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Gluteal Region and Posterior Thigh

by James Pickering, PhD
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    00:01 In this lecture, we?re going to look at the gluteal and the posterior thigh.

    00:07 So we?re going to look at some muscles that form the gluteal region, gluteus maximus, gluteus medius, and gluteus minimus. We?ll look at the lateral rotators of the hip. We?ll look at some neurovascular relations. We?ll then look at the thigh in cross-section and look at the posterior thigh, look at the hamstrings and some neurovascular relations just briefly.

    00:28 We?ll then finish by looking at the popliteal fossa, its boundaries, and the contents. Within the posterior thigh, we have a whole series of muscles. We have gluteus maximus, we have gluteus medius, and we have gluteus minimus. I?m just going to concentrate on these, first of all. This is the posterior aspect of the right lower limb. So we can see we?ve got the iliac crest here, we?ve got the sacrum, and then we?ve got the posterior shaft of the femur. We can see gluteus maximus, and then we can see gluteus medius and gluteus minimus.

    01:04 And these muscles are all passing inferolaterally towards the femur. Gluteus medius and gluteus minimus are running down onto the greater trochanter, whereas, gluteus maximus passes through the iliotibial tract, and also to the gluteal tuberosity. So here we can see we have gluteus maximus, we have gluteus medius, we have gluteus minimus, and we can see their origins and their insertions. We can see for gluteus maximus, it?s coming from the ilium posterior to the gluteal line. It?s also coming from the posterior sacrum and coccyx and sacrotuberous ligaments. We can see that here, it?s coming from the posterior ilium, posterior to that posterior line. It?s coming from the sacrum, and it?s also coming from parts of the coccyx and sacrotuberous ligament. It then passes inferolaterally, and we can see it is passing most of it to the iliotibial tract, about 75%. The deeper quarter, so the deeper muscle fibres are passing through the gluteal tuberosity. It?s innervated via the inferior gluteal nerve, and it?s important in extending the hip, and it also assists in lateral rotation. So it?s an important extender of the hip. Gluteus medius, we can see coming from the external surface of the ilium, this time between the anterior and posterior gluteal lines. So it?s important to remember these gluteal lines now.

    02:36 We can see gluteus medius coming from between the anterior and the posterior gluteal lines, and it?s passing towards the greater trochanter of the femur. Gluteus minimus comes from, again, the external surface of the ilium between the anterior and inferior gluteal lines, and this also passes towards the greater trochanter of the femur. We can see the gluteus minimus coming again here now towards the greater tubercle. So we got gluteus maximus, gluteus medius, and gluteus minimus. Gluteus medius and gluteus minimus are innervated via the superior gluteal nerve, and they are involved in abducting and medially rotating the femur, abducting the femur with the hip joints and also medially rotating the hip joint.

    03:29 They?re also involved in keeping the pelvis level when the opposite limb is off the ground.

    03:35 This is important to prevent tilting of the pelvis when you?re walking. So we?ll see this as we go through the course when we look at the nerve lesions. The final muscle I want to draw a reference to is the tensor fasciae latae, and this alongside gluteus maximus passes into the iliotibial tract. So we can see tensor fasciae latae here. Tensor fasciae latae is coming from the anterior superior iliac spine, and it passes to the iliotibial tract which goes to the lateral condyle of the tibia. It?s also innervated via the superior gluteal nerve. It is involved in flexing the hip and also stabilizing the knee joint. Now let?s look at the muscles that lie deep to the gluteal muscles, of at least gluteus maximus and gluteus medius. We?re going to look at piriformis, the gemelli, obturator internus, and quadratus femoris. Here, we can see we?ve removed gluteus medius and we can now reveal piriformis, this muscle passing out of the pelvis through the greater sciatic foramen. We can see we got piriformis. This is passing through the greater trochanter.

    04:47 We can then see we have two gemelli muscles. We have superior gemellus and we have inferior gemellus. And here, we also have the tendon of obturator internus. So here we can see obturator internus, just the tendon really. This is the inside. This is the posterior view of the hip. This is the internal surface of obturator membrane. And this is actually sending a tendon away from that muscle belly and through the lesser sciatic foramen to the greater trochanter. We can see that this tendon is running in between the superior and inferior gemelli muscles. Most inferiorly, we find we have quadratus femoris, and that?s running from the ischial tuberosity across through the intertrochanteric crest on the posterior surface. We can see we have piriformis, the superior gemellus, obturator internus, inferior gemellus, and then quadratus femoris. What we can see is the origins and insertions in this table. We have piriformis coming from the anterior surface of the sacrum and passing to the greater trochanter. We have the two gemelli, superior coming from the ischial spine, and inferior coming from the ischial tuberosity. These also pass to the greater trochanter. Obturator internus, this is coming from the pelvic surface, as I said, of the ilium and the ischium, and the obturator membrane lining the obturator foramen. And this also is passing to the greater trochanter. These were all supplied by specific nerves.

    06:26 These are the root values, and the nerves known as to that specific muscle. So nerve to obturator internus comes from S1. Nerve to quadratus femoris comes from L5, S1. And nerve to obturator internus comes also from S1. Quadratus femoris, this is coming from the ischial tuberosity and it passes, as I said, to the intertrochanteric crest. This again is coming to nerve supply from L5 to S1. All of these muscles are known as lateral rotators of the hip. So lateral rotators of the hip, especially when it?s extended. They?re also involved in abducting the hip, so drawing it away from the body. And this should be obvious from their attachment onto the greater trochanter. The quadratus femoris as well as being a lateral rotator, it also helps to hold the head of the femur in the acetabulum. So if we look at these in a bit more detail with lots of the muscles all in place, then we can see we?ve got the posterior surface of the gluteal region here, and a deeper dissection here.

    07:37 We can see that we have a mass of muscles on the posterior gluteal region. When all of these muscles are put in place, a mass of musculature. We have gluteus maximus that has been removed, we have gluteus medius, and we have gluteus minimus. And then we have these lateral rotators and hip stabilizers. Most laterally, we can see tensor fasciae latae. If we?re then to see in more detail the fan-shaped gluteus medius, we can see here coming away from the ilium, and then deep to it, we have gluteus minimus. Gluteus maximus, this large muscle, has been removed. Laterally, we?ve got the tensor fasciae latae muscle, and this helps to stabilize the lateral aspect of the knee joint. If we look at the neurovasculature of this region, then it?s really important that we remember piriformis muscle. Here we can see piriformis, and this is a really important landmark. We can see lots of arteries and veins and nerves passing above piriformis and also passing from below piriformis.

    08:47 We can see the large sciatic nerve passing from below piriformis. We can also see the sciatic nerve passing down the posterior aspect of the thigh as it then splits into its common fibula and tibial nerves. And we can see some perforating arteries, and the perforating arteries are supplying the posterior aspect of the thigh. So piriformis is a really important landmark for some neurovascular relation. Piriformis exits, as I said, through the greater sciatic foramen. Superior to piriformis, we have the superior gluteal artery, vein and nerve. So in yellow, we have the nerve. In red, we have the artery and in blue, we have the vein. So superior gluteal nerve, artery, and vein. Inferior to piriformis, we find we have the opposite. We have the inferior gluteal artery in red, vein in blue, and nerve, we can see here, in yellow. Also coming out inferior to piriformis, we have the sciatic nerve. This large nerve about two centimetres wide and we can see it here passing down the posterior aspect of the thigh. Also coming out alongside it, is the posterior cutaneous nerve of the thigh we can just see here. Also coming inferior away from the piriformis is the pudendal neurovascular bundle. We have the internal pudendal artery, we have the internal pudendal vein, and we have the pudendal nerve. These leave the pelvis via the greater sciatic foramen, but then they go into the perineum via the lesser sciatic foramen.

    10:30 So the piriformis is a really important landmark to identify all of these neurovasculature.

    10:38 If we then move on to the thigh, we then want to look at the thigh in cross-section.

    10:43 We?re familiar with this view from the upper limb. We have the outer skin, and then we have the medial aspect here. Remember, we?re looking at it from below. So medially, we find the great saphenous vein within the subcutaneous tissue. Laterally, we find the iliotibial tract. And here we have fasciae latae, and this passes deep into the thigh. We can see the lateral femoral intermuscular septum here. And then we can see we have this posterior intermuscular septum passing through here, and we can see we?ve got this middle intermuscular septum. And these separate the thigh into three compartments; the adductor or the medial compartment which we can see here, we can then see the anterior compartment here, and we can see a posterior compartment which we can see here. And these are all separated by the intermuscular septum. So it?s been separated into the various parts. We can also see that we have the sciatic nerve here and we have various branches coming here from the femoral nerve, and these are going to supply the various muscles within these compartments. The anterior compartment supplied by the femoral nerve is going to be the extensor compartment, and this is going to extend the knee. The posterior compartment is the flexor compartment supplied by the tibial nerve, and this is going to flex the knee. And then we have the medial compartment known as the adductor compartment supplied by the obturator nerve and this is going to adduct the thigh. The movements of these muscles in the thigh, they act on both the hip and the knee joint, and there are two types of movement. We have flexion and extension that?s allowed to occur at the hip, and also at the knee. And we also have adduction. Adduction is created via the adductor compartment, the medial compartment, whereas, abduction is carried out by muscles within the gluteal region. So if we have a look at the posterior thigh, then we can see there are just a few muscles to see. We?ve got semitendinosus and we?ve got semimembranosus. These muscles are coming from the ischial tuberosity and they pass straight down the medial aspect of the leg, we can see here.

    13:09 We?ve got some biceps muscles that are running down the lateral aspects. And as we can see on this diagram, some of these muscles from a very intimate relationship as they have a common tendinous insertion onto the anteromedial aspect of the knee joint. So if we have a look, we?ve got biceps femoris, the long head and the short head, similar to biceps in the upper limb, it has two heads. The long head comes from the ischial tuberosity and the short head comes from the linear aspera and the lateral supracondylar line.

    13:46 So if we look at biceps, we can see the long head here is coming from the ischial tuberosity.

    13:51 It?s passing all the way down. It?s then joined by the short head that?s coming from the linear aspera, and these then combine to attach to the fibula. We can see them attaching to the lateral surface on the head of the fibula. Biceps is quite important.

    14:07 It has two nerves that supply it. The long head is supplied by the tibial division of the sciatic nerve. So the long head of biceps is supplied by the tibial division of the sciatic nerve.

    14:21 The short head, however, is supplied by the common fibular division of the sciatic nerve.

    14:27 So the biceps has two different nerve supplies, long head tibial division, short head common fibular. The biceps femoris is associated with flexing the knee joint, and also, laterally rotating it when flexed. It can also extend the hip joint. If we now look at semitendinosus and semimembranosus, these originate from the ischial tuberosity. We can see both of these muscles coming from the ischial tuberosity of the ischium and passing down the medial aspect of the thigh. Semimembranosus is deeper than semitendinosus with semitendinosus having this tough and cylindrical-shaped tendon. We can see both of these coming from the ischial tuberosity. Semitendinosus passes to the medial surface of the proximal tibia, whereas, semimembranosus passes the posterior surface on the medial condyle of the tibia. So, both of these are passing to the tibia. Semitendinosus is passing to the medial surface of the proximal tibia and membranosus is passing to the posterior surface of the medial condyle of the tibia.

    15:43 These are supplied just like the long head of biceps by the tibial division of the sciatic nerve. These muscles which collectively can be known as the hamstrings including biceps femoris, but semitendinosus and semimembranosus extend the hip joints and they can also flex the knee joints. They?re also associated with medial rotation when it is flexed.

    16:09 So if we?re going to look at these thigh muscles, then posterior to the femur within the thigh, we find these hamstrings, semitendinosus, semimembranosus and biceps femoris, especially the long head, because the short head doesn?t cross the hip joint, it?s not classically termed as a hamstring. We can see these large fleshy muscles, semitendinosus here with its long tendon and the long head of biceps. In this small radical dissection, we can now see semimembranosus and we can see the long head of biceps has been reflected here to reveal the short head. So we can see we have some big bulky muscles in the posterior thigh.

    16:55 They originate from the ischial tuberosity, the hamstrings, and they insert on to the tibia and the fibula. So they cross two joints, the hip and the knee. The short head is not a hamstring as it only crosses the knee joint, and it also has a different innervation.

    17:11 Remember it?s the common fibula. Blood supply to the hamstrings we?ll look at in more detail in a later lecture, but we did just comment on it previously via perforating branches.

    17:24 And these originate from the profunda femoris. This is a branch of the femoral artery, which we?ll look at in more detail in a later lecture. And these perforating branches, they pierce adductor magnus. We can see adductor magnus here. This adductor magnus is pierced by these perforating branches to enter the posterior compartment. But we will cover this in the later lecture. Now let?s turn to the popliteal fossa. This is the important region directly behind the knee joint. And we can see on this diagram, we?ve got a quite intact popliteal fossa with the deep fascia still in place, and some cutaneous veins, the great saphenous and the short saphenous is here where the small saphenous sometimes labelled. And here when it?s been removed, we can see into the popliteal fossa and look at its boundaries and the contents. So the popliteal fossa is this fat-filled diamond-shaped space located posterior to the knee joint. It contains all of the neurovascular structures that pass from the thigh to the leg. Its boundaries are formed by the muscles that we mentioned previously. So superolaterally, here, we?re looking at the posterior surface of a right leg, right knee joint. So this is going to be a lateral aspect. This is going to be a medial aspect. Superolaterally, we have biceps femoris. Superomedially, we have semimembranosus just running down here. And this forms the top parts of our diamond. Inferolaterally, we have the lateral head of gastrocnemius, so down here. And inferomedially, we have the medial head of gastrocnemius which is running down here. We can see now we have the contents of the popliteal fossa where we?ve got the boundaries being formed by these muscles, so the contents within the popliteal fossa. If we look at the roof of the popliteal fossa, then it?s going to be popliteal fascia that the deep fascia lying over the popliteal fossa, and also the skin. And then superficial to that facia, we?ve got the great saphenous and the small or the short saphenous veins. The floor of the popliteal fossa is going to be the popliteal surface of the femur, and also a small muscle which we?ll see later on known as popliteus. And the contents, these structures here, are going to sit on that floor. So as I mentioned, the popliteal fossa contains all of the neurovascular structures that pass from the thigh to the leg. It contains the small saphenous vein as it pierces the popliteal fascia and enters into the popliteal vein. So here we can see the small saphenous vein that?s going to pass all the way up. We?ve cut it here to show, but we can then see it passing into the popliteal vein. See the popliteal vein here. We can also see an opening for the small saphenous vein just there. We can see we?ve got the popliteal artery and its associated branches, some important genicular branches that go and supply the knee joint. We can see the tibial and the common fibular nerves, the tibial nerve passing straight down, the common fibular nerve forming part of the superolateral border. We can see the posterior cutaneous nerve of the thigh running down in this region.

    20:58 We can see popliteal lymph nodes, and it?s going to be full of fat. So in this lecture, we?ve looked at the gluteal region, we?ve looked at the muscles that make up the mass of the bulk of the gluteal region, gluteus maximus, gluteus medius, gluteus minimus, piriformis, gemelli, obturator internus, and quadratus femoris. And then we used piriformis as a landmark to look at some important neurovascular relations. We then quickly looked at the thigh in cross-section, the fasciae latae and how the intermuscular septae separated the thigh into anterior, posterior, and medial compartments. We then looked at the posterior thigh. We looked at the hamstrings, and we looked at biceps femoris, and also very briefly, the neurovascular relations. The popliteal fossa, we looked at the boundaries, the roof, the floor, and we just finished off by looking at the contents of this space.


    About the Lecture

    The lecture Gluteal Region and Posterior Thigh by James Pickering, PhD is from the course Lower Limb Anatomy. It contains the following chapters:

    • Gluteal region and posterior thigh
    • Gluteal region
    • Neurovasculature
    • Posterior thigh: Cross-section
    • Posterior thigh muscles
    • Popliteal fossa: Boundaries
    • Popliteal fossa: Contents

    Included Quiz Questions

    1. Piriformis
    2. Obturator externus
    3. Obturator internus
    4. Superior gemelus
    1. Originate from the ischial tuberosity
    2. Flex the hip and extend the knee
    3. Include semimembranosus, semitendinosus, short head of biceps femoris and the hamstring part of adductor magnus
    4. Originate from the ischial spine
    1. Adductor magnus
    2. Sartorius
    3. Gluteus maximus
    4. Adductor longus
    1. Vastus medialis
    2. Sartorius
    3. Vastus lateralis
    4. Adductor longus

    Author of lecture Gluteal Region and Posterior Thigh

     James Pickering, PhD

    James Pickering, PhD


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