Download MBBS (Bachelor of Medicine and Bachelor of Surgery) Latest Introduction of the Leg Lecture PPT
? The leg is that part of the lower
limb between the knee joint
and ankle joint.
? The bony framework of the leg
consists of two bones, the tibia
and fibula, arranged in parallel.
? Tibiaweight-bearing bone
lies on the medial side of leg
? Fibulasmaller than the tibia
lies on the lateral side of the
leg
? The leg is divided into
--anterior (extensor)
--posterior (flexor) and
--lateral (fibular) compartments by:
? Interosseous membrane
? Two intermuscular septa Anterior
Posterior
ANTERIOR (EXTENSOR) COMPARTMENT OF THE LEG
? Boundaries
Anterior: Deep fascia of the leg.
Medial: Lateral surface of the shaft of the tibia.
Lateral: Anterior intermuscular septum.
Posterior: Interosseous membrane
? Contents
Muscles:
Tibialis anterior,
Extensor hallucis longus,
Extensor digitorum longus,
Peroneus tertius.
Artery: Anterior tibial artery.
Nerve: Deep peroneal nerve
(anterior tibial nerve).
Muscle
Nerve supply
Action
Tibialis anterior
Deep peroneal
Dorsiflexion of the ankle
nerve
Inversion of the foot
Maintenance of the medial
longitudinal arch of the foot
Extensor hallucis Deep peroneal
Dorsiflexion of the foot
longus
nerve
Extension of the phalanges
of the big toe
Extensor
Deep peroneal
Dorsiflexion of the foot
digitorum
nerve
Extension of MP, PIP, and
longus
DIP joints of the lateral four
toes
Peroneus tertius Deep peroneal
Dorsiflexion of the foot
nerve
Eversion of the foot
ANTERIOR TIBIAL ARTERY
? Main artery of the anterior compartment of the leg
? Branch of popliteal artery
? It begins in the back of the leg at the lower border
of popliteus.
? Enter into the anterior compartment of the leg
through an aperture in the interosseous membrane
? It runs vertically downward into anterior
compartment and enters the foot as dorsalis pedis
artery
? Branches
1. Anterior and posterior tibial recurrent arteries:
They take part in the arterial anastomosis around
the knee joint.
2. Muscular branches to adjacent muscles.
3. Anterior medial and anterior lateral malleolar
arteries: They take part in the anastomosis around
the ankle joint.
DEEP PERONEAL NERVE (ANTERIOR TIBIAL NERVE)
? It is terminal branches of the common peroneal
nerve at the neck of the fibula.
? It begins on the lateral side of the neck of fibula.
? It enters the anterior compartment of the leg by
piercing the anterior intermuscular septum.
? It pierces extensor digitorum longus and descends in
this compartment with the anterior tibial artery.
? In the leg
? It accompanies the anterior tibial artery.
? Upper &lower 1/3rd --It lies lateral to artery
? Middle 1/3rd --It lies anterior to artery
? In the middle 1/3rd the nerve hesitates to cross the
artery from lateral to medial side
? Deep peroneal nerve is also called as nervus
hesitans.
? Branches
1. Muscular branches supply all the four muscles of
the anterior compartment of the leg
2.Cutaneous branch supplies the skin of the first
interdigital cleft.
3.Lateral and medial terminal branches
? Lateral terminal branch runs laterally and ends
in a pseudoganglion deep to the extensor
digitorum brevis.
? Medial terminal branch runs forward and ends
by supplying the skin first interdigital cleft.
? First dorsal interosseous muscle
DORSUM OF THE FOOT
? MUSCLES OF THE DORSUM OF THE FOOT
? Extrinsic tendons of the muscles of the anterior
compartment of the leg
? Intrinsic muscle Extensor digitorum brevis
? Medial-most part of the extensor digitorum brevis is
known as extensor hallucis brevis.
? Nerve supplylateral terminal branch of the deep
peroneal nerve.
? Actions
? Extends the metatarsophalangeal joint of the big toe.
? Other three tendons extend the metatarsophalangeal
and interphalangeal joints of 2nd , 3rd , and 4th toes,
DORSALIS PEDIS ARTERY
Continuation of the
anterior tibial artery
i)Lateral tarsal arteries
Ii)medial tarsal arteries
iii) Arcuate artery
3 dorsal metatarsal art
(2nd ,3rd ,4th ) dorsal
digital arteries
iv)First dorsal
metatarsal artery
dorsal digital arteries
CUTANEOUS NERVES ON THE FRONT OF THE LEG
1.Infrapatellar branch of the
saphenous nerveskin over
the ligamentum patellae.
2. Saphenous nerveIt
supplies the skin on the
medial side of the leg
3. Lateral cutaneous nerve of
calf branch of the common
peroneal nerveupper two-
third of the lateral side of leg.
4. Superficial peroneal nerve
branch of common peroneal
nervelower one-third of
the lateral side of the leg.
SENSORY INNERVATION OF THE DORSUM OF THE FOOT
1.Superficial peroneal (musculocutaneous) nerve: most
of the dorsum of the foot and medial margin of the
great toe except the skin of the cleft between the first
and second toes.
2. Deep peroneal nerve:cleft between the first and
second toes.
3.Sural nerve:lateral margin of the dorsum of the foot
and little toe.
4. Saphenous nerve:medial margins of the dorsum of the
foot up to the head of the first metatarsal.
5.Digital branches of the medial and lateral plantar
nerves: distal parts of the dorsal aspects of the toes
Superficial Veins
1. Dorsal venous arch--
proximal parts of the
metatarsals
2. Dorsal digital veins two
veins joins dorsal
metatarsal vein dorsal
venous arch.
? dorsal digital vein(medial
side)+ dorsal venous arch
great saphenous vein
? dorsal digital vein (lateral
side) + dorsal venous arch
small(short) saphenous vein
RETINACULA IN FRONT OF THE ANKLE
? Superior Extensor Retinaculum
? It is a broad band of the deep fascia, just above the
ankle joint. Vertically it is about 1.5 inches wide.
? Attachments
Medially lower part of anterior border of the tibia.
Laterally lower part anterior border of the fibula.
? Relations
? Medially Splits to enclose the tendon of
tibialis anterior with its synovial sheath
? Extensor hallucis longus, anterior tibial artery,
deep peroneal nerve, extensor digitorum
longus, and peroneus tertius pass deep to the
retinaculum. Tendons of these muscles are
not surrounded by the synovial sheaths
? Inferior Extensor Retinaculum
? Is Y-shaped,
? Attachments
? LaterallyBase to the lateral side of the upper
surface of the calcaneus
? Medially
? Upper arms to the medial malleolus
? Lower arm attaches to the medial side of the
plantar aponeurosis
? Relations
? Stem of Y forms a loop around the tendons of
extensor digitorum longus and peroneus tertius
with their common synovial sheath
? Upper band of Y splits to enclose the tendons of
tibialis anterior and extensor hallucis longus
? The anterior tibial artery and deep peroneal nerve
pass deep to it.
? Lower band of Y passes superficially to the tendons
of tibialis anterior and extensor hallucis longus.
? Anterior tibial compartment syndrome/shin splints
(Fresher's syndrome):
? It occurs due to
? Overexertion of the muscles of the anterior
compartment
? When the untrained persons who lead a sedentary
life are asked to walk or run for long distances.
? Shin splints also occur in trained runners who do
not warm-up.
? Muscles of the compartment swell may impede
venous return accumulation of more fluid inside
the compartment increased pressure compress
the anterior tibial artery reducing the blood
supply to the muscles leading to ischemia & pain.
?
? It is frequently seen in freshers (newly admitted
medical students/newly recruited army personnel)
who are made to run excessively.
? This condition is also referred to as army fresher's
syndrome
Dorsalis pedis artery pulse
? It can be easily felt
between the tendons
of extensor hallucis
longus and first
tendon of extensor
digitorum longus
Deep Fibular Nerve Entrapment
? Excessive use of muscles supplied by the deep
fibular nerve (e.g., during skiing, running, and
dancing) may result in muscle injury and edema in
the anterior compartment.
? This entrapment may cause compression of the
deep fibular nerve and pain in the anterior
compartment.
? Compression of the nerve by tight-fitting ski
boots, for example, may occur where the nerve
passes deep to the inferior extensor retinaculum
and the extensor hallucis brevis .
? Pain occurs in the dorsum of the foot and usually
radiates to the web space between the 1st and
2nd toes.
? Because ski boots are a common cause of this
type of nerve entrapment, this condition has
been called the "ski boot syndrome";
? The syndrome also occurs in soccer players and
runners and can also result from tight shoes
This post was last modified on 30 November 2021