Download Leg

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Regio cruris - Leg
o between knee & ankle joint
o includes most of tibia & fibula
Distally, structures pass between
the leg & foot mainly through
tarsal tunnel on the posteromedial
side of the ankle,
Except anterior tibial artery &
ends of the deep and superficial
fibular nerves
Deep fascia of the leg
Crural fascia
Two intermuscular septa pass,
together with the interosseous
membrane, divide the leg into
3 compartments
Anterior compartment
Lateral compartment
Posterior compartment
Inferiorly, two band-like thickenings of the fascia form retinacula
that bind the tendons of the anterior compartment muscles,
preventing them from bowstringing anteriorly during dorsiflexion of
the joint:
Superior extensor retinaculum
Inferior extensor retinaculum
Flexor Retinaculum
Between medial malleolus &
calcaneus
Binds posterior leg’s deep
muscles’ tendons to medial
malleolus
Superior Peroneal Retinaculum
Connects the lateral malleolus to
calcaneus
Binds the tendons of peroneus
longus & brevis to lateral
malleolus
Inferior Peroneal Retinaculum
Binds the tendons of the
peroneus longus and brevis
muscles to calcaneus
Dorsiflexor (extensor) compartment
Located anterior to the interosseous
membrane
between the lateral surface of the
shaft of tibia and medial surface of
shaft of the fibula
anterior to the intermuscular septum
that connects them.
Bounded anteriorly by the deep
fascia of the leg and skin.
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Tibialis anterior
Extensor hallucis longus
Extensor digitorum longus
Fibularis tertius
Tibialis anterior
Dorsiflexes the foot at the ankle joint and inverts the foot at the
intertarsal joints. During walking, provides dynamic support for the
medial arch of the foot.
Extensor hallucis longus
Extends lateral four digits and dorsiflexes ankle
Extensor digitorum longus
Extends great toe and dorsiflexes ankle
Fibularis tertius
Dorsiflexes ankle and aids in eversion of foot
Passes forward into the anterior
compartment of leg through an
aperture in the interosseous
membrane.
Begins at the inferior border of the
popliteus muscle
@ ankle joint
midway between the malleoli
Name change  dorsalis pedis
artery (dorsal artery of the foot).
Distally,
gives rise to
anterior medial malleolar artery anterior
lateral malleolar artery
pass posteriorly around the distal ends of the
tibia and fibula, respectively.
Deep fibular (peroneal nerve)
anterior tibial artery
innervates all muscles in the
anterior compartment;
[continues into the dorsal aspect
of the foot] innervates the
extensor digitorum brevis, first
two dorsal interossei muscles,
and supplies the skin between the
great and second toes.
 Fibularis longus
 Fibularis brevis
Everts foot and weakly plantarflexes ankle
Neurological Examination
Superficial fibular (peroneal) nerve
Fibularis longus & fibularis brevis
Skin on the distal part of the anterior surface of the leg and dorsal
areas of the foot and toes except for:
the web space between the great and second toes,
 Gastrocnemius
 Soleus
 Plantaris
 Popliteus
 Flexor digitorum longus
 Flexor hallucis longus
 Tibialis posterior
Gastrocnemius:
Plantarflexes ankle when knee is extended; raises heel during
walking; flexes leg at knee joint
Soleus:
Plantarflexes ankle independent of position of knee; steadies leg on
foot
Popliteus acts on the knee joint
Unlocking the extended knee @ the initation of flexion
Others plantarflex the ankle with two continuing on to flex the toes.
Tibialis posterior:
Plantarflexes ankle; inverts foot
Popliteal artery
Major blood supply to the leg and foot
Passes
into the posterior compartment of leg
between the gastrocnemius and popliteus
muscles.
under the tendinous arch formed between
the fibular and tibial heads of the soleus
muscle
@ posterior compartment of leg divides
into anterior tibial artery & posterior tibial
artery
Posterior tibial artery
two major branches, the
circumflex fibular artery and
fibular artery:
Nutrient artery of tibia
Largest nutrient artery in the
body
Arises from the origin of the
anterior or posterior tibial artery.
Tibial nerve
Passes
o under the tendinous arch formed
between fibular and tibial heads of the
soleus muscle
o vertically through the deep region of the
posterior compartment of leg on the
surface of tibialis posterior muscle with
the posterior tibial vessels.
Tibial nerve
Leaves the posterior
compartment of leg at the
ankle via tarsal tunnel behind
the medial malleolus.
Enters the foot to supply most
intrinsic muscles and skin.
Tibial nerve
In the leg, gives rise to:
• branches that supply all
the muscles in the posterior
compartment of leg
• 2 cutaneous branches
sural nerve
&
medial calcaneal nerve
Lymph from the skin and superficial
fascia on the front of the leg
end in
superficial inguinal lymph nodes
Lymph vessels from the skin and
superficial fascia on the back of the
leg
end in
superficial inguinal nodes
or
popliteal nodes