 Now let's come to the deep gluteal muscles. So we have reflected the gluteus maximus This is the prone cadaver left side of the cadaver and I have lifted up this muscle here We can see the remnant of the gluteus medius just in front of my instrument here. This is the pyriformis It is roughly pear shaped This is a unique muscle in so far that the origin takes place from inside the pelvis It takes origin from the front anterior aspect of the sacrum and then it emerges Through this opening here where my finger has gone in and this is the opening. This is the greater sciatic foramen and Then the tendon comes and it gets inserted onto the of the greater trochanter and that we can see here This is the insertion of the pyriformis This pyriformis and the other deep group of muscles have got a common action and we shall mention them all together The pyriformis is supplied by S1, S2 anterior division This pyriformis serves some important functions 1. As it is emerging from the greater sciatic foramen It divides the greater sciatic foramen into a suprapyriformis compartment where my instrument has gone in and it divides it into an intrapyriformis compartment From the suprapyriformis compartment. We have the superior gluteal artery and the superior gluteal nerve emerging and we can see all the neuro vascular structures here and From the intrapyriformis compartment. We have three sets of nerves coming out We have the sciatic nerve coming out the biggest nerve in the human body Then we have the inferior gluteal nerve and the gluteal artery and then we have Pudendal nerve and the pudendal artery coming out So these are the three structures which come out from the intrapyriformis compartments That is one aspect about the pyriformis So that brings me to an important clinical correlation pertaining to the sciatic nerve The sciatic nerve can be compressed in inflammation or swelling of the pyriformis when a person falls on his back Especially during skiing or during exercise Swelling of the pyriformis can compress the sciatic nerve and can produce a condition known as pyriformis syndrome And if it is a chronic condition and the painful Patient has repeated pains going along the sciatic nerve shooting electric shock pain which mimics sciatica Then the only treatment is either to give Botox injection or to do Insides the tendon of the pyriformis from the tip of the greater trochanter The superior border of the pyriformis is used as a landmark For giving sciatic nerve block This is the region of the posterior superior iliac spine and this is the greater trochanter So if we were to draw a line Then that roughly corresponds to the superior border of the pyriformis and if you go one inch below that We can do a sciatic nerve block So these are some clinical importance of the pyriformis Next muscle in the deep group is this muscle which I have lifted up here with my probe This is the tendon of the operator in turn us The operator in turn us muscle takes origin where my finger is located and please take a look at the axis of my finger It takes origin from the inner surface of the operator memory on the inner on the inside the pelvis So this is the surface from where the operator in turn us takes origin and as it comes posteriorly It makes a 90 degrees bend and this is the axis of the bend this bend Takes place across a bone which we can feel under this and that is the ischial spine So this 90 degrees bent is the location where there is a person called the operating turn us versa to prevent friction And then the tendon continues and it gets inserted on to the Media surface of the greater trochanter where my fingers located called the trochanteric fossa. So that is the operator in turn Now let's take a look just about the operator in turn us and for that I'm going to just remove the probe a little bit and show you this muscle here this muscle which I have lifted up This is the superior gemelus This takes origin from the ischial spine where my finger is located and the tendon gets inserted onto the operating turn us itself Now I'm going to remove this probe to show the next muscle under the operating turn us and that is this one here This is the inferior gemelus This takes origin from the ischial tuberosity and the tendon gets inserted on to the operator in turn us So therefore these three muscles the superior gemelus The operating turn us tendon and the inferior gemelus. They are collectively called the triceps oxy Last muscle of this group is this muscle here. This is the quadratus femoris it takes origin from the ischial tuberosity It's a quadrangular shaped muscle and it gets inserted onto the quadrate tubercle on the posterior aspect of the femur So we can see that the deep group of muscles except the pyriform is namely the superior gemelus Operator in turn us inferior gemelus and the quadratus femoris. They form a bed Between the ischial tuberosity and the greater trochanter and running on the surface of the bed is this big Nerve, which is the shading now the largest now in the human body So that brings me to the action of these deep group of muscles Collectively the party form is operating turn us superior gemelus inferior gemelus quadratus femoris all of them are lateral rotators of the hip So this is the action of this By the form is supplied by a separate nerve called the nerve to party form is which is only one that your division s1 s2 Operator in turn us and superior gemelus are supplied by the nerve to operate in turn us an Inferior gemelus and quadratus femoris are supplied by nerve to quadratus femoris So this is the nerve supply of the deep group of gluteal muscles. Thank you very much for watching Dr. Sanjus and you're signing out if you have any questions or comments, please put them in the comment section below Have a nice day