Hello anatomy friends this is Dr Alsup and we are going to introduce the major
joints of the lower limb. There are certainly more than the ones we're
going to discuss and you can refer to the learning objectives for the names of these
but I only want to discuss the largest most clinically relevant of the joints of the lower
limb. But these first two joints are more joints of the pelvic girdle than the lower limb but
their stability are important in the efficient movements that are allowed at the lower limb,
particularly of the neighboring hip joints. So the first of these it are the sacroiliac joints which
we've talked about in other sessions sometimes you hear these referred to as the SI joints
and these are going to be located between the sacrum and the coxal bones. And this is a compound
joint composed of a synovial and a fibrous portion a very sturdy joint with only slight movements
allowed. More anteriorly located and also medially placed will be the pubic symphysis which is where
the two pubic bones will articulate kind of more in this median plane. Now this is a cartilaginous
joint and will only permit very slight movements similar to what we had with the sacroiliac joints.
The hip joint is the connection between the pelvic girdle and the lower limb
and you can even see a bit of the pubic symphysis here on this image, so you can get an understanding
of how close these joints are because the hip joint is going to be located right in this region.
This is a ball and socket joint you can see that in this image here where the joint has been opened,
you can see the head of the femur which is the ball portion and the acetabulum which is of
the coxal bone and this is the socket portion of the joint. The hip is very well protected by some
of the strongest ligaments of the body and that's what these images here or what these
kind of color images here of the ligaments are indicating the actual ligaments of the hip joint,
we'll talk a little bit more about identifying these in upcoming sessions.
Moving distally the knee joint is next which is formed by the articulation of
the distal femur, you can see the femoral condyles right here really well on this posterior view
of the knee joint, and the proximal tibia so this is tibia these are the condyles of the tibia here.
In this anterior view you can see the patella which has been reflected inferiorly really
in a more anatomical position without dissection that patella would be sitting right here on this
patellar surface. There are a lot and I mean a lot of accessory structures associated with the knee
joint as the bones do not have a very strong fit so to keep the primarily hinge motions of flexion
and extension allowed here you have to have a lot of ligaments throughout so more to come
on these in upcoming sessions. Lastly the ankle joint is also a hinge joint. iIt is formed by the
distal ends of the leg bones. The tibia is going to be the primary one you can see it
right here this distal portion but the fibula will also play a role. And these the tibia and
the fibula are going to articulate with the most superior tarsal or ankle bone the talus
or the talus you'll hear it either way. And you can see this pretty smooth area here on the
talus which makes sense as this is a major side of articulation with these bones. The majority
of ligaments associated with the ankle joint are located on the medial and lateral sides you can
see one pretty well right here. These are kind of forms of collateral ligaments and we'll talk
quite a bit about these particular ligaments in upcoming sessions. Excellent this has been your
introduction to some of the largest joints of the lower limb we will discuss each one of these in
more detail and upcoming sessions. I thank you for your time here and have a great rest of your day