Re: JAck, Any Comment on Ferroli?
>>> I want to know how much you favor Steve Ferroli's hip rotation model (by now, you are probably familiar with Hit Your Potential).
In Hit Your Potential, it describes hip rotation in impressive detail. I will quote approximately three pages of a passage for the sake of presenting his argument.
According to Hit Your Potential, assuming the batter has timed his swing correctly
"If the hitter chooses to let the by, the pendulum movement will stop when the hitter lands. However, if he decides to swing, the pendulum will continue harmoniously into the rotation of the hips........when the hitter decides to swing from a position where his weight is evenly distributed from leg to leg, the bent front leg begins to extend, begins to straighten out, therefore pushing the front hip back and around the corner towards the catcher. Meanwhile, at the exact same time the back leg, which has also remained bent from the cocking motion, pivots on the ball of its foot. Due to its bent position, this thrusts the back hip forward and around its corner....
Good technique demands two separate forces at opposite ends of the lever, pushing in unison from opposite directions. The result is a pinwheel-type movement--rotation of the hips by both legs......
Note that if the front leg had not landed cotrrectly after the stride--if it had reached out.....extending the knee prematurely, the front hip would be left with no power source to push it. Now the hitter would have to rely solely on the rotation of the bent back leg, which is just not enough. Hittersb who reach out their stride leg by extending their stride knee prematurely are left with less momentum when it comes time to hit because they have eliminated a power source [Ferroli believes that '........the front leg is the stronger power source of both legs' (Figure 4-16), (Ferroli 49)]. It's much like asking someone to hop without first bending their knee. This is another reason the front knee must turn in during the cocking motion. The hitter is bending it more to be used later in the swing.
Similar is the preparation and use of the back leg. If the knee of the back leg is not bent at least in the stance, the back hip will not thrust forward because its power source is a pivoting bent back leg. If that leg is not bent the hitter depends solely on the front leg for rotation, and again, that's not enough. Good hip rotation depends on the proper use of the legs for support." (Ferroli 48-50)
Jack, your opinion on his model? <<<
I wrote "Rotation and the Stationary Axis" which describes the above actions of the lead leg (and knee) in 1989. I'm not sure when Ferroli first described it.
Mr. Ferroli and I do agree on how energy is developed by the body for the swing (Rotation and the Stationary Axis). But we teach very different principles on how that energy is transferred into bat speed. I teach "rotational" mechanics (circular hand-path and torque). He teaches "linear" mechanics (extending the hands in a straight line at the pitcher and snapping the wrist or whip action).
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