regarding what John Yandell says in his "The Myth of the Wrist: The Modern Pro Forehand":
"…
As the racket moves forward, the torso will now rotate 90 degrees or more back through the hit, continuing until the shoulders are parallel to the baseline or beyond. This shoulder rotation drives the hitting arm and the palm of the hand.
At the same time that the shoulders are rotating, however, there is a second critical rotation. This second rotation is the internal rotation of the hitting arm.
As the racket moves forward, the entire arm is rotating independently, as a unit, from the shoulder. As the high speed digital footage clearly shows, the arm is actually turning over from bottom to top. This rotation can be up to 180 degrees as the racket moves through the swing.
As it rotates from bottom to top, the hitting arm stays in the double bend or power palm position. This means the angle of the wrist and elbow relative to each other remains unchanged. This allows the palm to drive the racket head upward and outward through the shot.
… "
i wonder what exactly is the "internal rotation of the hitting arm". To my understanding, internal rotation of arm is related to pronation or supination. arm pronation is supposed to turn the palm from facing up to facing down, not from bottom to top. Does he talk about external rotation of arm that rotates the hitting elbow from pointing down to pointing forward?
Thanks for your input.
"…
As the racket moves forward, the torso will now rotate 90 degrees or more back through the hit, continuing until the shoulders are parallel to the baseline or beyond. This shoulder rotation drives the hitting arm and the palm of the hand.
At the same time that the shoulders are rotating, however, there is a second critical rotation. This second rotation is the internal rotation of the hitting arm.
As the racket moves forward, the entire arm is rotating independently, as a unit, from the shoulder. As the high speed digital footage clearly shows, the arm is actually turning over from bottom to top. This rotation can be up to 180 degrees as the racket moves through the swing.
As it rotates from bottom to top, the hitting arm stays in the double bend or power palm position. This means the angle of the wrist and elbow relative to each other remains unchanged. This allows the palm to drive the racket head upward and outward through the shot.
… "
i wonder what exactly is the "internal rotation of the hitting arm". To my understanding, internal rotation of arm is related to pronation or supination. arm pronation is supposed to turn the palm from facing up to facing down, not from bottom to top. Does he talk about external rotation of arm that rotates the hitting elbow from pointing down to pointing forward?
Thanks for your input.
