Purpose – Strengthens both the hip and shoulder muscles. Stretches shoulder extension muscles and hamstrings (rear legs) when done correctly. 
 
Criteria – All feet remain still, square drop with everything in alignment, into a bow, parallel hocks, elbows staying in. Elbow joint to be extended (not bent) and off the ground. Point of hip to be slightly behind the hocks. Avoid hyperextension of the spine. 
 
Placement of reward – Move the food towards the dog in between their front legs and aim for food to be between the elbow and wrist at the end position. Then lure them back up for the stand position. 

Training tips –Initial stand position needs to be extended more than normal for them to be able to do this exercise correctly. Take them back slowly and initially reward them in higher positions to get them used to the movement we want. Eventually take it deeper. Sometimes having the rear feet on a very slight slanted target can help them feel more secure. Some dogs sink through their rib cage in this position and I just put my hand under their ribs to encourage them to lift more as they go back. If their spine is hyperextending this can be a reason for that. 
 
Increasing difficulty – Can be done on elevated platforms and take them lower than level. Can do on unstable equipment as long as they can maintain the same form. 

The video below shows a few varitions. First is just bow to stand. Second Brill is working on bow to drop to pop back up to bow. Lastly with Bright I actually have her come in to bent elbows on the way back to stand because she doesn't like to bend her elbows in exercises. So this will work on those muscles she tries to avoid using generally.