Water Treadmill Rehab in Horses: Pros, Cons, and Case Selection

Water treadmills are everywhere in equine rehab and sport-horse programs—and they can be incredibly helpful. But they’re not a one-size-fits-all “easy workout.”

What the research shows is this: a water treadmill changes how a horse moves, and those changes depend on things like water depth, belt speed, water temperature, and the individual horse’s way of moving (their “movement strategy”).

In other words, how you use it matters just as much as using it.

Why water treadmills can be a great rehab tool

1) They can reduce impact through buoyancy

As water gets deeper, it helps “float” part of the horse’s body weight. Reduced body weight can reduce the stress traveling up the limbs and joints. In order to achieve buoyancy that is beneficial to reducing impact strain water height needs to be at least at the level of the pelvis. This depth is rarely reached in most programs that utilize a water treadmill.

• Additionally, at this depth of water lateral bending is reduced and horses adopt an altered pattern of movement which is usually contraindicated for most sport horses.

2) They can change stride mechanics and encourage more range of motion

Water creates resistance. Horses typically take slower, longer steps in water, and hindlimb mechanics can change depending on the depth and speed. Even walking/trotting through a water track (not a treadmill belt) changes stride timing and the way the limbs swing.

• Changes in biomechanics based on water depth:

1. Pelvic flexion increased vs baseline at most water depths (anything deeper than hoof level)

2. Axial rotation increased at carpal (knee) depth and higher.

3. Lateral bending decreased at highest depths (elbow/shoulder)

3) They may help the back and pelvis move differently (sometimes for the better)

One controlled water treadmill study found that, at certain depths, horses showed more pelvic flexion and more rotation through the back, which can be helpful for horses that move stiffly through the topline—if the horse is using the treadmill with a good posture.

Used correctly, water work may support healthier topline and pelvic mechanics—but depth and posture are key.

• By week 40 of water treadmill use horses show adaptation:

  1. Horses showed increased limb protraction (limb moving forward) and decrease retraction (limb moving backward).

  2. Back mechanics alter: caudal thoracic (mid back) flexion-extension and lateral bend range of motion are greater compared to baseline (day 0).

4) Horses adapt over time (which can be good)

A longer observational study (40 weeks) showed horses can adapt their movement patterns with regular water treadmill use, including measurable changes in how the limbs and back move over time.

• Water depth remains the dominate driver of movement changes, but frequency of water treadmill sessions, prior experience, and the way the sessions are designed ie. water depth, belt speed, and frequency also influence the adaptations over time.

The downsides (and why the “right horse” matters)

1) Myth: deeper water = harder workout

Reality: deeper water can reduce workload because buoyancy unloads body weight. In many cases, shallower water can actually be more demanding—more resistance, less unloading. A horse can get tired (or sore) in shallow water even if the session looks “easy.”

2) It can reinforce the wrong posture

We discussed negative posture a lot in the swimming post. Some horses respond to the water treadmills in the same way due to the chest bar, cross-tie setup, or their dislike of water splashing in their faces.

Some horses respond to water work by:

• bracing and hollowing

• elevating the head/neck

• pushing through the shoulders

• tightening through the back

  
  

At very high water levels, some back motion patterns can also change (for example, reduced side-to-side bending in one study at the highest depths). And in real-world reports, operators have seen stiffness, lameness flare-ups, and movement pattern changes after water treadmill use. If a horse looks tense and hollow in the treadmill, we may be practicing the exact compensation we’re trying to fix.

3) Skin, hoof, and safety issues are common enough to take seriously

In an international survey, the most commonly reported issues were skin problems, and facilities also reported horse and handler injuries. Water treadmill work needs good management—clean water practices, skin checks, hoof/frog care, and safe handling.

4) Horses need time to get used to it

Studies and real-world protocols both emphasize habituation (a learning period). Heart rate and stride variables can take multiple sessions to stabilize. Many facilities use 2–3 habituation sessions, gradually increasing depth.

Who is a good candidate for water treadmill rehab?

At Kinetic Equine Medicine, water treadmill work tends to be most helpful when the goal is one of these:

1) Controlled reconditioning for select tendon/suspensory cases

Only after a veterinarian has cleared the horse for that stage of rehab. Water can help us introduce controlled movement without immediately adding full rider weight and variable footing.

2) Horses that need movement without a rider

This includes many “body lameness” patterns—horses that are stiff through the back/pelvis or guarding their topline—if the horse can move through the treadmill with a healthy posture.

3) Horses who benefit from predictable, measurable exercise

Water treadmill sessions are adjustable and repeatable: depth, speed, time. That makes it easier to control the dose and track progress.

Who is NOT a great candidate (or needs a different plan first)?

We’re cautious with:

• Horses that can’t stay relaxed and safe in the treadmill (anxiety and reactivity raise risk)

• Horses with fragile skin/hoof health or recurring dermatitis/mud-fever issues

• Horses that consistently brace/hollow in water (we address comfort, mobility, and basics first)

• Owners hoping water treadmill = fitness replacement (research suggests it’s typically low–moderate intensity and should complement, not replace, proper conditioning)

• Horses with unresolved neck, back, or pelvic pain. Because water treadmills can lead to bracing through the neck and increased flexion through the back, horses with current back pain can and often do become more painful during water treadmill session.

  
  

How we think about using a water treadmill at KEM

1. Start with the goal (reduce loading, rebuild stride quality, improve topline strategy, etc.)

2. Pick the depth intentionally (because depth changes mechanics)

3. Habituate first (calm, consistent sessions before “work”)

4. Monitor closely (posture, soreness, skin/hoof health, and whether the movement changes match the rehab goal). This is probably the most important part of any water treadmill session. Having operators who can analyze and respond to the earliest signs of fatigue in a horse and stop the session instead of operating on a time standard.

   
   

Bottom line

A water treadmill can be an excellent tool—when the program fits the horse. The best outcomes come from matching depth + speed + duration to the diagnosis, and making sure the horse is moving in a way that supports healing instead of compensation. Water treadmill exercise should not be a "menu" item added on at a rehabilitation center, it should be specifically selected and used to help correct, strengthen, and improve certain conditions under strict guidance.

References

• Mooij, M. J. W., et al. “Biomechanical Responses of the Back of Riding Horses to Water Treadmill Exercise.” The Veterinary Journal, vol. 198, 2013, pp. e120–e123. https://doi.org/10.1016/j.tvjl.2013.09.045.

• Nankervis, Kathryn, et al. “Kinematic Responses to Water Treadmill Exercise When Used Regularly within a Sport Horse Training Programme: A Longitudinal, Observational Study.” Animals, vol. 14, no. 16, 2024, article 2393. https://doi.org/10.3390/ani14162393.

• Tranquille, Carolyne A., et al. “Current Knowledge of Equine Water Treadmill Exercise: What Can We Learn from Human and Canine Studies?” Journal of Equine Veterinary Science, vol. 50, 2017, pp. 76–83. https://doi.org/10.1016/j.jevs.2016.10.011.

• Tranquille, Carolyne A., et al. “International Survey of Equine Water Treadmills—Why, When, and How?” Journal of Equine Veterinary Science, vol. 69, 2018, pp. 34–42. https://doi.org/10.1016/j.jevs.2018.05.220.

• van Donk, Meike. The Effects of Water on Limb and Upper-Body Kinematics in Horses Walking and Trotting in a Water Track. Utrecht University, 2022.