Backhand topspin forearm extension

Master Rosario,

I watched your beautiful videos but I dont understand ...

For backhand topspin - should I use forearm(slightly extend from the elbow from triceps brahii) in the ball contact ?

Or the angle in the elbow should not to change?

Thank you in advance.

Hi Il,

The more time you have the more forearm you can use.  I like the forearm to really extend out when you have time with your backhand topspin.