Download MBBS Introduction of the Leg Lecture PPT

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