KH 2220Laura Abbott, MS, LMT

Day 19

Pelvis Boney Landmarks

SOME TERMINOLOGY

• Pelvic girdle------pelvic bones

• Thigh bones--------femur

• Leg bones----------tibia and fibula

• Ankle bones----------tarsals

• Foot bones-------metatarsals

• Toe bones---------phalanges

The Pelvic Girdle

• The pelvic girdle consists of 2 hipbones (also known as the pelvic bones, ox coxae, and innomate bones).

• Their function is to brace the lower extremity very firmly on the sacrum.

Pelvic Bones

• In adults, each hipbone consists of 3 fused bones – Ilium– Ischium– Pubis

• At birth, they are not fused, but joined to each other by cartilage. Fusion occurs between the ages of 20 and 25.

• The point where all three bones connect is called the Acetabulum . This is where the head of the femur inserts.

Ilium

• The ilium is the largest of the 3. • Its special features are:

– The iliac crest is the top rim of the ilium.– The anterior superior iliac spine (ASIS) is the most anterior point

on the crest.– The posterior superior iliac spine (PSIS) is the most posterior

point on the crest.– The anterior inferior iliac spine (AIIS).– The posterior inferior spine (PIIS)– The greater sciatic notch is inferior to the PIIS. The sciatic nerve

exits the pelvis and goes into the thigh through this notch.

Ischium

• The ischium forms the posterior inferior part of the hip bone. Its special features include:– the ischial spine.– The lesser sciatic notch is inferior to the ischial spine.– The ischial tuberosity is a prominent bump on the

lower end of the ischium. This is what you sit on.– The ramus of the ischium projects anteriorly from the

ischial tuberosity and fuses with the pubis.

Pubis

• The pubis is the anterior inferior part of the hipbone.

• Its special features include – the superior ramus which extend medially to meet the

superior ramus of the other pubic bone. – The point of merger of the 2 pubic bones called the

pubic symphysis. – The inferior ramus projects down from the superior

ramus and fuses with the ramus of the ischium.

Four ligaments

• Inguinal ligament: links the ASIS and pubic bone

• Sacroiliac ligaments - links the sacrum to the sacrum

• Sacrotuberous ligament - links the sacrum to the ischial tuberosity

• Iliolumbar ligament - links the ilium to the 5th lumbar vertebra

Male/Female Pelvis

• The male pelvis is relatively narrow, its upper end is tilted backward, and the bones are thick. It is built for strength and speed. The female pelvis is relatively wide with a broad pelvic outlet and pubic arch, which make it ideal for child bearing.