Just to chime in, I'd expect an article like this to go just a bit into the evolution of the quite distinct limbs? For example by briefly discussing multi toed basal horses and such. FunkMonk (talk) 21:45, 14 September 2013 (UTC)Reply
Fair enough. I'll have a look through the source material and see what I can come up with. This is my first article of this sort, so suggestions on where things are missing are definitely welcome. Dana boomer (talk) 22:00, 14 September 2013 (UTC)Reply
I would note that we have extensive discussion at Evolution of the horse and some of the theories have some controversy. We want to be careful not to open this article up to some of that stuff over there. What's been added looks OK to me, though I think that only the splint bones are vestigial remains from the three-toed intermediate species, I don't think there are vestiges of the 4th and 5th toes...? (also the forest-dwelling stuff is a bit of a tangent and not needed, IMHO). BTW, I'm not a reviewer on this because I was too involved at various points in the process, so just weighing in as a WPEQ member and supporter of this GAN. I'll help as I can. Montanabw(talk)00:52, 15 September 2013 (UTC)Reply
Ok, here are some notes (I may will add some more). I think the "limb anatomy" section still needs some general work, and I hope my notes will help you with that.
What about adding this image, for an general overview? Otherwise, only the lower forelimb is illustrated but not the upper, and the forelimb is illustrated in side view while the hind limbs are in back view, making comparisons difficult.
You start with listing the individual bones, followed by a separate list of the joints. For a reader who wants to learn about horse limbs, these lists may are not useful. It may be better to describe the whole limb from thigh to hoof, so that the reader gets a general picture of the different sections and the joints that connect them. Perhaps you should start with general aspects (e.g., proportion of limbs in comparison with the body; horse is a cursorial animal -> short thigh, long foot bones; odd-toed ungulate that retains only the third digit, general trend towards reduction of limb bones that are not necessary for running).
I've integrated the lists of bones and joints. This, combined with the reorganization and expansion of the section as discussed below, alleviates the above issue, I think. Dana boomer (talk) 18:33, 15 September 2013 (UTC)Reply
You did not explain terminology that is only used for horses. When you write "knee", you should explain that this has nothing to do with the knee in other animals, but refers to the equine knee that actually is the wrist. Otherwise readers may be bemused.
These terms are all linked to the proper name of the correct bone/joint/muscle/whatever, and the correct term is used first, followed by the horse-specific terminology used to describe that structure. Comparing each structure to corresponding structures in other animals would take too much focus off of the horse, which is what is being discussed in this article, especially when there are links that the reader can follow if they are truly interested in the topic. Dana boomer (talk) 13:46, 15 September 2013 (UTC)Reply
The section "Hoof" is very detailed. In contrast to that, most other aspects of limb anatomy are described only superficially.
I have re-read this section, and I don't see how the hoof section is any more detailed than the other aspects of limb anatomy. Could you provide some examples? Dana boomer (talk) 13:46, 15 September 2013 (UTC)Reply
Information that could be included (would be nice if some of these could be added to the article, but of course, do not try to include everything I list here):
limb length proportions (are fore and hind limbs equally in length?)
proportions of the individual limb bones (femur and humerus are proportionally short, while the lower limb bones are long -> adaptation to a cursorial habit)
neutral position while standing (The limbs are not straight columns, the carpal phalanges are more angled than the cannon, and the humerus is inclined toward behind …)
How much do the fore and hind limbs contribute to locomotion, respectively? Is much of the thrust generated in the hind limbs?
The section starting with Horses are odd-toed ungulates, or members of the order Perissodactyla. can be found within the section "hofes". This should be explained at the beginning of the anatomy section.
(not necessary for reacing GA) The reader should find out about Functional anatomy: The horse has only one functional toe left. The ulna also is reduced, leaving the radius as the only functional element of the lower leg of the forelimb. Why this simplification? Its also an adaptation for running, similar features can be found in other cursorial animals.
There is a long section about the suspensory apparatus and the stay apparatus. However, for me it seems a bit unspecific and does not make the point. I have not understood how that is supposed to work; for example, when the suspensory consists only of tendons, ligaments and sesamoid bones, how can it carry much of the weight? --Jens Lallensack (talk) 11:35, 15 September 2013 (UTC)Reply
Jens, I believe I have replied to the majority of the issues above. I am still doing a bit of research on a couple of points, but they are minor. Do you have further comments, especially on the later parts of the article that don't seem to figure into your review above? Dana boomer (talk) 18:33, 15 September 2013 (UTC)Reply
Thank you for all the improvements, Dana! Just a few more minor points:
then they are when the originate in the chest – can you check this, I don't understand it. Should it be "they originate"? But the forelimbs always originate in the chest, don't they?
Yes, that's a typo, should have been "they". This sentence is a comparison: when the legs/hooves are closer together at the ground then at the shoulder, the horse is base-narrow. When the legs/hooves are farther apart on the ground then at the shoulder, the horse is base wide. Dana boomer (talk) 20:28, 16 September 2013 (UTC)Reply
The ulna shrank in size and its top portion became the point of the elbow, while the bottom fused with the radius to form the radiocarpal (knee) joint – the formulation may be mistakeable; I think the ulna does not contribute to the radiocarpal joint, it ends just above it.
Clarified the sentence slightly (the fused portion is part of the radiocarpal joint, not the whole thing). The source says "...the lower...end of the ulna is fused with the distal end of the radius to form part of the radiocarpal joint..." Dana boomer (talk) 20:28, 16 September 2013 (UTC)Reply
The sources seem to be all over the board on this. I've changed the wording to just say they merge above the joint, which is true, and lets me keep the wording about the wrist/knee connection. Dana boomer (talk) 00:48, 18 September 2013 (UTC)Reply
Thank you for the link explaining the suspensory and stay apparatus, now I understand. A question though: This apparatus carries much of the weight – even in neutral rest position, or only when the fetlock joint is extended while walking? For a better understanding, what about adding the information that the suspensory apparatus is an elastic structure on the back of the cannon, fetlock and pastern that acts like a spring; when the fetlock is extended, it stores energy, and then provides the rebound effect. Before reading the PDF, I have wondered where the rebound effect comes from. --Jens Lallensack (talk) 08:01, 16 September 2013 (UTC)Reply
Jens, if it would help for someone to whip up an article on the stay apparatus, let me know, I can probably do up something fast to create a link so that this doesn't drag the article off track. One reason we spend time on this is that in the past, people have begged us to put in stuff about how horses can sleep standing up into various appropriate articles (including horse) because it seems to be the one thing small children and other people know about horses, if they know anything else other than that they go "neigh." Montanabw(talk)20:17, 16 September 2013 (UTC)Reply
I don't think we need a separate article on the stay apparatus: it would be fairly small, IMO, and would just be a candidate to be merged back here. What we were trying to prevent with this article was a bunch of little ones on various topics relating to the legs. The stay and suspensory apparatuses are not off track for this article, because they relate solely to the legs of the horse. I'll add in more from the source I provided, which covers it quite well. That also looks like an interesting link from The Horse, so I'll skim that as well. Dana boomer (talk) 20:28, 16 September 2013 (UTC)Reply
OK, I've expanded the paragraph on the suspensory apparatus to include information from both sources (the UC Davis paper I linked and the The Horse article Montanabw linked). I'll probably continue tweaking things, but I think I have the majority of the issues you've brought up corrected. Dana boomer (talk) 20:46, 16 September 2013 (UTC)Reply
Happy with changes, but spotted a nitpick in the lede: "The majority of the weight is borne by the front legs, while the rear legs provide propulsion." I would add something like "...at a standstill," as the faster the horse travels, at least if collected, the more weight is shifted to the hindquarters. You might want to note in the body text the average percentages, this source says it's 60-65% (also has some good stuff on conformation defects, though that may exceed the scope of this article, which is more on anatomy than judging...). Note at this source that one hind leg also bears 100% of the weight in the gallop at one point. I'm not finding a source for how weight shifts back in terms of percentages, but the concept is crucial in dressage. (Found a non-RS mention in passing that the trot is distributed 50-50...which is probably sort of true, depending on a lot of other variables) (This shifts back to 60-40 at a racing gallop, I guess, this study is not relevant here, probably, but is interesting) Y Montanabw(talk)18:02, 17 September 2013 (UTC)Reply
I've expanded the stuff in the body on weight bearing, adding the caveat that dressage encourages the horse to move weight back, and tweaked the lead wording a bit. However, every article I've seen that gives percentages gives the front legs as bearing more weight (moving from 55-70 percent depending on gait/speed/sport). Dana boomer (talk) 01:22, 18 September 2013 (UTC)Reply
Second, more minor nitpick: I put the word "lock" in quotes in the article where you discuss the stay apparatus; it's a colloquialism we horse people use all the time, but there might be (somewhere, I don't know where) a more technical term out there. (I did the same for "knee" per comment of reviewer above). Montanabw(talk)18:02, 17 September 2013 (UTC)Reply
I removed the quotes around "knee", because this is the technical term in horses, and I did end up adding in a comparison with the human wrist later. "Lock" is the word that the sources use, but there may be a more technical term out there, so I left the quotes.
