 Good day everybody. Welcome to a discussion of the gluteal region. Today we are going to demonstrate the superficial gluteal muscles. This muscle that you see in front of you, this is the largest muscle of the gluteal region and this is the gluteus maximus. Straight away you can see that the fibers are running obliquely backwards and this is the one which gives the bulk to the buttock. This is the very thick coarse muscle fibers and latest research has shown that this is composed of both type 1, slow twitch and type 2, fast twitch muscle fibers. So it's a type of postural muscle but it also has other actions. So it takes origin from the sacrum, coccyx and also takes origin from the ileum behind the posterior gluteal line. Insertion is a double insertion. The superficial three-fourths of the muscle gets inserted onto this tough facial structure that you see here. Going on the lateral side of the thigh, this tough facial structure is the ileotibial tract. So the superficial three-fourths of it gets inserted into the ileotibial tract and the ileotibial tract goes all the way down to the leg and it gets inserted onto the lateral aspect of the tibia in a tubercle known as the anterolateral tubercle of GERD. So that is the superficial three-fourths of the muscle. The deep one-fourth of the muscle gets inserted onto the gluteal tuberosity on the back of the femur. So this is the insertion of the gluteus maximus. What is the action of the gluteus maximus? It is responsible for extension of the thigh or extension of the hip joint and lateral rotation by virtue of its double insertion. There are a few special points about the gluteus maximus. The gluteus maximus, as you can see, it is crossing the ischial tuberosity and it is crossing the greater trochanter. I have reflected the gluteus maximus by incising it at its origin. So there is a bursa between the gluteus maximus and the ischial tuberosity, this is known as the ischial bursa. Similarly, when it crosses the greater trochanter, there is a bursa between the gluteus maximus and the greater trochanter, that is known as the trochanteric bursa. And finally, there is another bursa between the ileotibial tract and the lateral intermuscular septum which covers the vastus lateralis muscle of the thigh. And that bursa is known as the gluteal femoral bursa. So, we have seen the origin insertion and the bursa of the gluteus maximus. What about the other actions of the gluteus maximus? The gluteus maximus is the muscle which is responsible for making us standing up from a sitting position, which helps us to sit down, which helps us to climb up stairs and climb uphill. So, these are some functional uses of the gluteus maximus. I am going to reflect the gluteus maximus. And after reflecting the gluteus maximus, we see the other superficial group of muscles. The muscle which immediately comes to our vision or field of view is this muscle here. This is the gluteus medius. And you can see the origin of the gluteus medius is again on the outer surface of the gluteus surface of the ileum between the posterior and the anterior gluteal lines. If you take a look at the fibres, most of the fibres are coming down vertically, they are meeting and they get inserted onto the greater trochanter. So, therefore the action of the gluteus medius is abduction and medial rotation. The gluteus medius is supplied by the superior gluteal vessels, the superior gluteal nerve, the superior gluteal artery. And we can see the branches of the superior gluteal nerve here after reflecting it, superior gluteal nerve. The superior gluteal nerve, it is coming through the suprapyriformis compartment and this is the branches of the superior gluteal artery. And they are all supplying the gluteus medius and you can see the cut portions of them here. So, that is about the gluteus medius. Now, there is a very important clinical correlation about the gluteus medius. If this nerve is injured, the superior gluteal nerve is injured, then the person cannot hold his pelvis horizontal when he is standing on the paralysed side. And the opposite side pelvis will sag down and that is known as the trendlinburg sign. And this will give him one of the three gluteal gates, one is an out swinging gate, high stepping gate or a waddling gate. That is about the gluteus medius. Now, let's reflect the gluteus medius. And what do we see under that? We see a third muscle. And this muscle is the gluteus minimus. This takes origin from, again, the outer gluteal surface of the ilium in the anterior and the inferior gluteal lines. And the fibres also get inserted onto the greater trochanter. My finger has gone in and gets inserted onto the greater trochanter. The nerve supply action is all same as the gluteus medius. And we can see one of the branches of the superior gluteal nerve is supplying not only the gluteus medius, it is also supplying the gluteus minimus. And finally, the last muscle of the group, if we were to reflect this and look further antrolaterally, we see a muscle here. We see a muscle here. This is attached to the tubercle of the iliac crest on the lateral surface and it gets inserted onto the iliotibial tract. And you can see the iliotibial tract here. This is the muscle I was referring to and we can see that muscle here from inner surface and we can see the same muscle from the outer surface. This is known as the tensor fascialata. We can see that the iliotibial tract is considered as the eponeurotic expansion, long eponeurotic expansion of the tensor fascialata. And this same iliotibial tract then again gets inserted into the antrolaterally tubercle of Gerdie. So therefore, to summarize, the iliotibial tract is considered as the eponeurotic expansion of both the gluteus maximus as well as the tensor fascialata. The tensor fascialata also has the same nerve supply and action as the gluteus medius and minimus. And before I conclude, I need to tell you one more thing. The iliotibial tract on the lateral side is the counterpart of another insertion that we shall see on the medial side of the thigh which is known as the pestanserinas. So this is about the superficial group of gluteal muscles. Thank you very much for watching ladies and gentlemen. If you have any questions or comments, please put them in the comment section below. Have a nice day. Dr. Sanjay Sanyal signing out. Don't forget to like and click the subscribe button.