however, it is key to extend arm fully just prior to impact. The racket is offset at an angle and the entire arm is then rotated into impact which extends the racket in-line with the arm (post impact)

also ... swing fwd not around ... only come around when the arm no longer extends toward target

The longer the lever ... the greater the power ... ANNND the smaller the effort

feel like a cord is pulling the racket head down and resisting your upward pull on handle

Racket head is below hand ... wrist goes into extension AND ulnar deviation at start of fwd swing ...this is key for effective topspin