight body turn during the chasse steps (from pointing DW to facing DW), while the fwd lock-step starts with CBMP and the body between FW and DW (shoulder leading) throughout.
Hope this helps.

"Answering 7/12/2011 11.46. That is not a slight turn. It is a Quarter of a turn to the left on the Progressive Chasse. Hold that position for the Lock Step. Back to basic eh."

The post to which you respond described the body. You are giving the amount of turn in the feet, which is something different. Further, that post was describing not the rotation in the CBM, but a subsequent body rotation from a pointing to a facing DW body alignment.

As a piece of practical advice, at quickstep tempo the emphasis of continued body travel over swing may make it advantageous to turn the body somewhat less than the feet - particularly if the goal is to accomplish substantial sideways travel down the LOD using a series of quarter turns and progressive chasses as a simple and highly effective approach to quickstep.

I have to say anymouse's advice is good and this is what I make my beginners do!