Sunday, February 6, 2011

The Gastocnemius is an upside down hamstring- more evidence.

Ankle Dorsiflexion Range of Motion and Landing Biomechanics- Fong et al, JAT Jan '11.

On page 8 speaks of the importance of the gastroc in force attentuation at the knee during landing.  Greater dorsiflexion was associated with smaller ground reaction forces.

9 comments:

Jack Martin said...

Joe, Alot going on here with the gastroc. Can we really coach dorsiflexion? Or is it one of those things that just happens? I just finished watching Frans' Running DVD (I thought I lodt the disc) and noticed that all of the runners have great dorsiflexion.
My main point- I think-based on my own pain and weakness- that the entire posterior chain has a big impact on the knee. I also have factored in my bunion into the equation.
Now, can we train these individual areas? I know it does not fit into the whole functional equation, but sometimes the discomfort from an injury affests our ability to do so functionally. What say you- if I am making sense. As always, I enjoy the blog. Martin

Joe Przytula said...

Good topic Jack, as usual. But it all depends on who you ask. Frans believes the ankle dorsiflexion is a manisfestation of "positive running", that is the pelvis being over the foot at ground contact. If you are "posterior chain" running, you are pulling yourself over the ground without enough vertical displacement of the
COG and it could give the illusion of poor ankle dorsiflexion. I'm saying that even if your "Real" dorsiflexion on the PCA test is a "5", you would not be able to functionally use that motion. However, as you get over 40, you are lucky if you score a "3" on the PCA ankle. Throw a bunion on top of that and yes, the body will compensate- probably along the long axis.

We've done the PCA on injured world class runners- they test lousy as excpected, including ankle dorsiflexion. But Frans still feels you don't need as much as you think- as long as you are positive running.

Personally, my fascia training so far tells me there is not one "chain" that dominates the other. At the end of this month, I'm excited to spend time with the Steccos. They have thousands of hours of fascia cadavor studies under their belt, and I hope to share it with my blog readers.

BJ Maack said...

Excellent topic. As I work with a lot of runners, I am looking forward to reading more on this.

Joe Przytula said...

Let me make it clear, that is definately not the author's opinion, it's a Joe P interpretation. I emailed the author and asked him what he thought. He emailed me some research from Fleming from '01 that said the angle of pull on the distal fib created a Lochman test effect and had an anti ACL stability effect. I disagree, because of the gastroc's angle of pull when the knee is near full extension (where most ACL tears occur) would negate that effect. Besides, the gastroc's partner is the soleus, which attaches to the tibia, as opposed to the femur, cancelling out the anterior draw effect (if any) of the gastroc

Kev said...

Coincidentally, Eric Cressey has a post on this topic as well.

http://ericcressey.com/the-importance-of-ankle-mobility

Joe Przytula said...

Phew Kev, that looks awfully familiar:

http://www.gambetta.com/pdf/shoulderclearing.pdf

Kev said...

Phew Joe!!! Your presentation (a good one BTW) sounds a lot like some Anatomy Trains stuff ... ;)

Joe Przytula said...

...and I gave him mad props:

http://www.gambetta.com/pdf/shoulderreferences.pdf

http://www.gambetta.com/pdf/shoulderclearingnotes.pdf

Jack Martin said...

Joe, I came across this test in trying to solve the problem of my recent hip pain while running:
http://sportspodiatryinfo.wordpress.com/2010/02/28/the-lunge-test-forget-ankle-range-think-ankle-stiffness/

I faile miserably by the way.
The recent posts have been great. Martin