Chapter 8 Pelvic Girdle Flashcards
4 bones of the pelvis
- Sacrum
- Coccyx
- Right ossa coxae
- Left ossa coxae
Right and left ossa coxae refers to pelvic girdle
Functions of the Pelvis
Protects and supports the viscera in the inferior part of ventral body cavity
Supports the weight of the body from the vertebral column
Pelvic (Hip) Girdle Structure
3 bones fuse together 1. Ilium 2. Ischium 3. Pubis Two coxal bones are joined anteriorly by the pubic symphysis, and posteriorly by the sacrum (sacroiliac joints).
Ilium
Largest of the 3 hip bones
Forms the superior part of the hip bone
Consists of the: ala, body, acetabulum, iliac crest (hip) and greater sciatic notch - sciatic nerve
Ischium
Inferior and posterior part of the hip bone
Most prominent feature is the ischial tuberosity: the part that meets the chair when you are sitting on it
Pubis
Inferior and anterior part of the hip bone
Superior and inferior rami and body
Pelvic Brim
A line from the sacral promontory to the upper part of the pubic symphysis.
False pelvis lies above this line.
True pelvis
The bony pelvis inferior to the pelvic brim, has an inlet, an outlet and a cavity. Contains the sex organs
Pelvic axis
Path of baby during birth
Male pelves
Bones are larger and heavier Pelvic inlet is smaller and heart shaped Pubic arch is less that 90 degrees Coccyx is less movable and less curved anteriorly Sacrum is longer and narrower Pelvic outlet is narrower
Female pelves
Wider and shallower Pubic arch is greater than 90 degrees More space in the true pelvis (sex organs) Coccyx more moveable and more curved Pelvic outlet is wider
Muscles that move the Coxal joint and thigh
O: pelvic girdle and vertebral column
I: various places on the femur.
F: 1. Stabilizes the hip joint
2. Provides support for body during locomotion
3. Most are massive muscles
4. Divided into anterior, posterior and medial groups
Muscles that move the femur (5 groups)
- Anterior (flexor)
- Posterior (extensors, abductors, and rotators)
- Medial (adductors)
- Deep lateral (rotators)
- Lateral group
Iliacus
Anterior Group
O: iliac fossa of ilium
I: lesser trochanter of femur
F: flexes and rotates thigh laterally
Psoas Major/Minor
Anterior Group
O: transverse process and body of lumbar vertebrae
I: lesser trochanter
F: flexes and rotates thigh laterally
Sartorius
Anterior Group
O: Anterior superior iliac spine
I: Medial surface of body of tibia
F: longest flexor and rotator muscle of the thigh. Flexes abduct and rotate leg medially.
Rectus Femoris
Anterior Group
O: Anterior inferior iliac spine
I: Tibial tuberosity
F: Extends and flexes thigh at a hip joint
Gluteus Maximus
Posterior Gluteal Group
Forms roundness of buttocks, powerful hip extensor and lateral rotator
Medius and Minimus
Posterior Gluteal Group
Abduct and medially rotate thigh at hip joint
Adductor Magnus
Medial Group
- Adducts rotates and extends thigh at hip joint
Adductor Longus
Medial Group
Adducts rotates and flexes thigh at hip joint
Adductor Brevis
Medial Group
Adducts rotates and flexes thigh
Gracilis
Medial Group
Flexes the knee/leg
Pectineus
Medial Group
Adducts and flexes thigh at hip joint
Deep Lateral Group
- Piriformis
- Superior gemellus
- Inferior gemellus
- Obturator internus
- Obturator externus
- Quadratus femoris
F: all muscles rotate and abduct the thigh laterally
Tensor Fasciae Latae
Lateral Group
O: iliac cres/spine
I: Tibia (iliotibial tract)
F: flexes and abducts thigh medially at hip joint
Innervation
Lumbar Plexus (L1-L5)
Femoral Nerve –> Posterior division of lumbar plexus –> innervates the anterior and medial portion of the thigh and medial side of the leg and foot
Obtuator Nerve –> Anterior division of lumbar plexus –> innervates the medial and adductor muscles of the thigh
