-: So I wanna talk to you guys about using cuffs
instead of holding things in your hands,
and whether or not that is a good idea.
But in order to understand that,
you need to understand why we have two joint muscles,
muscles that cross multiple joints.
Because if we think of it,
so for instance we have the bicep here which is just,
its main job is going to be to flex the elbow.
Why does it not just attach here and here.
That would be way more efficient at doing elbow flection
instead of attaching all the way through
to this scapula where,
so it has to pull up all the way here,
right and its actually less efficient
at doing elbow flection that way because its gotta cross
all this tissue and lose its leverage a little bit there.
But I have other muscles that can do just that by itself.
I have muscles that can isolate the should joints, right.
So I have the anterior delts and the coracobrachialis
that can do shoulder flection this way.
So the reason that we have two joint muscles
is to actually be able to repurpose force.
Okay, and let me explain what that means.
So we take Adam this way.
And I put a dumbbell in his hand, right.
So say there's 20 pounds this way.
If this wasn't secure, what would happen is that 20 pounds,
if his elbow was locked, say we glued his elbow
at this 90 degree,
what would happen is it would (click),
it would hang that way, right?
So because this load's essentially going to rebalance
and recenter underneath that shoulder joint,
if this could freely pivot.
So one of the things that having two joint muscles
is that bicep actually being able to pull against this,
but what its also doing
is its kind of providing some force this way.
So it functions as a fixator at the shoulder.
That is very different than saying that the bicep does this,
which would be incorrect.
Anatomically, you could say, well okay,
if we pulled the bicep, it would do that.
But when we incorporate what the joint functions as
and how the nervous system works and what we look at
is we actually see well the bicep when we were doing that,
it can't do this, because in order to do that,
it would have to provide more tension to do that.
So the only force that the bicep actually ever replies here
is just repurposed from the load that is here.
So combining this is not more bicep,
and training this is not more bicep function.
Just like training this is not more tricep function, right.
The only load that the tricep is actually going
to contribute to say force that would act
as shoulder extension is going to be repurposed from here.
So its not acting as a shoulder extensor,
it's just repurposing the tension that its using
to do elbow extension to help decrease the load
on all of the other muscles that have to control
the shoulder position.
Because if I'm already creating whatever amount of tension
that it takes, so if this is 20 pounds,
let's say that its 100 pounds of tension in the bicep,
but if I'm already creating that 100 pounds of tension,
wouldn't it make sense if I could use that hundred pounds
of tension other places without having to expend
more energy, more ATP.
It allows me to reuse that same work at no extra cost.
So we have two joint muscles,
muscles that cross multiple joints,
to repurpose force, to save energy,
and to make it easier for us to stabilize that joint.
So what we have to look at is what happens when we start
doing things like cuffs.
So let's use a chest fly as an example.
So we'll see people, right,
and instead of actually having a load out here
in their hand doing a fly this way,
what they'll do is they'll put an ankle cuff here,
and they will do the fly this way.
So what that does is it shortens the lever, right,
it takes the bicep out of the equation.
But now my pec does not cross multiple joints.
It just crosses the shoulder.
So its gunna pull in,
and so if I have Adam turn around.
As that pec pulls in, right,
there's nothing that's being repurposed
to stabilize the joint this way.
So if we have our free moving joint here.
As Adam starts to pull in with that pec, right,
the pec pulling across is creating this type of force.
So what has to happen is one, the scapula muscular has
to allow for the appropriate articulation of that scapula.
So again we don't want to be over retracting or repressing,
we need to let this go.
But that still requires there to be quite a bit
of stability cuz the pec is not only pulling out,
its also pulling this way.
So if you think of that, right.
So the pec is pulling this out and this way, right,
so you see that force?
Now imagine I had tension in the bicep that was pulling
the joint back in that way.
That would be pretty efficient, right?
So if the pec is pulling this way,
but the bicep is pulling this way,
and both of them are helping actually contribute
to this should AD duction, if you will.
So if we bring Adam back around,
if he has load in the bicep, right,
so say if we're doing a fly,
and he's got, we'll use the same 20 pounds over here.
So he's got 20 pounds out here.
That 20 pounds is gonna be loaded in the bicep,
but the bicep is not going to curl this way.
What its gonna do, since Adam's trying to a fly,
he's not trying to flex his elbow,
is that isometric contraction in the bicep
is going to provide a force that is pulling in this way.
It would be the same as if we took a band in Adam's hand,
his bicep essentially, look at it this way,
right, imagine it, we've got this thing crossing two joints.
It's taking the load here,
and using it to pull this joint tight that way, right?
And what that also does is that then it allows the tricep
to also contract, so essentially what I've done here
is I've made an almost compression-type force
on that joint to be able to hold it together,
so now as the pec pulls around,
my bicep and my tricep are actually able
to stabilize the joint.
So they're repurposing the force of whatever's
in my hand to actually help hold the glenohumeral joint
together, to hold the humorous and the scapel together,
as this pec pulls across.
What that does is it means I don't have to make
as much antagonistic forces.
So if I didn't have that, if I don't have biceps here,
as this pulls across, what that means is,
I have to actually contract more stuff,
I have to contract more infraspinatus,
more tarries, more superspinatus,
all those rotator cuff muscles have to contract way harder
and produce way more force to stabilize that joint.
But those things are all pulling as this way
and I'm trying to get the arm to go this way.
So the first thing that's gonna happen
is I'm gonna lose the ability to contract my chest
as hard, but I'm going to feel it more because my body's
going to be hypersensitive to the fact
that I'm stressing out this joint.
So there's gonna be sensation,
while simultaneous loss of tension, right?
So you're gonna feel more, but be doing less,
and you're gonna risk injuring that shoulder more.
The other thing that you're gonna do is,
because all of this stuff has to over contract and stabilize
is now that scapula has to get pulled around
a little bit more.
You don't get to track it as efficiently as you would like
because you've basically taken out two of the main things
that are actually working upon that scapula.
So if you imagine we're here,
we have the bicep coming in this way,
and then we have the long head of the tricep this way,
right, and they're pulling that shoulder in tight,
stabilizing this glenohumeral joint,
keeping that together.
We lose those, alright, now I have to accomplish the slack
and that's from muscles
that go this way, this way, this way, right?
And so now these muscles that are in here
that are contracting are gonna effect the rhythm
of the traps and the rhomboids in terms of being able
to move this stuff.
So what you see is overall the body trying
to restrict movement and that will translate into sensation.
So you'll think you're getting more
when you're actually getting less,
and you're training yourself to be weaker.
So instead of building muscle,
you're gonna be building poor motor patterns
to put more of that tension
into the small stabilizer muscles,
and that'll keep going until you get injured.