PT21: Lower Limb Overview

Lower limbs primary function

weight bearing

Lower limbs secondary function

locomotion

Hip joint

structure favors stability; supported by strong ligaments of fibrous capsule; extensive muscular support

Lower limb region

extends from pelvis to phalanges

Gluteal region

buttocks and hips

Superior gluteal region

iliac crest

Lateral gluteal region

greater trochanter

Inferior gluteal region

gluteal fold

Medial gluteal region

intergluteal cleft

Thigh region

femoral region

Proximal-anterior thigh region

inguinal ligament

Proximal-posterior thigh region

gluteal fold

Distal-anterior thigh region

knee

Distal-posterior thigh region

popliteal fossa

Leg region

calf and shin

Anterior leg region

knee

Posterior knee region

popliteal fossa

Distal knee region

ankle

Foot region (pes/pedis)

dorsum; plantar surface

Proximal foot region

ankle

Distal foot region

toes

Lower limb osteology

pelvic bone, femur, patella, tibia, fibula, 7 tarsals, 5 metatarsals, 14 phalanges

Pelvic bones

paired; fused ilium, ischium, and pubis

Pelvic girdle

comprised of pelvic bones and sacrum; distributes body mass to lower limbs

Femur

long bone of thigh; articulates with pelvic bone and tibia and patella

Tibia and fibula

long bones of leg; both articulate with talus

Tibia

weight bearing; articulates with femur and patella

Patella

sesamoid bone; helps quadriceps muscles move tibia; protection for knee joint

Tarsal proximal row

talus and calcaneus

Tarsal distal row

navicular, cuboid, medial cuneiform, intermediate cuneiform, and lateral cuneiform

Foot bones

tarus, metatarsus, antetarsus

Hallux

first toe

Superficial fascia

deep to skin; composed of loose connective tissue, adipose tissue, cutaneous nerves, superficial veins, and lymphatics

Deep fascia types

fascia lata, crural fascia, intermuscular septa, retinacula

Fascia lata

deep fascia of thigh; consists of iliotibial tract and saphenous opening

Iliotibial tract/band

lateral thickening of deep fascia; stability for lateral thigh/knee

Saphenous opening

hiatus below inguinal ligament; great saphenous vein drains into femoral vein here

Intermuscular septa of thigh

from deep aspect of fascia lata; attaches to linea aspera

What are the three compartments that the intermuscular septa of the thigh separate?

anterior, posterior, medial

Crural fascia

deep fascia of leg; distal continuation of fascia lata from iliotibial tract to foot

Intermuscular septa of leg

from deep aspect of crural fascia; attach to fibula

What are the three compartments that the intermuscular septa of leg separates?

anterior, lateral, posterior

Posterior compartment of leg layers

triceps surae and deep flexors

Retinacula

extensions of deep fascia; tendon stabilization

Plantar aponeurosis

modified deep fascia; supports and protects structures on plantar aspect of foot; contributes to arch support

Anterior thigh general actions

knee extensors and hip flexors

Anterior general thigh innervation

femoral n.

Medial thigh general actions

hip adductors and hip flexors

Medial thigh innervation

obturator n.

Posterior thigh general actions

knee flexors and hip extensors

Posterior thigh innervation

sciatic n.

Anterior leg general actions

dorsiflexion and toe extension

Anterior leg innervation

deep fibular n.

Lateral leg general actions

eversion and plantar flexion

Lateral leg innervation

superficial fibular n.

Posterior leg general actions

plantar flexion and knee flexion

Posterior leg innervation

tibial n.

Lumbar plexus

nerve network formed from fibers in ventral rami of spinal nerves L1-L4; innervates anterior and medial thigh; supplies part of abdominal wall and external genitalia

Sacral plexus

nerve network formed from fibers in ventral rami of spinal nerves L4-S4; innervates gluteal region, posterior thigh and leg; supplies part of pelvis and perineum

Lumbar plexus nerves

femoral nerve and obturator nerve

Sacral plexus nerves

sciatic nerve and gluteal region nerves

Sciatic nerve branches

common fibular n. and tibial n.

Tibial nerve branches

medial and lateral plantar nerves

Common fibular nerve branches

superficial and deep fibular nerves

L2-L3 myotome action

hip flexion

L2-L3 myotome memory device

lift my knee

L2-L3 myotome nerve

femoral n.

L3-L4 myotome action

knee extension

L3-L4 myotome memory device

kick the door

L3-L4 myotome nerve

femoral nerve

L4-L5 myotome action

ankle dorsiflexion

L4-L5 myotome memory device

foot points to the sky

L4-L5 myotome nerve

deep fibular n.

L5-S1 myotome action

toe extension

L5-S1 myotome memory device

toes point to the sun

L5-S1 myotome nerve

deep fibular n.

S1-S2 myotome action

plantar flexion

S1-S2 myotome memory device

on the tips of my shoes

S1-S2 myotome nerve

tibial n.

S2-S3 myotome action

toe abduction

S2-S3 myotome memory device

toes spread free

S2-S3 myotome nerve

medial and lateral plantar nerves

Cutaneous innervation

Lower limb dermatomes

spiral pattern due to limb rotation during embryonic development; most areas overlap

Lower limb arterial pathway

abdominal aorta -> common iliac a. -> external/internal iliac aa. -> femoral a.

Femoral artery branches

profundus femoris a. and popliteal a.

Profundus femoris artery branches

lateral and medial circumflex femoral arteries; 3-4 perforating arteries

Popliteal artery branches

anterior and posterior tibial arteries

Anterior tibial artery branch

dorsalis pedis artery

Posterior tibial artery branches

fibular a., medial and lateral plantar arteries

Superficial veins of lower limb

veins that run independent from arteries

Deep veins above the knee

true veins that accompany arteries

Deep veins below the knee

venae comitantes accompany arteries

Veins of lower limb

superficial and deep layers; all drain toward IVC; contain valves

Great saphenous vein drains into...

femoral vein

Great saphenous vein course

arises from medial side of foot and passes through saphenous opening

Small saphenous vein drains into...

popliteal vein

Small saphenous vein course

arises from lateral side of foot

Popliteal nodes

receives lymph from vessels traveling with small saphenous vein; in popliteal fossa

Superficial inguinal nodes

receives lymph from vessels traveling with great saphenous vein; in femoral triangle