The harmful truth of 'training aids'

Gadgets, we're here again, I thought i'd create some visuals to help train your eye for correct movement and hopefully help you see why these 'training aids' DO NOT create correct movement ... ever . As riders/ trainers our ultimate aim should be to have the horse carrying itself in balance. For them to do this they need to lift through their thoracic sling & back. As previously mentioned, the thoracic sling is a combination of muscles that attach the forelimbs to the rib cage - no bones involved so these muscles need to be strong and switched on in order to lift through the wither. Gadgets that hold your horses head down DO NOT allow this to happen in ANY capacity. Some even pull down on the back - horses will not work into pressure so therefore collapse through their thoracic sling & core. Instead your horse will brace their necks - we should not be able to see individual muscles under tension when working a horse (red arrow), the neck should be uniform and smooth except for the jugular groove seen in the last photo (white arrow). They will brace Brachiocephalicus (yellow arrow). If this muscle is braced the horse cannot physically lift through its thoracic sling - this is a fact of science. The weight will shift forward putting unnecessary strain through the forelimbs & feet. The head will come behind the vertical again causing tension in the neck muscles as the nuchal ligament that supports the head cannot function as it should.
To the untrained eye this horse may look pretty, these are the actual advert pictures for these devices and they seem to have helped sell 1000s of these things. But really they just train for dysfunction. They will build muscle - fact, but not in the areas we want muscle to build. If a horse is continuously worked with neck tension and no thoracic sling engagement we will run into problems such as navicular, tendon problems, kissing spine, hock and stifle problems, SI strain, suspensory damage, lower neck arthritis & nerve impingement- unfortunately I deal with these issues as a result of incorrect training on a daily basis. We can create as much energy as we want from behind but if the front end is trapped there's nowhere for that energy to go.
So please, for your horse's sake, do not reach for these gadgets. Train your eye and help your horse help itself. There are no quick fixes, only correct training will lead to a sound healthy horse. I will admit, I am not the best rider in the world, but I strive to improve myself and my horse and at no point try to cut corners, in fact sometimes I take a few steps back.
Please note: this is not just an opinion, everything outlined above is proven by science and horse biomechanics.
*I will also add I once upon a time dabbled with training aids. I too was told how amazing they were, we were even told to use them as rehab aids at uni. It wasn't until I studied horses working in them and watched my own horse go incorrectly in them alongside really getting a grasp on biomechanics and horsemanship that I started asking questions and looking in to the science. We learn through experience in life and there's no reason we cannot change our practices in line with what we learn for the benefit of our horses.
Edit: I have added a photo of a horse being lunged without any 'aids' as it was suggested the free moving stock image horses i used could have had their training aids edited out (they haven't as they wouldn't be moving like they are) Photo courtesy of Amy Skinner Horsemanship .