How to hit harder in tennis without swinging harder

Hit harder without swinging harder.

Traced from real footage

See it, eight instants at a time.

Every frame is traced from real match footage, so you see the shape of the stroke, not a drawing of an idea.

Sinner's forehand, instant 5 of 8 — Sinner's forehand: eight instants traced from the footage, frame for frame. Hover or tap to flip; the dot marks contact.

Sinner's forehand: eight instants traced from the footage, frame for frame. Hover or tap to flip; the dot marks contact.

Key facts

1
On the serve, internal rotation of the shoulder is the biggest single contributor to racquet speed, about 40%.
Elliott, "Biomechanics and tennis", British Journal of Sports Medicine, 2006
2
Other serve work puts the shoulder's internal-rotation share as high as about 54%.
Tanabe
3
On the forehand, shoulder horizontal flexion contributes about 45 to 48% of racquet speed and elbow extension about 17 to 21%. Elite forehand racquet speed at impact is 21.8 to 22.6 m/s.
Reid et al., Sensors, 2022
4
In a 2024 serve study, slow and fast serves were measured at 34.89 and 45.43 m/s.
Gorce & Jacquier-Bret, Frontiers, 2024
5
The ball is on the strings for only about 4 ms, too short to push it.

Why it works

You can't push the ball, because it's gone in about 4 ms. You can push the court. The court pushes back, the hips turn that push into rotation, the trunk uncoils on top of the hips' speed, the arm inherits the trunk's, and the racquet, the lightest link, gets all of it last.

Each link peaks, then brakes, and the braking is what throws momentum outward. That's why a short, stiff finish costs you speed: it can't brake the links nearer the body properly.

Speed and energy live at opposite ends of the chain. The racquet is the fastest thing at contact, but the legs supplied the most energy. If the arm fires first, you're arming the ball and throwing away everything below it.

The line to say on court
“The arm is last.”

Drill: The chain count

15 min · alone

Shadow-swing 20 forehands, counting out loud: legs, hips, torso, arm, racquet.
Drop-feed 20 forehands starting from a deep knee bend. Let the legs start the swing.
Count how many land past the service line without you trying harder.

Number to beat12 of 20 deep balls from the legs

More drills like this: forehand

Faults and fixes

Arming the ball

The legs and trunk never fire, so the arm supplies everything.

FixExaggerate the leg drive and unit turn. Hit from a deep knee bend.

Firing the arm early

The outer links fire before the inner ones peak.

FixShadow strokes, counting the order out loud.

Poor separation

Hips and shoulders turn as one block.

FixDo band-resisted rotations: hips open while the shoulders hold.

An off-balance base

A falling stance can't push the court.

FixLand balanced, load evenly and keep your base under the shot.

Blocked deceleration

A short, stiff finish can't brake the links nearer the body.

FixLet the finish run its full length.

Questions players ask

Does tennis power come from the arm?

Mostly not. The arm is the last link in the chain. On the serve, the legs supply an estimated half or more of the energy, and the arm inherits speed built by the legs, hips and trunk.

What is the kinetic chain in tennis?

It's the sequence of body segments, legs, hips, trunk, arm and racquet, that fire in order so each one adds speed to the next.

Which part of the body is fastest at contact?

The racquet. But the legs supplied the most energy. Speed and energy sit at opposite ends of the chain.

Do the links have to fire in a strict order?

Legs to racquet is a strong rule of thumb, not a law. Sensor work on pro servers finds how much each link contributes can matter as much as strict order.

What this doesn't cover

Proximal-to-distal order is a strong heuristic, not a law. Sensor work on pro servers finds the size of each link's contribution can matter as much as the order. The share of energy from the legs is an estimate, and the percentages differ between studies.

Sources

Elliott (2006), "Biomechanics and tennis", British Journal of Sports Medicine
Reid, Whiteside & Elliott (2006), Journal of Sports Sciences
Kovacs & Ellenbecker (2011), Sports Health
Reid et al. (2022), Sensors
Gorce & Jacquier-Bret (2024), Frontiers

StrikeHow to use hip and shoulder separation for a heavier forehandFor a heavier forehand, coil the shoulders against the hips on the unit turn, then fire the hips first while the shoulders hold for a beat. That stretches the trunk like a spring, and the shoulders uncoil on top of the hips' speed. A longer backswing isn't a speed source. The coil is.StrikeHow to use your legs on the tennis serveTo use your legs on the serve, bend into a deep load and push the court away, then leave the ground and land on your front foot inside the baseline. The court pushes back with the same force, and that force is the budget your hips, trunk and arm spend. Elite servers push about 1.5 to 2.1 times their body weight into the ground.StrikeHow to get racquet lag on your forehandYou get racquet lag on your forehand by keeping your hand soft while your body turns, so the racquet head trails your hand and then releases. Don't snap the wrist for power. In elite forehands, forearm pronation adds almost nothing to racquet speed, while the shoulder adds about 45 to 48%. The wrist's job is to get out of the way.StrikeHow to hit a modern topspin forehandTo hit a modern forehand, turn early, meet the ball about a racquet-length in front of your front foot, and swing up as much as forward. Contact has to happen out front, where the racquet head is still accelerating. The topspin isn't a wrist trick. It comes from a path that arrives at the ball travelling upward.