Posted by: Jack Mankin (MrBatspeed@aol.com) on Sat Dec 5 11:36:01 2009

>>> Jack, I was reviewing your thoughts on the Rose clip as well as the Giambi wanted to make a quick comment. You point out that Rose begins to rotation his shoulders at the same time as his hips. This is not what is showing the Giambi clip. Around the 2:45 make you see his front hip begin to open up while his shoulders remain squared up to home plate momentarily with a slight delay. After this opening of the front him, his shoulders will then rotate. <<<

Hi Nate

I agree with your observation, there is a momentary delay between Giambi's hips and shoulder rotation. I find this to be the case with a most batters. However, I do not find this delay is due to a delay in activating the torso muscles that induces the shoulders to rotate. It is the added load of overcoming the inertia of accelerating upper-body mass and the bat that causes shoulder rotation to lag behind the hips during the initiation of the swing.

One of my concerns in the matter is with the mechanics of a drill being taught by a number of California coaches (little league through college). Some coaches refer to it as the "1,2,3 Drill." In the drill, the students are taught, (1) Stride, (2) Fully open the hips while keeping the shoulders closed, (3) Swing. When I inquired as to the purpose of the sequential steps in the drill, the most frequent response was to "attain maximum separation of the hips and shoulders." They believed the greater the separation, the greater the power and quickness produced.

I find this is not supported by either video analysis or bio-mechanical principles. Once the muscles of the legs are used to fully open the hips (under no load), only the contraction of the torso muscles is left to power shoulder rotation. I would advise that allowing the hips to free-wheel open disconnect the muscle of the legs from the torso muscles.

For the large muscles of the legs to contribute energy to aid in powering shoulder rotation, the muscles of the torso must be engaged as hip rotation is initiated. -- This could be described as similar to the function of the clutch in a car's transmission.

Jack Mankin