The dynamic 3D horse: analyzing the relationship between whole body pathomechanics and joint degeneration in the fetlocks

Lameness is often associated with degenerative joint disease (DJD). Current therapies focus on minimizing pain or treating specific lesions but generally do not address the pathomechanical forces that are the root cause of degeneration. Treatments based on specific, whole-body therapies are becoming common in humans with DJD, but are still not routinely applied in equine cases. Designing targeted therapies for horses requires recognizing habitual postures and movements that are pathological. An important but often missing component for understanding movement postures is accurate and manipulatable anatomical models. In this case study, a three-dimensional model of a horse based on CT data is manipulated using advanced imaging and animation software Autodesk® Maya® to demonstrate the habitual working posture of a horse with DJD of the fetlock joints before, during, and after the application of a whole-body exercise regime focused on rebalancing the forces negatively impacting the hindlimbs. The horse's movement postures throughout the targeted therapy are compared by assessing qualitative and quantitative changes in spinal curvature and fetlock joint angles. This case study serves as proof of concept for the feasibility of modeling working postures before and after rehabilitative therapy for the purpose of demonstrating the effects of physical therapy or training programs. It also provides an example of how data obtained from advanced imaging techniques like computed tomography can be used for veterinary medical breakthroughs that are based on rethinking: (1) the relationship between equine posture/movement and pathological conditions of the musculoskeletal system and (2) related training and rehabilitative strategies.