Water Treadmills for Horses: Science-Backed Rehabilitation and Conditioning

Water treadmills have become an increasingly popular tool in both equine rehabilitation and performance conditioning. By combining the principles of buoyancy, resistance, and controlled locomotion, they offer a low-impact, high-benefit exercise modality that targets strength, flexibility, coordination, and recovery.

🔍 What Is a Water Treadmill?

A water treadmill is a specially designed treadmill housed within a tank that can be filled to various depths with temperature-controlled water. Horses walk (and occasionally trot) on a moving belt submerged in water, with customisable settings for speed, incline, and water level.

Key Benefits

Effects on Low-Impact Loading in Horses

1. Buoyancy Reduces Weight Bearing Water reduces vertical ground reaction forces (vGRF) by supporting a portion of the horse’s body weight. This results in lower impact forces on joints, tendons, and hooves—especially beneficial during rehabilitation.

2. Shock Absorption Through Water Resistance The water acts as a natural shock absorber, dampening the concussive load that typically occurs during hoof strike on solid ground. This creates a safer exercise environment for horses recovering from lameness, joint disease, or soft tissue injuries.

3. Joint-Friendly Conditioning Horses can maintain or build fitness without the repetitive concussive stress of land-based locomotion. Particularly valuable for conditions like arthritis, navicular disease, or chronic laminitis, where minimizing load is critical.

4. Variable Load Based on Water Depth The deeper the water, the greater the buoyant effect, resulting in progressively reduced limb loading. Shallow water provides mild offloading, while stifle- or hip-depth water can reduce loading by up to 60% or more, depending on the horse's conformation.

🧪 Research Support

• Takahashi et al. (2005): Found significant reduction in peak ground reaction forces in equine limbs as water depth increased.

• Scott et al. (2010): Demonstrated reduced loading rates and longer stance durations, indicating gentler impact forces.

• Greco-Otto et al. (2020): Observed improved spinal and pelvic motion with reduced limb loading, supporting safe rehabilitation.

🟢 Clinical Implications

• Post-Injury Rehab: Ideal for horses recovering from tendon, ligament, or joint injuries without risk of re-injury due to impact.

• Arthritis Management: Maintains fitness and joint range without aggravating degenerative joint conditions.

• Preventative Training: Can be used for off-season conditioning to maintain fitness with reduced risk of overload or concussion injuries.

⚠️ Considerations

Water depth is the primary determinant of offloading:

• Fetlock-deep: ~10–20% load reduction

• Carpus-deep: ~30–40%

• Stifle-deep: ~50–60%

• Hip-deep: ~60–70%+

Use caution with very deep water in horses with balance deficits or spinal issues—it increases core effort. Horses should be monitored closely to ensure even gait patterns, as compensatory movements may still occur.

Effects on Range of Motion (ROM) in Horses

1. Increased Limb Flexion Water resistance and buoyancy reduce limb loading and encourage greater flexion of joints, particularly in the carpus, tarsus, and stifle. Horses often show enhanced joint articulation as they work to overcome water resistance during swing and stance phases.

2. Enhanced Hindlimb Engagement Horses tend to protract and retract the hindlimbs more actively in water, promoting increased ROM in the hip and stifle joints. This is particularly beneficial for strengthening the hindquarters and addressing asymmetrical gaits.

3. Improved Spinal Mobility Studies have noted increased spinal flexion and extension, especially in the thoracolumbar region, due to the horse’s effort to maintain posture and forward momentum in water. This helps improve overall back flexibility and coordination.

4. Water Depth and Speed Modulate ROM Deeper water levels generally lead to greater ROM due to increased buoyancy and resistance. Treadmill speed and incline can also be adjusted to target specific joints and motion patterns.

🧪 Research Support

• Greco-Otto et al. (2017, 2019): Demonstrated increased stride length and flexion angles of the carpus and stifle in horses walking in water compared to dry treadmill walking.

• Tokuriki et al. (1999): Found enhanced joint angles and limb kinematics in water treadmill locomotion, especially at moderate depths.

• Nankervis et al. (2010): Reported improved thoracolumbar spinal motion when horses walked in water, indicating improved axial ROM.

🟢 Clinical Implications

• Rehabilitation: Especially useful for horses recovering from joint stiffness, post-surgical immobility, or neurological conditions.

• Performance Training: Helps increase flexibility, important for disciplines requiring agility and suppleness (e.g., dressage, jumping).

• Symmetry Correction: Promotes balanced use of both sides of the body, reducing compensatory movement patterns.

⚠️ Considerations

Optimal water depth varies by horse and therapeutic goal:

• Fetlock-deep: minimal ROM change

• Carpus-deep: moderate joint flexion increase

• Stifle-deep: maximal joint flexion, higher resistance

Monitoring is essential to avoid fatigue or overstretching in unfit or recovering horses. Should be used in conjunction with dryland work for functional transfer of improved ROM to regular training.

Effects on Postural Stability in Horses

1. Improved Core Activation The buoyancy of water reduces weight-bearing and encourages core muscle engagement. This can help strengthen postural muscles, particularly along the back and abdomen, improving overall balance and stability.

2. Controlled Instability Stimulus Water movement creates an unstable environment that the horse must adapt to. This instability can challenge the proprioceptive system, leading to better neuromuscular control and dynamic postural adjustments.

3. Reduced Impact with Enhanced Muscle Recruitment Water treadmills decrease concussive forces on joints while still requiring muscle activity for movement and balance. This allows for safe strengthening of stabilizing musculature, especially beneficial in horses recovering from musculoskeletal injuries.

4. Increased Proprioceptive Feedback Water resistance stimulates sensory receptors in the limbs and skin. Enhanced sensory feedback contributes to better body awareness and postural coordination.

🧪 Research Support

• Greco-Otto et al. (2020): Found that walking in water improves trunk and pelvic stability and symmetry, key components of postural control.

• Mendez-Angulo et al. (2014): Noted significant changes in stride parameters and spinal motion, suggesting beneficial effects on postural adaptation.

🟢 Clinical Implications

• Rehabilitation: Ideal for horses with back pain, neurological deficits, or recovering from lameness.

• Conditioning: Improves overall muscle tone, especially in core stabilizers, aiding balance in sport horses.

• Preventative Training: Enhances proprioception and may reduce the risk of injury by improving stability under dynamic conditions.

⚠️ Considerations

Water depth is crucial: Shallow water offers more joint load, deeper water promotes buoyancy and resistance. Not all horses respond equally—individual differences in conformation, injury, and fitness must be considered. Should be integrated into a balanced training program, not used in isolation.

Effects on Equine Fitness

1. Cardiovascular Conditioning Water treadmill exercise, especially at moderate speeds and shallower depths, can elevate heart rate and respiratory rate, contributing to improved aerobic capacity. Although not as intense as cantering or galloping on land, prolonged sessions can enhance cardiovascular efficiency.

2. Muscle Strength and Endurance Water resistance provides a continuous, low-impact strength stimulus, especially for hindlimbs, core muscles, and postural stabilizers. Horses develop muscular endurance from repeated resistance-based motion, particularly in deeper water or longer sessions.

3. Core and Trunk Stability Maintaining posture in moving water requires engagement of deep abdominal and spinal muscles. This supports improvements in core stability, essential for balance, straightness, and performance in all disciplines.

4. Increased Flexibility and Joint Mobility By promoting greater range of motion in limbs and spine, water treadmill sessions also contribute to functional mobility, supporting athletic movement and reducing injury risk.

🧪 Research Support

• Tokuriki et al. (1999) and Greco-Otto et al. (2017): Found improved stride symmetry, hindlimb activity, and joint flexion, contributing to improved fitness mechanics.

• Nankervis et al. (2006): Reported cardiovascular and muscular benefits with regular water treadmill use.

• Scott et al. (2010): Noted increased muscle activation in the gluteals, longissimus dorsi, and abdominal muscles without increased joint stress.

🟢 Clinical and Athletic Implications

• Cross-Training: Complements land-based exercise by improving fitness without additional impact load.

• Rehabilitation: Maintains or restores fitness in injured horses, minimizing deconditioning during recovery.

• Discipline Versatility: Benefits all performance types—dressage, eventing, racing, and western disciplines—through improved flexibility, strength, and stamina.

⚠️ Considerations

Water treadmill training is generally low to moderate intensity. For high-intensity cardiovascular conditioning, combine with land-based exercise. Fitness gains depend on frequency, water depth, speed, and duration of sessions. Careful monitoring is required to prevent fatigue and ensure progressive conditioning.

🏥 Clinical Applications of Water Treadmill for Horses

The water treadmill is a valuable tool in equine veterinary practice and rehabilitation, offering a versatile, low-impact exercise option with wide-ranging clinical benefits. Its ability to reduce joint stress while maintaining or improving musculoskeletal function makes it ideal for managing both acute and chronic conditions.

🔍 Key Clinical Applications

1. Orthopaedic Rehabilitation

• Tendon and Ligament Injuries

  • Progressive, controlled loading of flexor tendons, suspensory ligaments, and check ligaments

  • Buoyancy helps reduce strain while promoting correct limb use during healing

  • Example: Superficial digital flexor tendon rehabilitation

• Joint Disease / Osteoarthritis

  • Reduces concussive loading on affected joints

  • Maintains limb motion and joint lubrication

  • Particularly beneficial in carpal, hock, and fetlock arthritis

2. Back and Pelvic Conditions

• Improves thoracolumbar flexion, spinal alignment, and core stability

• Used in recovery from kissing spines (overriding dorsal spinous processes) or sacroiliac dysfunction

• Promotes even, symmetrical use of the hindlimbs and pelvis

3. Post-Surgical Recovery

• Facilitates early mobilization once wounds are closed and tissue healing is underway

• Ideal for arthroscopy recovery, fracture repair, or soft tissue surgeries

• Offers controlled reintroduction of exercise in a hydrotherapeutic environment

4. Neurological Rehabilitation

• Encourages proprioceptive feedback and neuromuscular re-education

• Useful in mild-to-moderate cases of ataxia, stringhalt, or nerve injury (if horse is safe to balance)

• Stimulates coordinated movement in a safe, supportive medium

5. Muscle Atrophy and Deconditioning

• Helps restore muscle mass in horses after extended stall rest

• Builds strength in gluteal, paraspinal, and abdominal muscles

• Reduces asymmetry between left and right muscle groups

6. Obesity and Metabolic Management

• Offers low-load aerobic exercise for overweight horses or those with Equine Metabolic Syndrome (EMS)

• Supports safe conditioning without undue joint stress

• May be combined with dietary programs to assist in weight loss and insulin sensitivity

7. Laminitis Recovery (Subclinical or Chronic)

• Allows gentle, supportive movement without overstressing the deep digital flexor tendon or laminae

• Encourages circulation and limb use during controlled rehabilitation

• Only appropriate in chronic, stabilized stages and under strict veterinary supervision

8. General Fitness Maintenance During Injury or Rest

• Helps maintain cardiovascular function and muscular tone in horses that can’t perform regular ridden or turnout work

• Reduces risk of compensatory injuries during lay-up periods

• Used in pre-return-to-training phases across all disciplines

🧪 Research Support

• Greco-Otto et al. (2020): Water treadmill improves trunk and pelvic symmetry—key in spinal rehab.

• Scott et al. (2010): Showed safe kinematic changes during limb loading, beneficial post-injury.

• Takahashi et al. (2005): Demonstrated reduced limb loading, supporting laminitic and arthritic cases.

🟢 Integrated Clinical Use

Water treadmills are most effective when included in a multi-modal rehab plan, alongside:

• Veterinary evaluations and imaging

• Physiotherapy (stretching, manual therapy, laser)

• Groundwork and in-hand exercises

• Patient monitoring and outcome tracking

⚠️ Contraindications for Water Treadmill Use in Horses

While the water treadmill offers many benefits in conditioning and rehabilitation, certain medical, orthopaedic, and behavioural conditions can make its use unsafe or counterproductive.

🔴 Key Contraindications

Open Wounds or Infections

Skin lacerations, surgical incisions, or hoof abscesses can become contaminated despite water filtration.

Risk of delayed healing, infection, or worsening of the wound.

Avoid use until full epithelial healing has occurred.

Uncontrolled or Severe Lameness

Horses with non-weight-bearing lameness or active pain may adopt compensatory gaits in water, increasing the risk of further strain or imbalance.

Water may mask lameness temporarily, leading to misjudgment of recovery.

Use only under veterinary supervision if mild lameness is present.

Severe Neurological Deficits

Horses with ataxia, incoordination, or proprioceptive deficits may not be able to balance or walk safely in water.

Risk of stumbling, falling, or panic responses is significantly increased.

Contraindicated unless carefully monitored in specialised rehabilitation settings.

Cardiopulmonary Compromise

Conditions like heaves (RAO), congestive heart failure, or severe respiratory disease may be exacerbated by:

• Hydrostatic pressure on the thorax

• Increased exertion or anxiety in water

Exercise tolerance must be evaluated by a vet prior to use.

Severe Behavioral Issues or Claustrophobia

Horses that are panicky, reactive, or aggressive in confined environments may be unsafe on a water treadmill.

Risk of injury to the horse or handlers during water filling, belt movement, or loading.

Must be trained gradually or excluded from use altogether.

Recent Surgery (Early Post-Op Phase)

Horses post-orthopaedic or abdominal surgery should avoid immersion until:

• Wound is fully closed

• Surgeon approves water therapy

Water pressure may alter circulation or scar development in healing tissues.

Unresolved Skin Conditions

Issues like pastern dermatitis (scratches), rain scald, or fungal infections can worsen with prolonged water exposure.

Ensure proper dermatological treatment and clearance before use.

🧪 Supporting Evidence

Scott et al. (2010) and Nankervis et al. (2006): Emphasised the importance of screening for pre-existing conditions prior to hydrotherapy.

Clinical practice guidelines recommend caution with neurologic horses, and post-op management protocols often delay aquatic exercise until late-stage healing

🟡 Use with Caution (Relative Contraindications)

Condition	Recommendation
Mild osteoarthritis	Vet guidance and controlled sessions
Low-grade tendon injury (late phase)	Start shallow, progress slowly
Equine obesity	Low-impact conditioning, monitor joints
Behavioral issues (mild)	Gradual desensitization

Conclusion

Water treadmills are a powerful, science-backed modality for equine rehab and conditioning. They offer measurable benefits in reducing limb loading, increasing ROM, strengthening core/back muscles, and supporting aerobic capacity. However, careful planning, individualised protocols, and integration with land-based work are essential to achieve safe, effective outcomes.

In summary, water treadmill exercise offers a multifaceted approach to rehabilitation, training, and conditioning by simultaneously reducing impact loads, enhancing joint mobility, improving postural stability, and promoting cardiovascular and muscular fitness in horses.

When properly prescribed and monitored, it is an invaluable tool in modern equine sports medicine.

📚 References

• Greco-Otto, P., Bond, S., Hodson, E., and Warren-Smith, C., 2017. Effect of water treadmill exercise on joint kinematics in horses. Equine Veterinary Journal, 49(4), pp.486–492. https://doi.org/10.1111/evj.12642

• Greco-Otto, P., Bond, S., Nankervis, K., and Warren-Smith, C., 2019. Influence of water height on limb and back kinematics during water treadmill exercise in horses. Equine Veterinary Journal, 51(2), pp.220–226. https://doi.org/10.1111/evj.12995

• Greco-Otto, P., Bond, S., Warren-Smith, C., and Nankervis, K., 2020. Effect of water treadmill exercise on equine back kinematics and symmetry. Journal of Equine Veterinary Science, 92, 103175. https://doi.org/10.1016/j.jevs.2020.103175

• Nankervis, K., Wright, M., and Ellis, M., 2006. The use of water treadmills in equine rehabilitation and training. Comparative Exercise Physiology, 3(4), pp.171–175. https://doi.org/10.1017/S1478061506000269

• Nankervis, K., Murray, R., and Brown, S., 2010. Back movement in horses during water treadmill exercise. Equine and Comparative Exercise Physiology, 7(4), pp.169–174. https://doi.org/10.1017/S1478061510000185

• Scott, M., Nankervis, K., and Marlin, D., 2010. The effect of water treadmill exercise on equine limb kinematics. Equine Veterinary Journal, 42(S38), pp.662–668. https://doi.org/10.1111/j.2042-3306.2010.00218.x

• Takahashi, T., Hada, T., Ishihara, A., and Aoki, T., 2005. Effect of water depth on limb kinematics of horses walking in a water treadmill. Journal of Equine Science, 16(1), pp.17–23. https://doi.org/10.1294/jes.16.17

• Tokuriki, M., Aoki, O., and Yamada, H., 1999. Electromyographic and kinematic studies of walking in water in Thoroughbred horses. Journal of Equine Science, 10(3), pp.29–38. https://doi.org/10.1294/jes.10.29