This exercise starts with your pup in the correct sitting position (see Sit to Stand).
From here you use a treat to encourage them to move their front feet forward and into the down position. Then lifting your hand up above them, it encourages them back up into the sitting position.
As you can see from the video this exercise uses a lot of muscles in the shoulder region and round the elbows. Having strong muscles in these areas will protect the joints and dramatically reduce the chances of injury when your pup is playing in the way only pups do.
It will also help to strengthen and stabilise the elbow region, which is crucial in breeds prone to elbow problems (notably springers, labradors, staffies, rottweilers and many more).
Sit to Down from the side
Sit to Down from the front