I made lots of exercises with my dogs turning round clock- and anti-clockwise on an bucket, balancing with the front legs on a big gymnastic ball and a wobble ball. They've also learning going backwards in front of me, following the curves I make and stepping up on a stairway, then onto the wobble ball, then onto a bench. So far  all goes well.

What doesn't work at all is climbing forward up on a ladder by luring them. They do this, but only until  the step they can reach by stretching themselves out theimselves..I hoped they would somewhen start to lift at least one hind foot on to the lowest step. They don't.  I then bent down to their hind feet, thought I could lift gently one of them on that. step, no force, just to give them the idea. But as soon as i bend, they come down to me, lol. I simply don't know how  else to try..

Has any one got the glorious  idea?  Or am I expecting too much from them?

Have you tried laying the ladder flat on the ground and letting them walk over it like that first? I find this usually helps dogs become aware of their back legs and start using them. 

Yes, I've tried this. I also put items in diferent forms and heights in a row or circle. They walk over them forwards as well as backwards without problems.

Might it help if I'd use the stay comand? They keep sit-. down, stand-stays well also with distractions, but I doubt it with keeping it being in stretched position on the ladder.

I can't get rid of the impression that they can feel a certain instability of the ladder although I'm  holding  it firmly. So they might feel uncertain or even frightened.

I've seen in the internet very stable, shorter ladders with steps on both sides. With them I'd have the opportunity to step onto it from the otpposite  side and lure them from there. Doing this I could also avoid to bend down and could catch the dog's rear foot easily. The stable ones though are very expensive and for importing them to Brazil I'd additionally have to pay taxes, 60% to the original prices + transport. I'd do this if I knew, if this is a useful exercise. for the dogs.