Have you ever hit a serve where everything just seemed to come together? You felt coordinated. Powerful. The ball came off your racquet like a rocket.
On the flip side, we’ve all hit serves that felt off-balanced. Off-centered. Lacked pop. And landed everywhere but the service box.
Place technique to the side for a moment and briefly consider these 2 scenarios. In scenario 1, you’re likely striking the ball ‘on time’. Power is coming from the transfer of energy (we’ll get to this in more detail below). And it’s all happening in a properly sequenced manner.
In scenario 2, none of this happens. You accelerate the racquet when you should be driving with your legs. You can barely hold your balance, missing the center of the strings in the process.
These scenarios are closely related to what we call in the biomechanics field, the summation of forces.
Summation of Forces – Timing Side of the Coin
Here’s Kovacs (2011), describing part of this ‘summation of forces’ concept as it relates to the serve:
“The difficulty in the movement results from the summation of forces from the ground up through the kinetic chain and out into the ball.…Effective servers use the kinetic chain via a muscle activation synchrony of the coordinated lower extremity muscles that provide a stable base for the trunk/core to rotate and extend and flex while also helping to produce force. If any of the links in the chain are not synchronized effectively, the outcome of the serve will not be optimal (i.e., velocity, spin, placement, and reliability)
Note that he’s not talking about serve mechanics/technique. In other words, the positions of the limbs/joints at various moments. The speed at which those joints rotate. The forces acting on the involved tissues and so on.
The serve, as described above, is just as much about mechanics as it is about proper timing and synchronization. It’s the coordination of various segments and timing their involvement in the correct order.
When a player does this well – harnesses energy from the ground, up the kinetic chain and into the racquet / ball interaction – as Kovacs implies above, this is what leads to better power, spin, placement and consistency.
Irrespective of how much force a player can generate, if poorly timed, energy leaks present themselves. Not only will this inpart less velocity on the ball, it may lead to suboptimal mechanics (and more stress on certain tissues/structures over others).