Influence of draw reins on ground reaction forces at the trot.

According to riding texts, draw reins are supposed to support increased collection. This has not been measured objectively. Therefore, the objective of this study was to determine whether a horse ridden with draw reins would relatively increase weightbearing of the hindquarters while worked with the draw reins compared to a normal rein. Ground reaction forces were measured in 8 horses at the slow trot over a force plate in 3 different experimental set-ups: 1) riding with only a draw rein (DR); 2) riding with the combination of a normal and a draw rein (NR-DR) and 3) riding with a normal rein (NR). Horses ridden with NR-DR showed significant higher vertical impulse in the hindlimb compared to riding both with only DR and only NR. Several significant differences were also seen in the horizontal force. It is concluded that draw reins, when used correctly, together with a normal rein, achieve the desired result of shifting the weight of the horse caudally. This was not the case when the draw rein was used alone. It is important that trainers, as well as veterinarians, recommending draw reins in a rehabilitation programme, know about these possible effects.