Medial Thigh Muscles – Anterior and Medial Thigh

00:01 Now, let’s move on to the medial compartment of the thigh. And we have a whole series of adductor muscles, the medial compartment of the thigh. We can see these are closely related to pectineus. So we see pectineus passing in this direction, as we mentioned, and we have a whole series of adductor muscles, adductor longus, adductor brevis, adductor magnus, and also, gracilis. And here, we can see the adductor longus is being cut. That’s the most superficial of these adductor muscles. And then running next the pectineus, we have adductor brevis, and then we have adductor magnus, we can see here. Most medially, we have gracilis. Let’s look at their anatomy. If we start off with adductor magnus, it has two parts to it. And this is due to its origin and its insertion, and therefore, the function that it can carry out. So the adductor part comes from the ischiopubic ramus. And it passes to the linea aspera. So it’s going to the linea aspera of the femur coming from the pubic bone, the ischiopubic ramus. The hamstring part is coming from the ischial tuberosity.

01:14 And this passes straight down to the adductor tubercle. So if we were to look, we could see that we have adductor magnus here. Part of it is passing to the linea aspera, and the hamstring portion is passing to the adductor tubercle on the femur. So we can see because of these two different insertions, it has two different functions. The adductor part can adduct the hip, and that’s innervated therefore by obturator nerve, whereas, the hamstring part can extend the hip, and that’s innervated via the tibial nerve along with the other hamstrings. Adductor longus sits medial to pectineus, and this is from the body of the pubis, and it attaches to the middle third of the linea aspera. Adductor brevis that also sits medial to pectineus, and it’s coming from the body and inferior ramus of the pubis. This attaches to the proximal part of the linea aspera. We can see this here.

02:19 We see adductor brevis and adductor longus both positioned medial to pectineus running from the pubic bone across the various parts of the linea aspera on the femur.

02:31 These are both supplied by the obturator nerve, and they’re involved with adducting the hip, so drawing the hip towards the midline. We also have gracilis, and this comes from the body and inferior ramus of the pubis, so a similar position to adductor brevis, and it passes to the medial surface of the proximal tibia along with semitendinosus and sartorius as we’ll see. This is innervated via the obturator nerve. And as well as adducting the hip, it’s also involved in flexing the knee. Let’s look at these muscles in a bit more of an anatomical orientation. We can see now here more superficial dissection, we have pectineus. Lying medial to pectineus, we have adductor longus, and then we have gracilis. If we were to cut adductor longus, we would reveal adductor brevis, we can see here.

03:25 So now we have pectineus, adductor brevis, and then we can see gracilis. We can also, having cut adductor longus, see adductor magnus. If we were to look on this more radical dissection of the medial compartment where we’ve got both adductor longus reflected and adductor brevis reflected, we’ll see this large muscle adductor magnus. And that really is separating this medial compartment from the posterior compartment. We can see it’s got its adductor portion passing towards the femur. And we’ve also got the hamstring portion that is passing down towards the adductor tubercle on the medial condyle of the femur. Notice this important aperture here, and this is known as the adductor hiatus, and we’ll return to it in a few slides time. The medial compartment contains the adductor group and it includes those muscles that I’ve mentioned, adductor longus, adductor brevis, adductor magnus, and gracilis.

04:27 The final muscle I want to mention is obturator externus. And to look at obturator externus, we have to look deep within the medial compartment. Here, we can actually see we’ve got obturator externus. We’re looking at this from the posterior aspect. So we’re looking through the hip on the posterior aspect. And this is obturator externus. It’s coming from the external surface of the obturator membrane. So, obturator internus came from the internal surface and it passed out via the lesser sciatic foramen. This muscle is passing away and towards the greater trochanter, obturator externus. The adductor compartment is supplied by the obturator nerve and it’s supplied by the obturator artery. Adductor magnus is the largest of the group and it has two parts I’ve mentioned, adductor and hamstring. These have different attachments, innervation, and function. Between the distal adductor portion and the tendon of the hamstring part, we have the adductor hiatus. And this is an important passageway as it is the exit for the adductor canal, which we’ll see. This allows the passage of the femoral artery and vein from the anterior compartment to the popliteal fossa.

05:57 So it allows these anterior blood vessels to pass posteriorly into the popliteal fossa.