If not you may need to reinforce this with an up down movement in the lead rope at the same time. For training purposes, properly using and reading posture can increase the quality of your training. Another thing you will learn is to draw your horse in to you with posture. You can use this to your advantage too. When round penning your horse you can step back and draw a horse into you.
Posture carries over into the saddle.
If you stay relaxed and don't over react you will teach your horse to be calm. When you know what to look for the posture of the horse can tell you whether you are making progress or how the horse feels. Since you can't ask them if they understood something or what they are thinking, this is a valuable tool. Posture can be as subtle as the worried wrinkles around they eye or as obvious as a strike or kick. Experience is the best way to learn to read the horse's posture.