Easy to use but... There is a 'but'...
Lately, I have seen many horses trotting, cantering and even doing pole work with this type of system so I just wanted to give you an opinion from a therapist point of view and help you to understand.
Firstly, any fitters will tell you that we need to leave the spine free from pressure, contact and stimuli and this is not the case with this system.
The rope will generate contact around T10-T11 and lateral friction, especially on the thoracic region when walking, trotting and cantering. Precisely on T11 and T12- which are in the horse the orthosympathetic neurological connection essentially of the stomach. Hyperstimulation on a spine area will have an impact on the related organ.
And do you know what emerges from T10?
The eleventh cranial nerve (or accessory nerve innervates the trapezius and the sternocleidomastoid muscles) which is the reflex point in the wither area. Indeed, when a horse/ mare is bitten by another horse/ stallion the nerve sends a signal to the brain and to stop the limbs from moving forward.
While we are in this area we can also mention the latissimus dorsi (largest muscle of the back). Its function is to flexes the shoulder and supports the back. Its Origin is Thoracolumbar fascia and the Insertion is the tuberosity of the humerus. which means this is going to have an impact on the whole body and its functions (muscle atrophy, muscle contraction, imbalance).
Biomechanically this is not ideal either, horses will tend to avoid the pressure from the rope on the wither when they drop their head down so they will not be willing to lift their back!
Remember Less is More…