In this video AnnA explains the basics of riding a square. The key to mastering the square is to start slow and explain the exercise to your horse. By riding the square at the walk, you can get a better idea what tendencies your horse has before moving on to a faster gait. You should be emphasizing straightness with your leg and rein aids to help your horse learn the lines and turns. AnnA also says don't worry if it gets a little messy - mistakes will happen but it's important not to let your horse get frustrated while they're learning.
DT On Demand members can watch the full video by clicking here.
If you are not a member, you can sign up for a 10-day free trial with subscription by going here: https://ondemand.dressagetoday.com/join.