FEMALE PELVIC FLOOR 101

R E B E C C A A R K I N O T R / L I L L U S T R A T I O N S : J E S S I C A S I O T R / L Introduction

Coming in for an initial evaluation for chronic pelvic pain may be intimidating for many clients. It could be that they have been bounced around from doctor to doctor, have looked up information on the internet that may be frightening, or for a variety of other reasons. Many of these clients may have never been to a pelvic floor therapist and don’t know what to expect. Likely they have never had an internal exam to assess the muscle integrity and strength of their pelvic floor. As practitioners it is our responsibility to educate and make them feel comfortable. This guide is intended to be used to educate and familiarize clients with the pelvic floor during the initial evaluation and to be referenced back to as treatment progresses. When creating this guide, I felt that many pictures found in textbooks or atlases can be overwhelming and are not client friendly. For this reason, I worked with an artist to create illustrations that focused on what is most important for clients to learn. These illustrations can be found in section one of this guide. Section two of this guide is intended to be used by practitioners to provide them with anatomical information about these illustrations. This information is not intended to be comprehensive, but rather to be used as a reference for new practitioners still learning about pelvic floor anatomy. To best use this guide, it is recommended practitioners first familiarize themselves with the illustrations and information in this guide and then prepare in their own words how to best explain and share this information with clients. The practitioner should use their clinical judgment to determine what would be best to educate the client and at what time. Remember that each client will have different symptoms and come from different backgrounds. Practitioners who need additional information should reference other comprehensive sources.

Sacrum

Ilium

Anterior Superior Iliac Spine

Ischial Pubic tuberosity

Rebecca Arkin Jessica Si

Mons pubis

Clitoris

Labia minora

Urethral orifice Labia majora

Vestibule

Anus

Rebecca Arkin Jessica Si

Layer 1

Pubic bone

Ischiocavernosus muscle

Bulbospongiosus muscle

Superficial transverse perineal muscle

Rebecca Arkin Jessica Si Layer 2

External urethral sphincter

Compressor urethra Vaginal opening

Deep transverse perineal muscles

Rebecca Arkin Jessica Si Layer 3

Pubic symphysis

Puborectalis

Pubococcygeus External anal sphincter Iliococcygeus

Coccygeus Sacrospinous

Sacroiliac

Rebecca Arkin Jessica Si Layer Three

Pubic symphysis

Puborectalis Urethra

Pubococcygeus Vagina

Illiococcygeus Rectum

Anterior sacrococcygeal Coccygeus ligament

Piriformis

Coccyx

Rebecca Arkin Jessica Si Combined Layers

Superficial Layer Deep Layer

Urethra

Ischiocavernosus muscle

Vaginal opening Bulbospongiosus muscle

Pubococcygeus

Superficial transverse perineal muscle

Illiococcygeus

Sacrotuberous ligament

External anal sphincter

Rebecca Arkin Jessica Si Pelvic Wall

Piriformis

Obturator internus Sacrotuberus ligament (cut)

Rebecca Arkin Jessica Si Pelvic Lateral View

Uterus

Bladder

Rectum

Pelvic bone

Pelvic floor

Rebecca Arkin Jessica Si Pelvic Floor Anatomy Reference Tool In this section you will find an outline of the anatomy depicted in the illustrations.

Pelvis The part of trunk that is inferoposterior to the abdomen, the area of transition between the trunk and lower limbs. It is surrounded by the pelvic girdle (bony pelvis).

Pelvic Girdle (Bony Pelvis) The basin-shaped ring of bones that connects the to the two femurs • The pelvis is formed by paired right and left hip bones, the and coccyx • The hip bones are formed from the fusion of the ilium, , and pubis • The right and left hip bones join anteriorly at the pubic symphysis • The hip bones articulate posteriorly with the sacrum at the sacro-illiac joint • The sacrum is formed by the fusion of five sacral vertebrae • The pelvis articulates with the back and legs

Perineum The perineum refers to both the area of the surface of the trunk between the thighs and the buttocks, extending from the coccyx to the pubis, and to the shallow compartment lying deep to this area but inferior to the pelvic diaphragm. The perineum includes the anus and external genitalia. • Mons pubis, labia majora, labia minora, posterior fourchette, clitoris, clitoral hood, vaginal introitus, perineal body • Vestibular glands (lubricate vagina) o Greater (Bartholin’s) o Lesser (Skene’s, or paraurethral gland) • Function: o Bear weight of the upper body while sitting and standing o Transfer the weight for standing and walking from the upper axial skeleton to the legs o Provide attachment for muscles of locomotion and posture and those of the abdominal wall

Rebecca Arkin Jessica Si and : • The primary joints of the pelvic girl are the sacro-iliac joints and the pubic symphysis. Sacro-iliac joint • The sacro-iliac joint links the axial skeleton (skeleton of trunk) and the inferior appendicular skeleton (skeleton of lower limb) • The sacro-iliac joint is a but allows limited mobility to allow the transfer of weight from the upper body to the hip bones • Weight is transferred from the axial skeleton to the ilia through the sacro-iliac ligaments and then to the femur during standing, and to the ischial tuberosities during sitting • The sacrum is suspended between the iliac bones and attached to them by posterior and interosseous sacro-iliac ligaments • Interosseus sacro-iliac ligaments (lying deep between the tuberosities of the sacrum and ilium) are the primary structures involved in transferring the weight of the upper body from the axial skeleton to the two ilia of the appendicular skeleton Pubic Symphysis • Consist of a fibrocartilaginous interpubic disc and surrounding ligaments uniting the bodies of the pubic bone • The fibers of the attachments of the rectus abdominus and external oblique muscles strengthen the pubic symphysis anteriorly Lumbosacral joints • L5 and S1 vertebrae articulate at the anterior intervertebral joint formed by the L5/S1 intervertebral disk between their bodies and at two posterior zygapophysial joints (facet joints) between the articular processes of these vertebrae • These joints are strengthened by iliolumbar ligaments radiate from the transverse process of the L5 to the ilia Sacrococcygeal joints • A secondary cartilaginous joint with an intervertebral disk • Fibrocartilage and ligaments join the apex of the sacrum to the base of the coccyx • Anterior and posterior sacrococcygeal ligaments reinforce the joint Pelvic Fascia • The connective tissue that occupies the space between the membranous peritoneum and the muscular pelvic walls and floor not occupied by the pelvic viscera • Parietal pelvic fascia: the membranous layer of variable thickness that lines the inner (deep or pelvic) aspect of the muscles forming the walls and floor of the pelvis (the obturator internus, piriformis, coccygeus, levator ani, and part of the urethral sphincter muscles) • Visceral pelvic fascia: includes the membranous fascia that directly ensheathes the pelvic organs, forming the adventitial (external covering) layer of each

Rebecca Arkin Jessica Si • The parietal and visceral layers become continuous where the organs penetrate the pelvic floor. The fascia is thickened, forming the tendinous arch of the pelvic fascia, a continuous bilateral band running from the pubis to the sacrum along the pelvic floor adjacent to the viscera

The Pelvic Floor • The pelvic floor is formed by the bowl-shaped pelvic diaphragm, which consists of the coccygeus and levator ani muscles and the facias covering the superior and inferior aspects of these muscles • The pelvic diaphragm separates the pelvic cavity from the perineum

Functions of the pelvic floor • Support organs • Stability • Sphincteric • Sexual • Sump pump: blood, lymphatic fluid • Posture and breathing

The pelvic floor muscles are described in three layers • Layer 1: Superficial Perineal Pouch • Layer 2: Urogenital Diaphragm • Layer 3: Pelvic Diaphragm

Layer 1: • Superficial transverse perineal • Bulbocavernosus or bulbospongiosus • Ischiocavernosus • External anal sphincter

Layer 2: Deep to layer 1 is a thick fibrous sheet of dense fascia the perineal membrane.

Rebecca Arkin Jessica Si • Sphincter urethrovaginalis • Compressor urethra • External urethral sphincter • Deep transverse perineal

Layer 3: Helps with core stability and to support the organs in the abdominal cavity. • Levator ani: • Pubococcygeus § Pubcorectalis • Ilicococcygeus • Coccygeus

Pelvic Wall: • Piriformis • Obturator Internus

Rebecca Arkin Jessica Si Layer 1 Muscles Layer 1 Origin Insertion Innervation Function Muscles of External Anal (S2 and S3) and Closes anal canal Sphincter branches directly from S4

Deep part Surrounds superior aspect of anal canal

Superficial part Surrounds lower part of Anchored to perineal anal canal body and anococcygeal body Subcutaneous part Surrounds anal aperture

Layer 1 Origin Insertion Innervation Function Muscles of superficial perineal pouch Ischiocavernosus and Crus of clitoris Pudendal nerve (S2-S4) Move blood from crura ramus into body of the erect clitoris Bulbocavernosus Perineal body Bulb of vestibule, Pudendal nerve (S2-S4) Move blood from perineal membrane, attached parts of clitoris body if clitoris and corpus into the glans cavernosum Superficial transverse Ischial tuberosity and Perineal body Pudendal nerve (S2-S-4) Stabilize the perineal perineal ramus body *Chart adapted from Herman and Wallace

Rebecca Arkin Jessica Si Layer 2 Muscles

Layer 2 Origin Insertion Innervation Function External urethral sphincter Inferior ramus of pubic Surrounds membranous Perineal branches of Compresses membranous on each side and adjacent parts of urethra pudendal nerve (S2-S4) urethra, relaxes during walls of deep perineal micturition pouch

Deep transverse perineal Medial aspect of ischial Perineal body Perineal branches of Stabilizes position of the ramus pudendal nerve (S2-S4) perineal body

Compressor urethra Ischiopubic ramus on Two sides join together Perineal branches of Function as accessory (Women only) each side anterior to the urethra pudendal nerve (S2-S4) sphincter of urethra

Sphincter urethrovaginalis Perineal body Courses forward lateral to Perineal branches of Accessory sphincter of vagina to blend with pudendal nerve (S2-S4) urethra, may also help partner on other side, close the vagina anterior to the vagina

*Chart adapted from Herman and Wallace

Rebecca Arkin Jessica Si Layer 3 Muscles

Layer 3 Origin Insertion Innervation Function Muscles of the pelvic diaphragm Levator ani From posterior pubic Superior surface of Ventral ramus S4, Supports pelvic viscera, bone, across tendinous perineal membrane, in inferior rectal branch of maintains anorectal angle, arch to ischial spine midline at perineal body, pudendal nerve (S2-S4) reinforces external anal sides of anal canal and sphincter anococcygeal ligament

Coccygeus Ischia spin, Lateral coccyx, sacral Branches from anterior Supports pelvic viscera, pulls border rami S3 and S4 coccyx forward after defecation (pelvic surface)

Layer 3 muscles Origin Insertion Innervation Function of pelvic wall Obturator internus Anterolateral wall of Medial surface of greater Nerve to obturator Lateral rotator of extended hip, pelvis (deep surface of trochanter of femur internus L5, S1 abduction of flexed hip and surrounding bone)

Piriformis Anterior surface of Medial side of superior Branches form L5, S1, S2 Lateral rotator of extended hip, sacrum between border of greater abduction of flexed hip anterior sacral foramina trochanter of femur *Chart adapted from Herman and Wallace Rebecca Arkin Jessica Si References

Herman & Wallace (2020, March). Anatomy. In Kimberly Glow. Pelvic Floor Function, Dysfunction and

Treatment (Level 1). Lecture conducted from Princeton, NJ.

Moore, K. L., Dalley, A. F., & Agur, A. M. (2013). Clinically oriented anatomy. Lippincott Williams & Wilkins.

Rebecca Arkin Jessica Si