[quote author="davan" date="1229512930"]No, video is important because it isn’t just about foot positions, COM, etc., but also about GCTs and other factors.
Further, Carl focused on ankle stiffness in his post. You continue to just say stiffness and refer to overall leg stiffness, which is an important difference as it relates to what Carl says he is targeting by doing the drill in this fashion.
You then go on to post some nonsense about how this is bad if a person uses this as their sole or main mean of improving acceleration–I hope you weren’t serious when you posted that. I am not aware of anybody that uses the sled as their primary means of improving acceleration.
I’ll ask once again, like in the thread on cleans, to post vid. Your comments need some back-up with video because what you are saying is either unclear or isn’t phrased in a way that has a clear application. Not saying you need to post some 6.3-6.4 60m sprinter or something, just one of your high school athletes doing what you would consider a solid job on how to do this particular drill. It would make what is being discussed much clearer.
I gave author references for joint torsional stiffness for people to refer to. You can make the links there or you can refer to my website were I talk about the subject of angles using all three authors (Farley, Devita, and McCaw) I referenced. You could go further and link it to research of other authors and come to the same conclusion that stiffness is going to be reduced, it has to be, and the issue isn’t volitional extension here it’s flexion since when we are measuring stiffness we essentially discussing flexion at the ankle, knee, and hip at ground contact which correspond directly to leg stiffness and vertical stiffness and since the added mass is causing resistive forces against the line of pull and not gravitational forces normally associated with added loading. It’s kind of like running into a 20mph wind or greater that crosses the body at angle in the saggital plane. [/quote] You are arguing things that weren’t even being debated.
As the sole training purpose we’d see why sled pulling has little transference in motor learning of unloaded accelerations and yes there are coaches who only do sled pulling, hill running or other means as acceleration training.
That is not what we are discussing though. Saying this kind of detracts considering Carl and his athlete (and numerous other people) have explained that this is a drill that makes up a very small portion of their training and is in addition TO sprinting.
I said I would figure out how to post something to Carl’s request. As for your request of video, what good will that do? It doesn’t end the debate, it may only worsen the debate, if you need a video reference just pay attention to Carl’s athlete’s first 7 steps only in the video. Myself posting a video of a 14+s female sprinters pulling a non-weighted 15lb sled is virtually worthless, not to mention I might have 2 video segments at most or none at all in about 120 hours of tape to go through. I put them in sleds to develop the initial impulse and I am not sure it worked better than the slight inclines we used. I highly doubt I have any on my digitized copies as those are all mostly competitions, tests, and assorted exercise sequences and demonstrations I wanted for reference of which sled pulling is not one of them.
I’m not concerned about how fast they’re going–if they’re doing the drill correctly in what you define as the proper way to do it, I am interested in seeing it. I want to see if doing it your way also has no tibial rolling, over striding, and has optimal stiffness at specific shin angles.