Hello anatomy friends this is Dr Alsup and in this video we will be discussing the major muscle
compartments and groups of the lower limb. So a major focus will actually be on understanding
the basic locations of these structures as well as understanding which joints are affected when these
muscles contract. So let's start in the proximal hip and specifically the posterior proximal hip
and what is referred to as the gluteal or gluteal region. These muscles will have an attachment on
the axial skeleton such as the sacrum as well as the other major component of the pelvic girdle
which is the coxal or hip bone. And the distal attachment will be on the appendicular skeleton
so different parts of the proximal femur. Meaning that these muscles will move the hip joint because
they're crossing the hip joint. The muscles in the gluteal region will vary greatly in size
with the larger muscles being more superficial so the gluteus maximus is the best example and
the deeper muscles being considerably smaller and so here you're seeing the piriformis but there are
muscles around this region as well so considerably smaller. Much variation in these muscle sizes.
Moving slightly inferiorly there are three compartments of muscles that tend to have
relatively longer bellies and often longer tendons. The anterior compartment is mostly composed of
the muscles of the quadriceps femoris so in this general region right here. But there are also some
muscles that are more superiorly placed as well as a few other long muscles like the sartorius.
These muscles in the anterior compartment will move both the hip and the knee joints dependent
on the muscle. The medial compartment is also called the adductor compartment based on the
primary action that occurs with contraction of these muscles, so kind of looking over in this
region here. So adduction is moving the hip joint in the sagittal plane back towards the midline.
The posterior compartment is primarily the hamstring muscles
with a few other muscles or parts of muscles associated.
And the posterior compartment muscles will move both the hip as well as the knee joint.
All right to the leg, again there are three compartments, but instead of a medial compartment
there is a lateral compartment which is by far the smallest compartment really made up of only
two muscles the fibularis longus and brevis which we'll talk about in more detail in upcoming
sessions. The anterior extensor compartment is a bit more laterally placed as well overall but
still positioned more anteriorly than the lateral compartment so muscles right around this region.
You can see that there is not much muscle coverage on the medial portion of the tibia,
and that's why that portion of the tibia is so easily palpable. The posterior compartment
of the leg can really be divided into two subcompartments with the more superficial region
made of muscles that most people associate with with their calf muscles, whereas the deeper muscles
so kind of in this region these are the more superficial, they're going to attach on this
calcaneal or achilles tendon, and the deeper muscles which you can see in this image here
are going to, they don't tend to be quite as large but still also have long bellies and tendons.
The muscles located in the leg tend to affect action of the talocrural or
the ankle joint, but many of those long tendons extend past the tarsal bones
and to the phalanges and can affect many different joints of the foot.
Lastly there are muscles that have their proximal and distal attachments
all within the foot and therefore will affect only the joints of the foot. The majority of the
muscles of the foot are located on the plantar or the sole of the foot so all of these images are
showing muscles that are associated with the sole of the foot. But there are some intrinsic dorsal
muscles as well but a lot of times you see those long tendons from the muscles of the leg as
well. These muscles tend not to be as robust and fine-tuned as what is located in the hand and if
you think about hand movements as opposed to foot movements the movements in the hand tend to be
more complex or precise so there's not typically as much discussion of these intrinsic foot muscles.
Excellent we have reached the summary slide and I thank you for your time and attention here.
Please take time to review and reach out
with any questions you may have. Have a great rest of your day