Hip Bones

00:01 So now let's start looking at the individual bones in some detail that make up the lower limb.

00:06 Let's start with the hip bone.

00:09 So first of all, let's orientate ourselves.

00:11 And it's important to imagine we have our two hip bones, which united centrally via the sacrum we can see here in green.

00:18 This is the inferior continuation of the vertebral column.

00:21 And then obviously, we have the coccyx following more inferiorly at the very inferior tip of the vertebral column.

00:28 Then either side of the sacrum we have our two pelvic bones.

00:32 These, as I said united posteriorly by way of the sacrum, and then most anteriorly, we'll see we have the pubic symphysis which unites the two pelvic bones at the most anterior aspect.

00:44 The pelvic bones are very broad, they're quite thin bones.

00:47 And they're vitally important in both protecting the growing embryo and fetus in the female, but also forming attachment sites for the femur, which forms that important beginning of the lower limb musculature that helps us to move and maintain our posture.

01:05 Here we can see where the sacrum and the pelvis are united at the sacroiliac joint.

01:09 And then if we look at the individual pelvic bone on its own, so we've removed the sacrum, we've removed the corresponding pelvic bone from the other side, we're just looking at the anterior surface here of an isolated pelvic bone.

01:24 We can see we have this medial internal surface, we can see here that's an important site for muscle attachments which we can come to later on.

01:32 We also have a lateral or external surface and just at the bottom there, you can see where we'd have the acetabulum as we rotate the pelvis now, so we're just looking at its lateral surface.

01:43 And that is where the head of the femur will sit.

01:47 If we look at other structures, the pelvic bone, we can actually make out that there are three bones that form it.

01:53 In green here, we have the ilium.

01:56 In blue here, we have the ischium most posteriorly and then finally, the third bone is the pubis.

02:03 And actually all of these three bones adhere together at the acetabulum.

02:08 There is a union between the ischium and the pubis most inferiorly at the ischium pubic ramus.