Mr. Donald asked me a difficult question - Page 1

Hi all,

In this thread

http://www.pedigreedatabase.com/german_shepherd_dog/forum.read?mnr=179922

Mr. Louis Donald asked me a very difficult question and this is a quote of what he asked:

Good response. Maybe I should have posed a tougher question; One dog has forelegs that are at a ratio of 45% of the dogs height, the other has a shoulder that is of correct length but set at 50 degrees and the other has an upperarm that is the correct lenght but set at 60 degrees. Place 1st  to 3rd?
Regarding the upperarm question. Putting aside specific breeding partners, their parentage and in general terms modern lines, short steep upperarm have  always been an issue in the breed. The length has improved more than the angle over recent years. The answer is therefore a relative one.
For interest, my observation is that in an historical sense using Siegers as a measure the first good length appeared with Dido v d Werther Konigshale in 1968 and good lengtht with good angle in 1973 with Gundo v Klosterbogen and consolidation in a breeding sense occurred in 1983 with Uran.
Both are hard to fix, harder to consolidate and difficult to perpetuate with consistency and when even when it is consolidated over many years because of its history within the breed both can dissapear very quickly.

Louis

I think I have the correct answer but I will first take the chance to test my understanding of movement/front reach infront of Mr. Donald & the experienced on this board and make this thread a little fun to interested members. Therefore I shall make an introduction to how I understand the front assembly of the GSD , its various components, their inter- proportions, angles, plus the relation of the front as a whole to principal proportions of the dog plus have a look at what balance really means.
I want first to confess to you that I made a big mistake in a previous thread about the front assembly of Dingo vom haus gero especially the front upper arm angle
http://www.pedigreedatabase.com/german_shepherd_dog/bulletins.read?mnr=516137&pagen=4

I say that was a big mistake because I forced my wrong understanding then of front assembly components varying effects on front reach, which I bet many GSD enthusiasts do not know the whole truth abou what role each component plays on front reach, on the good front reach of Dingo, thinking that good movement= good length + good angle of front upper arm only.
If one reads available material by many experts on the front assembly, much talk is done on length of upper arm and its angle to the point that one thinks that the most important two factors of the correct front and thus correct reach/movement is the front upper arm and its angle which is in my humble opinion is not totally correct. It all clicked and became clear to me after I read Mr. Donald's paper, the unconnected pieces then became much closer and the picture became more clear.
So to those interested in sharing their valuable knowledge on this thread and to those interested in understanding the front of the GSD/front reach better than they do at the moment this is an invitation to read first what Mr. Donald wrote about the front part of the GSD and please pay attention to diagrams that explain how front reach is affected by length of front upper arm, its angle and length of fore leg.
http://www.gsdcouncilaustralia.org/louis_donald_article.pdf

I will later on introduce what I think is a major role the shoulder blade plays in all this and see what Mr. Donald & you comment on it.

To be continued

This is Dingo vom haus Gero, he is admired for his excellent gait and front reach and usually used as an example of correct gait, but his frong upper arm angle is considered steep compared tp today's VAs, then why does he have a great gait/front reach if the front upper arm angle is the major deciding factor for proper front reach !!!!!!!


I think this is a more correct visualization of Dingo's shoulder than I posted in that thread.


For a start part of the answer to this big why is he had an extraordinary long front upper arm, but that's not all.

To be continued

Please while watching Dingo gaiting pay close attention to where his toes reach in full fore-front extension, here's a picture with some line to demonstrate that.



Look at the green lines 1 pastern, 2 fore arm/leg & 3 front upper arm, he has good length & proportion of all these three bones, especially number 2 then 1 then 3, this is another part of the answer for the big why. Please note the good lay of the shoulder blade, and I talk about later.

To continue

So what is front reach? When the dog moves it is simply the distance dog covers in a trot by its fore leg between point b to A in each forward move and I'll call it fore-front reach if no one suggests anything else and distance B to C I'll call it fore under-reach.

Think of the trangle with the blue lines as a closed triange with the base being horizontal and the red line being a vertical divider in ideal dogs. Now the remaining two lines are representetives of the for leg in maximum front reach and backwards reach.
According to standard the red line which is the height at withers is limited for the male from 60-65 cms and we can not go beyond that but simple mathematics tells us the longer this line then the longer line AB become and therefore better reach. Also the longer the blue line A W the longer the line AB gets and therefore better reach. For discussing front assembly we deal with line WA, the longer we can make it the better front reach gets, but what makes this line longer ?

To be continued

Let us have a look at the front assembly

Here are the ideal angles

 


Please refer to how Mr. Donald explained the angles of the shoulder should be correctly determined
http://www.gsdcouncilaustralia.org/louis_donald_article.pdf

Please note the vertical red line that passes from the center of the tip shoulder blade to the pasterns, this line is an indication of a good front assembly, good lay of shoulder blade and correct fore arms. It has also to do with correct balance of the fore assembly, here's some of what Mr. Donald says about it:

Quote:I have mentioned the importance of the dog maintaining its centre of gravity. This is in stance as well as in movement. To better understand this, to better understand Figure 19 and to feel this for yourself – stand up dead straight and in doing so you will find the most natural position for you to stand is when your two feet are together and your heels are in a vertical line with your legs, hips, spine, and head. This is because the central line of gravity is being transferred in a basically straight line down through the centre of your body and through the centre of your heels. As a result you feel totally balanced. If you tilt your upper body forward at the waist, you will feel the centre of gravity shift toward the balls of your feet. This has shifted the line of gravity and you feel less stable. For the dog to have ideal transfer of gravity through the forehand when it is standing naturally, the centre of the shoulder blade needs to be vertically in line with the axis point where the upper arm meets the foreleg and this vertical line needs to continue on down through the fore leg to the pastern. This can be seen in part in Figure 19.

End of quote, I couldn't copy figure 19 here, sorry for that.

To continue

In above figure, the front assembly consists of the shoulder blade 10 then the front upper arm 12 (and a joint in between) and then the front arm/leg 14 (and a joint in between) then the pasterns and a joint in between then the toes and underneath the pads.

All the components are connected and act in motion as a system, for motion brain gives signal to nerves and then muscles carry out the action by moving the bones which are connected via the joints and connections between muscles surrounding the bones. Extent of move and extent of resulting angles/inside movement of bones in the joints is governed and limited by the muscles and joints themselves. So there are limitations to maximum changing angles between various bones in movement.
To easily understand the movement of bones consider the shoulder blade itself as a fixed bone with no movement, in reality it is semi-fixed and does move vertically and horizontally to a relatively limited extent, a side note here the movement of shoulder blade and its role in transferring forces either didn't have its way to my brain or I disagree with what Mr. Donald says in his paper but this is another issue, let's just for ease consider the shoulder blade a fixed bone. The upper arm moves inward and outward via the joint with the shoulder blade, and the fore arm/leg moves outward and inward via the joint with the front upper arm, also the pasterns move up and down via the joint with the fore arm/leg.
Each bone has an allowable extent of movement and thus decreasing or increasing angle with preceding bone is governed by the muscles and joints themselves.

To continue

How does bones look like in full forward extension? if we have a dog whose front reach is close to ideal and trace his various bones then we can analyse the limitations of each bone extension and we can analyze the effect of each length and its angle on the total fore- front reach. Luckily Mr. Fred Lanting did this, he posted the picture on this forum so we may use them for learning purpose.



To continue

Let us have a look at above bones trace



I drew these lines between the various bones using the above mentioned directions by Mr. Donald on how to represent the lines and angles of bones. Mr. Donald or any of the experts might give us the exact angles if exact data is availavle, for now I will give estimates, angle of front upper arm has increased a lot, almost doubled, while ideal in standing position is 53 degrees it is now about 90 degrees (excuse my bad line representing the front upper arm). Angle B which is 45 degrees has become approximately 55. Unluckily I do not have a standing picture of the above dog which is Rommel's Jasemin to estimate its true B angle in standing, but let us assume it was close to ideal say 50 degrees and that means the change in this angle is 5 degrees which represents about 10% from original while standing.
If we also assume angle A was close to ideal say 60 degrees then the change is 30 degrees which is  50% from original, comparatively change in angle A is minor, therefore for simplicity of understanding while considering fore- front reach assume the shoulder blade is fixed.
Now ideal angle C in standing is 180 degrees and in well conformed GSD it is usual, now in full extension  it is approximately 125 degrees which means there is a decrease by 55 degrees.



To continue

My paper was designed to encourage people to think for themselves, to work things out for themselves, to question what they read including what I have written and to question what they have been told by the plethora of 'experts'. In that context your response Ibrahim has been excellent and it has given me the greatest of pleasure.

Louis Donald

 

Mr. Donald,

As I said before, my personal understanding of dog and GSD structure and movement was taken to higher grounds after reading your paper, I may not be able to think of and connect all pieces of bones & angles in the GSD, it needs dedication, knowledge, experience, wide exposure to dog specimens, resources to info, history and much more. I shall only concentrate on the fore parts in a mathmetical approach and through this open live thinking process see how you & other respected knowledgeable here on the board evaluate my understanding of the fore assembly of the GSD/front reach and the answer I come up with to your question which started all this.

Ibrahim