The Gluteus Medius:
Function of the Gluteus Medius
and
Cause, Postural Effect, and Treatment of the Tight Gluteus Medius
The major/true function of the gluteus medius
The gluteus medius is a muscle that all students and therapists are aware of; we
all learn it. If you ask someone what the function of this muscle is, most likely you
will be told that it abducts the thigh at the hip joint. Even though this is an action
of the muscle and the one that most everyone learns in school, it is not its most
important function. After all, how often in life do we really need to lift our thigh
out to the side of our body? This may be what is taught in school and written in
most books, but it does not reflect its major/true function in everyday life.
The major function of this muscle is its ‘reverse action’ when the thigh is fixed
and it pulls on the pelvis, not when the pelvis is fixed and it pulls on the thigh!
This occurs most often during the gait cycle (walking). When standing, our
weight is balanced over our two feet. However, when we walk and take a step by
lifting one foot up, our body weight is no longer balanced and instead is
unsupported in thin air. This should cause our pelvis to fall to that (’swing limb’)
side. It is the role of the gluteus medius on the opposite side of the body to
prevent that.
When the foot is on the ground (described as a closed chain position), the thigh is
not free to move. Therefore, when the gluteus medius contracts, it pulls upon the
pelvis instead, pulling it in the downward direction, known as depression or
lateral tilt to that side. If one side of the pelvis is pulled down, the other side is
elevated (also known as hiking the hip). The major function of the gluteus medius
is to stabilize the pelvis with this downward direction of pull. For example, if I lift
my right foot to take a step, my pelvis should fall to the right side. My left-sided
gluteus medius prevents this by isometrically contracting and pulling downward
on the left side of the pelvis, thereby preventing the pelvis from falling to the
right. This is the true function of the gluteus medius! Every time we take a step,
the gluteus medius on the ’support limb’ side contracts to stabilize the pelvis. You
can easily test this by standing up and palpating the gluteus medius on both sides
by palpating immediately distal to the midpoint of the iliac crest on each side.
Then slowly walk in place by lifting one foot at a time. You will feel the gluteus
medius contract on the support limb side every time!
Tip for students: Always look for the reverse action of a muscle. It is often its
most important, even if you did not learn it in school!
Tip for teachers: Teach the reverse actions of muscles, especially those that attach
to the pelvis. The pelvis is incredibly important toward body posture and motion.
Further, give real life examples of when muscles function!
Tip for therapists: Always look for how the postures and activities of a person can
lead to overuse and injury. Evaluate the client posturally and when dynamically
moving too!
For more on this role of the gluteus medius, see Section 8.7, Relationship of
Pelvic/Thigh Movements at the Hip Joint, of Kinesiology, The Skeletal System
and Muscle Function. For more on the gluteus medius itself, see pages 321-324 of
The Muscular System Manual, The Skeletal Muscles of the Human Body, 2ed.
What might cause a tight gluteus medius?
We have now spoken about the major/true function of the gluteus medius being
depression (lateral tilt) of the pelvis at the hip joint, NOT abduction of the thigh
at the hip joint. A tip was given to therapists to consider a client’s postures and
dynamic activities when evaluating why that client has a tight gluteus medius.
After all, if we can determine what s/he is doing to create the problem, then
perhaps we can prevent it from occurring in the first place, or at least eliminate a
perpetuating factor. SO.. what is one common and simple postural habit that
would tend to lead to a tight gluteus medius…?
The habit of standing with all or more of one’s weight on one leg! This will cause
the gluteus medius on that side to tighten. Why? The last post said that if you
palpate the gluteus medius bilaterally while walking in place, you would feel the
contraction of the gluteus medius on the ’support leg’ side each time the other
foot lifted off the ground (it contracts to stabilize the pelvis - see last post). Redo
this palpation exercise, but this time, do not even lift your feet off the ground.
Instead, just shift your weight from one side to the other. You will feel the
support side gluteus medius contract just by shifting your weight to that side!
This means that when someone posturally stands with more weight shifted to
that side, that side gluteus medius will have to isometrically contract to stabilize
the pelvis far more than the other side gluteus medius has to; especially in
someone who stands like this for hours and hours each day! This will likely lead
to a tighter gluteus medius on that side!
Asking questions like this in your history can help you find these things out. Also,
observing your clients’ postures when they are not aware that you are watching
will help too. Keep in mind that when you do a ‘formal’ postural exam with a
client, they are very often self conscious about their posture and do not show you
their true patterns.
Good information to apply clinically!
The postural effect of a tight gluteus medius
We have recently discussed what the major function of the gluteus medius is:
creating an isometric stabilization force of depression of the pelvis at the hip
joint. We also discussed that people who tend to stand and put more weight on
one leg than the other predispose themselves to having a tight gluteus medius.
Now let’s look at what the postural effect of having a tight gluteus medius is.
Whenever a muscle contracts, it creates a pulling force toward its center. This
pulling force is equal at both attachments. Which one moves is based upon which
one is more mobile, in other words, less fixed. We usually think of the distal
attachment of a muscle doing the moving. However, as you know if you read my
blog posts, articles, and books, the proximal attachment can move too! When this
occurs, it is called a reverse action. Reverse actions occur very frequently in the
lower extremity because the foot is so often fixed on the ground.
So, when the gluteus medius is tight and we are lying down, it stands to reason
that the femur is more likely to move than the pelvis (see illustration of gluteus
medius in previous post) because it is free to move (open chain scenario here). If
we assess the client in this scenario, we may see the femur slightly abducted, in
other words, slightly “lifted up and out” toward the outside. Looking at the
relative alignment of the feet, that side foot may seem a bit higher and many
therapists would describe it as being a short leg (i.e., short limb).
BUT, if we are standing up, the foot is fixed on the ground (closed chain) and will
not easily move. So the pull of the gluteus medius acts at the pelvis and can cause
it to depress. If we are assessing the client’s posture in this scenario, we will likely
see the iliac crest a bit lower on that side and again, may describe the client as
having a short limb on that side.
Result: A tight gluteus medius can affect the posture of the client and create a
“short limb.”
Tip for Therapists: Working backward with this knowledge, when you find a
client with a short limb, it is worthwhile to check out the tension of their gluteus
medius on that side. Do this assessment when the client is relaxed and lying
down.
Tip for students: Learning these muscles well in your science classes will make
you a better clinical therapist!
Tip for Instructors: These real life postural examples make learning more
interesting. You can apply this knowledge kinesthetically in class if you have the
time. Have students check each other standing postures, looking for a short limb.
Then have them lie down and assess to see if the gluteus medius is more often
tight on the short side than the ‘long’ side.
For more on the gluteus medius and its role in posture, and posture in general,
see Kinesiology, The Skeletal System and Muscle Function, chapter 17, Sections
17-1 through 17-7.
Of course, let’s always keep in mind that there are other factors that can create a
short limb. The gluteus medius is only one piece of the puzzle.
PS Something to think about: Could a tight gluteus medius also pull the pelvis
down into depression when the client is lying down? Would the pelvis be
sufficiently mobile in that position?
Treating the gluteus medius
Now that we have addressed understanding the function and postural effect of
the gluteus medius, let’s look at treating it.
With respect to massage, keep in mind that the posterior fibers of the gluteus
medius are deep to the gluteus maximus and the anterior fibers are deep to the
tensor fasciae latae (TFL); the middle fibers are superficial but are deep to a fairly
thick layer of fibrous fascia. Cross fiber techniques coupled with some long
stripping strokes from proximal to distal work very nicely. Working it on stretch
can be effective for the middle fibers but is usually not effective for the deeper
anterior and posterior fibers.
Stretching is extremely effective for the gluteus medius and should be done after
it has been warmed up with massage and/or heat. To see two stretches of the
gluteus medius (the lateral line of the hip joint) along with stretches for the other
functional groups across the hip joint, go to
http://www.learnmuscles.com/MTJ.WIN07_BodyMechanicsLR.pdf
OR – paste it in your browser
OR – Go to www.learnmuscles.com, click on the link for articles, and open the
article titled: stretching the hip
Joe