Kelly, I know, I was playing devils advocate...

Cam

the scapula would move forward and into the neck if it was set at this mythical 90 degree angle!


the pic is blurred so is not easy to see, but it is not 11, 12, 13 etc it is T1, T2, T3, T as in T for thoracic veterbrae.  there are are 7 cervical verterbrae, with the letter C preceding the number.  C7 is  numbered on the second picture, it is just too blurry to see, sorry.  the dog has 13 thoracic veterbrae, but only the first 5 or or show are shown as the picture is concentrating on the front assembly. 



we are, and i was just showing that the interpretation of "perfect" anglation being 90 degree is a myth!

Hi

Just wanted to say how interesting this has been and how much i have enjoyed reading the comments.  Wouldn't it be good if we could all get together one day and discuss this.   I would certainly find it helpful.

Thanks very much.

Judy

Kelly,
Gilbert and Brown(K9 structure and conformation) Hypothesis that the vertebral bodies vary in length and this can account for the increased angulation at the scapula which allows a 90 degree shoulder angle. Not outwith the realm of possibility as we all come in different shapes and size, your bones will not be the same size as mine etc,etc.
It would be great to get a Gait lab to do studies on  fit working dogs, one considered of "standard" angulation, one of reduce and one of over.
Do some calculation relating to mass and power (body segment parameters, you would have to work out ratios for canines in the first instance and even these wouldn't be universal as they would vary by breed) then do gait analysis, loaded and unloaded to see how they performed.
It would cost a lot of money and take months to analyse the data but it would prove beyond a doubt what was optimum and what compensations were going on.
Its not likely it will happen any time soon.
Guess we'll just have to rely on good eyes and evidence based practice meantime.

With reference to the 90 degree angle. Is it not the angle formed by the ridges on the sides of each of the bones rather than the centre lines of the bones? So in appearance, the angle may look larger and create a steeper front end?

If we win the lottery, we're commisioning you to do a study Linda!

I read something recently in an ISHC publication that said loose movement was of benefit. Although it looked ungainly, the fastest dog teams generally moved in that fashion. I wonder if this is what I am seeing in the dogs that inspired me to post this thread?

Cam

The only way to find that out would be to race a team with the "ungainly" movement over the same distance under the same condtiions and with the same level of fitness as an "efficient" team see which one was faster. Of course the fastest team would have to be your criteria for superiority in defining which team was better.

I still don't actually agree that speed is neccessarily the quality we should be looking for  - if you are using a dog as a method of long distance transport in a harsh environment where food is scarce what you want is efficiency. Unless my physics is worse than I think, a dog whose movement involved sideways effort as well as forwards effort can never be optimally efficient. Out on the tundra you want a dog who will work reliably for very long distances without tiring or breaking down through injury and who will eat the minimum of food while doing it. Efficency of movement is the only way to achieve this, as far as I can see.

I feel we are in danger of trying to prove a circular argument here - we have not established that this "ungainly" movement is actually superior to the "standard" movement in any way - we don't know if these dogs are faster, have more stamina, recover more quickly, use food more efficiently and so on. Because of that we can't develop an argument to say why "standard" movement (and the bone structure that goes with it) is inferior to "ungainly" movement, because we don't know if it is.

I've been reading some philosophy recently (I must be mad) and this is a classic "ontological argument" - apparently. 

Very messy to clean up though...   

AJ.

Well, I have managed to get a couple of short runs in recently and been watching Willy Wilson run. I take back the comment that I had about the movement looking a little messy or ungainly. He has matured a lot in this last summer and is now just awesome! Very tidy and efficient and not too dissimilar to Norris's movement. (Maybe I have just become more educated over the summer break? lol )

Ok, bear with me. And Linda, feel free to jump in and help me out with the technicalities. I think the difference is the movement is lower, if that makes any sense. I see pictures of gait analysis etc but these are of free moving dogs. The difference in working is that with each stride the dog is pulling. To be able to pull the level of the dogs back must be slightly lower that at a free trot / run / whatever to be able to exert the required force through the angles created by its bones and joints efficiently. This means that the dog’s joints will have different limits of movement than in free movement? In a sprint the speed is higher so the dog is essentially exerting more energy so the dogs back level is lower and there is a lot more doubling up. At a steady lope the dogs are using less energy so can move closer to the diagrams you see in these books?

Like sometimes you see a dog in the show ring that a lesser trained eye might think has great movement, drive and reach when really it shouldn't look like that at all. This just shows that at a free movement the dog is at its limits at a relatively slow speed with no weight to pull. When really the dog should look so laid back when achieving the same speed it should almost look lazy, and be able to move much faster whilst still looking laid back.

I know an experienced musher told me to watch the dogs on an Iditarod video closely to see that they were trotting and at a nice speed. Legs almost a blur they could trot so fast. This is maybe why some of the dogs I have seen in magazines and on websites have appeared to have slightly too much angulation (for what we are used to in the UK). With this slightly greater angulation can these dogs trot close to the text book diagrams whilst still maintaining power through the angles created by the bones and joints? In the UK we don't run any distance that requires running the dogs at a trot for so long, so it has maybe not been such a requirement (or noticeable requirement) to breed dogs with the same angulation as those I have mentioned. So to get back to my very first post, in my opinion, I feel that dogs in the UK generally have quite steep shoulders and less angulation at the rear (this is a sweeping generalisation by the way and in no way reflects on the majority of good working dogs here IMO).

It would be interesting to hear back from you to see if I have managed to articulate what I am thinking and to say if it makes any sense? If I'm looking at movement wrongly, I'd sooner know about it now.

Cam

So what your saying Cam is that Willy was young and soft so his movement was all over the place and now he's had a chance to mature he has smooth cadence. Most excellent.

I think the lower movement you're talking about is just the effect of resistance to inertia, ie at initial start-up there will be a rear crouch induced due to effort to pull the rig and musher forward, the back will slope and if constructed correctly there should be a corresponding if not equal crouch of the forelimbs in the effort to pull the load forward, but after the initial inertia is overcome the dog is essentially move in free flight, unless you brake or the gradient changes. The reason the height of the gangline attachment to the brushbow is so crucial is to reduce wasteful movement ie the dogs centre of gravity has to be as close to in line with this to produce maximum gain from there effort and you don't want turns to cause excessive torque unbalancing them on the corner.

The joints will not have different limits of movement then loaded or unload, the joints range of motion is only limited by anatomy which is why good angulation is so essential to start with.
The show dog with its pretty show trot can look right if it is balanced front and back ie lacks reach both fore and rear but that same dog on the trail is going to have a reduced stride length and will struggle to keep up with the dog of better angulation who has an increased stride as a result.
Like wise doubling- up has more to do with good anatomy and the balance of it than speed. Yes, the dog doubles-up at speed but it is also by this stage in the gallop relying on balanced leg length to reduce the tendency of drop in its centre of gravity as it propels itself forward, good balanced angulation and musculature in single support, (ie in gallop often there is only one paw on the ground at any one time) are essential to keep the top line "level"

The dogs on those Iditarod videos don't have good angulation by accident if they didn't they just wouldn't be in the team