It is important to pay attention to correct fitting. This is not a collar (there is a tendency to fit it too low where a collar would usually lie). Aim to allow the breastplate to sit so that it lies flat against the horses chest (Angle fit) and at the correct height to leave the windpipe free, and the points of the shoulder free (Height fit).
1. Height fit - first look at the height at which your breastplate should fit. The bony shoulder joint should be clear of the breastplate, and positioned just below the upward sweep of the breastplate each side. The windpipe should be free of the breastplate, so that the windpipe is not restricted in any way. Once you have established the correct height, you can look at the angle fit.
2. Angle fit - the breastplate should lie flat against the horse, so that neither the top edge nor the bottom edge dig in. There are 3 positions for the wither straps. The buckle pieces each side are re-moveable so that you can select what works best for your horse. You may use the front two positions, or the back two positions, or one front and one back position. You can also use different holes on the wither strap. Do not think that you have to use the same holes. You may need to have the front strap on a lower hole than the back one. All these options are there to be used, and help to custom fit the breastplate to suit the conformation of your particular horse. For example, a horse with a broad chest and low set neck (Fjord, Exmoor, Shetland etc) may need the breastplate to be tipped at a greater angle than a horse with a very upright shoulder or high set neck (Hackney/ Gelderlander etc)
3. Martingale - the martingale is padded, because it needs to lie a little more snugly than a normal false martingale. It helps to keep the breastplate in the optimum position, flat against the horse.
Once you have fitted the breastplate as above, there is a little more work to do! The first few times you use the breastplate, watch carefully to see if your adjustments are working. Is the breastplate staying flat against the horse when he is in draft? Get someone on the ground to walk alongside and watch. It is common to make a few more adjustments until you are satisfied that the breastplate is positioned correctly. Also be aware that you need to work the horse in his new breastplate regularly before going off to do a tough marathon. The bearing area is slightly different to a straight breastplate and you need to allow the horse time to get used to this, like you would if you had a new pair of walking shoes.
Can you see that shoulder joint working and flexing? If you can't see it, the breastplate is too low.
Every horse is a slightly different shape, so if you use the breastplate on more than one animal, you may need to re-adjust each time.
You will see that the Empathy breastplate is not as long as an ordinary breastplate This is because it does not need to be long! Pressure tests prove that the only part of the collar that really take heavy pressure against the horse are the front and shoulder area, in the same way that a full neck breastplate does.