I actually like this question. Suggests to me that you may be running some experiments.
One could of course ask you about the muscles in the elbow that make the hand move ..... but that would be silly.
I believe what you are asking is if it is the desire to slot the elbow that causes the hands to move, or the desire to use the hands that cause the elbows to slot. The answer is the hands ..... that is, it is the formation of the connection process to the hands that causes the slotting process.
Fiveframe, i am a hitter. always have been. a good one. I always try everything, ask my wife.lolo.
I am old now, 56. i can still hit, with more power now, than ever before, From the tips here, and bbd. coil, tip and rip, seperation.
You guys are awsome. Teaching how to hit, this i am only 3 years into it at this point. Still a newbie.
The muscles are in the forearm, but that is silly.
the hands are the boss. got it.
and,Fiveframe, i record every girls first time session, so please play fair.