Erector spinae (back muscles)

[Music] [Applause] [Music] [Applause] [Music] [Applause] hello okay this is a challenging one then last week we looked at vertical bones and I said that we would next look at the muscles of the back so I've got lots of different models that show lots of different bits of the back the trick is that there are an awful lot of bits of the back and lots of layers so there's a student your difficulty is oh my how do I untangle all of this how do I work out what's what how do I manage all of these structures and understand what they do where they are is stuff like that I mean I imagine the last you just kind of look at the back and give up so what we'll do is we'll break it down into chunks into layers and it will make sense right but the other trick I've got is do I have enough things to show the things that I want to talk about don't know the thing applies they forgot your skeleton here I can fit him in and as I go in here I go wee man over here so we'll rotate around until we can do right okay the muscles on the back then see let's see this model here on this side we see the superficial muscles of the back so you can see trapezius up here and we can see latissimus dorsi all of these muscles of the back are very very superficial you can see the spinous processes covered by the nuchal ligament here we will talk about the spinous processes of the vertebra last week and you can palpate me on your own back on you and these superficial muscles are actually moving the upper limb really so we talked about those when we're talking about the shoulder on the upper limb so that this is the most this is the superficial layer of muscles of the back today we can ignore them these also known as a layer of extrinsic muscles of the back so trapezius that isthmus d'Orsay the rhomboids all these guys think they're gone in that first layer of the superficial muscles of the back in the next layer are the intermediate group and there are only a couple of muscles here right so do you see this this is serratus posterior inferior hopefully you remember serratus anterior as the boxers muscle the sweetest anterior muscle is passing from the ribs gives you all those fingers so slips of muscle you see and on the sides of super-heroes massive chests and these pull length of the scapula and they pull the scapular anteriorly right which gives you that reach give the box for some of the power of their punch so that's the rate as anterior that's not a muscle of the back that's a muscle of the shoulder of the upper limb but this is why this is called serratus anterior because this is serratus posterior and this is serratus posterior inferior so laters could is serrated serrated because it's a passion to the ribs and it's going down to the vertebra here we're doing all these muscles today as well we talked about these muscles when we talked about respiration so so eaters posterior inferior braces the ribs and I'll pull the ribs down helping with exploration right and if there's a serratus posterior inferior and there must be a straightest posterior superior and there it is up here we can't see it but these are the intermediate layers which we just posterior superior there are tears form underneath the rhomboid and they're elevating the ribs and also bracing the ribs that's going to need a group of muscles of the back also extremely muscles of the back also something we're going to ignore today and then we get down to the intrinsic muscles of the back also known as the deep muscles of the back this is the deep group of the deep layer and they're these muscles that you can see here now we need to think about what the function of these muscles is if these other muscles we've been talking about moving the upper limb and bracing the ribs and that sort of thing what do the deep group of muscles of the back do women need our backs to do it's one of the reasons there's always a skeleton in my Amin frame is that he's usually what I focus on so that when I stand by it I should be in focus he's more focused on me she is focused on me okay so what we do with our backs then well one of the big things we do is that when we're bent over we stand up straight again and what we're doing here is all this is them so this would be flexion of the back of this way and then just stand up again this would be extension of the vertebral column or extension of the back right so these deep muscles of the back I mean one thing they're working eccentrically to lower us like this and then they're contracting working concentric ly to extend the back and you can extend further as well right currently something else we can do is because we can flex laterally and yes we were also using the muscles of our core here there are other muscles involved just as there are pretty much in any move we make there are other muscles involved but the muscles of the back will also give some lateral flexion and a little bit of rotation but we know you can do these movements you can feel all these other muscles and deep muscles like quadratus lumborum all these other thing these are also laterally flexing the back and a probably more powerful at it but the muscles of the think group of the back can also do a better lateral flexion but their main job is extension right and this group of muscles then if we look at if this is a series of spinous processes here which you can feel you can feel lateral to that on either side a good chunk of muscle right and it kind of it bulges out around here and that's the deep group that we're talking about and there are lots and lots of muscles here and this is where students can get lost but when you when you do that and when you extend the back you can feel those muscles you can feel that bulge of muscles when you have your back and that bulge of muscles if you group all of those muscles together we call those erector spinae alright so we've got a lot of muscles in there lots of different muscles lot of different groups which we'll talk about in a minute if we group all of those muscles together all of that deep group of intrinsic muscles of the back we call them erector spinae an erector spinae is main job then is extension of the vertical column when you're bent over that is also lower you you know what I'm talking about that's erector spinae these are the muscles we're interested in today what we need to do what we need to do next then is is look at the groups within the heck within that group don't give up stay with me it's not so bad okay who should we look at so local women if you're wise we men like that he means we he's little so this is the erectus Spinney muscle group here there's serratus posterior inferior so imagine that's not there much that's been removed these are all the superficial muscles forget them it's this bulge here now we've got three layers of muscles and we can think of those three these three groups of muscles from medial to lateral and the most medial group of muscles are called spinalis or spine eyeless and the spine arles muscles or spin Arliss still Ali sounds nicer than just buying spoilers display nihilus muscles then are the most medial and for them to be the most medial then they're going to have to run between the spinous processes of the vertebrae so you can see how those muscles running between the spinous processes can help with extension of the bat first spinalis then we have a long isthmus so long muscles and the long muscles then a little bit more laterally and these are running between the transverse processes our vertebrae okay and then we have a Yoko stylist now elio cost Dallas you can break down any Oh ileum so the ileal cost Arliss muscles are coming from you can see these guys here they're coming from the iliac crest and the sacrum and they're running up to the ribs costal right up to the ribs up here like you can see here how they running out to the ribs we have spinalis most medially then Langham it long Isthmus and then any across stylus over your three groups that's almost it you have to think about we have we have groups of muscles kind of running across a number of vertebrae alright they're not attached to the vertebrae next to them they're running across a few vertebrae so we've got lots of groups of muscles overlapping and running up the length of the vertebral column so we then group those muscles by whatever region Erin lumborum if they're in the lumbar region thoracis if then they're in the thoracic region and services if they're in the neck and if they go to the ahead and head is coupled right home so if they go to the head then they get called capitis so we've got spin analyst long is Imus iliocostalis here we can see these iliocostalis muscles so these would be in eco stylish thoracis muscles do you see what I mean now not all of these layers extend the full length of the vertebral column the longest immersed group for example don't really go down into the London region so they don't have a lumborum section so we have long asommus thoracis long asommus services and that's almost here that's almost the whole picture well spoilers there's more but not for today's video we've also got some other models up some other muscles up in up in the head as I said cathetus which go to the head right ok so now up in the neck we can see this muscle here and this is another muscle of the back and it's part of that intrinsic group that do play as you can see the superficial intermediate and deep layers now do you remember when we were looking at the half section of head and we looked at the splendor of the corpus callosum like and I said splaining was a roller bandage well for some reason these muscles get called roller bandages as well why think anyway this is a bandaged muscle splenius and it's going to the head so it's capitis can you see it's going to the mastoid process here and you can feel your masters young area here right and you can feel your mastoid process here big lump of muscle pretty important anatomical landmark and that's where splenius capitis is going for so you can imagine the splenius capitis alright then another muscle as well actually deep to it it's under here and we can't see it but there's also splenius services so another splenius muscle versus of isis or services because it's just going between cervical vertebrae little gap we're looking through here that that may well be it what's under there somewhere and it's running between the vertebra at about the t3 t4 level not so bad c1 so it's covering this region here right and then we have splenius capitis here which is running from again c6 c7 t1 t2 t3 kind of down here maybe a little bit higher and then that's running out to the mastoid process of the head so you can imagine then that these going laterally is going to help with rotation of the neck and head but also like other like a rector spinae muscles it's also extending if they work together on both sides right it's going to extend the neck as part of that extension of the back that make sense plus chipiya start a whole bunch of other muscles they're all they're all acting together as they always do but that's all those muscles do okay so have that last week we looked at the vertebrae you know all about the spinous processes and the transverse processes and allowing the pedicles and things like that and today we've talked about many of the deep muscles of the back of the superficial intermediate and deep muscles we've talked about the deep muscles of the back and how those attach to the vertebrae and work together as erector spinae to extend the back the other muscles we talked about in the upper limb as I said now hopefully the back doesn't seem too terrifying or too complicated to you anymore even if it did in the first place there is a lot going on here but just think about those functional units but unfortunately there is more this is got a block that comes out so there are also there's an even deeper layer of the muscles of the back now you might read different descriptions and different textbooks for Groovy's these groups of muscles differently don't worry about that we would you like to describe things in different ways but while I was talking about erector spinning being part of the deep muscles of the back which is one way of describing them and being part of the intrinsic group of muscles of the back there's an even deeper layer of muscles called the transverse Oh spinal muscles and these guys are really really deep and they run between the processes of pretty much adjacent vertebrae and they do a whole bunch of other things these guys are involved in back pain back spasms that sort of thing whole battle will come back to those guys next week to chunk by chunk by chunk and then you'll understand the anatomy of the musculature or the musculature at the back all right well yeah there is a lot here [Music]

Channel: Sam Webster

Views: 469,956

Keywords: anatomy, human anatomy, back, vertebrae, spine, erector spinae, longissimus, spinalis, iliocostalis, lumborum, cervicis, thoracis, Sam Webster, dontbeasalmon

Id: ng5ToMRptT0

Length: 15min 48sec (948 seconds)

Published: Mon Jul 10 2017