Aviemore Running Martingale Black. The Aviemore Running Martingale is a great tack addition should you require a little more control on your horse. This plain running martingale can be adjusted along the shoulders and at the girth for a perfect fit. Finished off with durable, stainless steel fittings. A running martingale is best used on horses that tend to raise their head too high to avoid contact or throw their head up to avoid work. Designed to add pressure on the reins through to the bit on the horses mouth whenever their head is above the desired point. This pressure/leverage encourages the horse to lower their head. Great for young horses, young riders, jumping, eventing or for those who struggle to keep a contact in their horses mouth.