 In this video, I will identify the muscles that move the acetabulophimoral joint and list the origin, insertion, and action of the major muscles that move the acetabulophimoral joint. Here with a posterior view, the muscles that move the acetabulophimoral joint or hip joint, we see the most superficial muscles in the gluteal region have been cut to allow us to see the deeper muscles of the gluteal region, but we'll start by going through the muscles that have been cut. Gluteus maximus is one of these muscles. We can see the origin attached along the sacrum and coccyx and ilium of gluteus maximus, and then you can see on the other side. See its origin is all along here for gluteus maximus, and then the insertion for gluteus maximus we can see down here on the femur at the gluteal tuberosity. The action of gluteus maximus is to extend the acetabulophimoral joint or to lateral rotate the acetabulophimoral joint. And so the acetabulophimoral joint commonly referred to as the hip joint, the femur is extended or lateral rotated at that acetabulophimoral joint by the large superficial muscle, the gluteus maximus. Now, just deep to gluteus maximus and slightly anterior is the gluteus medius, which has also been cut in this image, but again I'll highlight here its origin along the crest of the ilium. And then its insertion is onto the greater trochanter of the femur. The actions of gluteus medius are to abduct or medial rotate the acetabulophimoral joint. Deep to gluteus medius is gluteus minimus, another muscle that performs abduction, abduction, and medial rotation of the acetabulophimoral joint. Inferior to gluteus minimus, here we see piriformis. Piriformis is a muscle that performs lateral rotation of the acetabulophimoral joint. There are several more muscles that perform lateral rotation that we can see from this view. There is a group of three muscles collectively known as the triceps coxae, which includes the superior gemellus, the obturator internus, and the inferior gemellus. So the superior gemellus, obturator internus, and inferior gemellus all perform the action of lateral rotation. And then deep to the triceps coxae group or just anterior to the obturator internus is this obturator externus. Another muscle that performs lateral rotation of the acetabulophimoral joint. Now inferior to the obturator externus is quadratus femoris. So quadratus femoris is a rectangular shaped muscle, quadratus means rectangular shape, so quadratus femoris is this rectangular shaped muscle that also has the action of lateral rotation of the acetabulophimoral joint. And so while gluteus, medius, and gluteus minimus performed medial rotation, gluteus maximus piriformis superior gemellus, obturator internus, inferior gemellus, obturator externus, and quadratus femoris all perform lateral rotation of the acetabulophimoral joint. Next we can see the adductor group. There's adductor magnus, adductor longus, and adductor brevis that are forming the adductor group of muscles that perform the action of adduction of the acetabulophimoral joint. Similarly the gracilis is a muscle that performs adduction of the acetabulophimoral joint. And gracilis is a thin muscle located along the medial side of the femoral region. It's a superficial muscle forming the medial side of the femoral region. So the origin of gluteus maximus is the posterior of the ilium, the sacrum, and the coccyx. The insertion of gluteus maximus is the gluteal tuberosity of the femur. And the action of gluteus maximus is to extend or lateral rotate the acetabulophimoral joint. The origin of gluteus medius is the crest of the ilium, and the insertion of gluteus medius is the greater trochanter of the femur. The action of gluteus medius is abduction or medial rotation of the acetabulophimoral joint. The origin of piriformis is the sacrum, the insertion of the piriformis is the greater trochanter of the femur, and the action of piriformis is lateral rotation of the acetabulophimoral joint. Now here we have a deep anterior view of muscles that perform flexion of the acetabulophimoral joint. The psoas muscle group, the psoas major is the largest of the psoas muscles, but there's also a psoas minor. Our muscles that share an insertion with the iliacus. So the iliacus and the psoas muscles together are commonly referred to as the iliosoas muscle group. The iliosoas muscle group includes the iliacus as well as the psoas, and they insert together onto the femur at the lesser trochanter. To perform that action of flexion of the acetabulophimoral joint, flex the femur at the hip. The origin of psoas major is the lumbar vertebrae, and see from the bodies and transverse processes of lumbar vertebrae, then the insertion of psoas major is the lesser trochanter of the femur, and the action is to flex the acetabulophimoral joint. The origin of the iliacus is the iliac fossa. The insertion is shared with psoas major at the lesser trochanter of the femur, and the action is to flex the acetabulophimoral joint. Finally, in the lateral femoral region, we can see tensor fascia latte. Tensor fascia latte is a muscle that performs abduction of the acetabulophimoral joint. The muscle inserts into a long band of connective tissue, the fascia on the lateral aspect of the femoral region, known as the iliotibial band, or IT band. Tensor fascia latte causes an increase in the tension of the fascia on the lateral aspect of the femoral region, the iliotibial band, the IT band. Now, moving medially, we can see pectinus is a muscle that performs abduction, the opposite action from tensor fascia latte. Pectinus is a synergist with the adductor group, including adductor longus that we can see located just medial to pectinus. Adductor magnus is the largest of the adductor group, and most of adductor magnus is located deep to the other muscles that we see in this illustration. For example, the gracilis is superficial to adductor magnus along the medial aspect of the femoral region, and gracilis is another muscle that performs abduction of the acetabulophimoral joint. A superficial muscle that we see coming diagonally across the anterior femoral region is sartorius. Sartorius gets its name from the posture of sitting cross-legged that a person would sit cross-legged while they are stitching seams, and a sartor is a person who does that work of sewing to make clothing. A sartor makes clothing sitting cross-legged traditionally, and sartorius is a muscle that performs the actions of lateral rotation, flexion, and abduction of the acetabulophimoral joint. Lateral rotation, flexion, and abduction are all actions needed in order to move into a cross-legged position. Similarly, sartorius does insert onto the tibia to be able to flex the knee joint to have action of flexing the knee joint, which would be another part of this motion to sit cross-legged. Although I'm focused now on the muscles that are moving the acetabulophimoral joint, the hip joint, some of these muscles can also have action at the knee joint. Sartorius and gracilis are both examples of muscles that perform flexion of the knee joint. However, sartorius performs abduction, the opposite action, abduction is the opposite action of gracilis, which performs abduction of the acetabulophimoral joint. The origin of sartorius is the anterior superior iliac spine, then the insertion of sartorius is the medial condyle of the tibia, and the actions of sartorius include lateral rotation, flexion, or abduction of the acetabulophimoral joint. The origin of gracilis is the inferior pubic ramus, the insertion of gracilis is the medial condyle of the tibia, and the action of gracilis is adduction of the acetabulophimoral joint. Here we have a deep view showing us the adductor group, the adductor brevis is the smallest and most superior we see here in this view, then just inferior and medial to adductor brevis we see adductor longus. The adductor posterior to adductor longus, this very large muscle adductor magnus, and so the adductor group performs the action of adduction at the acetabulophimoral joint. Adductor magnus has an origin from the ischial tuberosity, has its insertion on linea aspera of the femur, and performs the action of adduction at the acetabulophimoral joint. Adductor longus has its origin from the body of the pubis on the anterior surface of the body of the pubis, and has its insertion on the linea aspera right next to adductor magnus, and its action is to adduct the acetabulophimoral joint.