Transcript Dorsalis pedis artery

Arteries
Blood supply to the foot is by branches of
the posterior tibial and dorsalis pedis (dorsal
artery of the foot) arteries.
• The posterior tibial artery enters the sole
and bifurcates into lateral and medial
plantar arteries.
• The lateral plantar artery joins with the
terminal end of the dorsalis pedis artery
(the deep plantar artery) to form the deep
plantar arch. Branches from this arch
supply the toes.
• The dorsalis pedis artery is the
continuation of the anterior tibial artery,
passes on the dorsal aspect of the foot
and then inferiorly, as the deep plantar
artery, between metatarsals I and II to
enter the sole of the foot.
Dorsalis pedis artery
• The dorsalis pedis artery is the
continuation of the anterior tibial artery and
begins as the anterior tibial artery crosses
the ankle joint .
• It passes anteriorly over the dorsal aspect
of the talus, navicular, and intermediate
cuneiform bones, and then passes
inferiorly, as the deep plantar artery,
between the two heads of the first dorsal
interosseous muscle to join the deep
• The pulse of the dorsalis pedis artery on
the dorsal surface of the foot can be felt by
gently palpating the vessel against the
underlying tarsal bones between the
tendons of extensor hallucis longus and
the tendon of extensor digitorum longus to
the second toe.
• Branches of the dorsalis pedis artery
include
• lateral and medial tarsal branches,
• an arcuate artery,
• a first dorsal metatarsal artery:
Posterior tibial artery and plantar
arch
• The posterior tibial artery enters the foot
through the tarsal tunnel on the medial
side of the ankle and posterior to the
medial malleolus.
• Midway between the medial malleolus
and the heel, the pulse of the posterior
tibial artery is palpable because here the
artery is covered only by a thin layer of
retinaculum, by superficial connective
tissue, and by skin.
• Near this location, the posterior tibial
artery bifurcates into a small medial
plantar artery and a much larger lateral
plantar artery.
Tibial nerve
• The tibial nerve enters the foot through the
tarsal tunnel posterior to the medial
malleolus. In the tunnel, the nerve is
lateral to the posterior tibial artery,
• Midway between the medial malleolus and
the heel, the tibial nerve bifurcates with the
posterior tibial artery into:
• a large medial plantar nerve;
• a smaller lateral plantar nerve .
•
Medial plantar nerve
• The medial plantar nerve is the major
sensory nerve in the sole of the foot. It
innervates skin on most of the anterior
two-thirds of the sole and adjacent
surfaces of the medial three and one-half
toes, which includes the great toe. In
addition to this large area of plantar skin,
the nerve also innervates four intrinsic
muscles-abductor hallucis, flexor digitorum
brevis, flexor hallucis brevis, and the first
• The medial plantar nerve supplies a digital
branch (proper plantar digital nerve) to the
medial side of the great toe and then
divides into three nerves (common plantar
digital nerves) on the plantar surface of
flexor digitorum brevis, which continue
forward to supply proper plantar digital
branches to adjacent surfaces of toes I to
IV. The nerve to the first lumbrical
originates from the first common plantar
More than you ever wanted to
know about the foot
FUNCTIONS OF FOOT
• Support body weight
• Serves as a lever to propel the
body forward in walking & running
FUNCTIONS OF FOOT
IF THE FOOT
POSSESSED A
SINGLE BONE
• It cannot adapt itself
to uneven surfaces
• Its propulsive action
depends entirely on
gastrocnemius &
plantaris
BUT
Gastrocnemius & plantaris
FUNCTIONS OF FOOT
IF THE FOOT IS
FORMED OF
SMALL BONES &
MANY JOINTS
• It can adapt itself to
uneven surfaces
• Long flexors & small
muscles of foot
assist in propulsive
action
WHY THERE ARE ARCHES?
• A segmented structure can hold up
weight only if it is built in the form of
arches
• Weight will be distributed on: 1) the
heel (behind) & 2) heads of metatarsal
bones (in front): pressure will be
minimized on nerves & vessels in sole
• Forward propulsive action will be
easier
ARCHES OF FOOT
MEDIAL
LONGITUDINAL ARCH:
•
•
Higher than lateral
arch
Formed of:
calcaneum, talus (key
stone), navicular,
three cuneiform &
first three metatarsal
bones
ARCHES OF FOOT
LATERAL
LONGITUDINAL ARCH:
• Lower than medial
arch
• Formed of: calcaneum,
cuboid (key stone),
fourth & fifth
metatarsal bones
ARCHES OF FOOT
TRANSVERSE
ARCH:
• It is only half an
arch
• It is formed of:
bases of metatarsal
bones, cuboid &
three cuneiform
bones
FACTORS MAINTAINING
ARCHES OF FOOT
• Shape of bones
• Strength of ligaments
• Tone of muscles
MECHANISM OF ARCH
SUPPORT
SHAPE OF BONES
• Bones are wedgeshaped with the thin
edge lying inferiorly
• This applies
particularly to the
bone occupying the
center of the arch
“keystone”
MECHANISM OF ARCH
SUPPORT
INFERIOR
EDGES OF
BONES ARE
TIED
TOGETHER
MECHANISM OF ARCH
SUPPORT
INFERIOR EDGES OF BONES ARE
TIED TOGETHER
• Medial longtitudinal arch: plantar
calcaneonavicular ligament, tibialis
posterior
• Lateral longtitudinal arch: long & short
plantar ligaments
• Transverse arch: deep transverse
ligaments, transverse head of adductor
hallucis, dorsal interossei
MECHANISM OF ARCH
SUPPORT
TYING THE ENDS
OF THE ARCH
TOGETHER
MECHANISM OF ARCH
SUPPORT
TYING THE ENDS OF THE ARCH
TOGETHER
• Medial longtitudinal arch: plantar
aponeurosis, medial part of flexor digitorum
longus & brevis, flexor hallucis longus, flexor
hallucis brevis, abductor hallucis
• Lateral longtitudinal arch: plantar
aponeurosis, lateral part of flexor digitorum
longus & brevis, abductor digiti minimi,
flexor digiti minimi
• Transverse arch: peroneus longus
MECHANISM OF ARCH
SUPPORT
SUSPENDING
THE ARCH
FROM ABOVE
MECHANISM OF ARCH
SUPPORT
SUSPENDING THE ARCH FROM
ABOVE
• Medial longtitudinal arch: tibialis
anterior, tibialis posterior, medial
ligament of ankle joint
• Lateral longtitudinal arch:
peroneus longus, peroneus brevis
• Transverse arch: peroneus longus
PES PLANUS (FLAT FOOT)
• A condition in which the medial
longitudinal arch is depressed
• The forefoot is everted
• The head of talus is forced downward &
medially
• The causes are both congenital and
acquired