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)
