The Hitting Stance(s)

By Michael Friedman, USPTA

Still photos by J. Gregory Swendsen

Ever wonder how tennis pros produce such awesome power off their groundstrokes? Even smaller players like Hewitt and Chang manage to generate a tremendous amount of force. Over the past decade a more efficient use of tennis footwork has evolved to create this power and also to keep up with the decreasing amount of time a player has to get to the ball and to recover in today's power game.

Stepping in - the back foot judges the contact point in order for the last step to trigger the swing. Notice how Agassi's right foot does not move until the completion of the swing.

The following article on the different hitting stances will demonstrate how the tennis tour's best movers generate effortless power in different hitting situations.

Three basic principles all the great players have in common are. balance, ground force, and the proper implementation of the body's kinetic chain.

The different stances described in this article are the Step In (Andre Agassi, Serena Williams), Open Stance (Leyton Hewitt, Serena Williams), Kick Back (Agassi, Hewitt) Resistance Stance (Serena) and the Running Stance (Pete Sampras). All of these stances have biomechanical similarities, including balance, ground force, and the proper linkage of the body parts which is called the kinetic chain.

Balance

Proper balance allows the body to rotate naturally through the stroke generating power and allowing for consistency. On groundstrokes, the body parts should be lined up vertically so the racquet can swing horizontally allowing the racquet head to move freely through the plane the ball is on at the point of contact. The axis can be the left side, the right side, or the center of the body but at the point of contact the racquet should be perpendicular to the spine. If the spine is vertical the racquet should be in a horizontal position. Rotating around a body axis that stays vertical until the end of the follow through is a sign of good balance.

Agassi plants his left foot parallel to the baseline. His right foot steps in toward the net, pointed at a 45 degree angle. This keeps his hips sideways until the left knee rotates towards the net. Then the hips and hands are fired toward and through the contact point. Note the toe touch (rear foot).

The topspin swing is a low to high diagonal. The majority of the force generated by the racquet through the plane the ball is on is horizontal, to make the ball fly quickly towards the court. The vertical force starts below the ball, brushes up, and finishes above it. This lifts the ball over the net and also creates topspin and control.

Stopping the rotation at the right time, from the contact point to the follow through, will create acceleration of the racquet head through the contact point much like the acceleration created when snapping a towel.

When braking the body parts, make sure to keep the head still through the finish of the swing. Plant the front foot flat on the ground when Stepping In, or what I call "sticking the landing", and by holding the toe touch on the back foot, or kicking the back foot back, or just by resisting movement in the resistance stance, you will be able to rotate the body and still maintain a balanced body axis to rotate around.

Ground Force

Ground force is the initial drive off the ground through the feet to initiate the kinetic chain. In each of the stances mentioned above, the back foot should be sideways or parallel to the net. This assures the proper relationship of the shin, knee, thigh, and hip to the contact point. The knee is bent and the ankle flexed. Whether stepping in or to hitting with an open stance, drive off the instep of the back foot to start the kinetic chain. To be able to hit the ball in a higher contact point you can jump off the ground driving off the front foot and kicking the back foot back towards the back fence as the body rotates.

Serena's drives off her right foot setting in motion a kinetic chain generating a tremendous amount of power. Her back knee begins to rotate into the "K" position where it will almost touch the front knee .

Open Stance

In today's game the open stance is used for two main reasons.

For every one extra step taken to the ball, it takes at least one (if not two) to get back to the middle, therefore, hitting with a closed stance slows recovery time.

Using the open stance, Serenas's shoulders turn 90 degrees to the net while her hips stay at 45 degrees to the net. When she drives off the right foot and rotates her right knee, she fires her hips a little, which rotates her shoulders a lot. This is the same principle used in the golf swing, where shoulders turn more than hips on the backswing. When the hips are turned on the forward swing, the shoulders are whipped through, creating greater club head speed.

Hewitt kicks back with his right leg to balance and brake the body rotation. Notice how straight up and down he keeps his rotating axis.	Agassi moves in on a short ball, steps in with his left foot and kicks back with his right foot to balance the body.
If the right foot comes around too soon the elbow flies away from the body, the racquet face closes and the ball goes into the net. Kicking back keeps the body from over rotating and keeps the elbow in so the racquet face stays perpendicular to the ground through impact.

Kinetic Chain

The Kinetic Chain is the sequential movement of linked body parts when swinging a racquet around an axis (the body) creating centrifugal force. If one link is missing it will throw the smooth transition of movement through the body and hence limit the potential power one could create at the point of contact.

Like a weight at the end of a rope, if your rotate your body a little, the weight will move a lot and at a much greater speed. The same centrifugal force applies in tennis, a little body rotation will generate much greater racquet speed.

The biomechanical sequence starts by pushing off the back foot, turning the back leg's shin, knee, and thigh towards the net creating the "K" position where the back knee rotates to a point almost touching the front knee, not unlike the letter "K". The core of the body - the hips, torso, and shoulders then rotate towards the net, in that order. The front leg absorbs the rotation by staying still, and you should be able to feel the pull from the inside of your front knee to the outside of the front hip.

The braking of body parts will keep the body from over rotating. This will generate more power by getting the body mass in motion and then stopping it to create acceleration of the racquet at the point of contact. The head and front foot should remain still through the stroke and the rear foot, whether using the toe touch or kicking back acts as an anchor, stopping the rotation.

Sampras' Running Forehand

Sampras's lethal running forehand uses the hitting arm to swing while stepping across with his left foot. He hits with a closed stance in order to keep his body from rotating too much as he swings.

Notice the heel toe landing of his left foot. When the foot lands heel/toe, the whole leg acts like a shock absorber. The ankle and knee bend naturally. If the toe lands first, this stiffens the leg, which does not allow the leg to absorb the weight being put on it, so it resists and pushes the weight back.

Resistance Stance

he resistance stance is used when there isn't time to get the entire body into the optimum position to swing the racquet. Here Serena faces a hard, deep shot at the baseline and is forced to hit a half volley.

Note how Serena maintains good body balance by widening her stance. She resists moving her body by staying down on her legs. This allows the hitting arm and racquet to go through the contact point while the body stays still through the follow through.