Quantitative comparison of pressure distribution exerted by different numnahs beneath the saddle of a ridden horse

Equine lameness and back pathologies are significant welfare issues and may be linked to saddle-fit during ridden exercise. Previously 74.3 % of animals presenting orthopaedic back pathology were shown to be concurrently lame and conversely, 41.1 % of horses diagnosed with primary lameness exhibited back pathology (Landman et al., 2004). Meschan et al., (2007) defined optimum saddle fit as those that transmitted lowest overall force and distributed force without generating pressure peaks. Incorrectly fitting saddles exert pressure peaks, for example overlying the longissiums dorsi in the caudal third of the contact. Numnahs are soft, cushion structures placed beneath the saddle to help dissipate the pressure of the saddle and rider over the horse’s back, away from the spinal area. They have been demonstrated to increase overall back pressure in a qualitative preliminary study (Harman, 1994). The present study determines quantitatively the effect upon pressure distribution between different numnahs using a pressure sensor mat.