Fay asked me to help her improve her tennis serve and the following is my analysis and suggestions on how to change her mental image of the serve technique and what drills to use.
Fay, I believe your serve technique can be improved with a few tennis tips and not necessarily by a massive amount of repetition and complex mechanical instruction.
Correct Mental Image On The Serve
1. The first thing you need to do is to imagine the serve differently – that is to hit up and not forward.
At the moment, you imagine getting the racquet behind the ball so that you can guide it in a straight line toward the target.
The difference in the mental image CAUSES the difference in the serve technique
This idea makes sense logically, but with the serve, things happen so fast that we don’t really consciously guide the ball toward the target.
This idea, I believe, causes you to use your arm fully and not really the forearm and the wrist.
The correct mental image is that you need to generate racquet speed first and do that mostly upwards.
That’s why I bend my knees and start building the energy from my legs. That’s also why my elbow is bent and pointing up – since I intent to »hit« upwards first.
Once the racquet builds speed/energy, it will simply make a half-circle because my elbow and my wrist work as joints, and the racquet rotates around them.
I look for a whip effect rather than linear force – which is what I believe you’re looking for.
So, the goal is not to hit toward the court, but rather to generate racquet head speed upwards.
This should help you imagine hitting upwards, and therefore, you’ll look to get energy from the ground and loosen your elbow.
The best drill to get the feel for that is the one I showed, which is simply to dangle your racquet behind your back and then imagine throwing it upwards.
A slightly more advanced way is to use the drill for fast serves.
You won’t need many repetitions of these drills before you feel a very relaxed arm and your elbow will be loose and down.
2. The second key mental image you need to change is to hit across the ball and direct the ball with the strings.
At the moment, your image is to direct the ball with the arm toward the target, and your technique reflects that.
You’re approaching the ball from behind, and that causes strain in your shoulder because it’s not biomechnically correct.
When elbow is not bent the long "lever" causes a lot of strain in the shoulder
To get the feel for hitting across the ball without worrying about directing it with the arm, you’ll need to use the slice serve drill where you toss the ball lower and hit it with slice.
That will give you more feel and understanding that you don’t need to follow the ball with the racquet toward the desired target.
The ball goes where the strings point (mostly), even when the racquet path is different.
That final direction of the ball is determined by the pronation of the forearm because the arm actually moves diagonally related to the target at the moment of impact.
The pronation of the forearm directs the ball towards the target at the last moment.
Summary
To summarize, the key points are:
1. Correct mental image – hit upwards to generate racquet head speed.
Drills that will help you improve the feel of serving upwards are the »dangling racquet« drill explained in the video and the drill for improving the speed of the serve.
2. Correct mental image – hit across the ball to the right with the arm – and then pronate to direct the ball toward the court.
The drill to get that feel is the slice serve feel drill.