Pelvic Girdle Anatomy

• Pelvic girdle supports the head, arms and trunk while providing proximal stability.
• Pelvic girdle includes the ilium, ischium, pubis, sacrum and coccyx.
• Main function of the pelvis is bearing the weight of the upper body.
• The pelvis protects the abdominal viscera.
• The three bones of the hip are the ilium, pubis, and ischium.
• Sacrum and coccyx, along with the two hip bones, make up the pelvic girdle.
• The pelvis is composed of two hip (coxal) bones, each consisting of the ilium, pubis, and ischium.
• The ilium, pubis, and ischium meet at the acetabulum.

Acetabulum

• Acetabulum serves as the socket for the head of the femur in the hip bone.
• Lunate surface is a smooth, moon-shaped weight-bearing surface inside the acetabulum.
• Pubis and ischium encircle the obturator foramen.
• Obturator foramen acts as a protective passageway for nerves and blood vessels of the leg.
• The hip bones join at two attachment sites to form a bowl shape.
• Pelvic girdle connects anteriorly via the pubic symphysis, a cartilaginous joint.
• The hip bone has a posterior attachment at the sacrum and an anterior attachment at the pubic symphysis.

Ilium

• Ilium forms part of the hip bone.
• Iliac crest is located at the superior border of the ilium.
• Iliac crest can be easily located by running your hand down your sides.
• The iliac crest can be thought of as the 'crown' of the ilium.
• Anterior superior iliac spine (ASIS) is the most advanced spot on the iliac side and is used for pelvis symmetry assessment.
• Posterior superior iliac spine (PSIS) is the most posed spot on the iliac side and is used for pelvis symmetry assessment.
• Greater sciatic notch is an opening under the PSIS for nerves and vessels of the lower extremity.
• Iliac tubercle is a bony attachment site for stabilizing sacroiliac ligaments.
• Iliac fossa is a concave attachment site on the front of the ilium where hip flexor muscles attach.
• Iliac blade is the broad span of bone beneath the iliac crest.
• Gluteal lines (anterior, posterior, inferior) attach to the posterior iliac blade.
• Auricular surface is a rough, L-shaped surface on the back of the ilium for attachment to the sacrum.
• Anterior inferior iliac spine (AIIS) is where the ilium narrows inferiorly beneath to form the posterior aspect of the acetabulum.
• Posterior inferior iliac spine (PIIS) is where the ilium narrows inferiorly beneath to form the posterior aspect of the acetabulum.

Ischium

• Ischium is the curved bone forming the base of each half of the pelvis.
• Ischium body forms the posterior portion of the acetabulum.
• Ischium body curves inferiorly and connects to the pubis, encircling the obturator foramen.
• The obturator artery, nerve, and vein pass through the obturator foramen.
• Ischial spine projects posteriorly, creating the lesser sciatic notch.
• The ischial spine can be imagined as a tiny 'spike' sticking out the back.
• Lesser sciatic notch is created by the ischial spine projecting posteriorly.
• Ischial tuberosity is the lower end of the ischium ramus, contact point with seating surfaces.
• Ramus of the ischium connects the ischium to the pubis.
• Ramus of the ischium forms part of the socket (acetabulum) and the opening for nerves and vessels (obturator foramen).

Pubis

• Pubic symphysis is made of fibrocartilage connecting pubic bodies of hip bones.
• Pubic symphysis helps absorb shock during activities.
• Pubic tubercle is a small bump on the front of the pubis where the groin (inguinal) ligament attaches.
• Superior ramus of pubis is the upper part of the pubis bone that meets the ischium to form the socket (acetabulum).
• Inferior ramus of pubis is the lower part of the pubis bone that meets the ischium to form the socket (acetabulum) and the opening for nerves and vessels (obturator foramen).
• Symphyseal surface is the surface for pubic symphysis articulation.
• Pectineal Line is an anatomical line on the pubis bone.
• Obturator foramen is an opening in the hip bone formed by the pubic and ischial rami that allows nerves and vessels to pass through.