This is a good warm up exercise that helps stretch the spine and surrounding muscles, affects balance and core, and is even a strength/weight exercise for dogs recovering from surgery depending on how you have your dog perform it.
Start with your dog in an even squared position, on flat stable footing.
Using a favorite protein treat (not a carbohydrate biscuit) you will be luring your dogs head to follow the treat to the shoulders, mid section, then hips, and for some dogs even down to the front and rear paws after suppleness is gained.
Often standing behind your dog, lightly holding under the belly to keep the body straight, you are asking your dog to bend towards the treat- NOT turn in a circle or step out to the side.
You may need to play with how you do this exercise, use a wall or your leg position to encourage standing still but bending.
Name the exercise for your dog, and praise when correct efforts are made.
Often 3-5 repetitions to each side with brief pause is sufficient and well tolerated.