What is the Kinetic Chain and how does it pertain to hitting?
The kinetic chain is a term for body parts working together in a specific order to create a movement.
Whether it's a jump, sprint, throw or swing, our body creates movement as a chain of muscles firing in a specific sequence.
For baseball and softball, one of these sequential, powerful movements is the swing! Here we go...
The Kinetic Chain in the Swing: Starts with The Legs and Hips
When swinging a baseball bat, the kinetic chain begins with the legs. The legs produce power by shifting weight. In the video above, you can see him load up at :05 and begin to shift his weight.
Then (and then is relative because it's happening really fast), the power he produces in the legs transfers to the hips as they begin to rotate. The hips start to fire at :08 creating rotational power.
Then, finally, the power is transferred through the torso (how's your core strength?), to the lead arm, the hand, and the bat.
Each body part in the movement creates power, then transfers it onward down the chain. In the end, the batspeed created is greater in a connected sequence of movements than any single body part could produce on its own – meaning the final product (i.e. a powerful swing) is the result of each body part acting in harmony by staying connected.
Let's note this is a basic summary of a complicated movement - complicated to the extent that someone would want to get into the weeds on the physics terminology. Are we talking about power in the hips, or it is acceleration of the hips? Are we creating power or transferring energy, or maybe it's both at different points in the sequence? This level of understanding has its place no doubt, but not every hitter (or coach) needs that pin-point accuracy to be effective. If the shoe fits...
The K-Vest for Baseball: Troubleshooting How Hitters Produce Power
Still, we do need a basic knowledge of physics to assess a swing. We also need coaches who understand how the body moves efficiently across different athletic disciplines.
Hitters may not be able to feel accurately what their body is doing. Ask a hitter, "where did you make contact?", and his recall may not be accurate to a video. Ask a hitter, "did your hips rotate too early?", and it would be hard to produce an accurate observation, especially at the amateur level. But hitters can discover, can be taught, and can become more self-aware with new technology in baseball.
There are all sorts of ways to grade or assess movement efficiency during the swing. A simple example is if the hands cast out in a loop, the resulting weak ground ball proves the broken kinetic chain. It's also pretty easy to observe the bat path casting out with a naked eye. However, other movements happen too fast and are simply too difficult to observe without technology.
A good piece of new technology in the baseball world is the K-Vest from K-Motion. This device is worn just like it sounds - as a vest - and it measures two main pieces of information that help hitters understand the movement of energy – energy flow - during their swing:
- The rotational speed of different body parts throughout a swing – legs, hips, torso, arms, hands.
- The sequence and time at which these body parts reach peak speeds.
In essence, the K-Vest measures the speed of body parts in the kinetic chain, and the order in which they’re creating power. As indicated on their website, K-Vest shows how to unlock a player's most efficient and powerful swing.
To understand how to use or effectively teach from a K-Vest, you'd need to be smart on biomechanics, baseball and interpreting graphs - yes, the x axis is here and and y axis is here. K- Motion offers courses to assist in filling the gap between baseball and science, and we encourage coaches to sign up.
Here's a quick explanation of the K-Vest from Chicago Cubs' Director of Hitting Justin Stone:
The Kinetic Chain in Hitting is a Sequence of Four Main Body Parts
In the swing, the proper kinetic sequence is critical for creating as much batspeed as possible. The main contributors to swing power, in order, are the following:
- Hips: The hips produce power first, beginning when the front foot strikes the ground.
- Torso: As the hips begin to rotate and accelerate, the torso is stretched, which causes a rubber-band effect as it too begins to rotate.
- Lead Arm: The lead arm - the left arm for right-handed hitters, and right arm for left-handed hitters - is the next body part to begin its acceleration. The lead arm takes power from the hips and torso and begins transferring it to the hand.
- Hand: The hands are the only parts in contact with the bat, with the lead hand doing most of the work.
Ultimately, the power produced by the hips, torso, lead arm and hand is delivered to the bat, which then smashes a baseball deep into the bleachers (hopefully!).
If the Kinetic Chain is Out of Sequence, Power Decreases
The sequence above is what every hitter needs in order to produce as much power as possible. If the lead arm generates its peak power before the torso, for instance, then the overall power produced (as batspeed) will suffer.
Each body part in the chain needs to reach peak power output before the next body part reaches its peak power output. If any parts are out of order, then we need to work on fixing this through hitting drills.
Baseball Hitting Drills That Improve the Kinetic Chain Sequence
The K-Vest is a great tool, albeit an expensive one. Your local hitting facility may have this equipment. If so, you can likely get an assessment to baseline where your swing is today and compare after you implement a program. Small changes in the sequence do lead to noticeable observations in exit velocity and ball flight distance.
Even if you don't have access to this technology, there are baseball hitting drills that can help. First, a drill to break the sequence down into each movement can build muscle memory and help a hitter become aware of what each movement feels like.
Here coach Andrew Beattie (@SilverbackAthlete) shows how to use a pvc pipe to work on the hip and achieving separation. Find him on Instagram for similar drills and training using K-Vest.
In this video from the Baseball Doctor on YouTube, Coach Cathcart explains how a proper hip load will help a hitter get his kinetic sequence in the correct order. This hitting drill would work with a batting tee or without, and it's relevant for baseball and softball hitting too, of course.
The Kinetic Chain: Do you understand what it is?
During your hitting drills, do you think about your kinetic chain sequence?
Do you work on getting your hips, torso, lead arm and hands working together in the proper order?
Practicing smart is crucial for long-term success, and every session hitting off a batting tee is a chance to get better.
At Tanner, we're here to help you get more out of your practice time. No matter where you're at in your baseball/softball journey, our mission is to support you.