Bought recently an action camera to use during the holidays with the family. So thought to combine usage and got to film a couple of my sessions. I was quite surprised to see that: 1. I did not have enough torso rotation although my take back was just fine and to generate power I was using the hand 2.The above created the following: to generate some top spin, the swing path of the arm was being driven by the shoulder and as such almost always after the ball left the strings no matter the vertical height of the contact point I raised my hand from the shoulder at almost eye level, which obviously led the racquet head to reach well above my head (!) before finishing the follow through above the left shoulder 3. As you can imagine the ISR was very limited So wanting to fix this my questions are: 1. If the horizontal lath (power and therefore depth) is created by the legs and torso movement, what happens to the arm? How does the shoulder move (always in relation to an horizontal level). Do we still close it to the chest before hitting the ball or we kind of "lock" the width of the two hands to remain almost constant, start torso rotation, hit the ball and then "release"/loosen up the hitting arm so it comes around? The latter sounds to me more of a proper "kinematic chain". (back when I started playing I was overusing the torso...or at least this is what I have been told was the reason I was mistiming the hits. I started moving the torso but the hitting arm was so loose that it was "left behind" and only when the torso and arm reached a point of no flex did the arm started moving to meet the torso.) 2. As regards ISR which i have read it is responsible to generate the top spin and therefore the vertical path (height) of the ball. Is this a by-product of the movement or do we need to intentionally start the ISR at such a point in the time window from before hitting the ball till right after the ball leaves the strings, depending how much spin and additional "weight" we want to put on the ball? Wouldn't this change the racket face tilt? Hope those are legitimate questions to be answered by you guys and thanks in advance for any help. EDIT: I use an Eastern grip with a straight arm swing.