Functional kinematics of the equine back

Abstract

The back is the structure that links the four extremities and is central to the entire equine musculoskeletal system. From a gait analysis viewpoint the back has long been considered a rather rigid and static structure, but more recently the insight has gained ground that back dynamics are essential to equine performance. Motion patterns of thoracolumbar vertebrae are, however, characterised by small ranges of movements, which makes it difficult to measure back kinematics accurately. The facts that the motion patterns of the thoracolumbar vertebrae are intricately linked due to anatomical constraints and that the vertebrae are difficultly accessible make the technical problems worse, but in the last decade much progress has been made. Invasive experiments have permitted the development of computer programmes that enable the accurate assessment of spinal movement from non-invasive skin markers and the basic kinematic motion patterns in the live horse have been established. Recent research focuses at the relationship between lameness and back pain, on saddle-related items, and on the relationship of back motility and performance. In the latter category back motion studies are also used to answer the question whether certain equestrian activities can be considered harmful or not from a biomechanical viewpoint. It can be expected that the rapid technological developments will lead to an increase in (applied) research into back motion with a possible emphasis on the effects of riding and handling of horses. Indirect mathematical reconstruction of movement (modelling) based on easily obtainable input parameters may to some extent replace the often-cumbersome current direct measuring techniques.