“Lower” and “slower” are seen as important guiding principles in the use of water treadmills for horses.
Experts caution that while there are potential benefits from water treadmill exercise, incorrect use could either directly oppose the goals of a conventional ridden training programme or increase the risk of injury.
Members of a hydrotherapy working group, reporting in the journal Animals, described the tendency to experiment with the full range of speeds, water depths and, more recently, inclines offered by their particular treadmill in their early involvement with it.
However, with growing experience, they gravitated toward “lower” and “slower” in their use of the treadmills.
Water treadmill exercise has become popular in recent years for the training and rehabilitation of horses.
Sessions can be tailored to individual horses and training/rehabilitation goals by altering the frequency, duration of exercise, water depth and belt speed.
Recent work suggests that there are large variations between users, despite shared training or rehabilitation goals.
In 2019, a group of researchers and experienced water treadmill users met in Britain to establish what was commonly considered to be best practice in their use.
The result of these discussions was the production of Water treadmill guidelines — a guide for users.
The guidelines describe the consensus reached to date on potential benefits, general good practice in water treadmill exercise, introducing horses to the exercise, factors influencing the selection of belt speed, water depth and duration of exercise, and monitoring movement on the treadmill.
“The long-term goal is to reach a consensus on the optimal use of the modality within a training or rehabilitation programme,” the researchers wrote.
In their just-published communication, they described the development of the guidelines and proposed them as a starting point for further collaboration between researchers and practitioners in the pursuit of “best practice”.
The guidelines are based on a combination of research evidence and/or the working group’s combined experience of exercising thousands of horses from a wide range of disciplines.
“As a result of our discussions, it is apparent that there is much work to be carried out before broad agreement, based on evidence, could be reached regarding the most appropriate application of water treadmill exercise for the rehabilitation and ongoing management of horses with specific orthopaedic injuries.
“However, by sharing experiences, both positive and negative, practitioners can inform the development of research questions, and research findings can be disseminated directly to users, with benefits for equine welfare and better recovery from injury.”
The authors said water treadmill exercise is firmly established as a popular form of cross-training for competition horses and a useful form of exercise within equine rehabilitation programmes because of the benefits of immersion, decreased impact shock and the gait patterns adopted (an increase in range of movement of lower limb joints and increased lumbar flexion).
However, further research on optimal use of water treadmills within training programmes is required.
“Given that longitudinal training studies are expensive and time-consuming in nature, the most valuable studies to the industry would be ones that focus on techniques used in practice.”
As a general guide, speed should be decreased as water depth increases, because of drag.
Most treadmill operators exercised horses at the walk (more slowly than overland was recommended).
“Whilst several of the working group had water treadmills with belt speeds that enabled trot, only one of the 10 venues represented within working group members routinely trotted horses.
“This venue dealt largely with event horses opting to use the water treadmill to enhance fitness.”
Anecdotally, group members felt that the benefits of water treadmill exercise could be achieved without trotting.
Research has shown that increasing water depth has a greater impact on the workload than increasing walking speed.
“It was recognized that the correct belt speed was horse specific rather than training/rehabilitation goal specific. The choice of water depth was more likely to be training/rehabilitation goal specific.
“Hence, the best combination of speed and water depth will vary greatly between horses and should be judged according to the individual horse’s response in terms of gait pattern and posture.”
The group agreed that assessing posture is essential in determining optimal water depth and speed combinations for each horse.
It was agreed that the alignment of the head-neck-back and hind limbs during water treadmill exercise should not differ from what would be considered acceptable overground.
“Quality of movement was considered to be that which supports and complements a ridden training programme of a sport horse. Straightness and a regular rhythm to the footfalls were deemed important.
“It was considered that the most common mistake was to combine high walking speed with high water, when many of the benefits of water treadmill exercise can be achieved at relatively slow speed.”
Observation of the dynamic posture of the horse during the session was considered important to ensure that the horse was “pushing” adequately from the hindquarters rather than relying on “pulling” from the forehand.
Most working group members considered that water treadmill exercise was useful as a form of cross-training for sport horses, and dressage horses in particular.
It was not possible to gain consensus on the suitability of water treadmill exercise for the rehabilitation of any specific orthopaedic condition without caveats relating to the horse’s conformation, dynamic posture and co-existing lamenesses.
“As water depth increases, buoyancy increases, impact shock reduces, and hydrostatic pressure on the limbs increases, all of which have potential benefits for the rehabilitation of certain conditions.”
However, studies on the use of water treadmill exercise within rehabilitation after treatment for specific injury are limited, and experimental design is challenging, given the highly individual nature of orthopaedic injuries, and the tendency for co-existing lameness.
“Large, multi-centre retrospective case studies might offer the best means of learning more regarding optimal use of water treadmill exercise for rehabilitation.”
The group suggested that standardization of reporting of protocols with respect to water depth, belt speed, duration and frequency of exercise would increase the opportunity for studies of this nature.
Nankervis, K.; Tranquille, C.; McCrae, P.; York, J.; Lashley, M.; Baumann, M.; King, M.; Sykes, E.; Lambourn, J.; Miskimmin, K.-A.; Allen, D.; van Mol, E.; Brooks, S.; Willingham, T.; Lacey, S.; Hardy, V.; Ellis, J.; Murray, R. Consensus for the General Use of Equine Water Treadmills for Healthy Horses. Animals 2021, 11, 305. https://doi.org/10.3390/ani11020305