What Causes the Hips to Rotate in a HL Swing?

[julray]

Heard many times, don't try to rotate your hips, your hips will rotate as a result of ....

As a result of what? What causes your hips to rotate?

 

[_MIA_]

Maybe this will help.

BP where it looks like Martinez is working on not rotating hips (although they do rotate a bit):


Game swing:

 

[Shawn]

Turn the torso/core and "let" the hips rotate.

 

[Shawn]

Where in this clip does the movement take place?

The pelvis/lower back can only move marginally by itself, while the thorax/spine (upper back) has a large range of motion.

 

[Shawn]

Teach the spinal engine and the let the hips rotate.

 

[Shawn]

You read Joey Myers book correct?

 

[efastball]

Rotate in? or rotate out?

 

[rdbass]

The rear leg is the Driver.

Learn to create the stretch between the rear leg and the rear hip by coiling the hip against an internally rotating leg. Just like the ratchet shows. The hip NEVER rotates. It is driven by the rear leg when the stretch is broken. It's called SUDDENNESS OF LAUNCH. Hip rotation is about as slow a launch technique as one could have. Hip rotation is nothing but 'muscling up'. Using two legs is nothing but 'muscling up'. Hip rotation around two legs lacks the mechanical advantage offered by the SnF load/unload. There is nothing sudden about hip rotation. Only with a stretch created by the rear hip resisting the rear leg, by coiling and constantly and continuously pulling rearward, against an internally rotating leg, will you ever find the suddenness that you need to hit high level pitching.

 

[Bobby Shirer]

The rear leg is the Driver.

First, let's stop talking about the hips and be more specific. There's the vertibrae, the femur, the pelvis, and the hip joint. I think most people referring to turning the hips actually mean turning the pelvis.
The pelvis turns through a combination of actions. Because the front leg is lifted, the pelvis has no resistance to the outward rotation of the femur, "pronation" of the rear leg. The pelvis turns toward the playing field, then the front leg comes into contact with the ground again, loads and extends at the knee joint pushing that side of the pelvis rearward continuing the rotation of the pelvis until has been rotated 90 to 120 degrees toward the playing field. I think this extension is the main driver of the power and control in the swing. The rotation of the pelvis is combined with counter rotation of the vertibrae allowing the removal of slack between the pelvis and the "shoulders". Since the slack in the spine is removed, the extension of the front leg turns the shoulders. The rotation of the vertibrae creates tension and the extension of the front leg further rotates the pelvis causing a super stretch which then snaps back in a faster rotation of the shoulders. The mechanism is the stretch shortening cycle (SSC) in both the front leg and the torso. Using SSC allows us to create more power than just a contraction of the muscles.
After all, we're trying to move the bat to the ball and we do it by turning the torso. Whether we use the legs or not is a matter of how fast you want to do it.

 

[efastball]

we do it by turning the torso

agreed