All trainers are familiar with a horse that makes a noise. If performance is poor, laryngoplasty has, for over 40 years, been the next consideration.

The aim of the procedure is to reverse the effects of larynx weakness that occurs due to a degenerative condition of the nerve that controls the muscles on the left side. A synthetic implant is placed along that side of the larynx to hold it open where the muscle is too weak.

It has long been suspected that the procedure has other effects on the airway, other than simply trying the collapsed part of the larynx back and out of the way.