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Lower Half Sequence Thread**
We'll check out what to look for on video and @KMOTION3D graphs from the end of the stride through impact. We'll cover...
1.) Open pelvis into foot strike
2.) Peak pelvis forward bend
3.) Hip extension through impact
Or... Rotate -> Flex -> Extend
We'll check out what to look for on video and @KMOTION3D graphs from the end of the stride through impact. We'll cover...
1.) Open pelvis into foot strike
2.) Peak pelvis forward bend
3.) Hip extension through impact
Or... Rotate -> Flex -> Extend
Opening the pelvis independent of upper body segments is the primary checkpoint at the end of the stride phase
Independent hip rotation stretches torso rotators leading to more powerful torso rotation in the swing phase
Example of doing this well
Independent hip rotation stretches torso rotators leading to more powerful torso rotation in the swing phase
Example of doing this well
We can see the independent pelvis rotation easily on the sequence graph. The red pelvis line rotates first while the upper body segments lag for a split second before rotating together to begin the swing
The upper and lower body positional graphs can show a bit more detail of how and when this is happening in the swing
In the example, the pelvis reaches 0 degrees (so, already rotated 25 degrees toward the ball) before the torso even begins forward rotation
In the example, the pelvis reaches 0 degrees (so, already rotated 25 degrees toward the ball) before the torso even begins forward rotation
The torso continues to coil while the pelvis rotates, but only slightly (2-4 degrees in the ex. graph)
Rather than actively turning away from the ball, the upper half should stay loose and ready to recoil as a result of pelvis rotation stretching the front side int. oblique
Rather than actively turning away from the ball, the upper half should stay loose and ready to recoil as a result of pelvis rotation stretching the front side int. oblique
The next checkpoint is peak pelvis forward bend (hip flexion), which is usually followed by peak torso forward bend
This move has two primary functions
1.) Set posture for the height of the incoming pitch
2.) Set up powerful hip extension
This move has two primary functions
1.) Set posture for the height of the incoming pitch
2.) Set up powerful hip extension
On the graph, peak pelvis forward bend occurs just after the pelvis begins forward rotation
We can see the slight bump after heel strike, indicating an aspect of added flexion as the pelvis rotates and picks up speed
We can see the slight bump after heel strike, indicating an aspect of added flexion as the pelvis rotates and picks up speed
At this point, the hitter has read the pitch and can add forward bend depending on pitch height
In theory, the lower/more away the pitch is, the more pelvis and torso forward bend you can add
In theory, the lower/more away the pitch is, the more pelvis and torso forward bend you can add
The swing on the left is mostly maintaining forward bend. The swing on the right is an example of adding forward bend for a slightly lower pitch
*Yes, I know the camera angle is a little different... Bear with me for the decent visual
*Yes, I know the camera angle is a little different... Bear with me for the decent visual
We can also think of peak hip flexion as the last "stretch" before exploding off the ground through hip extension
From behind, the hitter looks to be "sitting down" with the front hip flexing, rotating, and even moving slightly away from the plate
From behind, the hitter looks to be "sitting down" with the front hip flexing, rotating, and even moving slightly away from the plate
Last, we have hip extension, a primary power source for hitters/basically all athletes. On K-vest, this is the transition from posterior -> anterior pelvic tilt and is visualized by the green line descending rapidly during the swing phase
On video, a key marker is the hitter's belt buckle. We're looking for the belt buckle (waistband in this example) to move up throughout the swing, indicating the transition from post. to ant. tilt.
Some hitters (typically those with high bat speeds) will actually come onto their toes or move away from the plate during the swing phase
**Chucks may or may not equate to higher GRF and sweet lower half action
**Chucks may or may not equate to higher GRF and sweet lower half action
The key is having the ability to put a ton of force in the ground, transfer it through hip extension, and maintain upper body posture while you do so
That may lead us into another thread, but for now, we'll stick with the lower half and remember the rotate -> flex -> extend sequence!
