A Window into the Glutes: Anatomy lesson for the day.

A rather literal statement for a rather literal picture. Taken from the Human Body Exhibit at the Denver Museum of Science, this picture offers us a glimpse into, or in this case through, one of our favorite muscle groups. This group that we see here, is probably our second favorite group. They are often called the “deep six” and are the deep hip external rotators. If you count, you will notice there are only five….one remains unseen the obturator internus. More on that later.

See the linear white lines on the right of the window? That’ s the two portions of the sciatic nerve. Notice how it runs under the muscle at the top and over the others? The muscle it runs under is the famous piriformis. When this muscle gets tight, it can impinge the sciatic nerve, causing pain down the leg (known as sciatica). This represents one of many causes of pain radiating down the leg.

The next muscle south is the gemelli superior, then the obturator externus, gemelli inferior, and quadratus femoris. The sixth of the deep six is the obturator internus, which runs from the inside of the pelvis on the obtrobturator foramen (those huge “eyes” you see in an x ray when looking at a pelvis from the front) to a similar place on the femur.

A few observations you should make.

• when someone chews your butt off, or chews you a new one, this picture gives it a whole new meaning

• the sciatic nerve runs under the piriformis

• The top (superior) five muscles have a tendonous insertion to the femur that you can see as a whitish area on the left

• the last (or most inferior muscle) has a muscular insertion to the femur (which is a reddish area on the left)

• the positioning of these muscles allows them to be external rotators of the femur when the foot is in the air

• when the foot is planted, they become external rotators of the pelvis or can act to slow internal rotation of the femur during stance phase

• as you proceed caudally, the muscles become stronger adductors of the thigh

We will see this post as a reference for some future posts on this most fascinating muscle groups. Until then, study up!

The Gait Guys. Uber Foot Geeks. Join us in our mission to educate the world on the importance of understanding human motion and its impact on translating us forward in the gravitational plane.

all material copyright 2013 The Gait Guys/ The Homunculus Group. All rights reserved

Gluteal Asymmetry: it means something !

Two photos above, toggle the red bar on the right.  What do you see ?

Here is a case of a young football star we saw last night.  He came in with a fresh right mid-belly quadriceps strain.  This is a simple case if you know what the visuals are telling you.  Just be sure you test your visuals (which are ASSUMPTIONS !), in other words, prove or disprove your hunches.  What you SEE is not always what is present as the problem.

You can see clearly that in a  prone position this chap has significant right gluteal underdevelopment compared to his left.  This is a “quick peak” method of screening that i do on every patient when they turn over prone on the table as he is positioned.

There are many nuiances to this case, but here is what i was thinking the moment he told me about the injury….  “Doc, we were doing short 40 sprints, and my right quad just seized up?”.

I thought, hummmm….. i wonder if he was anchoring his thigh into his glutes and abdominals.  Lets test his glutes first.  If the glute is weak then i can assume he is quadriceps dominant and not anchoring the limb into the pelvis and core correctly.  If he is gluteal inhibited, that means he will have underdeveloped glute if it has been there long enough. And if so, the glute cannot power hip extension so that range will be deficient.  Sagittal extension will occur the next level above (lumbar spine) and inhibit the lower abdominals on the right.  The hamstrings can also be called in to drive hip extension (welcome to the world of chronic hamstring issues in athletes).  And if hip extension is limited, then internal rotation is likely somewhat limited.  And if internal hip rotation and hip extension are limited then ankle dorsiflexion (“ankle rocker”) will be impaired and limited during midstance thus creating early heel rise during push off thus forcing the calf muscles to create more body mass lift than forward propulsion.

I put him on the table……saw the atrophied right gluteal……and proceeded to confirm all of the above. Treatment is based on figuring out who started this whole mess and reversing the functional pathologies in the pattern that makes sense to that patient’s neurologic system.  It can be different for each person.  You cannot “cook book” good manual medicine.

Prove or disprove your differential diagnoses or hunches……. make sure your direction is the right one.  We all know what ASSUMING lead us to ……. it makes a donkey out of all of us.

We are….. The Gait Guys……. just a couple of donkeys.