-: Today we're gonna talk about how the rear delt functions
and why most people are doing rear delt exercises
that really aren't very efficient.
And to be honest, most people kinda grow this thing
by accident because they train it more on back day
or when they're trying to train their lats
and they actually are missing it when they're doing
a lot of direct rear delt work.
So what we have to look at is how the rear delt
actually situates and aligns with the upper arm.
So, we have a scapula on here, okay.
What you need to understand is those rear delt fibers
they come and attach to this ridge, okay.
So what that means is the orientation of those fibers
is going to change throughout the position.
So if Adam puts his arm kind of forward here,
right, the deltas, or the delts is gonna be
lined up differently 'cause the scapula does that.
As he pulls back, right, it's going to come around this way.
So the scapula goes through this type
of a motion as the arm would go through,
say a row or pressing type of position here.
When we get into stuff where we're
doing like straight here, okay.
What you also have then, is that the scapula,
because the arm is up it's, a-b-ducted like this.
Well you have the scapula at this tipping point, right.
Which means, okay, the fibers are here
but what I want you to understand is
when we look in a muscle that is
a convergent muscle, or fan muscle,
or anything that has like a long base of origin.
What that means is those fibers are gonna have
varying degrees of pull and there are going
to be places where more of those fibers can be involved.
So, if we look at Adam's shirt here.
What I've taken, is in green, is I've drawn
these rear delt fibers, not very well,
it's the limit of my artistic ability here
But, you see this border here and then you see
these fibers kinda coming at an angle here.
My goal, if I was gonna try and get
as much contraction out of this rear delt,
like every singe fiber, is what I would want is like,
I would want all of these fibers
to be actually 90 degrees from that.
'Cause what that would mean, so if we bring Adam
into something like this, and bring him here.
Now here's that ledge, and those fibers
are coming off this way.
What that means is, all of these fibers are efficient
and at a good length to be able to actually
produce force into pulling his arm into extension.
So, at that position, like and you can just tell,
like even with the shirt you can see
how big and bulked up that rear delt is.
So if we are looking at how to actually
get the most out of a rear delt contraction,
we would want to emphasize these exercises
where we're actually lining that up.
So when we do a, quote unquote, rear delt row,
what we're trying to find is where in this position
are these fibers lined up the most.
And the body gives you feedback that this is really
good in terms of being able to keep tension
on this and be able to stabilize that joint.
Because when you are perfectly lined up here
it will also be the greatest degree of extension
So that's what Adam can get there.
But if I bring him down lower, he can't get as much.
If I bring him up higher, can't get as much.
But if I line him up right here,
he can get the most extension.
His body's gonna allow him to go there
to the greatest degree because that's actually where
these fibers have the leverage to take him.
If I take him down here, what happens is this side
of the delt got short, this side of it got lengthened.
So the muscle's not gonna be able to go
to full lengthening or a full shortening of all the fibers
because some of them are pre-shortened and pre-lengthened.
Same thing up here alright, so these little guys now
are pre-shortened and these are pre-lengthened.
So, the leverage within that muscle changes.
I'm not able to use that whole delt as efficiently
because if the whole delt contracted hard,
these fibers down here would actually want to do this.
So, if my intent is I'm doing
one of these exercises like this.
I really can only attack to a certain portion
of that rear delt maximally and I can't really
produce maximal tension in here
because that would provide a kind of like down.
It would try to pull me back into this position.
So when you've got people up here
and you see them doing all sorts weird stuff,
like they can't maintain their elbow position,
they have a hard time and it jumps to the teres,
they shrug, they do all sorts of stuff.
Well it's because this is a crappy movement
to try and isolate the rear delt.
So, there's no way that you can maintain that movement
and maintain that tension if you're trying to maximally
contract this because it would take the arm somewhere else.
So you're gonna to get rotating forces.
And, if you're doing this on like a pec deck
where this can't move and you got people in here
and they're trying to push, right.
It doesn't matter that it can't move.
Their arm is still kinda like trying to do this
and so you'll as people who do this,
they're like, they get like that.
It's like a sag, it looks like a sagging position, right.
And when you see that, right.
Well if the rear delt was pulling,
it would be pulling this here.
If this happens, well that technically you see that that's
those fibers actually having to let go a little bit, right.
So, that's where, oh okay, well these guys got involved,
then those guys had to let go, more teres,
more infraspinatus, things like that had to be involved
in here to be able to facilitate that movement, right.
So you're actually taking away from the rear delt,
the harder and harder you try in those fixed movements.
So, if you wanna grow rear delts,
you have to use a position where all
of these fibers are going to be in line.
Another thing that's very common with this.
So when we're training rear delts,
is people like, oh you're not supposed to feel it here
you're supposed be like maximally depressing, right.
We don't wanna see any elevation
or, you know, we don't want to see these upper traps
'cause these are evil things that
shouldn't exist on people right.
Upper traps are bad, they cause scapular instability
and they just ruin everybody's posture.
BS.
Here's what you need to understand.
If, we put the scapula here on Adam, right,
and we have these, these rear delt fibers right.
They're pulling this way,
they're trying to pull this, this way.
What is going to prevent the scapula from being pulled
this way and allow the arm instead to be pulled this way?
Well, it's this stuff right here, this musculature.
The rhomboids and the upper traps
are what's directly stabilizing.
So it's these guys that are pulling up
that allows this stuff to pull on the arm.
'Cause if there was nothing to pull it,
to stabilize the scapula this way,
the rear delt would just pull the scapula around, right.
So when we see things like, oh we got winging
or people can't retract, or whatever.
Well if you are focusing on driving down
and that's, okay, we look at these rear delt,
or not rear delt, lower trap fibers here.
These guys are gonna take and they're gonna
pull this, this way, right.
So they're gonna take and rotate this this way, down.
Which means the arm should need to go up.
But if we're doing a row or if we're
holding something here and we're not allowing
that to move but we're trying to do this.
Well what I'm doing actually is I'm taking,
and by trying to do this, I'm inhibiting
the very musculature that needs to provide
the counterforce for this to be able to produce tension
against whatever load I happen to be doing.
So, if I'm doing a row, right.
I can only pull as hard with this rear delt,
it can only pull this way as much
as I have stability on this side.
'Cause there's nothing else holding
that scapula in place, right.
As you come up here, right, now the force
is a little bit more this way.
So then the rhomboid becomes a little bit more important.
And that's kinda how we differentiate
our upper back training.
It's like, okay, if we want rear delt,
we want everything to be lined up perfectly with that.
If we want the rhomboid to take a little bit more load
in that and we want it to function a little bit greater
in stability, we'll bring the arm up.
That way there's a little bit more of a horizontal
pull on that scapula that those rhomboids actually
come in and provide the counterforce for.
If I wanna work more lower trap.
Well what I actually wanna do then
is I wanna take Adam and put him in a position
where these delts are gonna be pulling the scapula
this way so that the lower traps have to counteract
by pulling it this way, right.
And what that's gonna do it that's gonna say,
well okay these guys they helped have,
need manage the tipping, right.
Which is what they should do.
They should be managing that scapular in motion.
But they're not actually contributing to the load.
Because the load here, If I were pushing Adam here,
it's gonna wanna pull the scapula that way.
You can see on the shirt like, it's gonna wanna pull
the medial and rear delts, pulling this way.
And that's gonna make these lower trap fibers
the best in terms of resisting that.
So when we're looking at,
how do I train any of this musculature?
I always have to look at, well okay
what needs to be stabilized in the scapula
in that particular position against
the muscles that are pulling on it.
So, what muscles are working to pull on the scapula
in this direction versus this direction?
I'd line those two up and then I'm gonna be able
to know exactly where I'm hitting
the upper back and shoulder musculature.