This is the number one power source
that pros use on their serve.
Some players and coaches call it serve pronation,
but that's only scratching the surface.
There are three keys that ATP servers use
to generate more power, spin and consistency
on their serves.
And just by learning this,
I was able to add 10 miles per hour to my own serve,
and I know that if you apply it,
it's gonna completely be a game changer.
Take a look at your favorite pro server
moments before contact.
What you'll notice is that they'll reach a position
where the racquet tip is pointing
to the back of the fence
while their hitting palm is pointing toward the side.
Then as we go through contact,
you'll see players start to rotate their racquet
in until it's facing the net naturally.
And this action of rotating your racquet into contact
in a counter-clockwise fashion
is gonna help to drive massive racquet head speed
into your shot.
Now, a lot of players do this,
but it's the way that it's executed
that separate the top servers in the world
from your average rec player.
So how should we go about executing
this serve pronation motion?
And should we let it happen naturally,
or should we try and manufacture it?
And also, if we have problems
like fixing the waiter's tray,
how do we simply let stuff like this happen naturally?
You see, the problem is if we don't understand
the deeper level biomechanics of what happens on the serve,
then we're actually gonna end up manufacturing
this pronation motion kind of like the forehand wrist lag.
So the first key to getting this motion down
is gonna be in your grip.
So for all of you guys out there who are trying to unlock
the power of this internal rotation,
we're gonna need to have some variation
of the continental grip.
Why?
Well, let's actually get into our continental grip here
on bevel number two,
and you'll notice that this creates a natural angle
in my racquet's grip and my forearm.
And now try the same motion,
but get into your Eastern grip like this,
or what's more commonly called the pancake grip.
You see the problem with this motion
is that with the pancake grip,
you're not able to put the blueberries on the syrup
and then, you know, your pancakes get all soggy.
And therefore, when you're actually getting into
your eating process-
- [Man] We're talking about serve here.
- Oh yeah, that's right.
(laughs)
I was hungry.
So going back to the Eastern grip,
whenever we have a milder grip,
this is actually gonna decrease the angle
that we have between our forearm and our racquet,
and therefore, when we start to do
this poor pronation motion,
this is only gonna help to turn the racquet over
instead of with the continental grip
helping to drive it forward.
Now, because you can't internally rotate in this case,
what do you do instead?
Well, we end up dragging our arm forward to contact,
which gives you that feeling of arming the ball,
or we end up just settling for a triceps exention motion,
which makes you feel like you're pushing the ball.
In either case, you're feeling tight.
Like you need to put a lot of effort into the shot
with less results.
So with the continental grip,
not only will you increase your power,
but you'll also be able to create that natural topspin
that's gonna give you that crazy kick and sick spin
that we'll cover soon.
Key number two is the pro drop position.
Coined by John Yandell over at tennisplayer.net,
this is the position where the racquet tip
is gonna swing all the way out
to the right edge of your body
until it's parallel to the trunk
if you view it from this angle.
This position is gonna give you
that full external rotation in both your shoulder
and your forearm, and it's gonna mark the end
of your racquet drop.
With this motion, you're gonna be able to execute
and utilize that powerful internal rotation
to get that maximum effect on the ball.
Now, anatomically, this is gonna put a stretch
on your internal shoulder rotation muscles
in the same way that a baseball pitcher
will be able to flip their arm back
before releasing the ball.
And this is also why making sure you have
the correct loading techniques
and engaging the right prime muscle movers into your shot
is really key for this.
According to a study done
by Dr. Bruce Elliott and colleagues,
the hitting arm is responsible for over 80%
of the racquet head speed you're gonna generate at contact,
but this isn't necessarily where all the power is generated.
Another article by Dr. Mark Kovacs
shows that over 50% of the force on the serve
is actually gonna come from something called
the leg hip kinetic chain sequencing.
So here, top pros accelerate
by driving their legs through the ground,
and that's gonna help to propel their hips and trunks
to explosively rotate into the net,
and then that's going to, with a relaxed hitting arm,
help to flip your arm back and down,
creating that nice stretch on your rotator muscles
to actually drive it back into contact.
And going into the upward swing,
top pros are gonna continue this external rotation motion,
giving them the appearance of leading
with the edge of the racquet before boom,
rotating into contact.
Now you can easily contrast this with going around
at your local club and taking a look
at how the majority of players execute their service motion.
What you'll notice is that,
instead of leading with their racquet edge,
they'll actually lead with their racquet strings.
And because of issues like we talked about with the grip
and other techniques like the waiter's tray issue,
players find themselves often feeling that pushing effect,
because they're not able to achieve the full foot motion
by getting into the pro drop position.
And again, if you don't pre-stretch
your hitting shoulder prior to contact,
then there's no way that you can actually
maximize the effects of this pronation motion,
unless you've got big old forums like Popeye or something.
(laughs)
And to execute this technique of leading up with the edge,
watch Daisha's video here.
Now, because pros have delayed this pronation effect
until the few milliseconds before contact,
they're forced to execute this motion a lot faster
and more explosively, leading to the amount of power
that you see on the tour.
All right, ladies and gentlemen,
we've reached the moment of truth.
Players here are gonna start rotating their racquet
in through contact with this pronation motion.
Now on the surface, this motion doesn't really sound
very intuitive, does it?
I would much rather personally hit with my entire arm
than have to like rotate it with this weird motion.
And this is also where players end up getting tripped up
and manufacturing the pronation,
and then worse, end up getting injured
like I did at one point.
So instead, it's pretty clear that we're gonna need
a step-by-step framework to make this happen.
According to Dr. Elliott's study, at the highest level,
this so-called pronation force
is actually gonna come from internal shoulder rotation.
Biomechanically, pronation is actually just
the independent rotation of the forearm.
The way you can tell this is by
grabbing your racquet in your hand
and put your elbow to your side.
This way, internal rotation
is not gonna be necessary here,
but instead, just rotate your forearm back and forth.
This motion of the racquet strings going from up to down
is pronation.
So if that's what pronation is,
then how am I expected to generate all this force
from just these little forearms here?
And that's exactly what elite servers figured out.
Pronation is actually only responsible
for 5% of the total racquet head speed that you get.
But another motion actually generates
over 50% of your power.
It rotates your humerus bone in your upper arm
and is propelled by muscles like your chest,
lats, other muscles in your shoulder, your back,
your infraspinatus.
It's called internal shoulder rotation.
(laughs)
So you might be wondering how does all of this
tie into your serve?
Psychologically, I found it personally very helpful
along with a lot of students of mine,
to think of a concept called long axis rotation.
This refers to the unitary rotation of both your shoulder
and your forearm.
And this is gonna help to turn your racquet over
with way more power than you ever experienced before.
And as we'll cover in future videos,
this is not exclusive on just the flat serve.
In fact, you still are gonna get that rotation motion
from the shoulder on the kick and the slice,
but because of a few changes in the forearm,
that's gonna change the direction of racquet head speed,
that's gonna affect the ball differently.
And that's a little sneak peek for you there.
Henry, a deal is a deal.
(laughs)
Now so far, we talked about the common threads
that all top servers use moments before contact.
But after contact, things start to get
a little bit complicated.
Sampras is gonna continue to rotate his racquet
through contact until his racquet and hitting palm
are facing the right side of the fence,
and his arm will actually bend
and his hand will stay above his hitting shoulder.
Federer rotates his racquet through just as well,
except he actually does it a little bit slower,
and he completes his hitting arm rotation
when his hitting hand comes to about his hitting shoulder.
Now, Murray, he doesn't execute nearly as much
of this rotation motion from the shoulder,
but instead brings his entire arm down with the racquet face
and the hitting palm facing the court.
Now, Nishikori also doesn't have
too much of this rotation through,
but he also bends at his wrist instead of snapping his elbow
like Sampras would do.
But most of them will rotate their racquet head
until it's facing the hitting side of the fence.
And this makes sense because, you know,
if over 50% of the racquet head speed
comes from this motion, then it wouldn't make any sense
if we slowed it down right before contact, right?
Think about a professional sprinter.
And if they were to like, right before the finish line,
decelerate at its final pivotal moments,
you're actually going to be slowing down
at the most critical moments of the shot itself.
So you won't have as much space to accelerate through
and thus, you won't have more power.
Now, if you might've had any elbow
or shoulder mobility issues in the past,
you don't have to worry about trying to rotate
all the way through like you see
Sampras or Isner doing.
But instead, just experiment with getting
different levels of this external rotation amount.
Like I said, Murray doesn't rotate all the way through,
but he still is able to utilize the stretch
and shorten cycle within the shoulder,
because he's rotated internally to contact.
But after contact, you can experiment
with going more forward toward the ball
through shoulder extension,
especially if you have mobility issues.
For you power-maximizers out there though,
do this carefully,
but you can rotate your shoulder and hand
all the way out.
Now, along with pronation, there's a huge power source
that I actually didn't cover at all yet.
This is the relaxed fluid whip-like wrist action
that every top server uses.
And Daisha's gonna be covering that
in an upcoming video as part
of our serve wrist action series,
so be tuned for that.
If you want, subscribe so that you get notified
for when it comes up.
And if this video gets 3K likes,
we're gonna release that right away.
So go and take these drills out.
Until next time, athletes, go out and train hard.
I'll see you in the next video.
You're not able to put the blueberries on the syrup
and then, you know, your pancakes get all soggy.
And therefore, when you're actually getting into
your eating process.
- [Man] We're talking about the serve here.
- Oh yeah, that's right.
(laughs)
I was hungry.
(laughs)