just a tiny bit of Physics ( no formulas I promise)

Originally I planned to post this a couple weeks ago and just never did so here it is.

At CrossFit Tulare we understand the difference between systems and programs, and we are very good at both. A program involves the selection of exercises, rep schemes, time domains, tempos, ect to elicit the desired response. A system however applies the program in a specific way and evaluates its success. A system is less about what movements you select and more about how the movement is taught and evaluated. Both programs and systems work over the long term and are less effective by them selves than with the other.  While Programming is a big topic in the world of CrossFit I do not hear as much about creating systems of athletic development for CrossFit. I am not talking about beginners classes, bootcamps, Onramps or elements ( though I personally find value in those things) but instead about how we as coaches train our athletes to move, think, and react. How we evaluate Movement Patterns using bar speeds, joint angles, and body types, instead of trying to force someone to fit an idea of what a particular movement should look like. Any good coach will tell you that the "correct way " to perform a movement will look different from person to person; that while their are some universal truths in movement the way these truths are expressed  changes from day to day, lift to lift and lifter to lifter. With Practice and good coaching your movement becomes more consistent as you are molded and shaped over years of practice.

As a CrossFit Coach  the problem of shaping a movement pattern is compounded by two big factors, Intensity and variety.  The sheer Amount of different movements we use can make learning all the correct motor patterns difficult and often frustrating. Add to it that we perform this variety of movements in intense workouts for time and the focus required of moving correctly can hard to maintain. This can be ( but does not have to be ) a recipe for potential disaster.

At CrossFit Tulare we address this problem with a system that strives to keep things as simple as possible on the athletes side while still providing the coach with enough information to shape any movement into the correct one. As head coach here I teach basic universal motor patterns that can be adapted to fit any challenge. Those who are familiar with this Gym will know that  we set up for any given movement ( barbell, body weight, or anything else) in the same way, adjusting only hand and foot position to accommodate any object we may have to lift. The First step to adapting our universal motor patterns then is to establish what proper start and finish positions look like,  and not worry about what happens in the Movement tunnel ( thanks K-star) while we master those positions. As we progress however the movement between start and finish positions will have to be refined. and the next step is to make sure the center of mass of the person or lifter barbell system stays over the base of support ( I will explain further shortly).  This will typically put the athlete into the range of acceptable if not ideal movements, and provide the coach with the first and most important cues and fixes that need to be made.

To understand more fully what I mean first we need some vocabulary

Center Of mass ;
We often refer to this as our center of gravity. it is the point at which all parts of an object ( or person) are in balance. when standing up in a neutral position it is usually about 3 inches behind the belly button in men and for women slightly lower.

Two important points.
first the center of mass does not have to reside within an object
second in some thing that is mobile and can change shape ( like us ) the center of mass can shift depending on position

Lifter barbell- system ;

 Sorry to be redundant but literally I mean the system created by a person grasping and holding on to a barbell. As far as we are concerned during a lift this system is only one object, and will be evaluated as such.

Base of  support:
For our purposes this usually ranges from balls of the feet to ankle bone and is the area over which the center of mass should remain in order to maintain control and balance of a movement. ( for gymnasts or certain gymnastic movements the base of support can also be the palm of the hand )


Now how do I uses this to evaluate movements ? In this post I will consider only weight lifting ( two words) movements. For this we must consider the lifter barbell system, or lifter object system as it is more rightly defined for CrossFit. We will need to learn to evaluate the center of mass of this system and its relation ship to the base of support.

First we must understand that the center of mass of the system will change depending on position, and how much weight is on the bar. When separate both the lifter and the barbell ( or object ) have their own center of mass together however their is only one. The heavier the barbell the closer the systems center of mass will be to the bar and farther it will be from the lifter when joined. While body types, and mobility will cause differing start positions in general the CoM should be kept as close to the lifter as possible  and always over the base of support. This is true of any and all Weigh lifting movements ( two words ) but most obvious in the sport of Weightlifting ( one word ).  The Clean and Jerk and Snatch are both fast, dynamic movements that require you to move a heavy barbell from the ground to over head.  The lifter must control the system and contend with an ever changing center of gravity while moving an external load to complete a lift. Failing to do so will result with a failed lift and plenty of frustration.

When watching a weight lifting ( two words ) movement, coaches must train them selves to observe the CoM of the system and its relationship to the base of support through out the entire movement. We must correct positions put the CoM outside the base of support ( or lead this this event ) . In general I have my coaches correct only one position at a time and start at the beginning ( position nearest the start position) I advise them to make only one correction in a given session, but to use that session to make sure our correction sticks. For some lifts this can result in small variations of start positions as the weight gets heavier, as in when you lean farther back in your heels at the start of heavier dead lifts. Where as in other lifts coaches must train athletes to hit the same positions regardless of load and to control the systems CoM through other means, as we do in pos 2 of a snatch.

As an athlete this concept is important because we can feel what is happening during the lifts and can learn to feel the variation from lift to lift. This can be an internal cue that gives us the ability to self correct, thereby reducing the number of missed lifts, and allow us to internalize what our coaches our telling us.

As a coach this concept is vital because after establishing proper start and finish positions we can coach our athletes to an acceptable range in their positions using simple cues that can be felt and understood easily by our athletes. Avoiding a lot of frustration for ourselves and our athletes, while maximizing their success by focusing their efforts on things that keep the CoM of the lifter barbell system over their base of support.