Anatomy Question

[Faith]

I didn't know where to post this so i just put it under PT since it is about anatomy.

I am having a hard time understanding the anatomy of the posterior pelvic ligaments, which is really bad since I am a nurse. But I didn't have any reason to know the pelvis in such detail until now!

I have read some things that say the origin of the Sacrotuberous (ST) ligament is at the sacrum just under the Posterior Superior Iliac Spine (PSIS) and it runs alongside the lateral part of the sacrum to its insertion at the ischial spine of the ischial tuberosity. Is this correct? In a lot of pictures (like the ones here on hope) it looks like the SI ligaments run into the ST ligament, but are they really just on top of the ST ligament? I guess I didn't realize the ST ligament was that big.

[Faith]

I see there have been 26 views but no responses. No one else understand the anatomy either or was my question confusing?

[carolynm]

I did some google=ing and couldn't quite find an answer to that either. I"m confused about all of it. I can't even figure out where Alcock's canal is. I don't have a lot of time to spend on the internet with the two kids but I really need to educate myself so I'm not a total bafoon:)

cari

[helenlegs 11]

Don't know if it helps at all but the borrejaker you tube videos show pelvic anatomy from different angles.
Anatomia SIstemica - PELVIS ARTICULACIONES Y LIGAMENTOS
Anatomia Sistemica - Repaso de Pelvis - Huesos y Ligamentos
Pelvic Ligaments by jablesjr33

[calluna]

There were some very good images in that chapter from Dr Dellon that was linked to quite recently. Chapter 12, I remember that, but I can't find it at the moment.

[Violet M]

I have read some things that say the origin of the Sacrotuberous (ST) ligament is at the sacrum just under the Posterior Superior Iliac Spine (PSIS) and it runs alongside the lateral part of the sacrum to its insertion at the ischial spine of the ischial tuberosity. Is this correct? In a lot of pictures (like the ones here on hope) it looks like the SI ligaments run into the ST ligament, but are they really just on top of the ST ligament? .

Faith, I'm not sure I understand your question right but if I do I think maybe the confusion lies in that the ischial spine and the ischial tuberosity are not the same. The ST ligament attaches to the the ischial tuberosity ( the sit bone), not the ischial spine. The ischial spine is a bone that protrudes higher up in the pelvis where the sacrospinous ligament attaches. The third picture down at this link http://home.comcast.net/~wnor/pelvis.htm shows where the ischial tuberosity and ischial spine are very well.

I think the SI ligaments are anterior to the ST ligaments as you can see in this picture http://www.pudendalhope.org/sites/defau ... Female.jpg. On the right (as you face the picture) you can see a section of the ST ligament is cut off near the top of the ligament so that you can see the SI ligament that is anterior to it. (Anteroir in your body since this is from the rear view) I could be wrong but that is my understanding of it.

[Faith]

Thanks for clearing that up about the ischial spine Violet. I guess my question is where does the ST ligament origniate. I know it goes from the ischial tuberosity, but does it just connect to the lateral sacrum or does it go all the way up to the iliac crest? Some sources I have read say it originates at the PSIS (posterior superior iliac spine) and a different one said PIIS (posterior inferior iliac spine). So like if a person is lying prone (on their stomach) when you say you think the SI ligaments lie anterior do you think that would mean more towards the top (if they are prone) and then the ST ligament is underneath all the way up to the PSIS? Does that make sense?

[Violet M]

Faith, the pictures you find online are sort of confusing, really.

One medical text says that the ST ligament inserts at the posterior inferior spine which you can see on this image http://en.wikipedia.org/wiki/File:Gray235.png.

If you look at a Gray's anatomy picture it shows the posterior sacroiliac ligament attaching to the posterior superior spine of the ilium. http://en.wikipedia.org/wiki/File:Gray320.png But in that picture it looks like the SI ligament is the top portion of the ST ligament. Heck, if the anatomy books don't even agree how are we supposed to know?

[Faith]

Dr dellon's new chapter on pelvic pain http://www.dellon.com/content/view/116/307/ has a good picture of the ST ligament and it is a "v" shape and looks like it goes from the bottom of the SI, probably posterior inferior iliac spine, to the ishial tuberosity. I think the long SI ligament goes from the Posterior superior iliac spine and lays over the top of the ST ligament but I can't tell where it ends, maybe it just merges into the ST ligament?