Influence of Aquatic Exercise on Postural Sway Characteristics in a Model of Equine Carpal Osteoarthritis

Underwater treadmill exercise significantly improved balance control in horses with experimentally induced carpal osteoarthritis under varying stance conditions. Authors’ addresses: Orthopaedic Research Center, Department of Clinical Sciences (King, Haussler, Kawcak, McIlwraith, Frisbie) and Department of Health and Exercise Science (Reiser), Colorado State University, Fort Collins, CO 80523; e-mail: Melissa.King@colostate.edu.

1. Introduction

Exercising in water provides an effective medium for increasing joint mobility, increasing muscle activation, promoting normal motor patterns, and reducing the incidence of secondary musculoskeletal injuries. The improved muscle strength and function associated with aquatic exercise significantly improve proprioception and motor control and reduce the abnormal postural sway characteristics typically reported in osteoarthritic adults.

2. Materials and Methods

Osteoarthritis was induced in one middle carpal joint of 16 horses. Horses were assigned to either underwater or overground (without water) treadmill exercise. Force platforms were used to collect postural sway data from each horse at four different time points. Horses were made to stand stationary on the force platforms under 3 stance conditions: normal square stance, base-narrow placement of the thoracic limbs, and removal of visual cues (blindfolded). 

3. Results

Displacement of the center of pressure differed significantly depending on the stance condition. Among horses exercised on the underwater treadmill, postural stability in both the base-narrow and blindfolded stance conditions improved in comparison to the overground treadmill exercised horses. Horses exercised on the overground treadmill were only effective at maintaining a stable center of pressure during the normal stance position.

4. Discussion

Variations in stance position had profound effects on the mechanics of standing balance in horses with experimentally induced carpal joint osteoarthritis. Underwater treadmill exercise significantly improved the horses’ postural stability, which is fundamental to providing evidence-based support for equine aquatic therapy.

Acknowledgments

Conflict of Interest

The Authors declare no conflicts of interest.