Swing Leg Retraction, Foot Plant From Above and Negative Y.

by Randy Sullivan
in blog

In high school, I was very good at math and scored well enough on my SAT and in college placement tests to exempt freshman mathematics classes at my first school, Erskine College.  At the time the enrollment at this South Carolina liberal arts school was around 500 students.  It was located in a tiny “town” called Due West.  I don’t know if any of this is true, but legend has it that is was called “Due West” because it was “due west of another town called Ninety-Six which was ninety-six miles from the state capital, Columbia.

During my first semester as a member of “The Flying Fleet” (that was really our nickname), instead of the usual freshman Math 101, I enrolled in Calculus (8:00 am every Monday, Wednesday, and Friday). By Christmas break, we were cyphering derivatives and integrals and by the second semester, we started differential equations.  I hated every minute of it but I got by. In retrospect, I wish I had paid more attention.

In the late 1500’s Galileo Galilei declared:

“Mathematics is the language in which God has written the universe.”

The more I study and learn, the more I realize this truth.  It’s why we hired a full-time mathematician/data analyst last year.

Here at The Florida Baseball Ranch, our approach to skill acquisition is based on a mathematical model known as the dynamical systems theory (DST).  DST is grounded in differential calculus and has emerged from the science of behavioral psychology as a useful tool in predicting the behavior of complex systems like ecological environments, economies, and political systems.  DST has also been used to describe and anticipate the behavior of complex biological systems, for example, a training athlete’s body.

In a complex biological system, small changes in conditions can result in widely disparate outcomes. This fact has spawned the popular “Butterfly Effect” also known as The Law of Sensitive Dependence on Initial Conditions which states that in a complex system, every component’s (i.e., every cell in your body) state and behavior at any given time is dependent on the state and behavior of every cell around it. And, the state and behavior of those surrounding cells are dependent on the state and behavior of the cells around it, and so-on.  In common lore, “The Butterfly Effect” suggests that something as simple and seemingly innocuous as a bird flapping its wings off the coast of Japan could cause a cascade of events that would lead to a hurricane of the coast of San Fransisco.

What this means to baseball training is that there are no insignificant variables.  There is no scientific “noise.” EVERYTHING matters.  All variables are important and any component of your movement or your training can contribute to or deter from optimal performance.

For this reason, we go to great lengths to identify and collect information on every possible contributor across the span of  6 types of contributors to sub-par performance or pain, first described by Coach Ron Wolforth in 2010.

Every athlete that enters our doors for training must undergo a comprehensive evaluation to identify all known possible contributors.  No one trains without an assessment. Our entry-level physical assessment, The New 3D-BRAT, examines 20 different test movements, each of which can identify the magnitude and quality of movement in up to 66 joints.  Our new Attractor-Based Biomechanical assessment involves 33 data points that can be graded on a scale of Green (acceptable), Yellow (caution), and Red (significant opportunity for improvement).  Our SAVAGE Strength training assessment investigates 25 additional variables. We insist on this thorough initial assessment for 3 reasons:  1) It allows us to screen for significant injury risk factors. 2) More importantly, the results of the assessment serve as the template for individualization of training — one of the hallmarks of our process. 3) It allows us to establish the stability (or lack thereof) of the attractors of the system?

What do we mean by attractors?

Glad you asked.  Bear with me while I pull out my old Calc 2 book.

If you assign each data point a number, (Green = 3, yellow = 2, red = 1) and throw them into a differential equation, you have a collection of numbers that will begin to self-organize into a waveform.  Some points in the wave, the numbers cluster together. These points are known as attractors.  The attractors serve to establish the boundaries of the wave but they also stabilize the system, making it more efficient. When the system’s attractors are stable, it becomes more “robust” (resistant to perturbations) and more “resilient” (resistant to state change/tissue failure).

The variable parts of the system are known as fluctuations.   As the attractors become more stable, the system starts to eliminate fluctuations.  Fluctuations provide adjustability but if too abundant, they can destabilize the system. The key to throwing efficiency to make your attractors stable (but not too stable) and to have some fluctuations available for adjustability, but not too many.

At the Florida Baseball Ranch, we have identified seven attractors in the throwing motion. We use leading-edge skill acquisition and motor learning strategies to train and stabilize the attractors. Then we add variability to develop just enough fluctuation options to achieve adjustability and maximal performance.

One of those attractors involves the lead leg, while it’s in flight and when it reaches weight-bearing foot plant.

If we put a force plate under your front foot as you land the force can be distributed in 3 directions.  Side-to-side force is known as “x force.”  Force straight down into the ground is called “Z force,” and if the force goes forward or backward it is “Y force.”

Y force is positive if it goes forward and negative if it goes backward.

Elite throwers typically generate a significant negative Y force.  This movement forces co-contraction of the lead leg and creates somewhat of a “clawing” action that propels the athlete forward. The video below shows it pretty well.


Full disclosure: the biomechanical picture on the left and the pitcher on the right are not the same guy.  The biomechanical video on the left is from a study conducted by our Savage Coordinator Garrison Roy last year. The pitcher is Matt Moclair, University of Tampa, a mid-to-upper 90s righty who was drafted in the 12th round last week. It only took me about six hours to time them up in Final Cut Pro so I could demonstrate this point. 🙂 


I’ve seen many instructors online and in social media describing this as lead leg blocking.  Videos show guys performing exercises that intentionally and independently drive the front knee backward, locking it into extension. In my opinion, this approach is incorrect and corruptive.  It’s not lead leg blocking and it doesn’t happen intentionally with the lead leg. Swing leg retraction, foot plant from above, and negative Y force occur as the result of efficient co-contraction and timely rotation of the back hip. As the back hip moves toward internal rotation, the swing leg retracts slightly, just prior to lead foot landing. This places the foot in a position to land from above and produces a negative Y force.  As the back hip continues to rotate to a position parallel or ahead of the lead hip, the front knee moves into extension.  The athlete’s hamstring length is adequate, the front knee locks into full extension.

Again, the front leg is not the driver of this action.  It happens as a result of efficient back hip rotation.

So how do you achieve this important attractor?

Get on your iron pyramid to gather and store energy by forcing symmetrical co-contraction on the back leg.  Ride your pyramid down the mound for as long as you can.  Keep your butt behind your heel so you can use your glutes and your hip adductors to internally rotate your hip.  When you reach the end of the ride and you begin to rotate, your swing leg will retract, setting the stage for foot plant from above and the negative Y.

Creating drills that allow the athlete to feel efficient glute load, pelvic ride, and back hip rotation can be vital to achieving stability in the lead leg attractor.

To learn more about our Attractor-Based approach to evaluating and training pitching biomechanics check out this new video we produced called Attractor-Based Pitching Biomechanics.

CLICK HERE TO ACCESS THE VIDEO.

Then get here an let us evaluate your mechanics and help you gain the velo, command, and secondary stuff you need to ascend to levels you never imagined could be possible.

It’s what we do.

We do it every day.

Get here. Get SAVAGE.

Randy Sullivan, MPT, CSCS
CEO, The Florida Baseball Ranch

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