Center of Gravity - Page 2

Thank you ecs, As I understand it you are basically speaking of lever arms with centre of gravity as the fulcrum. The longer the arm where animal's physical extremities are concerned the greater the energy required to keep it all 'hanging together'. A notion similar to my sense of some indefinable 'compactness'. Still somewhat surprised that centre of gravity should be located as far forward as you descibed under Front Assembly. As a tit-bit of minor acadamic,ecs, Bernoulli's fetching notions are quite straightforward in principle: a faster flow of fluid equates to less pressure or 'lift'. Force a foil (wing, keel, sail etc) to operate at particular angle in opposition air or water, in way that requires fluid to move faster across one side of foil than the other, lift is created at expense of 'drag'. There's a huge body of scientific work in respect of ideal foil shapes for different functions - their centres of effort, drag, stall and geometric profiles characteristics. Generally, foil's leading edge does most of the work, and the longer the foil, the greater its efficiency. You seem to be tad acadamically inclined, ecs, so I thought I'd throw that in. Also great self-serving opportunity for me to pretend what a clever little bunny I am!

Hello Patrishap, I see you too are acadamically inclined. In my opinion, good breeders need to know the technical business of action of the dog. If not, then how can they know in what diredtion they need to go when faults begin to rear its head. Even so, thanks for your kind words. I thought this would be a popular subject, even controversial, but evidentially not. I think I will now crawl back into my hole, and just read your contributions to the site. Take care. ecs

ecs, Great explanation. If I might add, we are losing the dimesnsion of height in this analysis. The vertical plane of GSD is inclined due to the structure of the bones and the 120 degrees rear. So, in 3D , the centre of gravity will actually shift slightly more. Do I make sense?

Regards ecs, In my preoccupation with that observant Bernoulli chappie, I feel I've let you off here just a shade too readily - despite your wonderful work above! Under previous related heading heading it was agreed between you, Lennie and the Standard that with rear legs in forward position (lined with hip-joint etc) that rear and hind angulation should both be in agreement and 90 degrees for each. On face of it, this seems wonderfully rational but, as was emphasised under Front Assembly, the fore and aft sections have different functions, with the rear providing most of the drive. I also mentioned earlier how angles in question are at different heights and therefore don't exactly 'slot' into each other, or correlate, when animal is on the move, as well as being seperated by mid-body, of course. Thus, is seeming elegance of having the same angulation fore and aft really that rational? Is there any anatomical or other substantiation that this the ideal structure? Don't knock yourself out here though! Off hand, I can't begin to rationalise a case here for one or the other! Cheers.

I don't know much about airplanes, other then if you pay for a ticket, you get to ride to where you bought the ticket to. from reading these posts I see I'm not acadamically inclined at all. I am out of touch with this new learning, I do know if a person, breeder, judge or just interested party allows the shepherd to trot naturally. it will find its center of "balance". Gravity is somethng we all live with by being on this planet. some humans allow there center of gravity to spread out in the belly line, which could distort their center of gravity, probably their balance also. I'll keep reading, if theres something new I want to keep up. LOL

Patrishap, You are pulling me out of my comfortable hole, aren't you. I had just about gone into hibernation and then your insightful and penetrating question. I almost get the feeling you already know the answer. As I reflect on your question, it occurs to me that this cannot be a one short paragraph answer. It appears we must do an analysis on the function of the rear angulation and then coordinate it with the front assembly. Quite frankly, Patrishap, I'm not quite sure I want to get involved in that much detailed writing at present. However, ahh me, I probably will. But right now it's bedtime for me, so will wait until tomorrow. I have a question. Where are the judges? Why can they not give a detailed criqique to your question? Judges SHOULD know these things. ecs

Howdedo, Good to talk to you again, though it is taking away from my bed time. I posted a note to Patrishop and wanted to make sure it got posted. I had had three previous postings not to post. I reread the thread and saw where you had made a posting. I disagree with you that we are loosing sight of the height deminsion. If you reread the thread you will see I made the statement that the rear thrust gave the dog some lift and that, therefore, gave the center of gravity not only a left and right motion but also an up and down motion. The desired design for the shepherd is to reduce this motion to the minimum. Also, this center of gravity is based on gravity and does not deviate due solely to the slant of the animal. I think I know what you are suggesting, but I do not think it has anything to do with the cg other than what we have already stated. If you have questions, ask away.....tomorrow. Gem, Sorry but all this is old stuff. Unfortunately, in my not so humble opinion, most enthusiasts do not themselves with the study of movement, its "whys", "hows", "whens", etc. When I see a dog that "kicks up" in the rear when he trots, I would like to know why. This type of study explains. There is not much that can be done to change one dog's center of gravity but it can help us develop better dogs in our kennel by improving the faults we can recognize from the action of the center of gravity. If you have questions, do not hesitate to ask. I'll tell you what I know. NOW to bed.

Patrishap, I meant to go to bed long ago, but after your last post I thought I would jot down a few points concerning it. That few points developed into a full page. Things seem to esculate. One thing leads to another. Almost enending. Give me time in some degree of unity. I really did wish to hibernate for a while. ecs

Kind Sir, Don't allow my fretful posers disturb your slumbers! I heard that even Rome wasn't built in a day! Yet, with all this earlier talk of decreed angulation and so forth, is it not valid to raise the deadly cry WHY? - for fore and aft angles to be the same, that is. When you said that other experts, including judges, should have a ready answer, truer words were never spoke! They wouldn't just unquestioningly accept what they were told/taught would they? Monkey see - monkey do? Tomorrow is another day.

ecs, thanks for the note. I don't quite agree with the analysis yet. No major disagreement, just a little. The slope does have an effect. patrishap,you might relate to this easily from your interest in boat design - the principle of changing bouyancy. That has additional parameters, but CoG is key. Example - consider a rectangular box whose CoG is the intersection of its solid diagonals. Now consider the same box, but you slice off a line from one edge to about 20% of the height from the top at the opposite end. Does it have the same CoG as before -No, it is lowered. This lowering typically keeps up and down shifts while moving to a minimum. I agree with you ecs, Where are the judges??? Also ecs, could you start a discussion on the hindquarters please? We never really got to tying the mechanics of hind to the front.