My husband and I love dogs, we recently added a new member to our family after our Husky passed. He is the cutest little ball of fluff! His name is Huter (sounds like cute) and is 6 months old. He is so wonderful with our family and people we have over. His only issue is he jumps up, all the time! He will sometimes nip, but the real issue is the jumping.
I have 2 little boys who are just the right height for him to do this and get knocked down. We run around the yard, go for walks and play with him all the time (especially now that it's nice out) but he will still do it, even when he looks exhausted from play.
I've tried down and putting up a knee. Of course he does it more to the kids bc they aren't as good about being stern and telling him "no" or "down". We got the dog so they wouldn't be afraid of dogs. But my boys are starting to become afraid and cry as soon as the dog comes near them...
Turn your thinking upside-down. You're talking to him (saying his name and "no") and wrestling (knee to the chest feels like play) when he jumps up. I bet he thinks jumping up is great fun.
Instead of teaching him NOT to jump, you need to teach him the correct position in order to get attention. Puppies who sit get praised and petted. Puppies who jump up don't get attention.
The way I've read it explained for kids is to "look for rain." When the pup is acting hyper and jumping, look skyward and raise your arms. No eye contact -- pretend he's not there. You might also want to turn your back on him.
When he calms down and sits (probably thinking to himself "What's that about?") you can lean over and pet him. Yes, he'll probably jump up again, but that's your cue to go back to ignoring him. Repeat as many times as necessary. Eventually he'll put two and two together.
Maybe if you turn into a game for the kids, they'll be on board, too. Teach it like a game of red light / green light. As long as the pup is sitting, he gets lots of petting. As soon as he's off his bottom, spin around and ignore him.