June 5, 2025 • 15 mins
Today's episode looks at the wild world of extension in the Pilates repertoire! We explore the muscles involved in extension, the planes of movement, and how our spinal flexors and extensors work together to move our spine into different shapes. Tune in!
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Show Notes:
Check out these related episodes to learn more about shapes of the spine!
The Shapes Your Spine Makes In Pilates
Shapes Of The Spine - Lateral Flexion
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Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
Olivia (00:09):
Hello.
Hello everybody.
Welcome and welcome back toPilates Students Manual, helping
you get the most out of yourPilates classes.
I'm your host, Olivia.
You get the latest updatesabout everything I'm working on
by joining the community atbuymeacoffee.com/OliviaPodcasts.
Or you can follow along onInstagram at
(00:29):
@PilatesStudentsManual.
Pilates Teachers' Manual (00:31):
The Book is now available for
purchase as both an EPUB and PDFand on Kindle.
You can purchase the book andother podcast merch at
shop.OliviaBioni.com.
As I shared in previousepisodes, we'll be looking at
the shapes that our spine makesin this little mini series on
(00:53):
the show.
One of the unique things aboutPilates is that we do move our
spine in all directions.
Not that every exercise byitself is gonna do everything
but Pilates as a system is gonnahave our spine bending forward,
bending backwards, sidebending, and rotating.
Today's episode is all aboutspinal extension, which is
(01:14):
sometimes called the J curve, aback bend, cow stretch, or even
the swan shape.
And the reason it's a J curveinstead of a C curve going the
other direction is because ourspine does not extend equally
across all the different bonesin our spine.
Our vertebrae or spine bonesdon't actually all look the
same, which means that they alsodon't articulate or move the
(01:38):
same.
When we do a back bend, ourlower back- or lumbar spine has
much more extension in it, likea greater degree of extension
than our upper back- or ourthoracic spine.
Our upper back, if you look atsomeone doing a backend kind of
looks flat when we're doing thebackend with the vertical part
(02:00):
of the J being like your upperspine, and then the curve of the
J being the extension that'shappening in the lumbar spine.
And the reason that our spinebends like that is because in
addition to the bones beingdifferent shapes so that they
move differently, our spine alsohas like curves in it, right?
(02:21):
So if you were lying on yourback on the mat, your neck bones
are not touching the floor,right?
Our neck curves away from themat, and that curve away from
the mat is called a lordosis,which just means extension in
the spine.
We also have a lower doses inour lower back.
(02:42):
There is a slight curve inbetween where our ribs attach
and the top of our pelvis.
In our upper back, we havewhat's called a kyphosis, which
is the opposite of a lordosis.
A kyphosis means that our upperspine is statically rounded a
little bit, or flexed, andbecause of those curves, our
(03:05):
spine kind of looks like asubtle S shape with a little
extension in the neck, a littleflexion in the upper back, and a
little extension in the lowerback.
Before you panic, the curvesthat we have in our spine are
normal and also have a veryspecific function.
Those curves help distributeimpact and just the load of our
(03:26):
bodies under gravity as we'removing, and they're an
adaptation that we have becausewe hold ourselves up vertically.
Babies, for example, havestraight spines because they
don't have to hold up theirtrunk against gravity.
As soon as we get vertical,this is just the shape that our
spine makes.
The S-curves in our spine aregreat and we don't have to worry
(03:49):
about them.
Given the neutral position ofour spine having curves in it,
this is also why extension looksa lot like a J shape, and also
why the back bend isn't going tolook evenly spread through all
the bones of the spine.
Our lumbar spine is doing themost extension, so it's not that
(04:11):
we're "dumping into our lowback," I've heard that said
before.
That's just the part of thespine that extends the most.
The plane of movement thatwe're working in when we're
doing spinal extension is thesagittal plane, which is the
same plane of movement forspinal flexion.
Remember that a plane ofmovement is like if you were cut
(04:32):
in half by a pane of glass, andwhat way could you move with
that pane of glass?
So for flexion and extension,we're cutting right down the
middle, separating our rightside and our left side, which
staying on that pane of glass,we would be able to curl forward
like in a chest lift or astanding forward fold, or the
(04:54):
roll up, and also extendbackwards like we could curl
forwards or extend backwards.
That happens in the same plane.
They both happen in thesagittal plane.
As I shared in the lastepisode, the sagittal plane is
also the easiest plane ofmovement for me to remember
because of the astrological signSagittarius.
(05:15):
Because Sagittarius is anarcher, that action of drawing a
bow back is movement in thesagittal plane and something
about that, I just always thinkflexion, extension, sagittal
plane, it makes sense to me.
So for our arm, that would bethe drawing the bow back.
That would be the sagittalplane.
For our spine, it would becutting us right down the
(05:37):
middle, separating our left sidefrom our right side.
Spinal extension shows up inour Pilates repertoire in quite
a few places.
It's in the one leg kick,double kick, swan dive, swimming
rocking, and Joe's version ofShoulder bridge can get us some
lumbar extension.
(05:58):
Remember that in order toextend the spine into that back
bend shape in our bridge, for itto be extension, our hips have
to be higher than our knees,which in Joe's version, we are
propped up on our forearms withour hands at the back of our
pelvis, and the length of ourforearm is quite a lot, and
(06:22):
that'll get our hips high enoughto get us some lumbar
extension.
In a hinge bridge, by contrast,where we make a diagonal line
from our knee to our hip to ourshoulders.
We aren't extending the spine.
We're pretty much in a neutralspine for our lumbar and
thoracic spine.
(06:42):
However, in both Joe's versionof Shoulder Bridge and a Hinge
Bridge, our cervical spine, orour neck bones are flexed,
almost exactly the same as theyare in a chest lift.
We're just lifting our torso upinstead of lifting our chest
(07:03):
up.
On the reformer, there's alsosome great extension work in
semicircle, snake and twist,thigh stretch, breast stroke,
rocking, swimming, pullingstraps, and down stretch.
So many great ways to move thespine into that extension shape.
The muscles that are primarilyresponsible for extending the
(07:25):
spine are what are called ourspinal extensors.
Their name is their job.
They extend the spine.
They are our erector spinae,they are our semispinalis, and
other deep posterior spinalmuscles.
And all of these muscles runalong our spine, up and down,
(07:47):
parallel with it.
When they get shorter, theypull our head, our shoulders,
our upper back towards our hips,towards our butt, and that is
the shape of extension.
We can visualize that if wewere lying on our stomach and we
wanted to lift our head,shoulders, and upper back off of
(08:07):
the floor, which is extendingthe spine from a prone position.
Those muscles in our back bodywould get short against the load
of gravity and our body weightand lift us into that shape.
It's extension.
When we arch our back or extendthe spine, we're shortening all
of those muscles in the backbody.
They're contracting and that'swhat's making us move.
(08:29):
But we are lengthening all ofthe muscles in the front of our
body because the muscles in ourback body, in order to get
shorter the muscles in the frontof our body have to get longer
to balance that.
The same thing happens when wecurl forward.
When you do the roll up, themuscles in the front of the body
(08:51):
are getting shorter contractingagainst load, but the muscles
on your back body have tostretch.
They have to get longer toaccommodate that change in
position.
Extrapolating from there, ifyou really strongly engaged your
abdominals and other spinalflexor muscles in the front of
your body, you would not be ableto do a back bend.
(09:14):
If you engage your abs so muchthat they prevent you from
moving because they're sobraced, you can't do a back
bend.
And you can't do a forward foldif you're tensing and
tightening all of the muscles inyour upper back.
Like sometimes if you are not asuper flexible person, when you
(09:36):
do a seated forward fold or astanding forward fold, you may
have been told, oh, this is abig stretch for the back of your
legs, but you might be like,actually, I feel a stretch in my
upper back.
You know, like it's all of thatback line that has to get
longer because the front body isshortening.
So that is a very simpleexplanation of extension, but
(09:59):
that's the general idea ofwhat's going on when we're doing
a backend.
Our spinal extensors are themuscles that pull us into our
backend, and they also take usout of spinal flexion.
Okay, buckle up.
What do I mean by that?
Let's think of the example fromlast episode about doing a
(10:23):
standing roll down.
We're starting standingvertically, neutral spine, and
we're rolling down and reachingfor our toes.
Our spine is flexed.
We're working with the load ofgravity and our body weight, and
gravity is always pulling ourbody weight straight down.
When we're standing up androlling down, our body weight is
(10:47):
going the same direction asgravity.
Even though we're making theround shape with our spine, the
muscles that are resistinggravity and stopping us from
collapsing in a puddle on thefloor, are our back muscles, our
spinal extensors.
But why?
What muscles are working andwhat we're doing is always
(11:12):
relative to the position thatwe're in.
So in a standing forward fold,when our spines are all the way
flexed, rolling back up tostanding is going from a flexed
spinal shape to a neutral spinalshape, and the action of moving
(11:32):
out of flexion, from flexion toneutral is extension.
Stay with me.
Let's talk about the conversebecause that is also true.
If we were standing up in aneutral spine and we did a
standing back bend, like we'repushing our hips forward, we're
looking up at the ceiling, eventrying to look behind us, and
(11:55):
we're making that standing swanshape.
Going into the back bend isextending the spine because
that's making that shape, butthe muscles that are holding us
up against gravity, because justlike folding forward, there's a
point in a back bend where yourbody weight and gravity are
going the same direction.
So the muscles that are holdingus up are actually our flexors.
(12:19):
When we're in a backend, what'sstopping us from collapsing is
our flexors.
And moving from that extendedspine shape, the standing back
bend and then pulling yourselfup against gravity to come to
neutral- from extension toneutral- is spinal flexion.
(12:39):
The muscles on the front of ourbody are pulling us out of that
back bend into the neutralposition.
Now I also want you to keep inmind that it's not like a
hundred percent, one musclegroup is doing one thing and
then they like all turn off andthen it's a hundred percent the
other muscle group, like there'ssome coordination so that the
(13:02):
front and back sides of our bodyare working together, and as
the front of our body is gettinglonger in that back bend, the
back of our body is resistingthat at a matching rate.
If the extensors totally let gowhen the flexor muscles were
pulling us back up, we would getwhiplash because we would just
(13:24):
be flung forward.
Our muscle groups have to worktogether as a team, and the
better we get at having ourmuscle groups work together,
that's how we make movementssmoother, and we're more
coordinated and we're moregraceful because there's like an
elegance and an ease, orhowever you wanna describe it,
(13:44):
but it's really just excellentmuscle control and they're
working together.
The best way to strengthen themuscles that perform spinal
extension is to find a way towork them against load, which is
often why we're lying on ourstomach when we work our spinal
extensors in Pilates.
When we're lying on our belliesin that prone position, it puts
(14:06):
us in a great spot to try tolift ourselves off of the
ground, which is using ourextensor muscles.
Get excited 'cause there's onemore episode in this Shapes of
the Spine series.
Stay tuned to learn more aboutspinal rotation next, and I hope
you're loving this series,learning more about how the
spine moves as much as I am,because I am really enjoying
(14:29):
talking about it.
Huge thank you to all mysupporters on Buy Me a Coffee.
It is June.
Holy moly.
So there's another newsletteron the way with that option to
have a coffee chat with me.
I'm really looking forward tothat.
I hope you have a great coupleweeks and we'll talk again soon.
Hello.
Hello everybody.
Welcome and welcome back toPilates Students Manual, helping
you get the most out of yourPilates classes.
I'm your host, Olivia.
You get the latest updatesabout everything I'm working on
by joining the community atbuymeacoffee.com/OliviaPodcasts.
Or you can follow along onInstagram at
(00:29):
@PilatesStudentsManual.
Pilates Teachers' Manual (00:31):
The Book is now available for
purchase as both an EPUB and PDFand on Kindle.
You can purchase the book andother podcast merch at
shop.OliviaBioni.com.
As I shared in previousepisodes, we'll be looking at
the shapes that our spine makesin this little mini series on
(00:53):
the show.
One of the unique things aboutPilates is that we do move our
spine in all directions.
Not that every exercise byitself is gonna do everything
but Pilates as a system is gonnahave our spine bending forward,
bending backwards, sidebending, and rotating.
Today's episode is all aboutspinal extension, which is
(01:14):
sometimes called the J curve, aback bend, cow stretch, or even
the swan shape.
And the reason it's a J curveinstead of a C curve going the
other direction is because ourspine does not extend equally
across all the different bonesin our spine.
Our vertebrae or spine bonesdon't actually all look the
same, which means that they alsodon't articulate or move the
(01:38):
same.
When we do a back bend, ourlower back- or lumbar spine has
much more extension in it, likea greater degree of extension
than our upper back- or ourthoracic spine.
Our upper back, if you look atsomeone doing a backend kind of
looks flat when we're doing thebackend with the vertical part
(02:00):
of the J being like your upperspine, and then the curve of the
J being the extension that'shappening in the lumbar spine.
And the reason that our spinebends like that is because in
addition to the bones beingdifferent shapes so that they
move differently, our spine alsohas like curves in it, right?
(02:21):
So if you were lying on yourback on the mat, your neck bones
are not touching the floor,right?
Our neck curves away from themat, and that curve away from
the mat is called a lordosis,which just means extension in
the spine.
We also have a lower doses inour lower back.
(02:42):
There is a slight curve inbetween where our ribs attach
and the top of our pelvis.
In our upper back, we havewhat's called a kyphosis, which
is the opposite of a lordosis.
A kyphosis means that our upperspine is statically rounded a
little bit, or flexed, andbecause of those curves, our
(03:05):
spine kind of looks like asubtle S shape with a little
extension in the neck, a littleflexion in the upper back, and a
little extension in the lowerback.
Before you panic, the curvesthat we have in our spine are
normal and also have a veryspecific function.
Those curves help distributeimpact and just the load of our
(03:26):
bodies under gravity as we'removing, and they're an
adaptation that we have becausewe hold ourselves up vertically.
Babies, for example, havestraight spines because they
don't have to hold up theirtrunk against gravity.
As soon as we get vertical,this is just the shape that our
spine makes.
The S-curves in our spine aregreat and we don't have to worry
(03:49):
about them.
Given the neutral position ofour spine having curves in it,
this is also why extension looksa lot like a J shape, and also
why the back bend isn't going tolook evenly spread through all
the bones of the spine.
Our lumbar spine is doing themost extension, so it's not that
(04:11):
we're "dumping into our lowback," I've heard that said
before.
That's just the part of thespine that extends the most.
The plane of movement thatwe're working in when we're
doing spinal extension is thesagittal plane, which is the
same plane of movement forspinal flexion.
Remember that a plane ofmovement is like if you were cut
(04:32):
in half by a pane of glass, andwhat way could you move with
that pane of glass?
So for flexion and extension,we're cutting right down the
middle, separating our rightside and our left side, which
staying on that pane of glass,we would be able to curl forward
like in a chest lift or astanding forward fold, or the
(04:54):
roll up, and also extendbackwards like we could curl
forwards or extend backwards.
That happens in the same plane.
They both happen in thesagittal plane.
As I shared in the lastepisode, the sagittal plane is
also the easiest plane ofmovement for me to remember
because of the astrological signSagittarius.
(05:15):
Because Sagittarius is anarcher, that action of drawing a
bow back is movement in thesagittal plane and something
about that, I just always thinkflexion, extension, sagittal
plane, it makes sense to me.
So for our arm, that would bethe drawing the bow back.
That would be the sagittalplane.
For our spine, it would becutting us right down the
(05:37):
middle, separating our left sidefrom our right side.
Spinal extension shows up inour Pilates repertoire in quite
a few places.
It's in the one leg kick,double kick, swan dive, swimming
rocking, and Joe's version ofShoulder bridge can get us some
lumbar extension.
(05:58):
Remember that in order toextend the spine into that back
bend shape in our bridge, for itto be extension, our hips have
to be higher than our knees,which in Joe's version, we are
propped up on our forearms withour hands at the back of our
pelvis, and the length of ourforearm is quite a lot, and
(06:22):
that'll get our hips high enoughto get us some lumbar
extension.
In a hinge bridge, by contrast,where we make a diagonal line
from our knee to our hip to ourshoulders.
We aren't extending the spine.
We're pretty much in a neutralspine for our lumbar and
thoracic spine.
(06:42):
However, in both Joe's versionof Shoulder Bridge and a Hinge
Bridge, our cervical spine, orour neck bones are flexed,
almost exactly the same as theyare in a chest lift.
We're just lifting our torso upinstead of lifting our chest
(07:03):
up.
On the reformer, there's alsosome great extension work in
semicircle, snake and twist,thigh stretch, breast stroke,
rocking, swimming, pullingstraps, and down stretch.
So many great ways to move thespine into that extension shape.
The muscles that are primarilyresponsible for extending the
(07:25):
spine are what are called ourspinal extensors.
Their name is their job.
They extend the spine.
They are our erector spinae,they are our semispinalis, and
other deep posterior spinalmuscles.
And all of these muscles runalong our spine, up and down,
(07:47):
parallel with it.
When they get shorter, theypull our head, our shoulders,
our upper back towards our hips,towards our butt, and that is
the shape of extension.
We can visualize that if wewere lying on our stomach and we
wanted to lift our head,shoulders, and upper back off of
(08:07):
the floor, which is extendingthe spine from a prone position.
Those muscles in our back bodywould get short against the load
of gravity and our body weightand lift us into that shape.
It's extension.
When we arch our back or extendthe spine, we're shortening all
of those muscles in the backbody.
They're contracting and that'swhat's making us move.
(08:29):
But we are lengthening all ofthe muscles in the front of our
body because the muscles in ourback body, in order to get
shorter the muscles in the frontof our body have to get longer
to balance that.
The same thing happens when wecurl forward.
When you do the roll up, themuscles in the front of the body
(08:51):
are getting shorter contractingagainst load, but the muscles
on your back body have tostretch.
They have to get longer toaccommodate that change in
position.
Extrapolating from there, ifyou really strongly engaged your
abdominals and other spinalflexor muscles in the front of
your body, you would not be ableto do a back bend.
(09:14):
If you engage your abs so muchthat they prevent you from
moving because they're sobraced, you can't do a back
bend.
And you can't do a forward foldif you're tensing and
tightening all of the muscles inyour upper back.
Like sometimes if you are not asuper flexible person, when you
(09:36):
do a seated forward fold or astanding forward fold, you may
have been told, oh, this is abig stretch for the back of your
legs, but you might be like,actually, I feel a stretch in my
upper back.
You know, like it's all of thatback line that has to get
longer because the front body isshortening.
So that is a very simpleexplanation of extension, but
(09:59):
that's the general idea ofwhat's going on when we're doing
a backend.
Our spinal extensors are themuscles that pull us into our
backend, and they also take usout of spinal flexion.
Okay, buckle up.
What do I mean by that?
Let's think of the example fromlast episode about doing a
(10:23):
standing roll down.
We're starting standingvertically, neutral spine, and
we're rolling down and reachingfor our toes.
Our spine is flexed.
We're working with the load ofgravity and our body weight, and
gravity is always pulling ourbody weight straight down.
When we're standing up androlling down, our body weight is
(10:47):
going the same direction asgravity.
Even though we're making theround shape with our spine, the
muscles that are resistinggravity and stopping us from
collapsing in a puddle on thefloor, are our back muscles, our
spinal extensors.
But why?
What muscles are working andwhat we're doing is always
(11:12):
relative to the position thatwe're in.
So in a standing forward fold,when our spines are all the way
flexed, rolling back up tostanding is going from a flexed
spinal shape to a neutral spinalshape, and the action of moving
(11:32):
out of flexion, from flexion toneutral is extension.
Stay with me.
Let's talk about the conversebecause that is also true.
If we were standing up in aneutral spine and we did a
standing back bend, like we'repushing our hips forward, we're
looking up at the ceiling, eventrying to look behind us, and
(11:55):
we're making that standing swanshape.
Going into the back bend isextending the spine because
that's making that shape, butthe muscles that are holding us
up against gravity, because justlike folding forward, there's a
point in a back bend where yourbody weight and gravity are
going the same direction.
So the muscles that are holdingus up are actually our flexors.
(12:19):
When we're in a backend, what'sstopping us from collapsing is
our flexors.
And moving from that extendedspine shape, the standing back
bend and then pulling yourselfup against gravity to come to
neutral- from extension toneutral- is spinal flexion.
(12:39):
The muscles on the front of ourbody are pulling us out of that
back bend into the neutralposition.
Now I also want you to keep inmind that it's not like a
hundred percent, one musclegroup is doing one thing and
then they like all turn off andthen it's a hundred percent the
other muscle group, like there'ssome coordination so that the
(13:02):
front and back sides of our bodyare working together, and as
the front of our body is gettinglonger in that back bend, the
back of our body is resistingthat at a matching rate.
If the extensors totally let gowhen the flexor muscles were
pulling us back up, we would getwhiplash because we would just
(13:24):
be flung forward.
Our muscle groups have to worktogether as a team, and the
better we get at having ourmuscle groups work together,
that's how we make movementssmoother, and we're more
coordinated and we're moregraceful because there's like an
elegance and an ease, orhowever you wanna describe it,
(13:44):
but it's really just excellentmuscle control and they're
working together.
The best way to strengthen themuscles that perform spinal
extension is to find a way towork them against load, which is
often why we're lying on ourstomach when we work our spinal
extensors in Pilates.
When we're lying on our belliesin that prone position, it puts
(14:06):
us in a great spot to try tolift ourselves off of the
ground, which is using ourextensor muscles.
Get excited 'cause there's onemore episode in this Shapes of
the Spine series.
Stay tuned to learn more aboutspinal rotation next, and I hope
you're loving this series,learning more about how the
spine moves as much as I am,because I am really enjoying
(14:29):
talking about it.
Huge thank you to all mysupporters on Buy Me a Coffee.
It is June.
Holy moly.
So there's another newsletteron the way with that option to
have a coffee chat with me.
I'm really looking forward tothat.
I hope you have a great coupleweeks and we'll talk again soon.
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