Thursday, December 16, 2010

Good question from Kev...

"Could you define pelvic drop since I am unable to view the article please? Is it in the frontal plane? Would farmer and waiter carries be an appropriate exercise to address the QL and GM in order to encourage stabilization of the pelvis and reduce lumbar shear?"

pelvic drop=non weight bearing pelvis dropping in frontal plane= Trendelenburg sign.

In these subjects, in was occurring in Treadmill walking.
The point I'm getting out of this article, and others like it, is don't piece meal muscles (of course occasionally you need to, but not in this case).  If we look at this issue from that point of individual muscle then we would also have to look at the same side erector spinae, the same side internal oblique, opposite ext. oblique- the list goes on and on.
As far as remedial exercise, Frans has a few that address the issue.
Others I can think of are SLS on the leg opposite the drop, while keeping the non weight bearing illum as high as possible...double time skips doing the same...extended walking/running in other planes & retro sagittal.

However, in my opinion it may be more of a physical competency thing.  Not enough of a lower extremity strength & power base.  Pelvic drop means the body is lollygagging in the force reduction phase, maybe as a protective measure.  Opinions?


activedc said...

Is the problem that we are reducing force in these situations when actually we should be producing force? Agree the system is malfunctioning, maybe multiple areas, maybe just never learned how to run? Might be compensation as well - which could explain it why it becomes more obvious when fatigued. As always Joe, you are trying to make folks think.

Joe Przytula said...

the body will choose it's own resonent frequency to perform at. I think you are correct, multiple areas manifesting itself in frontal plane hip drop.

Brian Green said...

First of all Joe back in the US of A on my way home and sitting in Newark International waiting for a connecting....the place is a zoo!
Excuse me but I'm going to entertain the hypothesis in the referenced study for a moment that isolated exercise of select muscles can improve a task that requires multiple muscles to interact with each other in order to perform, in this case, walking efficiently.  Just when its put that way it sounds ridiculous...Anyway, Trendelenberg gait is actually due to dysfunction of two muscles (Glute Medius and Glute Minimus). These muscles not only abduct the femur in an open chain (I know you're not fond of the term), controls frontal plane motion during ipsilateral WB'ing (closed chain), but we should also consider that these muscles perform external rotation (Glute Med) and internal rotation (Glute Minimus) in an open chain. We also know that the femur is reacting to events distal to it during heel strike to mid stance and finally toe off requiring it to internally rotate and then externally rotate through these kinematics stages of gait. Therefore these muscles not only must control the pelvis but also guide the femur to firstly decelerate (internally rotate) then accelerate (external rotation). Perhaps when the strength or control  of these muscles is compromised they maintain it's role in keeping the femur centered and guiding it's transverse plane motion but leave the pelvic control to the multitude of other muscles that live in the neighbourhood to keep an eye on the frontal plane? 
Look at the anatomy of these muscles. Not big cross sectional areas, not far away from the joint axis, and have small lever arms. Therefore, they cant be the main culprits...But like the interaction of the scapula to the glenohumeral joint during overhead motion sometimes when some muscles are on vacation something can get chewed up. Perhaps a lack of control of the frontal plane pelvic motion on a femur that also creates a transverse plane motion of the pelvis during late swing phase that this combination causes other structures such as the L spine to get chewed up. 
With all that said isolation exercises wouldn't make sense any way based on what we know of the kinematics during gait....I've come full circle, that's jet lag for ya, Feliz Navidad!

Joe Przytula said...

...and with Brians take now we can understand how a ruuner could develop stress fractures about the pelvis.