Mr. Donald asked me a difficult question - Page 6

I have worked drawings using the autocad software to show effect of various angulations and proportions of bones on fore front reach, I shall start posting them very soon.

Ibrahim

Hello again, I managed to make some drawings to illustrate the front assembly of the GSD and represent how each bone angle or length/proportion affects the front reach. Just so each of us remains on same page I remind you to refer to how Mr Donald explained how bones and angles of shoulder are to be correctly measured here
http://www.gsdcouncilaustralia.org/louis_donald_article.pdf

In all drawings I will show the line of center of gravity or one may call it the proper balance line will be used, you can refer to that in earlier posts on this thread.

In the drawings I used autocad software, it's a drawing software used for drawing to scale engineering drafts, accurate lines, distances and angles are drawn with extreme accuracy by this software, so no one should worry, once the software gives you a reading of length/distance and or angle it is 100% correct.
So let's go and I assure you the outcome of those drawings is very very interesting and educating.

Something is wrong with uploading pictures

I'm sorry for this inconvenience really !!!

On the left is a front assembly of ideal GSD. On the right are the dimensions. In all drawings I used a 65 cm high GSD. There is a small distance between top of withers where we measure the height of a dog to the mid point of top of shoulder blade, I guess this distance is approximately 2 cms. In this above case the chest depth is 45% from total height and that makes 29.25 cms. Now to get the distance between the top mid point of shoulder blade to elbow joint we deduct from this distance 2 cms and that makes 27.25 cms. Now the distance from the elbow joint to ground is 55% from total height and let's call it fore leg length and that is 35.75 cms.
I assumed the ideal proportion of vertical length of pastern to fore leg length to be 25% (if my assumption is wrong it does not affect the idea itself) and in this case that is 8.9375 cms, the pastern is set at 22 degrees and therefore the inclined actual length of the pastern is 9.66 cms. Please note that this length is from the pastern join to rear point of foot. If we deduct the vertical length of the pastern from the fore leg length we get 26.81 cms which is the length of bone between elbow joint and pastern joint (Radium).
Hopefully that is clear enough.
If any point is not clear please feel free to say so as all what comes later in regards to chest depth proportion and calculating length from mid point of top of shoulder blade to elbow joint, and length of fore leg bone and pastern will be done in same procedure.

Now we go to talk a bit about the shoulder. We have the 27.25 cm imaginary vertical line (in a well balanced fore assembly) that connects between the mid point of top of shoulder blade and elbow joint (again I refer you to Mr. Donald's paper), I set the shoulder blade angle at 45 degrees and front upper arm angle at 53 degrees which is the ideal case in a well structures GSD and got the length of shoulder blade 16.56 cms and front upper arm length 19.46 cms. And the ideal relation between the shoulder blade and front upper arm lengths is always found to be 1:1.15, and this ideal relation remains the same even when the chest depth varies as long as the above shoulder angles are the ideal (45 & 53).

I will talk later in detail about shoulder various combinations of bone lengths and angles, but for the time being we will limit our talk on the effect of chest depth on front reach.

Remember the tracing of bones Mr. made and I talked about before?

This one



In full reach I will use the Upper arm open (90 degrees), elbow open (125 degrees) in all full reach drawings, shoulder blade and pastern opens may vary.

Ok 45% chest depth standing, ideal shoulder

Corresponding full reach

So an ideal 65 cms high GSD of balanced for assembly, ideal shoulder angles, ideal length and angle of pastern make a fore front reach of 43 cms in a single trot (we're talking about distance covered in full reach between mid top point of shoulder blade and rear tip of foot in one stride)