Dr David Marlin over zadelstijfheid; boomzadels en boomloze zadels
OOrigineel bericht: https://www.facebook.com/DrDavidMarlin/posts/pfbid06tfDSR2TLWFksgXUB82Zg64pzxc8MtNuQKL4K6j3SoG7QQCHocXCRunDXtWK8pPPl
***LET’S TALK ABOUT SADDLE STIFFNESS ***Pretty much all the saddles we use fall into two categories – those with a tree and those without. Such a polarised position. When faced with such a situation this should suggest to us that there are advantages and disadvantages to both i.e. neither is ideal. And one major factor behind this I would suggest comes down to saddle stiffness. Stiffness is the extent to which something bends or deforms under load. The opposite of stiffness is flexibility or compliance.If you have ever picked up a conventional tree’d saddle and tried to bend it from cantle to pommel you will know they are quite hard to bend. This means they are relatively stiff. They are also relatively stiff across the gullet (pommel). The stiffness comes primarily, around ¾ of the total, from the tree with some contribution from the webbing. The rest of the stiffness comes from the leather and foam or wool. How do we know this? Because it’s something that can be measured: if a saddle is loaded with weight and the amount the saddle deforms is measured then we can calculate the stiffness. The loading can either be in the seat or across the stirrups to measure stiffness when in a 2-point position. By comparison, treeless saddles are much easier to bend – they are less stiff (more flexible).So what are the advantage and disadvantages of stiffness and flexibility? Let’s start with a conventional tree’d saddle. Because the saddle is stiff, the rider’s weight can be distributed more evenly over the horse’s back. But everyone is now shouting “what about those pressure mat images? they don’t look very even”. The reason these images are not perfectly even is because of a variety of factors including, rider position and movement, horse-back shape changes during locomotion and asymmetric and/or poorly fitting saddles.We also need to mention that when the horse and rider are moving we should really use the term force (weight x acceleration i.e. movement of horse and rider). So when moving riders effectively “weigh” 2-3 times more than they do when sitting still on a non-moving horse.A treeless saddle can conform better to the shape of the horse’s back. It can also move in close contact with the horse’s back as the horse’s back shape changes as it moves. This sounds perfect? But there is a limitation. It doesn’t distribute the rider’s weight as well as the tree’d (stiff) saddle. Also, when the rider adopts a 2-point or rising position, all the force is focussed across the gullet/withers.So treeless saddles are more flexible and accommodate the movement of the horse’s back better but don’t distribute rider forces as well. Tree’d saddles are stiffer and distribute forces better (more evenly) but don’t accommodate changes in the horse-back shape during locomotion. Neither is therefore ideal. The ideal is a saddle that accommodates changes in back shape as the horse moves AND a saddle that distributes rider forces evenly. But they don’t exist………
His comment on barebackriding
Dr David MarlinCOMMENT – A few people have mentioned bareback riding and one person posted a video. Bareback would allow the horse’s back to potentially move more naturally, although the rider is often more unstable at trot and canter when bareback. In addition, the riders weight is focussed onto the horse through their seat bones generating high localised pressure which is likely to be uncomfortable for the horse.