The Lower Extremity
Bones of the Lower Extremity
Bone
Ilium
Major Landmarks
Iliac crests, ASIS, AIIS, PSIS, PIIS,
and gluteal lines
Ischial tuberosity, ischial spine
Pubic tubercle,
Greater and lesser trochanters,
trochanteric fossa, spiral line,
trochanteric crest, gluteal
tuberosity, linea aspera
Tibial tuberosity, soleal line,
medial and lateral condyles,
medial malleolus
Lateral malleolus
Ischium
Pubis
Femur
Tibia
Fibula
Joints and Their Ligaments
Joint
Ligaments
Hip joint
Iliofemoral, Pubofemoral,
and Ischiofemoral
Knee joint
Medial and Lateral
Menisci, Anterior and
Posterior cruciate
ligaments, Tibial and
Fibular collateral
ligaments, patellar
ligament, Oblique
popliteal ligament
Vascularization
Obturator a., medial
and lateral circumflex
aa., superior and
inferior gluteal aa.,
deep artery of thigh
Descending and
genicular branches of
the femoral,
popliteal, and lateral
circumflex femoral
arteries in the thigh
and the circumflex
fibular artery in the
leg
Innervation
Femoral, obturator, and
superior gluteal nerves
and the nerve to the
quadrates femoris
Obturator, femoral,
tibial, and common
fibular nerves
Lumbosacral Plexus
Branches
Ilio-inguinal
Cord Levels
L1
Iliohypogastric
Genitofemoral
L1
L1, L2
Lateral cutaneous nerve of thigh
L2, L3
Muscles Innervated
Abdominal wall, skin of
anteromedial thigh
Skin on anterior central thigh
and anterior genital region
Skin over anterolateral thigh and
parietal peritoneum in iliac fossa
Femoral
L2,L3?, L4
Obturator
L2, L4
Superior gluteal
L4, S1
Sciatic
L4, S3
Inferior gluteal
L5, S2
Pudendal
Tibial
S2, S4
L4, S3
Common fibular
L4, S2
Anterior Thigh Compartment
and pectineus
Medial Thigh Compartment
Gluteal Region and tensor fascia
latae (gluteus medius and
minimus)
Posterior Compartment of Thigh
and Leg; and Sole of Foot
Gluteal Region (gluteus
maximus)
Part of adductor magnus
Short head of biceps femoris,
Anterior and Lateral
Compartments of the Leg, Dorsal
aspect of Foot
Spaces and Canals
Space
Obturator canal
Greater Sciatic Foramen
Borders
Obturator foramen, obturator
membrane, and the obturator
internis and externis muscles
Greater sciatic notch, upper
borders of sacrospinous and
sacrotuberous ligaments, and
the lateral border of the sacrum
Lesser Sciatic Foramen
Subinguinal Hiatus
(Gap between Inguinal Ligament
and Pelvic Bone)
Femoral Triangle
Base formed by inguinal
ligament, medial border is
Contents
Obturator nerve and vessels
Superior gluteal
nerve/artery/vein (above
piriformis)Sciatic nerve, Inferior
gluteal nerve/artery/vein,
pudendal nerve, Internal
pudendal artery and vein,
posterior femoral cutaneous
nerve, nerve to obturator
internus, quadrates femoris, and
gamellus superior and inferior
muscles (below piriformis)
Obturator internus muscle
tendon, pudendal nerve and
internal pudendal vessels pass
into perineum from gluteal
region
Psoas major, iliacus, pectineus
muscles, femoral nerve, artery
and vein, lymphatics, femoral
branch of genitofemoral nerve,
lateral cutaneous nerve of thigh
(lateral to medial) femoral nerve,
femoral artery, femoral vein,
medial margin of adductor
longus, lateral margin formed by
medial margin of the sartorius
Popliteal Fossa
Tarsal Tunnel
Semitendinosus,
semimembranosus, biceps
femoris, gastrocnemius,
plantaris
Flexor retinaculum and
depression formed by medial
malleolus, medial and posterior
surfaces of talus, medial surface
of calcaneus, and inferior surface
of sustentaculum tali of the
calcaneus
lymphatic vessels
Popliteal artery, popliteal vein,
and the tibial and common
fibular nerves (posterior
cutaneous nerve of thigh and
small saphenous vein in roof of
fossa)
Medial to lateral: “Tom (tibialis
post tendon), Dick (flex. Dig.
Long. Tendon), And (post. Tibial
artery) Very ( tibial veins)
Nervous ( tibial nerve) Harry (flex
hallucis long tendon)”
Gluteal Region: Abductors and Lateral Rotators
Muscle
Piriformis
Attachments
Sacrum to medial
greater trochanter
Obturator membrane to
medial greater
trochanter
Ischial spine to medial
greater trochanter
Ischial tuberosity to
medial greater
trochanter
Ischium to quadrate
tubercle on
intertrochanteric crest
Ilium to anterolateral
greater trochanter
Innervations
L5, S1, S2
Gluteus Medius
Ilium to lateral greater
trochanter
L4, L5, S1
Gluteus Maximus
Gluteus medius fascia,
ilium, erector spinae
fascia, lower sacrum,
coccyx to posterior
aspect of iliotibial tract
L5, S1, S2
Obturator Internus
Gemellus Superior
Gemellus Inferior
Quadratus Femoris
Gluteus Minimis
L5, S1
L5, S1
L5, S1
Action
Lateral rotation,
abduction
Lateral rotation,
abduction
Lateral rotation,
abduction
Lateral rotation,
abduction
L5, S1
Lateral rotation
L4, L5, S1
Abducts femur, medial
rotation, prevents
pelvic drop on opposite
side during walking
Abducts femur, medial
rotation, prevents
pelvic drop on opposite
side during walking
Powerful extensor of
flexed femur at hip,
lateral stabilizer of hip
and knee, laterally
rotates and abducts
Tensor Fasciae Latae
of fasciae latae
and gluteal tuberosity
Iliac crest to iliotibial
tract
thigh
L4, L5, S1
Stabilizes the knee in
extension
Anterior Compartment of Thigh: Contains Quadriceps Group, Extend the Leg at the Knee, Femoral nerve
Muscle
Psoas Major
Iliacus
Vastus Medialis
Vastus Intermedius
Vastus Lateralis
Rectus Femoris
Sartorius
Attachments
Posterior abdominal
wall to lesser trochanter
of femur
Posterior abdominal
wall to lesser trochanter
of femur
Femur to quadriceps
femoris tendon and
medial border of patella
Femur to quadriceps
femoris tendon to
lateral border of patella
Femur to quadriceps
femoris tendon
Anterior inferior iliac
spine (AIIS) and ilium to
the quadriceps femoris
tendon
ASIS to near tibial
tuberosity
Innervations
L1, L2, L3
Action
Flex thigh
L2, L3, L4
Flex Thigh
L2, L3, L4
Extends leg at the knee
L2, L3, L4
Extends leg at the knee
L2, L3, L4
Extends leg at the knee
L2, L3, L4
Flex thigh at the hip and
extend leg at the knee
L2, L3
Flex thigh at the hip and
flex leg at the knee
Medial Compartment of Thigh: Adduct Thigh at the Hip, Mostly Obturator Nerve
Muscle
Gracilis
Pectineus
Adductor Longus
Adductor Brevis
Adductor Magnus
Attachments
Pubis and ischium to
medial proximal tibia
shaft
Pectineal line to
proximal femur
Body of pubis to linea
aspera on femur shaft
Body of pubis to
posterior surface of
proximal femur, and
linea aspera
Adductor part:
Innervations
L2, L3
Action
Adducts thigh at hip,
flexes leg at knee
L2, L3 Femoral Nerve
Adducts and flexes
thigh at hip
L2, L3, L4
Adducts and medially
rotates thigh at hip
L2, L3
Adducts thigh at hip
L2, L3, L4
Adducts and medially
Obturator Externus
ischiopubic ramus
Hamstring part: ischial
tuberosity
External surface of
obturator membrane to
trochanteric fossa
rotates thigh at hip
L2, L3, L4 Sciatic Nerve
L3, L4
Laterally rotates thigh
at hip
Posterior Compartment of Thigh: Contains Hamstrings, Sciatic Nerve, Flex Leg and Extend Thigh
Muscle
Biceps Femoris
Semitendinosus
Semimembranosis
Attachments
Long head: ischial
tuberosity, Short head:
lateral lip of linea
aspera to head of fibula
Ischial tuberosity to
medial surface of
proximal tibia
Innervations
L5, S1, S2
Action
Flex leg at knee, extend
thigh at hip, laterally
rotate leg at knee
L5, S1, S2
Ischial tuberosity to
medial tibial condyle
L5, S1, S2
Flex leg at knee, extend
thigh at hip, medially
rotate leg at knee and
thigh at hip
Flex leg at knee, extend
thigh at hip, medially
rotate leg at knee and
thigh at hip
Posterior Compartment of the Leg: Superficial and Deep (separated by fascia), Plantar flex, Inversion,
Flex Toes, all innervated by Tibial Nerve
Muscle
Gastrocnemius
Plantaris
Soleus
Popliteus
Flexor Hallucis Longus
Attachments
Medial head: medial
condyle of femur,
lateral head: lateral
condyle to calcaneal
tendon
Femur to calcaneal
tendon
Tibia and fibula to
calcaneal tendon
Lateral femoral condyle
to posterior surface of
proximal tibia
Innervations
S1, S2
Action
Plantar flex foot and
flex knee
S1, S2
Plantar flex foot and
flex knee
Plantar flex foot
S1, S2
L4 to S1
Posterior fibula and
S2, S3
interosseous membrane
to plantar surface of
distal phalanx of great
toe
Stabilize knee, unlock
knee joint, lateral
rotation of thigh,
medial rotation of leg
Flex great toe
Flexor Digitorum Longus Medial posterior tibia to S2, S3
plantar surfaces of
distal phalanges of the
lateral 4 toes
Tibialis Posterior
Posterior interosseous
L4, L5
membrane, tibia, and
fibula to tuberosity of
navicular and adjacent
region of medial
cuneiform
Flex lateral 4 toes
Inversion and plantar
flexion of foot, support
of medial arch while
walking
Lateral Compartment of Leg: Eversion of Foot, Superficial Fibular Nerve
Muscle
Fibularis Longus
Fibularis Brevis
Attachments
Upper lateral surface
and head of fibula to
the undersurface of
lateral sides of distal
end of medial
cuneiform and base of
metatarsal 1
Lower 2/3 of lateral
surface of fibular shaft
to lateral tubercle at
base of metacarpal 5
Innervations
Action
L5, S1, S2
Eversion and plantar
flexion of foot, supports
arches of foot
L5, S1, S2
Eversion of foot
Anterior Compartment of Leg: Dorsiflexion, Extend the Toes, and Invert the Foot, Deep Fibular Nerve
Muscle
Tibialis Anterior
Extensor Hallucis
Longus
Extensor Digitorum
Longus
Attachments
Lateral surface of tibia
and interosseous
membrane to medial
and inferior surfaces of
medial cuneiform and
metatarsal 1
Middle ½ of medial
fibula and interosseous
membrane to dorsal
surface of base of distal
phalanx of great toe
Proximal ½ of medial
fibula and lateral tibial
condyle to bases of
distal and middle
phalanges of lateral 4
toes
Innervations
Action
L4, L5
Dorsiflex foot, invert
foot, dynamic support
of medial arch of foot
L5, S1
L5, S1
Extension of great toe
and Dorsiflexion of foot
Extension of lateral 4
toes and Dorsiflexion of
foot
Fibularis Tertius
Distal medial fibula to
dorsomedial surface of
base of metatarsal 5
L5, S1
Dorsiflexion and
eversion of foot
Anatomy Involved
Type 1: occur without
disruption to the pelvic
ring
Type 2: a single break in
the bony ring
Type 3: double breaks
in the pelvic ring
Type 4: at or around the
acetabulum
Neck, intertrochanteric
fracture, femoral shaft
Deep veins of the lower
limb and pelvic veins
Patient Presentation
Mechanism of Injury
Severe blood loss,
hematomas which can
compress nerves and
organs
Trauma, osteoporosis,
stress fractures
Compromised blood or
nerve supply, necrosis
Edema, , calf muscle
tenderness
trauma
Clinical Considerations
Disorder or Injury
Pelvic Fractures
Femoral Fractures
Deep Vein Thrombosis
Femoral Hernia
Unhappy triad
Femoral vein and
artery, lymphatics,
superior opening of
femoral canal
Anterior cruciate
ligament, medial
collateral ligament,
medial meniscus
Extreme pain
Pain, unstable knee
joint
Venous statis, injury to
vessel walls, and
hypercoagulable states
Part of abdominal
contents seep into
femoral canal
Forceful trauma to the
lateral aspect of the
knee (frequently in
football)
Tests for Muscle Groups:
Action
Hip flexion
Knee flexion
Knee extension
Plantarflexion
Dorsiflexion
Patellar Ligament Reflex
Calcaneal Ligament Reflex
Cord Level
L1-L2
L5-S2
L3-L4
S1-S2
L4-L5
L4-L5
S1-S2
Muscles
Iliopsoas
Hamstrings
Quadriceps Femoris
Posterior Leg Compartment
Tibialis Anterior