Farm+ Threads

Cut me Some Slack

Cut Me Some Slack

Muscle and Fascial Slack? What is it, why is it a performance limiter, and what are some strategies of removing it? In this thread, I will be outlining human movement principles that integrate work from @FransBoschBook, @BasVanHooren, and several other researchers. 

I’ll then be combining their work with my experiential knowledge of training hitters to make it applicable to our field.What is Muscle/Fascial Slack? I stole these two images from my good friend @RandySullivanPT from @FLBaseballRanch. We want to imagine our muscles like the…


ropes on the bones. Some of us have more/less muscle slack than others and just like the man trying to pull the car we must remove this slack to express power. Muscles don’t sit ready to express force.Can you imagine why this would be problematic and a major…

performance limiter for hitters? Hitting is an open skill, a skill that takes place in a dynamic and changing environment. Muscle slack increases the amount of time it takes to express power. In a game with ever-increasing pitch velocity and design, learning how to limit this… slack is in your best interest as a hitter.You know what’s awesome about the human body? It already knows this. That’s right before the brain can even come to terms with what’s going on inside the body, it’s already adapting and problem-solving. I can guarantee that you are… already using some of these techniques to remove slack from a system, but you just didn’t know you were. Here’s the problem though, two out of the three most common methods for our body to remove slack aren’t nearly as effective at higher levels of play. What are the two most…

common methods? 1.) Countermovement (i.e. Internally rotating the trunk or pelvis prior to rotation in the baseball swing. This stretches the muscle-tendon units and therefore effectively reduces slack.) Why is this the most common method of removing slack and why is it… problematic? Excessive counter movements can be effective at lower levels of play because the time constraint isn’t as restricting. There is a higher level of affordance, you can get away with more. We must remember that a countermovement IS an effective way of removing slack…

and expressing force WHEN the environment/task allows for it (i.e. Golf). I’ve been misguided by this same concept and mistaken small sample sizes or production at a lower level to be an indication of upward projectability. This was something @108_Performance helped me with.

With this lens, the commonly used, “That doesn’t play at this level” comes to mind. While the term is often overused and misplayed, in every criticism, there is at least some truth. Maybe some of these coaches with experience had knowledge they couldn’t express scientifically?

Just some thoughts, anyway, I digress.What is the second most common method of pulling out slack? 2.) External Load (i.e. Swinging a heavier bat, for example, the muscle-tendon unit is stretched and put under tension, therefore reducing slack.) While I use overload bats while

training athletes, early on I struggled to understand why some athletes moved so much better when swinging a heavier bat. I was one of those athletes for example. Even now when I swing a lighter bat it feels loose (in a bad way) and disconnected. I don’t have a good feel for the barrel. I was seeing the same thing with athletes I was training and struggled to understand why until I learned more about slack and connected the dots. So, what’s the downside to using a heavier bat? Think of it like having 400lbs on your back, when things go bad, they go bad.

You’re less adjustable and typically move at a slower rate of speed. So, while you are expressing more overall force, you typically lose speed and quickness. Two major components to striking a moving object. Now while I still use overload bats, I use them for a different… purpose than motor performance. I use them from more of a skill acquisition standpoint. I’ve talked about it before, but I’ll have to revisit it in a later thread and outline some of the details and intricacies of my process. So what’s the third method?

3.) Pre-Tensioning through Co-Contractions (i.e. Moving connected with limited hip/shoulder separation (agonist/antagonist muscles) contract simultaneously, they will stretch the muscle-tendon unit, therefore reducing the effects of slack.) “Recently” we uncovered the… countermovement method of removing slack, but didn’t understand exactly how it worked and may have started running the wrong direction. We’ve measured athletes in a Biomechanics lab and saw that hitters/pitchers were expressing more force with an increased degree of… counter movements. While we proved that this may be a valuable technique of expressing force, what we FAILED to prove was that this was the ONLY or most effective technique in regard to the task. One reason, in my opinion, why so many athletes use counter movements and the…

external load method of removing slack is because they often can be used as “right now methods” or for motor performance. Simply put, you can make force output numbers jump in a practice/lab typesetting. As stated earlier, these two environments have fewer variables and different affordance. For context, Pre-tension and Co-Contractions can be cued or provoked in some cases for instantaneous motor performance, but more often than not the CNS system needs to be trained to perform in this way. Until the body is constrained in a way where it must utilize this

method or approach, it’s unlikely to “just happen”. The body likes to use the path of least resistance to complete a task and when a situation affords an easier path for completion, WITHOUT impedance, the body will take advantage. *Additional Context: The best in the world still use all three of these methods when removing slack during performance, but while all of these methods can be effective in some capacity, certain tasks require different techniques for higher performance. Instead of having such a binary thought process to removing slack, we need

alter our lens to more of a mathematical perspective, viewing different techniques as different combinations of these methods. In the world of sports performance, time matters. So how do we alter our training techniques to reflect this slack removal method? On the S&C side of

things @ZachDechant & @Tywhite27 have put together some solid resources for you to dive into. And recently the @farm_system released a Mini-Course on the Essentials of Hitting where we address slack and a few other things we should be considering when training hitters. PLUS..

Even more, info for you to dive in to on Farm+. You see what I did there. 

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