>>> HI JACK> I DO REALIZE THAT THE SHOULDERS HAVE TO WORK IN THE CORRECT SWING .WOULD IT BE RIGHT TO SAY THAT AS BACK FOREARM AND ELBOW ARE ROTATING FROM THE HORIZONTAL TO THE VERTICAL POSTION, THE HIPS ARE AHEAD OF THE SHOULDERS AND ARE DOING THE BULK OF THE WORK. AND ONCE THE BACK FOREARM BECOMES VERTICAL THE SHOULDERS WILL TAKE OVER THE SWING AND BRING THE POWER OF THE HIPS AND LOWER BODY INTO THE ROTATING BAT. <<<
Yes, I would say with a little clarification, I could agree with your statement. I would need to point out that as the "back forearm arm and elbow are rotating from a horizontal to the vertical position," the bat should be accelerated rearward 90+ degrees from THT. The torque that induces the bat's rearward acceleration is derived from two sources. (1) From the rotation of the back-forearm as the elbow lowers. (2) From the hands applying force at the handle from opposing directions.
The video clip below addresses how THT is applied. -- I find the key difference between students that produce good rearward acceleration and those who do not is governed mainly by what the top-hand does as the elbow lowers. As I point out in the video, to apply maximum torque, the top-hand (and forearm) must apply a rearward force as the elbow lowers.
However, 99.9% of mechanics taught to batters have the top-hand being driven forward during initiation. Having both the bottom and top hand applying a forward force produces little or no torque. This also means that most of lead-shoulder rotation is used in taking up the slack caused from the top-hand being driven forward -- rather than used to provide a productive opposing force.
Jerry, the bottom line is -- The role of the hips is to induce a stronger shoulder rotation. That is the only way the power of hip rotation can be transferred to the bat. Also, the productive use of lead-shoulder rotation is essential right from the initiation of the swing.