Preliminary report into the function of the shoulder using a novel imaging and motion capture approach

Summary Reasons for performing study: The function of the forelimb is fundamental to understanding both sound and pathological locomotion. The precise movements of the equine shoulder are hidden by layers of skin and muscle and hence the shoulder is normally modelled as a simple pivot during locomotion which assumes that any translational motion is negligible. Objectives: To record and quantify the sliding motion of the scapula during locomotion, using a novel imaging technique. Methods: Scapula motion during locomotion in the horse was calculated by tracking the ripple of the shoulder blade's movement under an array of markers placed over the soft tissue. Results: Interstride variability was low. Sliding of up to 80 mm in the plane of progression (cranio‐caudal) was observed; however, the limits of motion varied by