A point to ponder - top line vs bottom line

[puddicat]

Following on from geegee22's post on neck muscles and how to get them, here's a point to ponder if you're really bored or an equine student or both.

Why do horse's that run around with their heads in the air build muscle on the bottom of their neck but horses that work in a long low outline or relaxed head carriage develop muscle on the top of their neck ? Wouldn't you expect it to be the other way around ?

 

[vickers22]

although im not sure what it really means, i think my boy works in a long low outline, he bends his head low down, and as you can see from pics he has muscle underneath!so im completely lost!lol

 

[spaniel]

As Im sure I dont need to tell you PC thers so much more to it than just a couple of muscles in one small area. I believe the term used is 'ring of muscles' which incorporates not only the neck (more so the back in reality) but also the abdominal muscles as well.

I wish I could draw on here! It would make things so much easier.

 

[puddicat]

In answer to a Q in your post, this is a nice image I found of a horse relaxing out and being long and low in its neck.

 

[vickers22]

thats exactly what he does when walking, but i think its when we do faster work that he pulls hard and tucks his head right in. My teacher says thats what is causing the build up in muscle underneath. Ive stopped doing fast work now and am working on schooling, so hopefully it will improve. Thanks for pic PC v helpful-what a pretty horsie!

 

[puddicat]

Ahhhhh nope not the answer

. The muscles on the lower neck we're referring to have an isolated action on the neck, they develop as a result of something the neck does. Certainly if the horse is stargazing or whatever, it will be hollow backed and so you could say the whole of the back is involved. That's not helpful if you are trying to understand the development of a local muscle group - all that matters then is what is happening to the structures to which they are attached that cause their over/under development. So what I was asking was how does one reconcile the action of the neck with the development of the neck muscles - sure the body will be doing things that will influence neck position but not directly, only via the neck muscles. It is only the action of the neck that determines the size of the neck muscles.

Incidentally it's true that some of the epaxial muscles, the muscles on the topline are effectively continuous along the back (although splenius isn't) however they are innovated separately so there is a functional separation between the neck region and the bit behind with the legs on. So muscle atrophy/hypertrophy in the neck region can occur separately from that in the rest of the horse, and does of course.

 

[vickers22]

WHOA!!i think i understood about a quarter of that!(im a little slow, although im meant to be going into vetinary-oh god!)ok so doing less faster work wont help?im so confused!

 

[legend]

I could well be making this up, but i always thought it was to do with contraction vs relaxation of the muscles? Because with top line i thought it wasn't so much the back muscles as the belly muscles needing to 'lift'?
Am only going to put a short answer in case i am not making any sense or am way off and reveal myself as a deluded person, lol!

I'll be reading with interest!

 

[puddicat]

Sorry, that was a bit of a detailed post because I know spaniel knows a lot about this sort of stuff. No, I think the answer is straight forward enough, it is to keep the long low outine that people talk about (easier said than done I know) and at all costs try to avoid getting into a pulling competition with the horse (easier said than done I know).

 

[Bess]

That is a very good question puddicat and one that I don't know the answer to, look forward to reading the answer. In my own experience my current horse doesn't have a very well developed top line, but that said he is very soft under the neck, there is no noticeable muscle development there thankfully. So he's a work in progress.

I try to allow him to stretch down regularly, which I think must help, and he's not a horse that sets his neck against you. He feels very light to ride.

The horses I have ridden and see ridden daily who have overdeveloped muscles under the neck all lean heavily on your hand and can when they want to evade you set their neck against you and just do what they please. But again, I don't know the answer so maybe its just that they use their already strong necks against the rider?

 

[vickers22]

Bess-i think thats what my boy does against me. Thanks PC, this has been very helpful in understanding whats going on

 

[puddicat]

No that makes sense to me, it is to do with contraction and relaxation of muscles in the neck. the connection with the belly or abdominal muscles is that if they are engaged and the horse relaxes the muscles along the top of its back you get a nice rounded back and that predisposes the horse to go with a relaxed head carriage (although it might not), however, it is still the neck muscles that control that head carriage. So the paradox is, if the topline muscles hold the head up, how come you work the horse with its head down to develop them. Conversely if the bottom line muscles pull the head down, why to they get bigger in horses that go around with their heads in the air? You can take it for granted that muscles get bigger when they're used. (the answer isn't obvious!)

 

[RachelB]

Not really in a sciency frame of mind this evening (business assignment to do) but don't the bottom muscles 'hold' the neck up, and the top muscles 'hold' the head and stop it from hitting the ground?? I know if I lean over and let my head nearly touch the ground, it would be my 'topline' muscles working to hold my head up where I wanted it, not the bottom ones as they would be relaxed. So when the horse is working long and low the topline neck muscles are contracted and the bottom ones are relaxed (in a very simplistic explanation). I know when my friend's horse starts relaxing as his topline becomes firmer and his 'bottomline' becomes softer.
Don't ask me to contemplate the way the back and hind end relate to this though, my head may explode I'm far too tired!

 

[puddicat]

Ah ha!

"So when the horse is working long and low the topline neck muscles are contracted and the bottom ones are relaxed"

Yep so that's why that works - but if you continue your reasoning doesn't it mean a horse that constantly has its head in the air on a short outline should have lots of top line because it's using it to keep its head up?

"Don't ask me to contemplate the way the back and hind end relate to this"

I wouldn't, you can forget the bit with legs on

"but don't the bottom muscles 'hold' the neck up"

Errrrrrrrrrrrrrr, no not really - I'll explain the hesitation later!

 

[legend]

I was thinking along similar lines Silmarillion, in that when the horse is working correctly the whole neck is always lifted from the base, almost 'arching' forward down and out, which lengthens the neck muscles which is far harder than acheiving contraction of them. Thats why if there is a dip in the neck muscle just in front of the wither you can tell that the horse hasn't actually been correctly schooled, just shortened and held into the contact rather than the neck/poll almost being elongated over the bit? Whereas tense 'upside' down horses don't use their whole necks?
I know i'm only skirting round the edge and avoiding the central point but just can't work it out in my head!

 

[RachelB]

See, now we're looking at this from a different angle and I can't get my head round it. Looking at it from the "why does topline develop when working long and low" angle was fine, but asking why topline doesn't develop when working upside down - I feel I'm missing something!
I tried to edit my post but my connection is slow tonight - I wanted to change that to "but don't the bottom muscles 'PROP' the neck up". Argh must get back to business assignment, don't ask such interesting questions PC!

 

[Blizzard]

[ QUOTE ]
Ah ha!


Yep so that's why that works - but if you continue your reasoning doesn't it mean a horse that constantly has its head in the air on a short outline should have lots of top line because it's using it to keep its head up?



[/ QUOTE ]

If you lift your head up and back as if you were a horse evading and running off, you can feel you are pushing the head up with the underside muscles, so that would explain why the theory still works.

 

[Spot1]

Just a thought from a non expert. If you hold a weight out at arms length it requires greater effort, in the horse if at the same time as extending the neck you can relax the lower neck muscles (serratus) then more of the load is held by the upper neck (splenius)

[ QUOTE ]
you can feel you are pushing the head up with the underside muscles,

[/ QUOTE ]

Can a muscle push?

 

[puddicat]

Ha, well, yes very true the neck has to be lifted [relative to the body] from the base so yep that bit in front of the whithers is doing that, but the shape you describe comes from muscle activity along the whole top line (which I guess is sort of obvious because you look for development along the length crest not just at the base).

Silmarillion: "I wanted to change that to "but don't the bottom muscles 'PROP' the neck up" No, you were nearer with what you actually before!

OK here's a couple of clues, first, to answer the question you need to have a very clear idea where the bones are in the neck. So legend described what the outside of the neck looks like, but what you really need to know is what position the cervical vertebrae are in and how would get them in that position. To answer the second bit you need to know where all the musculature goes but there is still a catch (will explain presently). So even though it looks like an innocent little question it is in fact extremely difficult to answer well.

The second clue is this, Vetebrae that have lots of relative movement potential (like the neck vertebrae) can be fiendishly difficult to control. Without knowing anything about muscles you can get the idea with a string of beads - so raid that jewelry box, the bigger the beads the better. Hold the beads with both hands so there are about 7 of them (the number of neck bones) dangling free between your left and right hand. Now your left hand is the whithers and your right hand is the skull, move your right hand up and down and notice what the beads do. They sag of course! so how many extra hands would you need to hold the beads a position that would give you the outline you want and what you you do with each hand (so to speak)? Your required extra hands are doing the job the muscles do in the horse!

 

[JLav]

Just what I was thinking Spotties.

I'm no expert but I thought muscles only contracted and relaxed so not sure I see how muscles on the underside of the neck could come into play to 'hold' the neck up.

I've always thought that to some extent muscular make up and distribution is genetic as I see many young unbroken horses who have huge under neck muscles as well as many who look like they've been correctly ridden for years dispite the fact that they've never been sat on.

I think that work can then help to improve the basic muscle structure but that an upside down neck will always tend to be that way compared to a naturally better conformed horse no matter how well it's ridden. (As always there will be some exceptions but am talking very generally)

 

[JLav]

This was a great question to post and as always your explanations are incredibly detailed and a pleasure to read and ponder over. Thankyou.

 

[puddicat]

"If you lift your head up and back as if you were a horse evading and running off, you can feel you are pushing the head up with the underside muscles"

But it doesn't really work like that, you might get a sensation of pushing from stretching the muscles on the underside of your neck but muscles don't push. If you put head back it is the muscles on the back of your neck that pull it back. Also humans are bad models for comparison in this case because we have much shorter necks and the musculature is different.

Spotties: "If you hold a weight out at arms length it requires greater effort, in the horse if at the same time as extending the neck you can relax the lower neck muscles (serratus) then more of the load is held by the upper neck (splenius) "

YES absolutely

, that's the answer to that paradox I think - it takes more effort to hold a lower head carriage and hence you develop more top line!

 

[Spot1]

[ QUOTE ]
but that an upside down neck will always tend to be that way compared to a naturally better conformed horse no matter how well it's ridden.

[/ QUOTE ]

Ahh how true, something for me to fall back on (or fall forward

)

 

[puddicat]

thank you

. When we get bored I'll post what I think is the complete answer if I don't get beaten to it!

 

[Spot1]

Thank you Puddicat

[ QUOTE ]
This was a great question to post and as always your explanations are incredibly detailed and a pleasure to read and ponder over.

[/ QUOTE ]

Well said Jlav

 

[ann-jen]

I think one of the reasons people have a job visualising how the muscles work in the neck is because a lot of people think the bony part of the neck runs along the top whereas in fact it is mostly in the dorsal or bottom half.
Apologies if this pic comes out too small.

 

[ann-jen]

Sorry is way too small - can't get the hang of photobucket. Can just see the black arrows showing how the muscles work to flex/extend head and neck I think.

 

[puddicat]

"I think one of the reasons people have a job visualising how the muscles work in the neck is because a lot of people think the bony part of the neck runs along the top whereas in fact it is mostly in the dorsal or bottom half."

Yes I agree - I managed to find/pinch this photo on the web which is a bit bigger:

 

[puddicat]

ANSWER
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Or at least, what I think the answer is, there is a disclaimer: Normally I only post stuff on HHO for which there is a lot of evidence, the evidence for the following explanation is "incomplete" from a scientific perspective However, there is still a good anatomical basis for this explanation so it is by no means guesswork

Ask if you want to know where the ambiguity is or say if you think there is an error in the explanation.


"what do the bottom line muscles do that causes them to over-develop"
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Functionally the muscles bend the the neck into an arch, this has a different effect depending on where the head is. If the head is in the air (stargazing) then the effect will be to pull against the bit if the neck is long and low they will bring the head back towards the forelegs, arching the neck. Because of the effects of leverage, when the head is in the air the muscles have to work harder to fight rein contact than when the head is low so a horse with its head in the air fighting the bit will develop these muscles. So the important thing is these are muscles that develop when the horse fights the bit - a connection that Bess made .

This still doesn't completely explain why the effect of these muscles is to pull against the bit and the answer to that is to do with the position of the neck vertebrae. As ann-jen pointed out they don't follow the top line of the neck but arch upwards as you go forwards from the whithers so contracting the muscles with the head in the air causes the arch to straighten, extending the neck away from the rider and pulling against the rein. There is no doubt that this is the function of the bottom line muscles concerned, I hesitated when Silmarillion suggested "the muscles hold the head up" because one muscle, brachiocephalicus, that has a slightly different function, long story but it doesn't hold the head up!


"Why does a long low outline develop topline?"
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The muscles on the topline raise the head and neck. Spotties pointed out that the force to support the neck in a long low outline is more than when the neck is shortened and the horse is stargazing and hence the muscles will develop more with a low outline. His analogy which I think is a good one is that it is easier to hold a weight closer to the body than it is at arms length. Another analogy which is slightly closer is to imagine balancing a ladder on its end, while the ladder is upright it takes little force to stop it falling over but once it starts to fall it takes more and more force to stop it. (the ladder and its angle is anagous to the neck). Again you have to know where the bones are in the neck to realise the vertebrae form an almost upright column when the horse is stargazing. Consequently the top line muscles don't need to do much work to keep the head in this position and so don't need to be well developed, (in fact rein force may be sufficient to support the head in this position).

"Why does a long low outline not develop bottom line muscles"
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Silmarillion said that the bottom line muscles are relaxed in a long low outline so they don't develop. While probably true it's not as obvious as it appears. If anyone did the beads experiment I described you'd have noticed that to get a long low outline you need to extend the neck and it is the function of the the bottom line muscles to do this. However the horse has a ligament (nuchal lig.) that attaches to the top of all the neck vertebrae so in practice the neck can assume an extended position when the headcarriage is low without using bottom line muscles to extend the neck. (The ligament is labelled '1' in the anatomical drawing in my previous post - all the black bits on that drawing are ligaments!)

 

[Spot1]

Ahh brachiocephalicus (B.C.) Big Clue?

[ QUOTE ]
one muscle, brachiocephalicus, that has a slightly different function, long story but it doesn't hold the head up!

[/ QUOTE ]

Could this be the elusive error?

or does it lie within

I can see that with a "normal" head carriage the muscular insertions on the nuchal crest and the humerus lie on a line below (ventral) to the cervicle vertebrae so contraction can only flex the neck not hold the head up, but...

[ QUOTE ]
the vertebrae form an almost upright column when the horse is stargazing.

[/ QUOTE ]

Could it be that in this position the line of the brachiocephalicus as it approaches the nuchal crest is above (dorsal to) the cervical vertebrae in a position where it could take over from the top line muscles (splenius?) and hold up the head?

[ QUOTE ]
when the head is in the air the muscles have to work harder to fight rein contact

[/ QUOTE ]

If my supposition is plausible then you could (?) perhaps substitute [ QUOTE ]
have to work harder

[/ QUOTE ] with "are able".