Pelvic Girdle (1/5)

Ischium

Begins at superior/posterior margin of acetabulum *Ischial spine* - prominent process that projects medially

Anterior Group - Hip flexor *Rectus femoris*

(Anterior inf. Iliac spine): Flexes thigh, extends leg

Anterior Group - Hip flexor *Sartorius*

(Anterior sup. Illiac spine): Longest muscles of the body. Flexes and rotate thigh laterally. Flexes and rotates leg medially.

Anterior Group - Hip flexor *Illiacus*

(Iliac fossa) Occupies most of iliac fossa Flexes the thigh laterally

Blood Flow to Lower Limb

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Venous Flow from Lower Limb

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Ilium

1) Largest of the three fused bones 2) Forms the superior portion of os coxae and acetabulum

Muscles that move coxal joint: *List of Medial group*

1. Adductor magnus 2. Adductor longus 3. Adductor brevis 4. Gracilis 5. Pectineus

Characteristics of diarthrosis

1. Articular capsule 2. Retinacular fibers 3. Iliofemoral ligament 3. Ischiofemoral ligament 4. Pubofemoral ligament 5. Ligament of head of femur

Muscles that move coxal joint: *List of Posterior group*

1. Gluteus maximus 2. Gluteus medius 3. Gluteus minimus

Muscles that move coxal joint: *List of Anterior group*

1. Illiacus 2. Psoas major 3. Sartorius 4. Rectus femoris

Muscles that move coxal joint: *List of Deep lateral thigh rotators group*

1. Piriformis 2. Inferior gemelius 3. Obturator internus 4. Obturator externus 5. Qudratus femoris

Posterior Group - Hip extensor and abductors *Gluteus maximus*

Has extensive attachments Forms roundness of buttock Powerful hip extensor. Rotate thigh laterally

Innervation of pelvic girdle: *Sacral Plexus*

I. Sacral plexus (L4-L5 & S1-S4) Innervates a. Lower back b. Pelvis c. Perineum d. Post. surface of thigh and leg e. Dorsum & plantar of the foot

Pubis

Inferior ramus - fuses with the ischial ramus to form a structure called the ischiopubic ramus

Medial Group of muscles *Gracillis*

Medial muscle *O*= Inf. ramus & body of pubis *I*= Upper medial of tibia Adduct, flexes thigh and flexes leg

Parts of Ilium

*Ala* - is the wide fan-shaped portion *Arcuate line* - a ridge of bone at the inferior border of the ala *Iliac fossa* - is the large depression on the medial surface *Anterior, posterior and inferior gluteal lines* - on lateral surface represent attachments of the gluteal muscles of the buttock

Contrast: Male/Female Pelvis: *Tilt of pelvis*

*Female* anterior tilt to superior end of pelvis *Male* superior end of pelvis relatively vertical

Contrast: Male/Female Pelvis: *Subpubic angle* (pubic arch)

*Female* broader, more convex, > 100 degrees *Male* narrow, v-shaped, < 90 degrees

Contrast: Male/Female Pelvis: *General Width*

*Female* hips are wider, more flared *Male* hips are narrower, vertically orientated and less flared

Contrast: Male/Female Pelvis: *General Appearance*

*Female* less massive, gracile processes, less prominent musle markings *Male* more massive, more robust process, more prominent muscle markings

Contrast: Male/Female Pelvis: *Body of pubis*

*Female* longer, more rectangular *Male* short, triangular

Contrast: Male/Female Pelvis: *Coccyx*

*Female* posterior tilt *Male* vertical

Contrast: Male/Female Pelvis: *Preauricular sulcus*

*Female* present *Male* absent

Contrast: Male/Female Pelvis: *Illium*

*Female* shallow: does not project far above sacroiliac joint *Male* deep: projects farther above sacroiliac joint

Contrast: Male/Female Pelvis: *Sacrum*

*Female* shorter and wider: flatter sacral curvature *Male* narrower and longer: more curved ( > sacral curvature)

Contrast: Male/Female Pelvis: *Acetabulum*

*Female* smaller, more lateral *Male* larger, more anterior

Contrast: Male/Female Pelvis: *Obturator Foramen*

*Female* smaller, triangular *Male* larger and oval

Contrast: Male/Female Pelvis: *Greater Sciatic Notch*

*Female* wide and shallow *Male* narrow & u-shaped, deep

Contrast: Male/Female Pelvis: *Superior inlet*

*Female* wide, spacious, and oval *Male* <3 shaped

Parts of Illium (cont.)

*Iliac crest* - superior ridge *Anterior superior iliac spine* - the anterior projection of the iliac crest *Posterior superior iliac spine* - the posterior projection of the iliac crest There are also inferior spines of the above two projections Greater sciatic notch - through which the sciatic nerve travel into the lower limb *Auricular surface* - articular surface with sacrum

Ishium (cont.)

*Ischial tuberosity* - roughened projection on the posterolateral border. This is the most inferior portion of the pelvis. These two tuberosities are called the "sits bones" because they support the weight of your body when you are seated. *Ischial ramus* - extends from the tuberosity to fuse with the pubis

Muscles that move coxal joint

*O*: pelvic girdle and vertebral column *I*: various places on the femur

Medial Group of muscles *Adductor longus*

*O*= Near pubic symphasis area *I*= linea aspera of femur Adducts and flexes thigh

Medial Group of muscles *Pectineus*

*O*=Pectinal line of pubis *I*= Pectineal line of femur Adducts and flexes thigh

True/False Pelvis

A continuous oval ridge that helps subdivide the entire pelvis into a true pelvis and a false pelvis.

Pelvic Girdle (anterior/posterior)

Anteriorly: ossa coxae unite at the symphysis pubis Posteriorly: ossa coxae unite at at sacrum to form girdle.

Diarthrosis

Ball-and-socket joint between head of femur and acetabulum of the ossa coxae

Innervation of pelvis girdle: Common Fib. nerve (Sciatic Nerve)

Common Fib. nerve (Sciatic Nerve) Innervates ant. & lateral leg& dorsum of the foot: 1. Superficial gluteal nerve 2. Inferior gluteal nerve 3. Nerve to piriformis 4. Pudendal (S2-S4)

Deep Lateral Thigh Rotators 1. Piriformis 2. Inferior gemelius 3. Obturator internus 4. Obturator externus 5. Qudratus femoris

Commonly inserted: *greater trochanter* *obturatory internus* *inter-trochanteric crest of femur* All these muscles are rotators that rotate thigh laterally

Anterior Group - Hip flexor *Psoas major*

Divides into the major and minor.. Originates from thoracic (T12) & lumbar (L5) vertebrae. Both muscles attach as the iliopsoas into the lesser trochanter. Flexes the thigh laterally

Ossa Coxae

Formed by the fusion of three separate bones (ilium, ischium and pubis) between the ages of 13-15

Innervation of pelvic girdle: *Lumbar Plexus*

Forms medial and lateral plantar nerves. Cutaneous innervation to calf leg, plantar surface of foot. Motor innervation to posterior thigh and leg muscles and intrinsic muscles of foot

Medial Group of muscles *Adductor magnus*

Largest & deep to other adductor, some fibers arise from the ischium Adduct thigh, extend and laterally rotates thigh *O*= Inf. ramus of pubis & ischial tuberosity *I*= Linea aspera of femur

Posterior Group - Hip extensor and abductors *Gluteus medius/minimus*

Lie deeper Abduct and medially rotate thigh

True Pelvis

Lies inferior to the pelvic brim Encloses the pelvic cavity and forms a deep bowl that contains the pelvic organs (sex organs, bladder and uterus)

False Pelvis

Lies superior to the pelvic brim Enclosed by the ala of the iliac bones Forms the inferior region of the abdominal cavity and houses the inferior abdominal organs

Medial Group of muscles *Adductor brevis*

Located in ramus and body of pubis Adducts and flexes thigh *O*= Inf. ramus and body of the pubis *I*= Upper third of femur

Lumbar Plexus: 2 important branches

Lumbar plexus 1a) Femoral nerve 2a) Obturator nerve 1b) Post. division of 2b) Ant. div. of lumbar plexus Lumbar plexus 1c) Innervates: 2c) innervates Anterior, lateral & Medial thigh & adductor medial portion of the muscles of the thigh Leg and foot

Lateral Group *Tensor fasciae latae*

Originates from lateral surface of iliac spine Abducts and rotate thigh medially

Function of Pelvic Girdle

Pelvic bones protects and supports: 1. Viscera such as the urinary bladder, sex organs & fetus in inferior part of the body 2. support the weight of the body from vertebral column.

Sciatic Nerve

Sciatic nerve to: Common fibular nerve to: Innervates ant. & lateral leg & dorsum of the foot Also innervates Superficial gluteal region Inferior gluteal region 3. Posterior femoral cutaneous 4. Pudendal

Function of coxal joint

Stabilize the hip joint Provide support for body during locomotion Most are massive muscles Divided into *anterior, posterior, medial and thigh rotator groups*

Muscles that move coxal joint: *Lateral group*

Tensor fascie latae

Components of Pelvic Girdle

The composed of four bones: 1. sacrum 2. coccyx 3. the right and left ossa coxae.

Acetabulum

The depression on the lateral surface of ossa coxae where the head of the femur articulates. *Three bones that form the ossa coxae all contribute to the acetabulum*