Wednesday, January 28, 2009

"Proper" Firing Patterns?

Muscular activation patterns during active prone hip extension exercises- Journal of Electromyography & Kinesiology Jan. 09.
A popular sports medicine certifying agency uses the prone leg extension test as a method of screening for "gluteus maximus latency". They claim a normal firing pattern goes something like hamstrings, glutes, contralateral erector spinae, ipsilateral. I've yet to see this pattern substantiated in a major scientific journal.
Yeah, I believe there is a plethora of weak butts out there; and all of the dysfunction it causes from ankle sprains to sore backs. I'm just wondering if this test needs to be thrown out. Your 2 cents please.


JH said...

Hmm - "Prone Leg Extension" test huh? Is there added resistance?

As I'm thinking about it I caught myself pondering the firing pattern when I realized that the position doesn't seem to merit any credibility. How many things would we actually do prone and requires leg extension? Swimming comes to mind but not much else.

So I don't think the test is even valid in my mind due to the fact that the test was performed in a prone position.

If you were to look at hip extension in gait for example, the firing pattern would be changed due to GFR and the fact that hip extension occurs as a result of the foot staying in contact with the ground while at the sme time the rest of the body proceeds forward.

So no the test isn't worth 2 cents.

Joe Przytula said...

what was interesting in this study was the prone leg ext. performed with the knee bent did not increase the "activation" of the glutes either. Indeed JH, the opposite side of the body coming forward indeed fires up the butt in all 3 planes quite nicely.

Brian said...

Shirley cites an EMG study, I think JOSPT, relating EMG timing of Glutes vs Hammers durng this test...Maybe the star excursion would be a better(functional) alternative....
What would be interesting is the EMG comparison of the open chain knee bent hip extension to a unilateral bridge exercise..

Joe Przytula said...

Thanks for tuning in Dr. Lehman- stop by more often! Your P.T./D.C. background has to be a true gift to your patients and clients.