Here's a video of some natural horsemanship,including bareback and bitless riding:
It will be very good to get Icelandic Horse riders, particularly those who are trainers, judges, and / or breeders, who may be certified / professional / FEIF trained / Holar graduates to ride more naturally like this young gal, so that the horse can be shown and evaluated in a more natural state, and gait without mechanical aids.
Horses need to have well-fitting saddles. Fitting a saddle to a horse need knowledge about equine anatomy, and saddle structure. Add to this the biomechanics of the horse and the mechanics of the saddle, and how they mesh.