Overview of the Lower Extremities

Divisions of the lower extremity

Gluteal region, thigh (hip to knee), popliteal fossa (posterior aspect of knee), leg (knee to ankle), foot (dorsal and plantar aspects)

What are the 7 tarsals?

Talus, calcaneus, navicular, cuboid, medial, intermediate, and lateral cuneiforms

How many metatarsals?

5

How many phalanges?

14 (proximal, middle, distal); the hallux only has a proximal and distal

Parts of the femur

Head, neck, shaft with linea aspera, medial and lateral femoral condyles

Parts of the tibia

Medial and lateral tibial condyles, shaft, medial malleolus

Parts of the fibula

Head, shaft, lateral malleolus

Acetabulum

Part of the hip bone that articulates with the femoral head

What type of joint is the hip joint?

Ball and socket synovial joint

Flexion of the hip joint

Reduces the angle between the thigh and trunk anteriorly

Muscles that cross the hip joint anteriorly will be capable of what?

Hip flexion

Hip extension

Increases the angle between the thigh and trunk anteriorly

Muscles that cross the hip joint posteriorly will be capable of what?

Hip extension

Hip abduction

Draws the thigh away from the midline of the body

Muscles that cross the hip joint laterally will be capable of what?

Hip abduction

Hip adduction

Draws the thigh towards the midline of the body

Muscles that cross the hip joint medially will be capable of what?

Hip adduction

Medial rotation of the hip

Rotates the femur medially along its longitudinal axis

Muscles that cross anterior to the longitudinal axis of the femur will be capable of what?

Medial rotation of the hip

Lateral rotation of the hip

Rotates the femur laterally along its longitudinal axis

Muscles that cross posterior to the longitudinal axis of the femur will be capable of what?

Lateral rotation of the hip

What do the femoral condyles articulate with?

Tibial condyles

What type of joint is the knee joint?

Hinge synovial joint

What type of joint is the ankle/talocrural joint?

Hinge synovial joint

With what does the talus articulate to form the ankle joint?

Distal tibia and lateral malleolus of the fibula

What forms the subtalar joint?

The talus and calcaneus

Inversion of the foot

Causes the sole of the foot to face medially

Eversion of the foot

Causes the sole of the foot to face laterally

Muscles that cross the subtalar joint medially will be capable of what?

Inversion

Muscles that cross the subtalar joint laterally will be capable of what?

Eversion

Is there a greater range of inversion or eversion at the subtalar joint?

Inversion. The lateral malleolus restricts eversion

Metatarsophalangeal (MTP) joints

Synovial joints between the metatarsals and proximal phalanges

Flexion of the MTP joints

Draws toes toward the ground

Extension of the MTP joints

Draws toes away from ground

Abduction of the MTP joints

Draws the toes away from the second digit axis

Adduction of the MTP joints

Draws the toes towards the second digit axis

Interphalangeal (IP) joints

Synovial hinge joints between the phalanges

Proximal interphalangeal joints (PIPs)

Located between the proximal and middle phalanges

Distal interphalangeal joints (DIPs)

Located between the middle and distal phalanges

Does the hallux have a PIP or DIP?

No. Only a single IP joint

Superficial fascia of the lower extremity

Contains fat, cutaneous nerves, superficial veins, lymphatic vessels and lymph nodes

Deep fascia

Dense connective tissue, helps prevent muscles from bulging during contraction, aiding in pumping blood back to the heart

Fascia lata

Deep fascia of the thigh

What is the oval window in the fascia lata called?

Saphenous opening

Where is the saphenous opening?

Just inferior to the inguinal ligament

What passes through the saphenous opening?

Great saphenous vein and lymphatic vessels

Iliotibial tract (or band)

Lateral thickening of the fascia lata

What divides the thigh into the 3 compartments - anterior, posterior, medial?

3 intermuscular septa

Crural fascia

Deep fascia of the leg

Synovial tendon sheaths

Facilitate sliding of tendons as they pass under a retinaculum. Can become infected or inflamed

Compartment syndrome

Swelling within a compartment that can compromise blood flow and/or innervation to tissues in that space

How do you treat compartment syndrome

Fasciotomy

Perforating veins

Connect the superficial and deep veins. Contain valves that allow blood to flow from superficial to deep veins

Superficial veins of the lower extremity

Great and small saphenous veins

Great saphenous vein location

Anterior to medial malleolus. Ascends along medial aspect of leg and thigh. Enters saphenous opening and drains into the femoral vein

Saphenous cut down procedure

Procedure to access the great saphenous vein to administer fluids, meds, etc

What vein is sometimes used as a graft for coronary bypass surgery?

Great saphenous vein

Location of small saphenous vein

Arises from lateral side of foot. Passes posterior to lateral malleolus of ankle, enters popliteal fossa and drains into popliteal vein

Musculovenous pump

Contraction of muscles help pump blood in the veins towards the heart

Varicose veins

Occur when valves in perforating veins become incompetent, causing blood to pool in the superficial veins

Where does lymph from superficial tissues of the gluteal region drain?

Superficial inguinal nodes to the external iliac lymph nodes

Where does lymph from deep tissues of the gluteal region drain?

Superior and inferior gluteal lymph nodes to the internal iliac lymph nodes

Where do superficial lymphatic vessels accompanying the great saphenous vein drain to?

The superficial inguinal lymph nodes

Where do superficial lymphatic vessels accompanying the small saphenous vein drain to?

The popliteal lymph nodes to the deep inguinal lymph nodes

Where do deep lymphatic vessels accompanying the deep veins of the thigh, leg and foot drain to?

Deep inguinal lymph nodes

Where do the superficial and deep inguinal lymph nodes drain to?

External iliac lymph nodes

What nerves make up the lumbar plexus?

Ventral rami L1-L4. Iliohypogastric, ilioinguinal, genitofemoral, lateral cutaneous nerve of the thigh, obturator, and femoral nerves

Ventral ramus origin of the iliohypogastric nerve

L1

Somatic motor muscles of the iliohypogastric nerve

Abdominal muscles

Somatic sensory and sympathetics of the iliohypogastric nerve

Skin of inguinal region and superolateral gluteal region

Ventral ramus origin of the ilioinguinal nerve

L1

Somatic motor of the ilioinguinal nerve

Abdominal muscles

Somatic sensory and sympathetics of the ilioinguinal nerve

Skin of inguinal region, scrotum and labia majora and superomedial thigh

Ventral ramus origin of the genitofemoral nerve

L1-L2

Somatic motor of the genital branch of the genitofemoral nerve

Cremaster muscle

Somatic sensory and sympathetics of the genital branch of the genitofemoral nerve

Skin of the scrotum and labia majora

Somatic sensory and sympathetics of the femoral branch of the genitofemoral nerve

Skin of superomedial thigh

Ventral ramus origin of the lateral cutaneous nerve of the thigh

L2-L3

Somatic sensory and sympathetics of the lateral cutaneous nerve of the thigh

Skin of lateral thigh

Ventral ramus origin of the obturator nerve

L2-L4

Location of the obturator nerve

Medial to psoas major, lateral wall of pelvis, exits the pelvis via the obturator canal

Somatic motor of the obturator nerve

Medial compartment of the thigh

Somatic sensory and sympathetics of the obturator nerve

Skin of medial thigh

Ventral ramus origin of the femoral nerve

L2-L4

Location of the femoral nerve

Lateral to psoas major, passes deep to inguinal ligament

Somatic motor of the femoral nerve

Anterior compartment of the thigh

Somatic sensory and sympathetics of the femoral nerve

Skin of anteromedial thigh, leg, and foot

What nerves make up the sacral plexus?

Ventral rami L4-S4. Lumbosacral trunk, superior gluteal, inferior gluteal, sciatic, and pudendal nerves

Lumbosacral trunk

Ventral rami of L4-L5. Joins ventral rami S1-S4 as they emerge from the anterior sacral foramina (and through piriformis)

Ventral ramus origin of the superior gluteal nerve

L4-S1

Location of the superior gluteal nerve

Exits pelvis via greater sciatic foramen superior to piriformis

Somatic motor of the superior gluteal nerve

Gluteus medius, gluteus minimus, tensor fascia latae

Ventral ramus origin of inferior gluteal nerve

L5-S2

Location of inferior gluteal nerve

Exits pelvis via greater sciatic foramen inferior to piriformis

Somatic motor of inferior gluteal nerve

Gluteus maximus

Ventral ramus origin of the sciatic nerve

L4-S3. Largest nerve in the body

Location of the sciatic nerve

Exits pelvis via greater sciatic foramen inferior to the piriformis

Somatic motor of sciatic nerve

Posterior compartment of thigh, all compartments of leg and foot

Somatic sensory and sympathetics of the sciatic nerve

Skin of foot and most of leg

Ventral ramus origin of pudendal nerve

S2-S4

Location of pudendal nerve

Exits pelvis via greater sciatic foramen inferior to piriformis, courses around ischial spine, enters perineum via lesser sciatic foramen

Somatic motor of pudendal nerve

Muscles of the UG and anal triangles

Somatic sensory and sympathetics of the pudendal nerve

Skin of the UG and anal triangles