Navicular Syndrome is any lameness in the rear third of a front foot which will block out with a posterior digital nerve block, usually both fronts are involved, although this is sometimes not evident until one is blocked. All methods of shoeing for NS are palliative in nature. A farrier can't cure or correct anything, he can only relieve the symptoms to some degree. This means that the farrier will do whatever he can to decrease the length of the phalangeal lever and to increase phalangeal angulation.
Turnover is enhanced, in the main, by shortening the phalangeal lever.
The lever is shortened, primarily, by cutting off as much toe as possible. Finally, and most important from the standpoint of enhanced turnover, the shoe must be set under so that an imaginary line from the front of the fetlock, bisecting the toe, to the ground, is as short as possible. By setting the shoe under, turnover is enhanced, and pressure on the DDFT is reduced as a direct result. The easiest method of protecting the rear third of the foot is the use of a bar shoe. Upright horses seem to respond better to the more circular style of egg bars or straight bars.