Our group dance instructor teaching the waltz at the local senior center says that the lady should stand straight and lean back against the man's hand on her back.

I have looked at the information on this web site about the weight connection, and don't understand how I can push against the man when he pushes and still push back against his hand.

Please explain.

Sack the Instructor immediately.

Try not to confuse "lean back" with "push back."
You can lean against something without pushing at all. Your instructor is probably just wanting to make sure you are not leaning forward or hunching your shoulders. The info on this website about the connection and how it should feel like a slight push for the man and a push/resistance for the lady is exactly correct -- and it's one of the more important feelings to dancing that you should try to master. But yes, it should also feel like you are leaning against the man's hand on your back -- because to not do so means you are not holding frame. Plus, it will be much easier to feel the lead in your back. As you get more experienced, that's where you'll feel the lead, more so than through the hands. The best advice might be, that once you get more experienced, you'll be "leaning back against the man's hand on your back" automatically, without even wondering about what it means. Pushing slightly forward with your hands/arms to create the proper resistance automatically should "push" or lean your back toward the man's hand on your back. Actually quite hard, and awkward, to do otherwise.

I think we may have a bit of a disagreement here.

If I EVER have any of my Amat. ( or Pro couples ) PUSH, then I will push them out of the door !!!.The choice of word ,is a bit too extreme and in all probability, will create other issues.

"Resistance " in "hold " is created thru body contact with the correct alignment and correct weight distribution over the standing leg/foot.

Pressure applied thru the mans right arm/hand stabilises the contact .

The left hand,man, and right hand lady,maintain contact thru very slight pressure, brought to bear thru the base of the hands( Its NOT a pushing match ! )
The positioning of the head, may also afffect weight and balance if incorrectly used and or placed .

To the poster. In a class, you are usually not going to receive the correct info. from a partnership standpoint ( unless its of a very high level ). In addition, if you are in a mixed group of singles, then a compatability issue may arise.

And , Please DONT lean !!.Let the natural curves in the body do their work .