by Dr. Kathryn Nankervis, The Equine Therapy Centre, Hartpury College, Glos. GL19 3BE
Back in September, myself and Carolyne Tranquille from the Animal Health Trust were asked to speak at an ‘Aquatrainer’ meeting at the Academy Bartels in Eindhoven, Holland. The Animal Health Trust have conducted a survey on the use of water treadmills around the world, the results of which ought to be released next year. We watched a horse on their ‘Aquatrainer’, and then I presented some of Hartpury’s research, which we have used to inform the way we work all of our horses, including Valegro.
Water is more viscous than air, you cannot move as fast through water as you can through air. Both horses and humans move slower through Water Treadmills water than they do through air – even Mo Farah. He uses a water treadmill when he has ‘niggles’ or when he is clocking up really high mileages. We found a comfortable speed to walk on a water treadmill is half to 60% of that overland, resulting in a heart rate similar to walking overland. Water treadmill exercise is therefore not nearly as hard work as swimming which gets the heart rate up to 170 beats per minute or more.
Dressage horses tend to suffer from repetitive strain injuries, so variety in their work is sensible if you want to avoid injury. Limiting the number of ‘skill training’ days and alternating with other, complementary types of exercise may decrease injury risk. Your horse doesn’t need to be fit to use a water treadmill, but is the movement in a water treadmill good for dressage?
As water depth increases, horses take fewer but longer strides and they do this because of drag. Drag means you can’t swing the limb quickly, but as water depth increases, buoyancy is also increased, making it easier to move the limb upwards (towards the water surface), leading to a slow rhythm and a ‘higher’ action. The consequence of this is more flexion of the lower limb joints, the fetlocks, knees and hocks.
If the hocks are flexed more – does this mean the back moves more also? We used back markers and tracking cameras to measure the ranges of movement in various regions of the back in horses walking on our water treadmill in different depths. We found that the range of movement of the back increases as water depth increases. In high water the lumbar spine (region behind the saddle) becomes more flexed (rounder). So there is lots to like about water treadmill exercise for the dressage horse. We can reproduce some of the gait characteristics we require in a dressage horse, but all with reduced weight bearing which may just reduce the risk of some of repetitive strain injuries when used as part of a cross training programme. We were pleased to learn that our Dutch colleagues use the water treadmill in a very similar way to ourselves, largely ‘low’ and ‘slow’. Carolyne and I very much enjoyed the Dutch hospitality and we’re looking forward to a reciprocal visit from their vets and physios in December.