Understanding Rock

[daviD A Morris]

Adam,

Thanks for clearing that up about "fired muscle". Terminology vs slang can be a stumbling block.

Not sure what "a bar with a lot of ball" is referring to, sorry...new to this area.

What I call "ball" is the side to side rock of the bar. I have heard other also use the term. But here is one of the great problems slowing down the advancement of saddle tree design - lack of some consistent terminology. It is making the communication very ineficient. however these forums are going to speed up the evolution of the terminology. The more we talk the quicker it will evolve.

To see a bar that has a lot of "ball" to it look at some of the older western saddle trees from back 1960 and earlier.

bye for now

dam

[David Genadek]

Adam,

I was trying to stay with in your bowl analogy when I said two hinges. You are correct to think in terms of many hinges as in each vertibrea being a hinge. There for the whole spine can be altered depending apon how it is acted apon. In this lies the rub. Does a saddle maker fit the horse as he is or should he fit tha actual back type the horse has. There is no right answer to this, it is a bussiness decision. If you make the choice to fit the actual back type you then have to have a team of people that can help the rider understand how they are effecting the conformation of thier horse. If you are more interested in the leather art portion of the saddlery world and you don't want all the hassle then you fit the horse as he is.

In your first post you prefaced your question from the Jineta perspective. From this perspective the rock will be closer to the base of the whither. In the Brida pholosphy the rock will be closer to the T14 postion as all these makers are talking about. The thing to understand is that if that portion of the back is the lowest point in the horses back It is highly likely that the rider is not getting engagement of the hind quarter or some other thing is causing the horse to operate his body upside down. Here is a link to Mustangs in the Pryor Mountains Here you can see a baseline for a given rib cage shape. Personally when I design a bar I design the rock for the baseline. At this point this is still largely a guess as no large amount of data has been collected and presented in a way that could be analized. Most of my business comes from people who are working with a skilled horseman who are addressing the horsemanship issues at the same time. We will often hold off on building a saddle until the horse has been taught to move right side up again at which time we can more accurately determine the ribcage and topline shape.

In regard to the Spinous process gaps limiting the downward movement of the back: I recently had a Client refered her from the U of Minnesota because her horse had Kissing spine. I can't remember the exact figure but she said the vet at the U had mentioned that over 70 percent of the horses out thier had some spinous process being fused together because of poor riding or poor care. To understand rock you need to understand collection then you need to get a handle on the ways that riding concepts can be distorted. Then you have to decide if you are in the Jineta or Brida camp. Clearly the popular thinking in the western tree design to day is in the Brida camp. So the age old argument goes on.

As for the rear of the bar I just flair the rear of it up a bit but I don't really consider it rock. I have found a correlation between rib cage shape and topline profile. In the end the twist rock and flair are all the same and they are just conceptual tools we use to understand the rates of change in the angles and thier directions as they pertain to a composite shape of a horse's back in movement.

David Genadek

Hi David,

Okay, that helps, but I guess my next thoughts concern where the flex "points" of those hinges would be.

For example, from Dr. Deb's writings and the dissection course I attended, I don't really recall there being much flexibility to the spine along the ribcage. But that said, "much" is relative. Can the area from around T12 back to the last rib be fitted with a rock that roughly equals what the back would allow when dropped (spinous process gaps limiting that)? Then, when the horse rounds up and releases the muscles of the topline, do those relaxed long back muscles "absorb" and conform to the rock that isn't technically ideal for the rounded condition?

As a result, is the rock at the back of the bar mainly designed to keep the skirt of a "western" saddle off the horse's back? (and by extension, would an "english" saddle with bars like a western saddle need any rock at the back end of the bar, given no skirt). Is rock at the front of the bar in excess of what the dropped back requires designed to account for scapula movement?

Lots of questions, sorry, but any help would be appreciated.

Adam

[AdamTill]

Does a saddle maker fit the horse as he is or should he fit tha actual back type the horse has. There is no right answer to this, it is a bussiness decision. If you make the choice to fit the actual back type you then have to have a team of people that can help the rider understand how they are effecting the conformation of thier horse. If you are more interested in the leather art portion of the saddlery world and you don't want all the hassle then you fit the horse as he is.

Well, that bit of the decision making process is easy - I make a decent enough living at the moment otherwise, and have no interest in the horse world from a business perspective. I worked in the hoofcare side of things part time for two years, and got a real eye opening lesson in how a lot of horse owners see their critters. The only thing that would prevent me from providing the best care for my horse that I can is the need to keep food on my own table and a roof over my head, but a lot of other horse owners seem to try to find the absolute cheapest way to do things (even while driving BMWs). I respect those willing to try to make a living from horsepeople, but have no interest in joining them So anything I make would be for my own use.

My first project will hopefully be an english-styled saddle with "western" style bars and seat like the one you made for the endurance saddle...possibly with the pommel, cantle, seat and bars molded from carbon fibre as a single unit. I'd like to learn what would be involved in making the flaps and seat using leather, but my first concern is shaping the underside of the bars.

I've been working with Alexandra Kurland (who studied with Bettina Drummond, Mr Oliviera's student) for a few years, and have also started clinicing with Josh Nichol on Dr. Deb's recommendation, so I'm happy that my horsemanship instructors are leading me in the right direction.

I'm also hoping that Dr. Deb's schedule allows for a skeleton assembly class up here this year, since the dissection class was so good last year. I've done a bunch of anatomy study via Equinology's courses (and am taking Dr. Ridgeway's saddle fit course this year), but being able to actually see and feel a psoas muscle vs learning "function, form and innervation" from a textbook, for example, was very helpful.

So, net result, I know enough anatomy to know how much anatomy I don't know. I'm just pretty new to thinking of it terms of saddle fit.

In your first post you prefaced your question from the Jineta perspective. From this perspective the rock will be closer to the base of the whither.

That would be because of a desire to get the rider's "center of motion" (or the average thereof) as close as possible to the horse's center of motion, correct? (and thus the sadde sits further forward)

In the Brida pholosphy the rock will be closer to the T14 postion as all these makers are talking about. The thing to understand is that if that portion of the back is the lowest point in the horses back It is highly likely that the rider is not getting engagement of the hind quarter or some other thing is causing the horse to operate his body upside down.

I didn't really read the other discussion regarding the low point of the back, but is placing the saddle on the horse's back so that the entire tree sits behind the scapula a brida concept? I had thought that the brida/jineta line was more to do with how the rider sits in the saddle (I have a copy of Conqueror's on order as well...just waiting for it to arrive).

Here is a link to Mustangs in the Pryor Mountains Here you can see a baseline for a given rib cage shape. Personally when I design a bar I design the rock for the baseline. At this point this is still largely a guess as no large amount of data has been collected and presented in a way that could be analized.

Most of my business comes from people who are working with a skilled horseman who are addressing the horsemanship issues at the same time. We will often hold off on building a saddle until the horse has been taught to move right side up again at which time we can more accurately determine the ribcage and topline shape.

I'll have to study those photos carefully...thanks for the link. Could you give a quick summary of a few of the points which you look at in seeing whether a back is healthy enough to accurately determine what it's proper shape might be?

In regard to the Spinous process gaps limiting the downward movement of the back: I recently had a Client refered her from the U of Minnesota because her horse had Kissing spine. I can't remember the exact figure but she said the vet at the U had mentioned that over 70 percent of the horses out thier had some spinous process being fused together because of poor riding or poor care.

I've heard statistics like that before...scary, but not overly surprising considering what's winning medals in just about every discpline (western or english) nowadays.

To understand rock you need to understand collection then you need to get a handle on the ways that riding concepts can be distorted. Then you have to decide if you are in the Jineta or Brida camp. Clearly the popular thinking in the western tree design to day is in the Brida camp. So the age old argument goes on.

I don't know all the differences between the two camps, but as a baseline I'd like to end up with a saddle that sits as close to the horse's "center of motion" as possible with without compromising shoulder movement but maintains sufficient support area under the bars, a rigging system that cradles the saddle evenly, and with a seating/stirrup arrangement that lets me sit in a balanced position (the "won't fall over backwards if the horse disappears" sort of balance).

As for the rear of the bar I just flair the rear of it up a bit but I don't really consider it rock. I have found a correlation between rib cage shape and topline profile. In the end the twist rock and flair are all the same and they are just conceptual tools we use to understand the rates of change in the angles and thier directions as they pertain to a composite shape of a horse's back in movement.

One of biggest concepts I'm struggling with the most is the degree of flexibility in the spin/rib cage that would factor into the bar design (ie the designing for movement part).

I understand the mechanics of collection, but horses don't always operate in a collected fashion if that describes a spinal shape with a "suppporting arch" (ie, highpoint in the middle, rather then lowpoint in the middle for a hollow back). I learned from Dr. Deb, for example, that in a true extended gait extension is actually defined by the spine oscillating between "arched" and "hollow" (to some degree), as opposed to standard gait which oscillates between arched and flat, or a collected gait which largely maintains the arched profile. That would still mean (in my mind) that some allowance has to be made for a "hollow" back...(ie) a bit more rock then a baseline, stationary back might otherwise show a need for. Is that how you think of things?

Thanks much!

Adam

[David Genadek]

Adam,

There are so many things that effect rock perhaps it would be best to begin with what effects it.

First let me say that everything I’m saying here is based on a horse in neutral position on level ground.

Let’s start with the concept of Orientation or how horizontal is the vertebral column. This is a very important concept in regard to saddle fit and it is largely ignored. We tell exactly where the spine is

Without an x-ray machine so what we will do is find easily identifiable points that give us a close idea. Dr Bennett came up with the whole x-ray vision concept a long time ago in regard to training horse judges and it has had a huge impact on the horse industry and can be of extreme value to the saddle maker. In this case we are trying to get a handle on where the actual vertebras are. You find the base of the neck which is pretty easy because it is where the neck gets really wide. Then you find the point of the hip and draw a line between them. This is what I call the line of Orientation (Photo spine 1). This is what tells you how downhill your horse might be, not the whither and croup as that can lie. Now we have a pretty good idea where the spine lies. Clearly this line is not always what we see on the top line however it is where the actual undulations in vertebral column that will be creating the range for the rock that you have been talking about in motion will occur.

In spine 2 I have changed the spines orientation by 5 degrees so you can get a handle on how it can affect the rock. You will also see a line drawing of a back in simplified form so you think about how the orientation will affect gullet width. To the side you will see side views of the simplified back in different orientations with a bar drawn in to show how this orientation line will affect the spread of the bars. If the seat is to be level then on a downhill horse (which most are today) then the saddle should be wider in the rear than the front. This concept will also affect how you view the rock of the saddle.

In spine 3 I have drawing the top line which is created by the lengths and angles of the spinal processes this is what is most often fit with no regard to the other influences. You can also see how the orientation affects this line. If the horse has been properly ridden so that the spine is still along the orientation line then this is not a problem but if you fit a horse whose spine has been pulled off that basic line for a multitude of reason then you will end up with a fit that will run into problem further down the road. I have not come up with an easy way to tell you if the spines basic line has been disrupted. Over the years and looking at thousands of horses you can tell by the muscles. Tightness in the top line and pockets behind the shoulders are good signs that the spines natural alignment has been effected by poor horsemanship. Here is the business decision for the saddle maker do you fit the horse as he is or as he should be?

Here is link to an article that Liz wrote that shows two horse’s with different conformations and how they need to be supported differently to achieve the same result. This is relevant to the topic of rock as it can help you understand how dependant the where and how the rock will be effected is on the overall conformation of the animal. The conformation will change which parts of the back will be affected the most in movement. When she refers to ventroflexed gaits she is talking about those gaits that require a hollowing of the spine as you mentioned from Debs perspecitve.

Here is a site with some good info on range of motion.

David Genadek

[Rod and Denise Nikkel]

On the whole, rock really isn’t that complicated. It is just a term (one of a number that are used) that means “the curve in the bar from the front to the back”. That is not an even curve by any means, but the term itself is a very general one and the concept is very straightforward.

As to the specifics of shape, again I come back to the basic fundamentals in building bars: #1) Don’t dig in anywhere, and #2) Have as much surface area on the horse as possible inside the bounds of #1. So you don’t want the saddle to consistently bridge, because that will cause soreness at the front and over the loin which can have severe ramifications. And you don’t want excess rock where the length of the bar, with the exception of the edges and ends where relief is built it, cannot contact the back. In that case the rider’s weight will only be carried in the center of the bar and over time that central area will get sore because of increased pressure over too small a surface area.

If you have a bare tree, put it on the horse, rig something to strap it down, and walk the horse around. You will find that as the horse moves there are times the tree is bridging slightly on one side as the center of the back falls. There are times of the rear of the tree on one side is lifted off and the front and center of the bar have all the weight. Turn him in a circle and you will see even more exaggeration in what is carrying the weight and what isn’t. Getting the shape to match exactly all the time just is not possible, not just because the bones move (and they do to a certain extent) but because the muscles are contracting and releasing all the time – which is what you want. So the amount of pressure under any particular area of the bar is always changing, which is a good thing. What you don’t want is constant high pressure, nor do you want intermittent very high pressure.

As the horse moves and his muscles contract, they will bulge a bit. This will lift the bar compared to when the muscle isn’t contracted. So you want to make sure that along the top and bottom edge there is enough rounding that the edges won’t dig in when the muscles are not contracted. Yet we want enough surface area to the bar so that when the muscles are contracted there is enough contact area that the PSI in that area isn’t too high.

On our bars, while the whole bar is rounded to varying degrees depending on which section of bar we are looking at, we build in the “relief” along the outside half inch or so of the top and the bottom edges. (Our bars are moderately thick which also increases relief.) We lift the back bar tip, say the last 2 inches, so that it won’t poke the horse in the loin no matter how he moves, though the underside of that area will contact the horse some of the time. We position the bar to start behind the shoulders with enough relief built into the front bar tip (again, the front couple of inches) to allow the back of the shoulder blade to slide under it when it is rotated farthest back. This happens when the leg is extended – which is an unweighted part of the stride – and thus does not cause high pressure. If the leg were weighted with the bar on the shoulder blade, that would be another story. But other than the edges and bar tips, we expect the full bar to be in contact with the horse most of the time as he moves, though the pressure changes from minimal to more under the different parts of the bar with every movement.

Overall, when building trees you are always looking for a balance. But it is not like you are walking a tightrope over Niagara Falls. The analogy is more like you are walking along a 6” wide line painted on the floor. Sometimes in trying to get too specific in one area, you can cause problems in others, so you always need to keep the big picture in mind.

[daviD A Morris]

I agree with Rod and Denise.

I also think that to keep things in perspective - I want to improve the "macro fitting" before I get to the "micro fitting"

From what I have read here over the last 6 months accross a number of topics on these forums - there is a spectrum of aproaches to this "fitting of saddles to horses backs". Starting at one end of the spectrum and working down I have seen:-

1. 
   The "one-size-fits-all" group who say " get a good saddle and it'll fit all good shaped horses. all you people that are into "fitting saddles" are just worrying yourselves for no good reason, are you goin to make a saddle specific for every single horse - where will it all end?"
   

1. 
   The 3 or 4 sizes fits all group - "full QH, semi QH, TB, Arab" thats all you need to know, nothing more nothing less.
   

1. 
   MACRO FITTING - This group is where I put myself - I just thought up this group now
   

1. 
   The "Micro fitting" group - who came up with this term? first I ever heard of micro fitting was on this forum. - I think their approach is to fit a tree specifically to a particular horse - and personaly I can't see why these trees won't fit other horses of similar shape. So whats wrong with that. Unless, that particular horse is very unusual.
   

1. 
   The "I'm so concerned about causing my horse the least discomfort that I realy should never even get on its back" group.
   

Tell me if you think I'm wrong

[jonwatsabaugh]

Rod, Denise, daviD A Morris,

Of all I've ever read or discussed on this subject, these last two posts are undoubtedly the most eloquent, and the most common sense approach to the philosophy of saddle trees I've ever heard! daviD, I love your analogies. Your subtle humor always makes me chuckle!

Jon

[ClayB]

I have to agree with Jon here. I try to read all the posts here on saddles and trees, and a lot of times I feel like I am just getting more confused. But, this last post by Rod and Denise explained "rock" in a way that makes sense to me. Thanks for keeping it going until even the slowest of us "get it".

Clay

[AdamTill]

Adam,

There are so many things that effect rock perhaps it would be best to begin with what effects it.

First let me say that everything I'm saying here is based on a horse in neutral position on level ground.

Let's start with the concept of Orientation or how horizontal is the vertebral column. This is a very important concept in regard to saddle fit and it is largely ignored. We tell exactly where the spine is

Without an x-ray machine so what we will do is find easily identifiable points that give us a close idea. Dr Bennett came up with the whole x-ray vision concept a long time ago in regard to training horse judges and it has had a huge impact on the horse industry and can be of extreme value to the saddle maker. In this case we are trying to get a handle on where the actual vertebras are. You find the base of the neck which is pretty easy because it is where the neck gets really wide. Then you find the point of the hip and draw a line between them. This is what I call the line of Orientation (Photo spine 1). This is what tells you how downhill your horse might be, not the whither and croup as that can lie. Now we have a pretty good idea where the spine lies. Clearly this line is not always what we see on the top line however it is where the actual undulations in vertebral column that will be creating the range for the rock that you have been talking about in motion will occur.

Okay, gotcha on the above. I did a few tracings a couple of years back as I was working through some conformation excercizes, and I'll add one to this post for the horse above. The dots in the cervical region were indicating joint spaces, and you seem to be going from the middle of C6, so I'll guesstimate that position. Then, ignoring all but the pink lines, I think this particular horse is built relatively level.

In spine 2 I have changed the spines orientation by 5 degrees so you can get a handle on how it can affect the rock. You will also see a line drawing of a back in simplified form so you think about how the orientation will affect gullet width. To the side you will see side views of the simplified back in different orientations with a bar drawn in to show how this orientation line will affect the spread of the bars. If the seat is to be level then on a downhill horse (which most are today) then the saddle should be wider in the rear than the front. This concept will also affect how you view the rock of the saddle.

Makes sense.

In spine 3 I have drawing the top line which is created by the lengths and angles of the spinal processes this is what is most often fit with no regard to the other influences. You can also see how the orientation affects this line. If the horse has been properly ridden so that the spine is still along the orientation line then this is not a problem but if you fit a horse whose spine has been pulled off that basic line for a multitude of reason then you will end up with a fit that will run into problem further down the road. I have not come up with an easy way to tell you if the spines basic line has been disrupted. Over the years and looking at thousands of horses you can tell by the muscles. Tightness in the top line and pockets behind the shoulders are good signs that the spines natural alignment has been effected by poor horsemanship. Here is the business decision for the saddle maker do you fit the horse as he is or as he should be?

Well, before I bought him this particular horse was used hard and unappologetically as a lesson horse even after foundering, so he has his fair share of issues (which we're working on). Taking your example and translating it onto the topline, it's interesting to see that the topline and "balance lines" are offset and showing those "issues". I guess in essence this is a continuous state of ventroflexion, for all intents and purposes. Very interesting - thanks for this.

Here is link to an article that Liz wrote that shows two horse's with different conformations and how they need to be supported differently to achieve the same result. This is relevant to the topic of rock as it can help you understand how dependant the where and how the rock will be effected is on the overall conformation of the animal. The conformation will change which parts of the back will be affected the most in movement. When she refers to ventroflexed gaits she is talking about those gaits that require a hollowing of the spine as you mentioned from Debs perspecitve.

Thanks for the article...I'll study that one to see what you mean.

Here is a site with some good info on range of motion.

Wow, that's exactly what I needed to get started...thanks tons. I'll play around with that ROM data and see if I can't come up with something interesting.

Cheers, and thanks again.

Adam

[Blake]

Rod, Denise, daviD A Morris,

Of all I've ever read or discussed on this subject, these last two posts are undoubtedly the most eloquent, and the most common sense approach to the philosophy of saddle trees I've ever heard! daviD, I love your analogies. Your subtle humor always makes me chuckle!

Jon

"Common Sense" being the Key phrase here.

I agree with Jon. Good Job Denise.

Blake