ANT 156a Quiz 4

pelvis!

Bones of The Pelvic Girdle

Os Coxae (hip bone, innominate)

Ilium

Pubis

Ischium

Sacrum (variably fused vertebrae)

Coccyx (variably fused vertebrae)

What is green?

Ilium

What is pink?

Pubis

What is purple?

Ischium

What is pink (top)?

Sacrum

What is coral (bottom)?

Coccyx

Full Pelvic Girdle Which side?

Anterior

Full Pelvic Girdle Which side?

Superior

Axial or Appendicular

both, connects them functionally, develops with lower limbs

Functions of the Pelvic Girdle

• Human pelvis have been shaped by

• - bipedal walking & running

• - giving birth to large babies

• weight transfer from torso to legs

• anchor abdominal and leg muscles

• support and protect abdominal & pelvic organs (viscera)

What is A? (Anterior)

ilium

What is v?

iliac fossa

(whole concave surface area for iliacus muscle)

What is w?

arcuate line

(birth canal entrance)

What is t?

pectineal line

What is d?

acetabulum/ acetabula

(most lateral socket formed by all 3)

What is c?

pubis

(where they meet)

What is b?

ischium

What is k?

anterior- superior iliac spine (ASIS)

What is I?

anterior- inferior iliac spine (AIIS)

What is i? (posterolateral)

iliac crest

What is h?

iliac/cristal tubercle

What is g?

iliac pillar

What is j?

gluteal lines

What is f?

lunate surface

(femoral head)

What is e?

acetabular fossa & acetabular notch

What is y?

superior pubic ramus

What is z?

inferior pubic ramus

What is r?

ischial tuberosity

What is t? (anteromedial)

iliac tuberosity

What is m?

posterior- superior iliac spine (PSIS)

What is n?

posterior- inferior iliac spine

What is o?

greater sciatic notch

What is p?

ischial spine

What is q?

lesser sciatic notch

What is bb?

obturator foramen

What is aa?

pubic symphysis

What is x?

iliopublic eminence

What is s?

auricular surface

(latin ear shape)

(sacrum articulation)

What is y?

pubic tubercle

Soft Tissue Inside Hip Joint

transverse acetabular ligament

ligamentum teres

Sacrum, how many vertebrae are fused?

typically 5

could be more or less

What is A? (anterior sacrum)

sacral promontory

(midline, superiorly)

What is b?

ala/alae

wings

fibrous joint

What is d?

sacral foramina

(sacral nerves pass thru)

What is e?

transverse lines/ridges

(ridges down center, marks fusions)

What is c?

auricular surface

What is f?

superior articular processes/facets

What is f? (posterior sacrum)

superior articular processes/facets

What is h?

median crest

What is k?

lateral crest

What is l?

sacral hiatus

What is the yellow arrow?

sacral canal

Coccyx (a,b,c)

sacral articulation

cornua

transverse process

(aka vestigial tail, tailbone, variable in 3-5 fused elements)

(fuses sometimes later in life)

Pelvic inlet and outlet

Sacral Ossification

All segments:

• centrum

• 2 halves of vertebral arch

Segments 1-3 also have:

• 2 costal elements (alae and transverse processes)

Secondary Centers

• 2 epiphyseal rings per segment

• Each auricular surface

• Each infero-lateral margin

Coccyx

• One primary center for each segment

• NO secondary centers

What is typical age for fully fused sacrum?

26 to 30 years old

Os Coxae Ossification

Primary

• Ilium

• Ischium

• Pubis

Secondary (5);

• Ischial tuberosity

• Iliac crest

• Anterior-inferior iliac spine

• Pubic symphysis (tubercle)

• Center of acetabula fossa

Age Estimation using Os Coxae

cartilaginous joint age estimation

looking at pubic symphysis

• horizontal ridges

• rimmed face

• depression inside rim

Sex Estimation using Os Coxae

sexual dimorphism

women have broader pelvis (for birth)

coccyx (males longer, females shorter)

greater sciatic notch shape (women= u shaped, men= j shaped)

What is purple? (ligament)

sacrotuberous

Sacrotuberous Ligament

(resists posterior rotation of the inferior sacrum)

attachments: lateral sacrum, posterior-inferior iliac spine, and internal margin of the ischial tuberosity.

What is yellow? (ligament)

anterior sacroiliac

What is green? (ligament)

posterior sacrioiliac

Sacroiliac Ligaments

(strengthen the sacroiliac joint)

attachments: anterior and posterior to the sacroiliac joint, including the iliac tuberosity.

What is blue? (ligament)

sacrospinous

Sacrospinous Ligament

(resists posterior rotation of the inferior sacrum)

attachments: antero-lateral sacrum, ischial spine

What is yellow arrow?

obturator canal

What is red?

obturator membrane

Iliofemoral Ligament

(resists hip extension)

proximal attachment: on and in the vicinity of the anterior-inferior iliac spine,

distal attachment: intertrochanteric line of the femur

Iliofemoral Ligament Movements

prevents hyper extension

Iliofemoral Ligament Movements (1)

hip flexion & hip extension = (anterior- posterior plane)

Iliofemoral Ligament Movements (2)

hip abduction & hip adduction = (medial-lateral plane)

Gluteal Muscles

Gluteus minimus, medius, maximus

Lateral Gluteus (1)

Gluteus minimus

(hip abductor & medial rotator) –

Origin: between the anterior and inferior gluteal lines of the ilium,

Insertion: greater trochanter (anterior part) of the femur.

Lateral Gluteus (2)

Gluteus medius

(hip abductor & medial rotator) – Origin: between the iliac crest and the anterior and posterior gluteal lines of the ilium,

Insertion: greater trochanter (posterior part) of the femur.

Posterior Gluteus (3)

Gluteus maximus

(hip extensor & lateral rotator) – Origin: posterior gluteal line of the ilium, sacrum, and sacrotuberous ligament,

Insertion: gluteal line/tuberosity of the femoral shaft.

Iliopsoas Muscle Group

hip flexor

• iliacus

• psoas major (sometimes minor but only 50%)

Iliacus

Origin: iliac fossa, anterior sacrum, Insertion: lesser trochanter of the femur.

Psoas Major

Origin: T12-L4 (or L5), Insertion: lesser trochanter of the femur.

Sartorius

longest muscle in the human body

(hip flexor, abductor, & lateral rotator; knee flexor)

– Origin: anterior-superior iliac spine, Insertion: proximo-medial tibial shaft.

Sartorius Movement (1)

hip flexion & hip extension (anterior-posterior plane)

Sartorius Movement (2)

hip abduction & hip adduction

(medial-lateral plane)

Sartorius Movement (3)

lateral medial rotation

Hamstring Muscles

• biceps femoris

• semitendinosus

• semimembranosus

(hip extensors, knee flexors)

Biceps femoris

Origin: ischial tuberosity (long head; supero-medial facet), distal

femoral shaft (short head), Insertion: proximo-lateral fibula

Semitendinosus

Origin: ischial tuberosity (supero-medial facet), Insertion: proximo-

medial tibial shaft.

Semimembranosus

Origin: ischial tuberosity (supero-lateral facet), Insertion:

proximo-medial tibial condyle.

Hamstring Movement (1)

extension & flexion

knee flexors

Where is body’s center of mass?

sacroiliac joint and hip joint

Changes in bony pelvis shape

humans more wide

Rearrangement of lesser gluteals

Sagittally oriented in humans

• Abduct hip during bipedal locomotion (hip abductor)

Coronally oriented in chimps

• laterally rotate hip during bipedal locomotion