Research at the Equine Orthopaedic Research Center at Colorado State University investigating the functional, biomechanical, and cellular effects of aquatic therapy on diminishing the progression of osteoarthritis show that aquatic therapy is a viable therapeutic option in managing OA in horses.
Benefits for horses with osteoarthritis
Aquatic therapy is a viable therapeutic option in managing osteoarthritis in the limbs of horses.
Using an experimental model within the equine middle carpal joint also known as the knee, the results of the study provided an objective assessment of the pathologic characteristics associated with OA and the clinical and disease-modifying effect allied with aquatic therapy.
Multiple variables were assessed in this study including clinical lameness exams and knee joint range of motion, magnetic resonance imaging, weight bearing forces and muscle activation patterns, alteration in balance control and assessment of cellular changes within the joint.
Analysis of the biomechanical data revealed that the amount of weight bearing that each horse applied to the front limbs remained symmetrical in those horses exercised in the underwater treadmill.
However, the control horses (no underwater treadmilling) demonstrated unequal front limb loading as the limb with induced knee OA bore significantly less weight than the non-OA limb. Similarly, the muscle activation patterns within select front limb muscles remained symmetrical between the front limbs in the aquatic therapy horses, while the control horses had a significant delay in muscle activation of the OA affected front limb.
Clinically, range of motion within the knee of the horses exercised in the underwater treadmill was significantly improved one week after starting underwater treadmill exercise and this improvement continued throughout the remainder of the study.
At the conclusion of the study, the range of motion within the OA affected knee in those horses exercised in the underwater treadmill had returned to the measurement taken before creation of OA, which was not the case for the control group.
MRIs demonstrated less scarring within the OA affected knee of horses exercised in the underwater treadmill compared to the control horses OA affected knee.
In addition, there was a significant reduction in the amount of inflammation present within the synovial lining of those horses exercised in the underwater treadmill; however, this was not the case in the control group.
In addition, this study demonstrated that underwater treadmill exercise significantly improves overall balance control under varying stance conditions in horses with knee OA.
Aquatic therapy for the management of knee OA demonstrated enhanced balance control, both clinical sign and disease-modifying improvements, evenly distributed front limb weight bearing and symmetrical timing of select front limb musculature.
Overall, results from this study indicate that underwater treadmill exercise is a viable therapeutic option in managing OA in horses. Furthermore, this work provides a considerable contribution to the field of equine rehabilitation as it is one of the first studies to provide evidence-based support for equine aquatic therapy.
This study was the Ph.D. project of Dr. Melissa King working with Drs. Haussler, Kawcak and McIlwraith together with Dr. Raoul Reiser of the Department of Health and Exercise Science.
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