in this video we're going to examine the pelvic or the hip girdle its main function is to attach the lower limbs to the axial skeleton and it accomplishes this via very strong ligaments so let's look at the overall components of the hip girdle it is made up primarily of two hip bones or what we call the coxal bones and these oxob bones actually represent three fused Bones from fetal development uh the ilium the isum and the pubis so we're going to go over the Hallmarks in a moment of the specific bones so when we look at the main joint um it's a ball and socket joint called the um aceto U acetab so this is where the femur is going to be connected to the pelvic girdle so it is a similar type of uh joint a ball and socket joint just like within the glenoid cavity of the scapula but it's a much deeper uh recessed opening so it's a much more stable joint uh and that stability means you're sacrificing Mobility uh all right so let's go over the ilium first so the ilium is the most Superior of the three bones and it has two main areas it has this body area and then it has this upper Wing area which we call the allaha okay and on the Alla you have this thickened region here on either side and that thickened region is known know as the ilc crest so this is what you uh feel when you put your hands on your hips that bony outcropping is uh this ilc Crest now at the end of The ilc Crest you have the anterior superior iliac spine so this represents a point of attachment for many of the thigh muscles and a little bit lower dep down you have the anterior inferior iliac spine so both of these are points of attachment if I wrap around the ilc crest and go over here it's sort of not in frame but if we go behind here or it's probably a little bit easier to see in this image here you have the posterior iliac spine and the inferior iliac spine so you can't really see that particular region in this particular frame but you can over here on this lateral view now if we actually switch to a medial view where that posterior Superior ilc spine is and posterior inferior earc spine you see this region here called The Oracle surface so that Oracle surface is where the sacrum is going to interact is where where it's going to articulate with the ilium so the interaction results in the relatively immobile joint the Sacro iliac joint now the stability of the entire pelvis is via several different types of ligaments uh the names we not going to get into too much uh just understand that it's not just bone uh there are a lot of crisscrossing ligaments here that will connect the sacrum to the pubis the sacrum to the isum and such all right so a couple of other Hallmarks right over here this little notched area this is uh referred to as the greater sciatic Notch and then a little bit lower down in the bones you have the uh lesser sciatic Notch shown right over here uh but that's going to be in the isum So speaking of the isum uh the isum uh is the most inferior component of the hip bone and it has this sort of uh thickened region uh that ultimately will join with the pubis at this pubic Arch region all right now for the pubis it is the anterior part of the hip bone so usually the bladder kind of sits on top of the pubis and it will join together the two pubis will join together along with the two isums at this pubic symphisis so this is a a fairly thick piece of um cartilage so a couple of other points to note you have this uh hole which is a it's a foramin um formed by the fusion of the pubis and the isum the opor foramin so it allows for the passageway of several blood vessels and nerves it looks much larger than it actually is because various uh ligaments will sort of seal that together to form a a more rigid Str structure now when we examine the pelvises of males and females we notice that there is a dramatic difference the female pelvis is adapted for childbearing and so this is where we have to sort of Define what is a true pelvis versus a false pelvis if we looked at the most Superior part so where the iliac crest is and the allaha and we kind of outlined the entire pelvis like this that would be the false pelvis the true pelvis is the actual sort of opening and so when you look at the opening of a female pelvis versus a male it's pretty obvious that the female one is much broader uh more circular while the male is significantly smaller so while females have a broader more well-rounded uh Arch region so if we look at the pubic Arch it's more rounded here oops it's more rounded compared to the male where it is a very very acute angle in the pubic Arch and it is much more sort of not broader but uh sort of heavier stockier um much more prominent okay and so this is an adaptation in males to support a much heavier weight uh and in addition because of this broader pelvis the location of the acetabulum is going to be a little bit different um so if we look at this particular figure here the angle of the femur relative to the pelvis is different between males and females we call this angle the Q angle so because of the sort of stockier tilted less forward p Vis the femur is going to go relatively straight down in males so again this is perfect to transfer that heavier weight of males down ultimately to the feet but because you have broader a broader and tilted forward pelvis in females this is going to generate sort of an angle where the femur does not directly place all the weight onto the bones of the lower Limbs and so this impacts places extra pressure on the knees of women now in general because women tend to be smaller Less in Mass it's not going to be as big of an issue as it would be if this was the case in males so again a side by side comparison if we look at the sacrum the sacrum is going to be wider in females narrower in males the uh sciatic Notch is going to be much wider and it's more narrow in males and then if we look at the overall brim much more narrow in males compared to females again an adaptation for childbearing uh necessitated with females not so with males