Yes. On the image above, loading mechanism is clearly visible.
There are 4 curves (except H+R): Ke LL, Ke Tr, Ke Uarm and Ke Larm. Their order in time is obvious: we start with legs, then there is torso, then upper arm, then forearm. Every curve has its own maximum. Ke LL has maximum at frame 24 - ca. 20 J, Ke Tr max is ca. 38 J, Ke Uarm - 22 J and Ke Larm - 30 J.
We can see good time synchronization here. If a curve has maximum, the next curve (in time) is perfectly at the half of its increasing slope. This is how "loading" works in tennis. This is what every tennis coach is talking about.
OK, guys. If you agree, then please add all those energies and check their sum.
You will be amazed.