We're going to go superficial to deep. So
let's start with the external obliques.
Now your external obliques fiber direction, which way does it go? This way
right. The way your fingers would be if you put your hands in your front pockets.
So you guys can write external obliques front pockets, to help you guys out a
little bit. How many of you guys look at pictures of bodybuilders and fitness
models, and you know you've seen a muscle and fitness magazine or a shape magazine,
and people get all striated in here right, you see the lines. Which direction
do those lines always go? Right because your external obliques are external
right, they're the ones that are most superficial that's what we're seeing. So
if the fiber direction is this way alright this muscle goes like this,
what joint actions is it going to cause? Yeah which rotation is it? If this
muscle shortens what's gonna happen to my spine? It's going to rotate this way?
Alright if this muscle shortens it's going to twist me this way right, which
would be contralateral rotation. So we got external obliques
contralateral rotation, what else might they do? Okay so we got we got the
obliquity thing, I told you guys muscles with a diagonal usually do
rotation, we got rotation out. There's got to be a couple other things this muscle
will do though. It's going to help with flexion right, because the obliques do lie in
front of the lumbar spine right, this is the joint that they cross there in front
of it. So external obliques flexors of the spine. I'm gonna say yeah. What else
might they do? Lateral flexion. How many of you guys think lateral flexion? Yeah I
mean how do people try to work their external obliques
a.k.a their love handles, because they're trying to spot reduce the fat over their
external obliques which absolutely doesn't work, and then they do an
exercise which is kind of ridiculous we already talked about this yesterday. They
do this one right we talked about this. Well your external obliques actually are
not your primary lateral flexor of the spine,
but do they lie lateral to the spine? Sure so they'll definitely help a little
bit, it will definitely help.
Now the other thing you have up on that chart there and this is more just some
extra information for you guys, we were talking about connective tissue this
morning right, when you open up a cadaver you don't see all these pretty red
muscles, you see a lot of white connective tissue that is especially
true in this area. The most superficial thing here on your six-pack is not your
rectus abdominis, but this abdominal connective tissue. And
you guys see a little evidence of that because what actually makes the 6-pack?
You have the Linea Alba which is the connective tissue in the middle and
then all of this these transverse little separations, which are also made of
connective tissue. They're probably there because connective tissue with its
rigidity and strength, probably improve the overall strength and ability for the
rectus abdominus to prevent what? What don't we want to do with the lumbar
spine? Forceful hyperextension right. So we have a nice nice bit of connective
tissue here to help help the rectus abdominus to its job. Just reinforce it a
bit. I think that's one of the next muscles up here, yeah rectus abdominus.
This one should be pretty easy for you guys right. Rectus abdominus runs, which
way does its fibers run? Up and down.
So it runs up and down in front of the spine. What plane do you think it's
probably going to work best in? It's a sagittal plane muscle, being that it's a
sagittal plane muscle and it's in front of the spine, what do we think it's going to
do as far as joint actions? Flexion. I
always love every once in a while I get these calls from like a writer for like one of
the magazines or whatever, and of course what do they always ask what's the best
exercise for the abs. And of course what are they talking about when they say abs
rectus abdominus, and my answer is always the same.
What's the best exercise for the rectus abdominus? Flexion. Do you have anything
other than flexion? No that's what the rectus abdominus does well. What else
could the rectus abdominus do a little bit of? Does anybody know? Like think
about your tilts, you remember your pelvic tilts right, it'll do this. Isn't
this still spinal flexion though? Yeah you have to do spinal flexion to
posteriorly tilt. So they'll be like so so the the rectus abdominus just is flexing?
Yeah and it'll posterior tilt your pelvis. But what do you mean? Oh you can
do a crunch, or you can do a reverse crunch.
I guess isometrically you could do a plank. Would anything else really affect
the rectus abdominus all that much? No. No the truth is when we look at EMG studies
guess what has the highest activity for the rectus abdominus? Crunches, reverse
crunches, like those things that actually do the action of really not that
complicated right. What keeps most people from having a 6-pack, is it the
exercise they chose? It's diet. How do you get a six-pack?
Shut your face, move your glutes right.
You want to get that tattooed, that was actually the original title of my first
book, and the agents were like you can't have shut your face and move your ass as
the title of your book, that's not going to work, and I was like why not. Internal obliques,
internal obliques. So we talked about external obliques being this way right,
those are the muscles you can see, it's fiber direction as if you put your hands
in your front pockets. Guess which way the internal obliques go? This way all
right. So it's like the direction your fingers would be if you put your hands
in your back pockets. You guys cool with that.
Internal obliques, so which way, what what joint actions are we looking at? Rotation.
We got the obliquity, we know it's on a diagonal. We know it's probably going to
contribute to rotation. You got to tell me ipsilateral or contralateral though.
If it's this way and it's going to shorten, and you guys see how that would shorten.
Exactly exactly ipsilateral, all right. What else might it do? Lateral, lateral
flexion. Yeah it's on the side of the, it's on the side of the lumbar spine.
I'll say lateral flexion. You guys think this can contribute to a sagittal plane
motion, like you can contribute to flexion or extension.
Flexion, why flexion? It's still in front of the lumbar spine right. Now remember
your lumbar spine is way back here, so all these anterior core muscles that
we spend so much, that we give so much attention right in the popular media,
they're pretty much all flexors.
Everybody's got this.
So yeah so this does get a little confusing, the contralateral versus ipsi-
lateral thing. So if you guys, let's pick two points right. These both, both these
muscles have pretty broad origins, pretty broad insertions, but let's take
the external obliques first, since we covered those first. Put one finger on
your ASIS okay, and then put one finger back on your ribs all right. Now try to
bring those two fingers closer. Which which direction did I rotate? I ended up
rotating a little bit to the left right, so that's rotation to the opposite side.
the muscle is on. Contra means against, right against our away, so that's
contralateral rotation. Now let's do the same thing with the internal obliques.
Let's pick a point, let's let's pick this little angle of your ribs here right, and
all the sudden changes let's do that one. Point on your posterior ilium and now
try to bring your fingers closer together. Yeah you guys see how that
works. So now we have a muscle on the right is rotating me which direction? To
the right. So that's the same side that would be ipsilateral. You want to totally
freak yourselves out? When I rotate to the left, which oblique am i working?
Oh yeah right external oblique right, but my left internal oblique. Muscles work
best in the direction of their fibers. Isn't it kind of true that if I rotate
this way, that this external oblique and this internal oblique kind of have the
same fiber direction, and then if I go the other way its. Transverse abdominus,
how many of you guys have heard of this muscle? Definitely a muscle a lot of
people talk about. Definitely a muscle of a lot of controversy. But the transverse
abdominus is an interesting one, because
what joint action based on its fiber direction do you guys think this muscle
Which is the fiber direction is is what? It's transverse right, that's why it's
called the transverse abdominus because its fibers are orientated transversely. Its
origin and insertion is basically the thoracolumbar fascia.
It's a little different than that in textbooks but you guys get what I'm
saying. The attachment goes from here, it
wraps all the way around and goes right back into here. So when it contracts what
actually happens? It's basically your weight belt right. You guys remember like,
you guys seen the big guys with like the, and they do, they have the big weight
belts and they it's like pull them as tight as they can before they get
underneath something like a squat, that's what this muscle is supposed to do. it's
supposed to cinch everything up ,which what that ends up doing is increasing
It also tightens this piece of fascia back here right, this thoracolumbar
fascia, it pulls it like this really tight. Is that gonna help stabilize my
lumbar spine? A little bit - yeah. It's like having guy wires on each side just
getting pulled really really tight So it'll increase stiffness in the
TLF not to be confused with the TFL right, we think that these two things
together increase the stabilization of the lumbar spine so that make sense.
Now there's some varying opinions on how effective that is,
but if you guys want to write down a couple researchers there's, I know
some of you guys are way into the core you got Richardson Hodges and Heinz, so
I'm gonna put Richardson et al. Then there's another guy named McGill who has
a little different theory, and then another guy named Liebenson who has
more research and a different approach. A lot of stuff out there. You guys heard of
Yeah so your multifidi are interesting little muscles, they're
fairly deep and they go from spinous process to transverse process. Spinous
process-transverse process, spinous process-transverse process. Very
segmentally. They're on the back of the lumbar spine
so what joint actions do you think they do? Extension, sure they have an obliquity
so what else might they can contribute to? Rotation.
So we got extension, rotation, and what we believe that's really important about
these muscles, these aren't the big extensors of the lumbar spine right.
These little tiny muscles that you see in those pictures, but they have
something different than the other extensors we're about to talk about,
which is they're segmentalIy innervated. They cross only a couple segments at a
time, so we think they're important for what we call segmental stabilization.
Which is basically, if you thought of your lumbar spine like Jenga, you guys
know the game Jenga, right you got to keep all your bricks stacked up, So if
these were the bodies of my lumbar vertebrae right, I got my five little
blocks there, what we think these muscles do is when movement or pathology or
dysfunction cause our blocks to be this way,
it might be these muscles that aren't doing their job. When movement causes us
to do something like that, one of our blocks to move out of place, we think
that these muscles doing their job will cause these blocks to do what? Straighten
back out again, does that make sense .So your multifidus
basically keep your blocks aligned. You guys ever heard the term segmental
stabilization? No. You would. That's segmental stabilization. All we're
talking about is keeping our block stacked on. It's a pretty bad thing right,
if one block slides over the other starts moving out of place, instinctively
guys do you think that's a good thing? No probably not. So we think the multifidi
have a big role in this. This is the joint actions they'll help with, but
this might be their more important function. Just like when we talked about
the rotator cuff, we talked about the rotator cuff doing external rotation,
internal rotation, abduction. But what was their important function? Dynamic
stabilization of the shoulder right. Same thing with the multifidi and the
TVA, they have an action, but their function-stabilize the lumbar spine.
Alright let's look at another big mover.
No no so the multifidi are very deep and lie right against the the facet joints
of the lumbar spine. Your TVA actually more or less stops at the thoracolumbar
fascia. Your multifidi there's layers to the thoracolumbar fascia it lies with,
sandwiched between a couple of those layers. Does that kind of make sense? I got a
bunch of pictures online, if you guys go to those muscular Anatomy articles, you
look up multifdi, you look up transverse abdominus; I have tons and
tons of pictures showing like cross-sections and stuff, so you get a
good idea of where all of this stuff exists relative to something else. The
Alright I'm going to ask a question knowing that I'm probably going to get
twelve-year-old laughs out of it, what does it mean to erect something? To
stand it up right. So if my erector spinae will erect me or stand me back up
and I started down here, what joint action is that for the spine?
It's extension. I like the erector spinae. I like the
little muscles of the back the erector spinae, even the multifidi, I just like
the way they're shaped, I think they're shaped cool, you know what I'm talking about? Looks
like an upside down Christmas tree.
Alright so if only this side of the erector spinae contracted, what would
happen to my spine? Yeah contribute just a little bit to lateral flexion.
You guys realize how long your erector spinae are? Yeah exactly, so just keep in
mind all the way down to your sacrum, all the way up to your mastoid process,
depending on which of the erector spinae muscles we're talking about. Another
thing to keep in mind, something once you guys start digging a little deeper into
your Anatomy is, is there one erector spinae muscle? Yeah, is there only one
erector spinae muscle? Yeah there's actually three, and they all do a
slightly different thing. So you have your spinalis, your iliocostalis and
your longissimus. You know at this level your okay calling it the erector spinae.
Like I said your next level once you guys get into graduate school, you start
tearing things apart, maybe do some cadaver work, you're gonna start needing
to know all of the different erector spinae muscles.
How many pushups per ring? I'm going to make you start dancing if it happens again.
You have to dance until you get your ringer to stop. Alright so what do I mean
by bilaterally and unilaterally, great question. So bilaterally means what? Both
sides. If both sides of my erector spinae fire at the same time, what are they
going to do? They're going to pull down on my spine,
pull down on my ribcage and I'm going to do this. But if only one side
unilaterally right, like unicorn one horn right, unilaterally pull down, what's
going to happen to my spine? This. Well we could see, this is where the layers come
in right, if we start dividing out these erector spinae muscles we'll see that at
least one of them will contribute a little bit to rotation, and that's one of
the larger erector spinae muscles being your iliocostalis. Usually when you see
that word cost, C O S T, costa, costol right it has to do with the ribs. Iliocostalis
is the big erector spinae muscle which goes into the ribcage, and it probably
can cause a little bit of that rotation.
Yes yeah it kind of looks like a Christmas tree depending on which one
we're talking about, but it'll be like the iliocostalis does this right. The
spinalis just goes from spinous process to spinous process like this.
The function of this class guys is to is to get down the joint actions. I'm
excited though because you guys are starting to ask deeper and deeper questions. But
as I kind of mentioned earlier when we were just warming up and going through
our Q&A today, this doesn't ever stop. It's one of the exciting things about
getting into this field is, like there are, we keep calling rabbit holes right.
There are rabbit holes to jump down forever, you find something you're into
you can just keep going, as I mentioned those those functional Anatomy articles
that I have up on my site, talking like six seven pages of text on one muscle,
and then pictures, and videos and illustrations and diagrams, and research.
Depending on what muscle you talk about you may have hundreds of research
studies to look at. Fun stuff. Quadratus lumborum,
how many of you guys have heard of this muscle before? Cool, so this muscle goes
from my 12th rib to my posterior ilium. The thing I want you guys to keep in mind
though, this isn't a superficial muscle like out here,
it's a twelfth rib to posterior ilium with some connections into these
transverse process; it's actually a very deep muscle, comparatively. Your erector
spinae are on top of them, your latissimus dorsi, transverse abdominus,
internal and external oblique, on top of them. So it's fairly deep it's like just
like this. What joint action do you think it's going to cause? Lateral flexion.
Anything else? Where would it have to be to cause extension? They'd have to be
here right, they'd have to be somewhere behind
the lumbar, at least on the spinous process, be behind the bodies of the vertebra,
this is right here. No rotation, what would it have to have to do rotation?
Some sort of obliquity, come forward a little bit, this is this is lateral
flexion. In fact your quadratus lumborum is your primary lateral flexor. This
exercise -quadratus lumborum exercise, a little bit of oblique but quadratus
lumborum. Sure quadratus lumborum is very important for stability. It is
one of those muscles we've kind of talked about though like the iliacus,
that has a propensity to get tight. If the quadratus lumborum got tight,
what is that going to do? It could pull you this way if it's one side, if it pulls on
both sides what's it going to do? Yeah it could, it could start to compress and
give you a little soreness, eventually contribute to maybe some pain and
dysfunction, you guys see how that would work. I'm not, I totally agree that the
quadratus lumborum is important to stabilization. Is this a muscle that I'm
going to write down and exercise for in a routine? Probably not. I don't think
this is something we have to individually strengthen, and I think
targeting it too hard might help contribute to that cycle of
this muscle getting a little overactive, a little tight, and contributing to some
of that low back pain that we see in so many individuals. This exercise
we'd never give anybody, and not just because it makes people look silly, like
they're trying to impersonate a wheel wobble, I think it contributes to low
back pain. Oh you guys didn't think you'd go a whole hour without doing a graph
did you? You know what that means though, we just did, you guys just finished all
the muscles for functional anatomy one. So the one thing I think I mentioned
there guys is the TVA, although it will play a role in all joint actions, it
doesn't have a joint action so it's not going to end up on this graph. Don't forget
about it though, that's what that little box at the top says. Action, plane, muscles,
exercise that includes that joint action. So this one's a little bit more like the
scapular graph we did. Whats that?
TVA what about it? TV, TV-transverse abdominus. I'm sorry did I not define
that? TVA, yeah TVA is transverse abdominus. Occasionally you'll see
it as TA, what's the problem with that one? Tibialis anterior. Your transverse
abdominus right, does that make sense? It just wraps around like this. he hasn't,
he yes exactly.