Hello all this is Dr Alsup and we are going to do a very superficial overview of the compartments
of the lower limb. We will build details in the upcoming sessions but now i just want to
give a quick look at what these compartments look like superficially.
Let's start with the most superior of the compartments and this happens to be
located posterior as well, which are the muscles of the gluteal or gluteal region. While these muscles
most certainly have their greatest effects on the hip joint they are located pretty superiorly
compared to the rest of the compartments. The most dominant muscle is the gluteus
maximus, which unless reflected you can only see a little glimpse of the gluteus medius right here
and you can't see any of the rest of the muscles, but as you do get this reflected you see there are
quite a few muscles deep and we will get into those details in upcoming sessions, but when
looking superficially really the majority muscle you see here is the gluteus maximus.
Now let's move to the muscle compartments of the thigh and there are three compartments: anterior,
medial, and posterior. The largest of these are the anterior or is the anterior compartment mainly due
to the quadriceps femoris muscle which you can see right here. And when looking at this anterior view
you can see a little peak of the medial compartment and of note you can see this
very thick condensation of deep fascia here called the iliotibial band or iliotibial tract sometimes
you hear IT band. Additionally you can really see how the tendon of the quadriceps muscles
is really prominent here this is going to be right at the knee joint region
so you can see the tendon is playing a big role in terms of that anterior portion of the knee.
Now the thigh in this image has been rotated medially a bit and you can certainly still see
the anterior compartment over here, so this would be the anterior compartment.
But medial to this femoral neurovasculature that you can see right in this region,
you're looking at the medial compartment sometimes referred to as the adductor compartment so not
quite as large as what we have in the anterior compartment but still fairly prominent muscles.
Lastly in terms of the thigh is the posterior thigh compartment.
You can see the gluteus maximus up here so up superiorly see as you move just distal
to the gluteal muscles you're looking at the posterior compartment of the thigh.
right here you can see a bit of the medial compartment here
and here's that IT band right here. So these are the hamstring muscles in the posterior compartment
of which there are three and those tendons of the hamstring muscles will extend past the knee.
Now moving to the leg and guess what there are three compartments here as well.
There is an anterior posterior compartment just like what we had in the thigh
but instead of a medial compartment there is a lateral compartment of the leg. We're going to
start with the anterior compartment of the leg and the thing I really want to point out here is that
even though this compartment is called anterior and it certainly is the most anteriorly oriented
the muscles in this compartment are going to be oriented much more anterolaterally,
because you can very clearly see the tibia right here so this bone right here
that you can see throughout the length is the tibia. You can literally or you can put your
hand and run it down the anterior portion of your leg and you can feel the tibia the entire length
and so the muscles are going to be oriented a bit more laterally in the anterior compartment.
The lateral compartment of the leg is the smallest leg component and it's composed of just two
muscles that are relatively slender, I'm circling the muscles of the lateral compartment here,
and even if you're looking at the strictly lateral view like we are right now you can still see
the muscles of the anterior compartment and the large posterior compartment so
again this lateral leg compartment is by far the most slender and smallest of the leg compartments.
Conversely the posterior compartment of the leg is the largest compartment of the leg and it's so
large that it's actually has two sub-compartments. However the most dominant muscles you can see
right here in the superficial dissection which are what most people think of when they think
of the calf which are the gastrocnemius which are you have the two heads of the gastrocnemius
and you can see the soleus deep to that and the very prominent calcaneal tendon which also
we most commonly hear this referred to as the achilles tendon. So this posterior
compartment then you have deeper muscles here which we'll get into in later dissections
but it's these muscles the gastrocnemius and the soleus that really form the prominence of the calf.
All right excellent thanks for your attention here and certainly more to come regarding each
one of these compartments in upcoming sessions. Have a great rest of your day