title: Relationship between the forces acting on the horse's back and the movements of rider and horse while walking on a treadmill.
abstract: BACKGROUND
  The exact relationship between the saddle pressure pattern during one stride cycle and the movements of horse and rider at the walk are poorly understood and have never been investigated in detail.
  
  
  OBJECTIVE
  The movements of rider and horse account for the force distribution pattern under the saddle.
  
  
  METHODS
  Vertical ground reaction forces (GRF), kinematics of horse and rider as well as saddle forces (FS) were measured synchronously in 7 high level dressage horses while being ridden on an instrumented treadmill at walk. Discrete values of the total saddle forces (FStot) were determined for each stride and related to kinematics and GRF. The pressure sensitive mat was divided into halves and sixths to assess the force distribution over the horse's back in more detail. Differences were tested using a one sample t test (P < 0.05).
  
  
  RESULTS
  FStot of all the horses showed 3 peaks (P1-P3) and 3 minima (M1-M3) in each half-cycle, which were systematically related to the footfall sequence of the walk. Looking at the halves of the mat, force curves were 50% phase-shifted. The analysis of the FS of the 6 sections showed a clear association to the rider's and horse's movements.
  
  
  CONCLUSIONS
  The saddle force distribution during an entire stride cycle has a distinct pattern although the force fluctuations of the FStot are small. The forces in the front thirds were clearly related to the movement of the front limbs, those in the mid part to the lateral flexion of the horse's spine and the loading of the hind part was mainly influenced by the axial rotation and lateral bending of the back.
  
  
  CONCLUSIONS
  These data can be used as a reference for comparing different types of saddle fit.
authors.affiliation: Equine Department, Vetsuisse Faculty University of Zurich, CH-8057 Zurich, Switzerland.
authors.forename: K
authors.initials: K
authors.lastname: von Peinen
authors.forename: T
authors.initials: T
authors.lastname: Wiestner
authors.forename: S
authors.initials: S
authors.lastname: Bogisch
authors.forename: L
authors.initials: L
authors.lastname: Roepstorff
authors.forename: P R
authors.initials: PR
authors.lastname: van Weeren
authors.forename: M A
authors.initials: MA
authors.lastname: Weishaupt
mesh_terms: D000818:Animals; D001415:Back / Q000502:physiology*; D001696:Biomechanical Phenomena; D005080:Exercise Test; D006736:Horses / Q000502:physiology*; D009068:Movement / Q000502:physiology*; D016138:Walking / Q000502:physiology*