4A. 1: Pelvis + LL

Upper Limb vs Lower limb

Upper Limb vs Lower limb

Why does extension happen on the posterior side in the lower limb?

Consequencive embryonic development

Consequencive embryonic development

around 8 weeks: limb rotation

• before that, arms and legs grow as little buds

arm: supinates

leg: pronates

Lumbosacral plexus

All of the anterior rami that recombine to form these peripheral nerves come off of the ________ and ______ regions

lumbar and sacral

the lumbosacral plexus extends from __ to __

L2-S4

Femoral nerve

extensors of the knee

• L2-L4

Obturator Nerve

adductors of hip (flexor)

• L2-L4

Sciatic nerve

a combo of Tibial & fibular nerves (everything posterior)

• L4 - S3

Tibial nerve

flexors of knee, plantar flexors & intrinsic flexors of foot

• 4-S3

Fibular nerve

(common peroneal)

Dorsiflexors, extensors, evertors of foot

• L4-S2

arterial supply

ALL blood starts of in the:

• Abdominal Aorta

AA then bifurcates to form the:

• L and R common Iliac arteries

These bifurcate again to form:

• Internal and external Iliac artery

external becomes:

• Femoral artery

Femoral goes through the Adductor canal, then through a hole called adductor hiatus to become:

• popliteal artery (back of the knee)

popliteal artery bifurcates to form:

• anterior tibial artery

This sneaks through interosseous membrane and comes round to the anterior aspect and becomes:

• the dorsal pedal artery (top of foot)

The other branch off popliteal is the:

• posterior tibial artery

which runs along the interosseous membrane to become:

• the medial plantar artery (bottom of foot)

This gives off a branch called:

• fibular artery (supplies the lateral aspect the shank)

Internal and external iliac arteries

Internal IA:

• supplies musculature and viscera of pelvis

External IA:

• supplies lower limb

When the external artery passes through the ______ it becomes the femoral artery

Inguinal ligament

*Deep artery of the thigh comes off of femoral artery

there are _ routes of venus blood

2

((deep veins - blue) - same as arteries)

(superficial veins - green)

deep veins are responsible for

returning blood during exercise

superficial veins are responsible for

returning blood at rest

Fascia lata

fascial sleeve, continuous with both the:

• inguinal ligament

• inferior abdominal wall

It covers the whole leg (think of a pair of tights)

• thickens on the Iliotibial tract

Deep fascia of the shank

“crural fascia”

• divides shank into 3 compartments:

  • Anterior, lateral, posterior

• remember compartment syndrome

The lower limb

Proximal femur

Femoral head

Indentation of the femoral head

Fovea

• where the ligament of the head of the femur attaches

• contains an artery

greater and lesser Trochanter

The pelvis

3 fused bones (plus sacrum)

→ The Ox Coxae

• Ilium

• Ischium

• Pubis

Or…

• Innominate bone

• Hemipelvis

Acetabulum

The area where these come together to form the hip joint

In anatomical position, the pubis is:

Inferior to sacrum

(pelvis is tilted forward)

The Os Coxae Fossa

Fossae

• Gluteal (orange)

• Iliac (green)

Auricular surface

The area where the sacrum articulates with the Os Coxae

‘ear shaped”

Acetabulum

socket for hip joint

Obturator foramen

hole in inferior aspect

Pubic tubercle

where it joins with the other half

Iliac crest

where your hands go on your hips

Anterior superior Iliac spine (ASIS)

bony point right on anterior aspect

anterior inferior iliac spine (AIIS)

Posterior Superior & Posterior Inferior Iliac spine (PSIS) (PIIS)

Ischial spine and tuberosity

*sit on your isch

Lateral view of Acetabulum

The socket of the hip joint

• labrum

• lunate surface (covered by articular cartilage)

• ligament of the head of the femur (attaches to fovea)

Bones of the pelvic girdle

radiograph of pelvis

Radiograph of femur

Ligaments of the pelvis

Sacrospinous

• sacrum to ischial spine

Sacrotuberous

• sacrum to ischial tuberosity

Sacroiliac

• SI joint

Greater Sciatic foramen

Lesser Sciatic foramen

→ both formed from ligaments

Joints of the pelvis

3 joints

What kinds of of joints are the 3 joints of the pelvis?

Sacroiliac

• synovial, Bilateral

Pubic Symphysis

• cartilaginous (fibrocartilaginous disc)

Hip

• Synovial, Bilateral

Sacroiliac joint

Sacrum + ilium joint

• Bilateral

• Synovial

• Immobile (due to strong ligaments)

• Anterior/ posterior sacroiliac

Pubic Symphysis

L + R pubic Rami

• Cartilaginous joint - symphysis

• Hyaline Cartilage on ends of bones, fibrocartilage disc in-between

• Relatively immobile

• during pregnancy, these joints become more mobile

Open book fracture

Separation of pubic symphysis

• normal = 4-5mm

• Pregnancy = 8-9mm

2 main causes:

• diastasis symphysis pubis (during childbirth)

• Traumatic injury

Complications:

• substantial blood loss in pelvic cavity

• Infection & hemorrhage

Summary