How important is it to lock the front knee on the stride?

[Bobby Shirer]

Locking out the front leg happens because the leg is extended , driving the front hip rearward. This is how good hitters rotate their pelvis and create power from the ground up.
The hitter strides into the front leg, loading the muscles of the leg (Stretch Shortening Cycle), extends the front leg, driving the pelvis rearward from a point offset from center mass, creating torque and that causes rotation.
The leg is locked out (extended) and, if the rotation continues, the leg flexes again as the pelvis unloads it, the leg is dragged and draws back into the core....much the way a sprinter's leg extends and then is dragged by the forward movement of the sprinter.
The first video you posted shows your dd not completely rotating...IMHO because she doesn't drive her rotation from her leg (front). In the second video, she rotates a little more because she gets her leg locked (extended) but a bit passively. Try having her actively drive her front hip rearward by extending the leg....push against the front leg.
The rearward tilt she has is a bonus in that she can really get against the front leg and create lots of torque against her pelvis.

Lots of folks talk about turning against the front leg creating knee issues. Solve that by having her open the front leg, pointing her toes at the pitcher. Then the rearward thrust is aligned to direction of movement (hip over knee over toes) and there is no torque on the knee.

 

[julray]

Here she is during the stride
View attachment 22130

Notice she has gone backwards (bad) vs forward (good), so far that her head is over her back foot.

What happens next is that she must reach with her front leg to finish the stride. Here she is at toe touch.
View attachment 22131

Notice her head has barely progressed past her back foot (yellow, bad), and her front leg (purple) is mostly straight (bad) vs very bent (good)

Also notice that her back foot is not pointed straight to the plate.

Practice dry strides (no tee,ball):
1. Point the back foot straight to the plate
2. Weight on the back heel and stay on the heel all the way (most people tell you to stay on the ball of your foot)
3. Start with head just past the back foot, pick up the front knee and fall forward and land on a very bent front leg. This will feel very strange at first.
4. At no point, do you go backwards.
5. You should be striding with the back leg, not the front.
6. Mark the position her head should be in (between the feet), and look down after every stride to see where she is.

BTW, the front leg should be very bent at toe touch, then from hip slot (elbow at hip) to contact, begin to fully straighten to contact. This leg straightening finishes the hip rotation, just like in baseball pitching.

Some good information here... just to illustrate and for comparison. Like E said, she's just reaching/striding with her front foot. Compare to the swing below.



Sometimes I like to look at the movement in a no stride swing, easier to see IMO

 

[Bobby Shirer]

Some good information here... just to illustrate and for comparison. Like E said, she's just reaching/striding with her front foot. Compare to the swing below.

View attachment 22210

Sometimes I like to look at the movement in a no stride swing, easier to see IMO

View attachment 22211

When I hold my cursor at the brim of each of the players hats, Trout moves rearward initially and forward only about half the distance between his ears....back 3" and then forward 6" ? (although he may move more after foot plant)
Hitter #2 moves forward the distance of the width of his head....6" ?
According to E-fastball's lines, I see the same overall movement of the original poster's dd....6" forward ?

 

[Cornbread]

When I hold my cursor at the brim of each of the players hats, Trout moves rearward initially and forward only about half the distance between his ears....back 3" and then forward 6" ? (although he may move more after foot plant)
Hitter #2 moves forward the distance of the width of his head....6" ?
According to E-fastball's lines, I see the same overall movement....6" forward ?

What do you think causes Trout to move rearwards intially?

 

[Bobby Shirer]

What do you think causes Trout to move rearwards intially?

He's a pretty big guy and I don't see the wind blowing him around...so I'ma guess it's his legs?

 

[Cornbread]

He's a pretty big guy and I don't see the wind blowing him around...so I'ma guess it's his legs?

Which leg? I see the backwards movement as part of the front foot being picked up. Not a thought to go back and then knee lift. Was just curious of your thoughts. You always seem to have a differing opinion from most on here and I like to hear differing opinions! I pick up stuff from all of y’all

 

[Shawn]

Which leg? I see the backwards movement as part of the front foot being picked up. Not a thought to go back and then knee lift. Was just curious of your thoughts. You always seem to have a differing opinion from most on here and I like to hear differing opinions! I pick up stuff from all of y’all

In Trout? I see the the pelvis/hip loading around the back leg. As Wright is showing, it doesn’t matter what the front leg does.

slowed down a little, the front leg doesn’t matter. What the front leg does is style.

 

[Shawn]

The back leg is the handle for the sling shot. It sets first.

 

[Shawn]

Front leg, the front leg can do several things.

 

[julray]

When I hold my cursor at the brim of each of the players hats, Trout moves rearward initially and forward only about half the distance between his ears....back 3" and then forward 6" ? (although he may move more after foot plant)
Hitter #2 moves forward the distance of the width of his head....6" ?
According to E-fastball's lines, I see the same overall movement of the original poster's dd....6" forward ?

I never look at how far rearward or forward... where’s OP’s DD’s head at heal plant compared to Trout and Wright... what does that tell us?