Pelvic Bowl

Let's get down into the pelvic bowl. So our pelvis we often think of as just one bowl or basin. The word actually comes from the Latin meaning basin. But the pelvis can be actually divided into two halves and each half can be further subdivided into three unique bones. Now these were three unique bones when you were born and then as you grew they fused together. You're actually born with about 300 or so bones and it's not that you lose some on the way but they begin to fuse and ossify together as you grow and expand. So looking at one half of the pelvic bowl we can see that there's kind of three segments of this bone. We have what's called the ilium which is the top half of this bowl. Now some points of reference on the ilium which you can feel on your own body are these iliac crests which you can feel if you take your hands to the top part of your pelvis and kind of squish it in a little bit and you can feel it almost looks or feels like a little bit of a heart shape. In fact one of the hypothesis of where that Valentine's Day heart shape came from because if you ever looked at a anatomical heart it doesn't really look like that Valentine's cookie kind of heart. One of the theories is that it came from a woman's derriere bending over and that has this kind of heart shape appearance. I kind of like that one I don't know if it's true but I'll go with it. So if you take your hands you might feel that kind of heart shape and if you follow it all the way around you might feel these little bump bones in the front of the pelvis. These little points are sometimes referred to the hip points you might feel them if they're particularly knobby when you're resting down on your belly on the floor might get a little irritated but these are really great points to reference what your pelvis is doing if one's higher than the other if one's going forward or back these are great markers because they're sharp and pointy and kind of close to the surface. This iliac crest terminates at what's called the anterior which means it's on the front superior which means it's on the top part. Anterior superior iliac it's on the ileum spine anything that's pointy is often referred to as a spine in the body kind of like your spinous processes. Now this anterior superior iliac spine is sometimes shortened and called the as is. I remember it like you're hey my hips come as is right so these hip points are as is. Now these another point of reference that we can see is where the ileum meet your sacrum and that's of course called the sacroiliac joint or SI joint for short. Now another part of this bone is what's called the ischium which is the bottom part of the bone. This is what you might feel if you kind of rock back and forth in your seat or if you want you can take your hand underneath your tish flesh and kind of poke around and that's just for fun or you can feel those little bump bones sometimes referred to by your teachers as the sitting bones or sits bones. The fancier word for it is ischial tuberosity and the tuber you might have heard like a tuberous vegetable like a potato these are the potatoes of the butt so these are kind of formed the feet of the pelvis the grounding earthy component of the pelvis. Another part of the pelvis is the front here and this is called the pubis or the pubic bones. Some points of reference that we might acknowledge here where the two pubic bones meet in the front of this pelvic bowl and you can see on the model there's a little bit of cartilage in between the two bones and this is the pubic symphysis. Now it's not just one big bony circle right it has this articulation in the front and the back which gives it a little bit of give which is important in a gynecoid pelvis like the one I'm showing here and the one I'm showing here because of perhaps a birth right obstetrics pelvis sometimes they referred to it so it has to have the give to support their growing child and then the ejection of said child. Another point that we can look at is what's called the pubic arch. Now this is the line of bone between the pubic bones and the ischial tuberosities and you can kind of see that it almost forms like a V shape. Now in a gynecoid pelvis the V is about like what if you take your thumb and your index finger and kind of open it normal human like this is about the angle of a female pubic arch or gynecoid pelvic pubic arch. It's greater than 90 degrees again for the carrying of the baby and the ejection of said baby. A male or closer to the Android pubic arch would be about if you take your index finger and your middle finger and spread it apart about less than 90 degrees is more common for the Android pubic arch. They're not ejecting babies. I haven't had a baby but I'm pretty sure they just eject. The three bones now combine to form this kind of cavern or cavity called the acetabulum. Acetabulum is actually means little vinegar cup and the days of alchemy they used to have vinegar as a carrier for some of their herbs or drugs that they were using and it was served in a very particular vinegar cup which apparently looks like this but this is the socket of the ball and socket joint of your femoral acetabular articulation or your hip joint. So a little bit of each bone contributes its worth to make this acetabulum. Now a little bit of difference between the gynecoid and the Android pelvis. The gynecoid pelvis is a little bit more the ilium is a little bit more widely flared. It's a little larger basin and a greater pubic arch and our hip sockets are a little bit more anterior medially placed. Closer to the Android side of the spectrum their ilium are a little bit more can medially wrapped a little bit more inward more narrow not as big of a basin and their sockets are a little bit more laterally placed out to the side. So your homework if you choose is to now you got to be cool about this but watch a man walk from behind be cool and then also watch a woman walk from behind and you might notice that there's a difference in their stride in their pelvis. When you watch a guy walk in front of you and you look at his posterior you're going to notice that it's almost a little bit like a tin soldier right there's a little bit more linear stride there's not a lot of wiggle in the pelvis or twerking of the pelvic ball so the butt will not move too much. If you watch a gynecoid pelvis the woman walk from behind because of our more anterior medially placed sockets and our wider pelvis and our not so stable SI joints we have to swing our leg a little bit out to the side and half of our pelvis will rise and roll forward every time we walk which gives women a little bit more sway when they walk which we can exaggerate or de-emphasize depending on what we're looking for but this pelvis will begin to move causing a little bit more instability to the SI joints because of that mobility that we find. This can be really thought of as we look at our bodies and maybe our friend's bodies in the practices of yoga. You might have a guy show up into your class who's done yoga for 20 years stretched every day of his life and when he comes to sit in that opening stance his knees might be up here when he sits. That's okay that's just maybe where his sockets are placed and if you're telling him well keep working on it keep stretching one day your knees will come down that may not happen. Conversely you might have a woman show up to class who's never done yoga or stretched a day in her life she might come into class and flop her knees really close to the floor and it has nothing to do with flexibility but where her sockets are placed. So respecting that we're all so unique whether it's gender differences or muscular tension or holding and teaching to what and who shows up in your class and your own body and it's all all of its uniqueness.