Anterior Aspect of the Leg by che

8/2/2019 Anterior Aspect of the Leg by che

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ANTERIOR ASPECT OF THE LEG

The superficial fascia of this area contains no special features but it is provided with a moderate amount

of adipose tissue.

It presents the following important structures:

A. SUPERFICIAL VEINS

1. Dorsal digital veins

one on each side of the dorsum of every toe

2. Dorsal venous archs

transversely across the dorsum of the foot along the distal part of the metatarsal bone

superficial to the cutaneous nerves

the medial end is joined by the median vein of the big toe to form the commencement

of the saphenous veins

3. Long saphenous vein

runs backward along the medial border of the foot then it goes up anterior to the

medial malleolus

4. Short saphenous veinsruns backward along the lateral border of the foot before it courses upward posterior to

the lateral malleolus

B. CUTANEOUS NERVES (anterior surface of the leg)

1. Infrapatellar branch of the saphenous nerves

-comes from L3 and L4

-distributed to the proximal and medial part of the leg

2. Lateral cutaneous nerve of the leg

-from L5 and S2

-supplies area below infrapatellar branch

3. Cutaneous part of the musculocutaneous nerve-from L4, L5 and S1

-it supplies the remaining skin on the anterior aspect of the leg

DORSUM OF THE FOOT

A. NERVES

1. Saphenous nerve

-supplies the medial side of the dorsum of the foot

2. Sural nerve

-lateral side of the dorsum of the foot

3. Cutaneous branch of the musculocutaneous

-continuation from the leg to the foot

-supplies the intermediate areas between the medial and lateral side of the foot

At the dorsum of the toes, there are 3 important nerves:

1. Medial division of the anterior tibial

supplies the adjacent sides of the big toes and the 2nd toe

*The sural nerves also reaches the and supplies the lateral side of the 5th toe

2. Musculocutaneous nerve


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also reaches it and supply the other remaining toe

also called the superficial peroneal

one of the terminal branches of the lateral popliteal nerve

it gives off muscular branches of the perineous brevis muscle and the medial and lateral

cutaneous branches

3. Sural nerve

arises from the medial popliteal nerve

it first runs downwards over the gastrocnemius and then it pierces the deep fascia

above the middle of the leg before it is joined by communicating branches from the

lateral popliteal nerve.

The deep fascia of the leg invest the whole leg but it is deficient along the medial surface of the

tibia. It is thicker and stronger at the anterior and proximal part of the leg where it serves as the origin

for some of the muscles of this region

At the region of the ankle joint, the fascia forms some thickening called retinaculum.

Retinacula-are the thickened bands of the deep fascia that crosses the distal portion on the ankle

-to keep the tendons beneath it in position so they will not be displaced when the muscle

contracts

4 retinacula

a) Superior extensor retinaculum

-also called anatomically as ligamentum transversum cruxis

-about 1 inch wide

-extends between the anterior border of the fibula and tibia just above the ankle joint

-holds the extensor tendon together with the blood vessels and the nerves in place

b) Inferior extensor retinaculum

-ligamentum cruciacum cruxis-Y-shape band that is placed sideward across the proximal part of the dorsum of the

foot

-binds the extensor tendons particularly that of the extensor hallucis longus and the

tibialis anterior muscle

c) Peroneal retinaculum

-lateral aspect of the ankle between the lateral malleolus and the calcaneous

-there are 2 distinct bands here

>the superior portion binds the tendon of the peroneal muscles to the lateral malleolus

>the inferior portion straps to the lateral surface of the calcaneous

d) flexor retinaculum

-also called ligamentum laciniacum

-broad band and spans the gap between medial malleolus and calcaneous

-binds the tendons of the flexor muscles in the posterior compartment of the leg

together with the blood vessels and the nerves, it binds them as they proceed to the

sole of the foot

Deep processes of the deep fascia of the leg projecting inwards from the deep surface of the deep fascia

projecting inwards to the fibulaintermuscular septa

1.) Anterior fibular septum


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1. Middle part- attached to the proximal part of the middle phalanx

2. Lateral part- joined by the lumbrical and interosseous muscles

-the single extensor tendon of the small toe will also divides in the same manner

and joined from the lumbricals and interrosseous membrane

Action: extends the four lateral toes

dorsiflexes the foot

evertor of the foot

Innervation: anterior tibial nerve

3. PERONEOUS TERTIUS

-small lateral slit of the extensor digitorum longus and sometimes in some individuals it

may be absent

Origin: anterior surface of the fibula at the distal form and interosseous membrane

Insertion: the fibers will converge medially towards the tendon which lies lateral to the

most lateral extensor of the digitorum brevis muscle and it is attached to the base of the

5th metatarsal bone

Action: dorsiflexor of the anlkle

evertor of the foot.

Innervation: anterior tibial nerve4. EXTENSOR HALLUCIS LONGUS

-narrow muscle, sitted between the two muscle and it becomes superficial at the region

of the ankle joint

Origin: Anterior surface of the middle of the fibula and interosseous membrane

Insertion: tendon at the distal of the muscle it passes beneath the extensor reinaculum

and inserts into base of the distal phalanx of the big toe

Action: extends the big toe

dorsifleexes the foot

Innervation: anterior tibial nerve

*synovial

-enclosing the extensor tendons1- tibialis anterior

-which encloses almost completely

1- halllucis longus

1- extensor digitorum longus

1- peroneus tertius

It provides facility of movement by diminishing the friction when theres movement of the muscle

Another important artery:

1. Anterior tibial artery

-small terminal branch of the popliteal artery

Commencement:

popliteal fossa at the distal border of the popliteus muscle

Termination: ankle region between the lateral and medial malleoli where it now

becomes the dorsalis pedis artery

-accompanied by phinacomytes(?) with the anterior tibial nerve with them

Branches of anterior tibial artery:

@ Posterior compartment

1. Posterior tibial recurrent artery


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2. Circumflex fibular artery

@Anterior compartment

1. Muscular branches

2. Anterior tibial recurrent artey

3. Malleolar branch

-going to the corresponding malleolus

2. Dorsalis pedis artery

-indirect continuation of the iliotibial artery

Commencement:

-at the front of the ankle joint

Termination:

-in the posterior end at the 1st interroseous space by

Anastomose: lateral plantar artery to form the plantar archs

Branches of the dorsalis pedis:

1. Cutaneous branches

2. Tarsal arteries

-middle tarsal

-lateral tarsal3. Arcuate artery

-arises from the lateral side of recurrent artery opposite the face of metatarsal bone

4. 1st dorsaL metatarsal

-appears as continuation of the dorsalis pedis but it runs in the dorsum of the first

interosseous membrane

Perforating branches of the peroneal artery

before it anastomoses with the lateral malleolar branch and tarsal branch of the dorsalis pedis

The important nerve:

Peroneal nerve

Origin: Lateral popliteal nerveBranches:

muscular, peroneal

terminal branches

-one of the branches is deep peroneal nerve

This nerve has 2 components:

1.) Medial component

-at the lateral side of the dorsum of the foot

2.) Lateral component

-passes beneath the extensor retinaculum brevis

Extensor digitorum brevis muscle

-small thin broad muscle lying on the lateral aspect of the dorsum of the foot

Origin: superior surface of the anterior end of the calcaneous and also part of the inferior stem

of the inferior retinacula that overlies it

Insertion: the broad belly of the muscle divides into four smaller segments and each proceeds

into small tendons that go to each of the four tibial toes. The most medial of the four is attached

to the base of the 1st phalanx of the big toe--Extensor hallucis brevis

The other 3 tendons crossed over the dorsum the and joined the corresponding tendon of the


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extensor digitorum muscle to be inserted into the base of the 2nd and 3rd phalnges of the

corresponding toes

Action: Extensor of the metatarsalphallangeal and interphllangeal of the four tibial toes

Innervation: lateral branch of the anterior tibial nerve

**LATERAL COMPARTMENT OF THE LEG

-smallest compartment

1. peroneous longus muscle

Origin: from the lateral surface of the proximal 2/3 of the fibula, the lateral

condyle of the tibia and adjoins the fascia in the intermuscular fascia

Insertion: long tendon into the lateral surface of the 1st cuneiform and the base

of the1st metatarsal bone

Action: evertor and plantar flexor of the foot

Innervations: Musculucutaneous nerve

2. peroneous brevis

-smaller and deeper muscle than the peroneous longus

Origin: Lower 2/3 of the lateral surface of the tibula and the adjacent

intermuscular septumInsertion: tuberousity and dorsal surface of the fifth metatarsal bone

Action: evertor of the foot and plantar flexor of the foot

Innervations: musculucutaneos nerve of the leg

Mucus membrane

-enveloping the peroneal

-above the lateral malleolus,

Also found in the lateral compartment of the leg is the musculucutaneous nerve

-between the preoneous longus and the extensor digitorum longus muscle

It lies in a sheet that is derived from the intermuscular septum-peroneal muscles of the lateral compartment

**POSTERIOR COMPARTMENT OF THE LEG

1. Sural communicating nerve

-From L5, s1 and s2

-arises from the lateral popliteal nerve in the popliteal fossa

-passes from the gastrocnemius before it fierces the deep fascia to unite with the sural

nerve at the proximal part of the calcaneous tendon

- it supplied the skin of the

Lymphatics of the lower limb

1. superficial group

-lies in the superficial aspect of the thigh

2. deep group

-divided into four

1. Anterior Popliteal glans

2. Popliteal glans

3. Deep subinguinal glans

4. Deep vessels from the gluteal region


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Deep fascia of the posterior compartment is thin and transparent at the proximal part but thick and

dense at the distal portion where it completely gives to the formation of the reticulum that supplies the

retinacular ligament and the peroneal and flexor retinacula.

The space that is bounded anteriorly by the tibia, the interroseous membrane and the fibula and the

posterior intermuscular septum and sides by the deep fascia of the leg it is called the posterior

osteofascial compartment of the leg.

Subdivided into 3 sections by 2 septa:

1. posterior septum

-stretches from the medial border of the tibia and it goes into the posterior border of

the tibula and from the flexor muscle

-it separates the superficial muscles from the flexor muscles from the toes

2. anterior septum

-extends from the and the vertical ridge of the tibia medially to the medial crest of the

fibula laterally

-it separates the tibialis posterior muscles from the rest of the flexor muscles of the toes

Muscles in the posterior compartment

1.) GASTROCNEMIUS MUSCLE

-strong superficial muscle

-has 2 heads

-occupies the most posterior part of the posterior compartment

Origin: by means of 2 heads that forms the distal part of the popliteal fossa

Lateral head: depression on the lateral surface of the popliteal surface

Medial head: medial part of the popliteal surface above the medial condyle of the fibula

-the fibers of this muscles are 1st separated by the median groove that lodges the short

saphenous vein and the sural nerve and then they unite to form the common tendontogether with the tendon of soleus muscle which is called calcaneal tendon which is

inserted into the middle of the posterior surface of the calcaneous,

-the upper part is separated by the small fossa

Action: plantar flexor of the foot, extends the ankle helps in flexing the knee

Innervations: medial popliteal nerve

2.) PLANTARIS MUSCLE

-small muscle that is characterized by having a short belly and long tendon

-located anteromedial to the lateral head of the gastrocnemius

Origin: small area on the posterior and distal surface of the femor just above the lateral

condyle

Insertion: belly which does not usually exist 3- inches in length gives rise to long tendon

distally and medially between the 2 superficial muscles

-lies medial to the calcanean tendon before they insert into the common tendon

posteriorly alongside the calcanean tendon

Action: flexes the knee,extends the ankle

Innevation: medial popliteal nerve


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3.) SOLEUS MUSCLE

-stout, flat

-located antrerior to the plantaris and gastrocnemius

Origin: fibuloposterior surface of the head and proximal 3rd of the shaft and from

iliosuleal line the superior and the medial 3rd of the middle border and from the fascial

septum that is found anteriorly

Insertion: by the fibers converging on a strong and stout which joins the gastrocnemius

tendon to form the calcaneal tendon

Action: plantarflexor of the foot extensor of the ankle

Innervation: medial popliteal nerve

Calcaneal tendon also called calcaneal tendon of Achilles

-most powerful tendon of the body

-formed by the union of the tendon of the gastrocnemius and tendon of the soleus muscle and

tapers as it descend but it expands when it is inserted into the middle of the posterior surface of

the calcaneous

-the terminal portion of the popliteal artery is seen here in the posterior compartment at

crossing the posterior aspect of the popliteus muscle

At the inferior border of this muscle the terminal part of the artery divides into:

1. Anterior tibial artey

-the 1st portion with 2 of its branches courses up to the anterior compartmet

2. Posterior tibial artery

-largest and direct terminal branch of the popliteal artery

Commencement: distal border of the popliteus muscle

-terminates at the lower border of the flexor retinaculum where it divides into medial

and lateral plantar artery

Branches:

1. Nutrient branch?2. cutaneous branch

-supplies the skin at the posteromedial surface of the leg

3. Muscular branch

4. circumflex fibular branch

-goes around the neck of the fibula upto the point where it anastomoses with the

inferior genicular artery

5. communicating branches

6. peroneal artery

7.posterior media maleolar artery

8. medial calcaneal

9. medial lateral plantar artery

Other important structure here is the

Peroneal artery

Commencement: from the posterior tibial

-it actually commences about 1 inch below the origin of the parent trunk

Termination: through numerous calcaneal branches all at the lateral sides of the ankle

-runs distally and laterally along the fibula -runs anterior to the flexor longus muscle at

the distal end


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-passes posterior to the distal part of the tibia and fibula and lateral malleolus before it

goes to the sides of the heel of the foot

-gives four branches

1. muscular

2. nutrient

3. perforating branch

-distal part

4. communicating branches to the posterior tibial artery

Posterior tibial nerve

-continuation of the medial popliteal nerve

-originates from the medial popliteal nerve

Commencement: at the distal border of the popliteal muscle

Termination: divides into lateral and tibial plantar nerves

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Anterior Aspect of the Leg by che