The turn on the forehand is the simplest of the exercises, asking the horse to move his hindquarters around his forehand, so that the hindquarters inscribe an arc. All these movements are performed in relatively one place, in a circular motion. The roll-back turn, seen in jumping events and in reining, is a variation on the pirouette. Additionally, the pivot on the hindquarters and turn on the center are seen in Western riding. There are three movements in place that are commonly used in dressage training: turn on the forehand, turn on the haunches, and the pirouette. Loss of position also tends to give incorrect signals to the horse, and if it creates a stiff seat, will make the horse move stiffly, discourage impulsion, suppleness, and forwardness, and therefore decrease the benefit of the exercise. Although it may be possible to perform correct movements when the rider's body is contorted, it makes it more difficult, decreases the balance of the rider, and reduces the independence of the seat which tends to decrease the clarity of the aids. Common faults to avoid include the dropping of a shoulder, raising or lowering a hand, collapsing a hip, leaning (rather than staying centered over the saddle), and twisting the body. To counteract this, it is often a good idea to have a person on the ground watch your position. Correct position of the rider: Some riders have a habit of riding crookedly when performing lateral movements, especially if the horse tends to do so.The rider should always begin and end a lateral movement with the horse moving on a straight line. Forcing a horse to do something before he is ready for it will never help his training. If the horse can maintain the bend for one or two steps, and then loses the bend, the rider should work slowly, gradually building a greater number of quality steps. If a horse is having a very difficult time maintaining correct bend, it is usually an indication that the horse is not ready for a movement physically, and it is best to go back to a slightly easier exercise (for example, back to shoulder-fore from shoulder-in) or perform movements to help strengthen him muscularly. The rider should be especially wary, as many horses will try to do movements with incorrect bend because it is physically easier. It can also teach a horse to move in a crooked manner. Incorrect bend, such as the shoulders or haunches falling in or out, decreases the benefits of the exercise (such as balance, impulsion, and collection), thereby eliminating the purpose of the movement. Straightness: The rider should always keep correct bend through the movements, with the horse moving from inside leg to outside rein.While a slight loss of forward movement might be acceptable when the horse is first learning what is expected, the rider should always ask for the horse to move forward after the movement is completed, and work towards keeping the horse's rhythm and freedom of movement constant before, during, and after the movement. Forwardness: lateral movements usually cause many horses to slow their tempo and lose their rhythm and freedom of movement.When performing a lateral movement, the rider should strive to maintain: The horse will usually become resistant and stiff, instead of more supple. Incorrectly ridden lateral movements, such as those that emphasize the horse to be forced into a position, rather than maintaining rhythm, relaxation, straightness, and acceptance of the aids, will create more training problems than they solve. Additionally, they may have a practical purpose, such as allowing the rider to easily open a gate, or to ask the horse to move sideways to avoid an obstacle. They are also required in some competition, such as dressage and reining. When performed correctly, they ask the horse to move their legs further under their body, thus increasing impulsion and improving movement, and can help build muscle evenly on both sides. Lateral movements are important tools to help with training problems, as they encourage better balance, suppleness, and response to the riding aids.