It's All In The Hips

Hips are one of the most important aspects of hitting. I know we've all been hearing that since tee ball, but many hitters don't use their hips to their full potential. To fully utilize our hips we need to rotate them 90 degrees before we make contact. There are several reasons for doing this, first by rotating our hips before our shoulders we create the "X-Factor Stretch", which stores energy then transfers it from each body segment to the next called a "Kinematic Sequence"...google it. Basically what happens is the largest muscles (hips) rotate first followed by the shoulders, then the hands, then finally the bat, creating bat speed with relatively little effort (Efficiency!!). This sequential motion starts BEFORE contact, ending with the hands to create the greatest bat speed AT contact. The longer the separation between lower and upper body rotation, the faster resulting bat speed.

Another reason for opening our hips all the way is so we can create an elliptical motion with our swing. When our hips are rotated a full 90 degrees, the top hand is able to reach out farther towards the pitcher, as shown below in Figure 1. This reach is called "extension through the hitting zone," the more extension, the better chance of hitting the ball.

a)

b)

Figure 1: Overhead view of extension. Without opening hips a), and with opening hips b). Click to enlarge images.

First, let's examine what happens when you don't rotate your hips, and why it's harder to hit this way. For argument's sake, let's assume that a batter has no hip movement at all, and uses just her arms. It would look something like this <here>. Notice the bat makes a circular motion, one which is quite inefficient. Now let's assume this hitter has a perfectly circular swing with a perfectly horizontal swing plane. Let's also assume that the ball is traveling in a straight line. As shown in the schematic shown in Figure 2, the ball only hits the sweet spot of the bat twice within the contact zone, once far back in the batter's stance producing a hard hit ball to the opposite field, and once in front of the batter's stance producing a hard hit foul ball, and last time I checked, games weren't won on foul balls. So, at every other point in this swing, the batter will get "jammed" hitting the ball off the inside part of the bat, this not only hurts your hands a lot, it also produces weak hits. I would not consider this swing to be very efficient, given it is only able to hit to one side of the field fair.

Note: This swing does not generally provide much power since the hips are not utilized, unless the hitter has a very strong upper body


Figure 2: Schematic of overhead view of circular swing. The sweet spot denoted by the green section on the bat traces the circle around the hitter. Notice the ball which travels in a straight line only hits the sweet spot twice on the circle. Click to enlarge image

Now if we examine a hitter who opens her hips all the way, looking something like this <here>.

We see that by rotating the hips, the top hand is able to reach farther out in front, creating an oblong, elliptical motion with the bat as shown in Figure 3. This motion is much more efficient because the sweet spot of the bat is more in line to the path of the ball, which means a better chance for solid hits. Also notice that with an elliptical swing, all balls in the contact zone will remain fair.


Figure 3: Schematic of overhead view of elliptical swing. Compared to the circular swing, the sweet spot is more in line to the path of the ball. Click to enlarge image

In summary, our goals as hitters are to first create separation between the upper and lower body for the X Factor Stretch resulting in power, and second to have the most extension through the contact zone as possible, resulting in more consistency.