With Dr. Bruce Indek
Butt Tucks are a really great way to improve your horse's engagement [tucking the pelvis in order to commence forward movement]. Butt Tucks are also a way of strengthening the core abdominal muscles which will help the top line of your horse.
All horses are rear wheel driven. Forward movement starts by your horse tucking the pelvis and moving their center of gravity from the shoulder region to the hind end. Abdominal muscles contract as well to raise the top line and start forward movement. If your horse has difficulty moving forward and or throwing the head up then this horse may need chiropractic evaluation along with rehab exercises to improve the engagement problem. You can also test your horse by backing them up an incline. Upon backing up if your horse is hesitating or attempting to go sideways then engagement is also at fault.
How Butt Tucks work is simple [See Picture]. Just stand up close and to the side of the horses butt. Start at the base of the tail and go out 3 inches to the side and down 5 inches. This will put you in the location of a crease between 2 muscles of the butt. Scratch sideways at a somewhat heavy pressure and watch the croup. The croup should rise evenly on both sides. Continue scratching for approximately 5 to 10 seconds. Rest for 5 seconds and repeat. If your horse is responding well then repeat 5 to 6 times. You can do this exercise as many times per week as you wish.