The back of the leg and the region of the ankle pdf - Lower limb

Basic Anatomy

the ground.

ning by using the foot as a lever and raising the heel off

the main forward propulsive force in walking and run

powerful plantar flexors of the ankle joint. They provide

Together, the soleus, gastrocnemius, and plantaris act as

Note the following:

described in Table 10.7.

The muscles are seen in Figures 10.45 and 10.53 and are

of the Leg: Superficial Group

Muscles of the Posterior Fascial Compartment

Tibial nerve

Nerve supply:

Posterior tibial artery

Blood supply:

gus, flexor hallucis longus, and tibialis posterior

Popliteus, flexor digitorum lon

Deep group of muscles:

and soleus

Gastrocnemius, plantaris,

Superficial group of muscles:

superficial and deep groups (see Fig. 10.45).

divides the muscles of the posterior compartment into

of the leg is a septum that

deep transverse fascia

The

liteal nodes (Fig. 10.4).

group of superficial inguinal nodes or drain into the pop

around the medial side of the leg to end in the vertical

the back of the leg drain upward and either pass forward

Lymph vessels from the skin and superficial fascia on

Lymph Vessels

great saphenous vein.

division joining the popliteal and the other joining the

join the great saphenous vein; or it may split in two, one

subject to variation: It may join the popliteal vein; it may

The mode of termination of the small saphenous vein is

medially and join the great saphenous vein (Fig. 10.19)

that run upward and

anastomotic branches

Important

with the deep veins of the foot

Communicating veins

from the back of the leg

small veins

Numerous

Tributaries

small saphenous vein has numerous valves along its course.

and 10.40); it ends in the popliteal vein (see page 478). The

muscle in the lower part of the popliteal fossa (Figs. 10.19

fascia and passes between the two heads of the gastrocnemius

up the middle of the back of the leg. The vein pierces the deep

lows the lateral border of the tendo calcaneus and then runs

the lateral malleolus in company with the sural nerve. It fol

behind

dorsal venous arch of the foot (Fig. 10.19). It ascends

arises from the lateral part of the

small saphenous vein

The

Superficial Veins

the posteromedial surface of the leg (Fig. 10.1).

(see page 463), gives off branches that supply the skin on

a branch of the femoral nerve

saphenous nerve,

The

eral surface of the leg (Fig. 10.1).

479), supplies the skin on the lower part of the posterolat

a branch of the tibial nerve (see page

sural nerve,

The

(Fig. 10.1).

on the upper part of the posterolateral surface of the leg

common peroneal nerve (see page 479), supplies the skin

a branch of the

lateral cutaneous nerve of the calf,

The

of the back of the leg (Fig. 10.1).

supplies the skin over the popliteal fossa and the upper part

the back of the thigh (see page 465). In the popliteal fossa, it

of the thigh descends on

posterior cutaneous nerve

The

Cutaneous Nerves

of the little toe (see page 498).

cent sides of the first and second toes and the lateral side

dorsal surfaces of the skin of all the toes, except the adja

the dorsum of the foot. In addition, branches supply the

to the skin on the lower part of the front of the leg and

Medial and lateral branches are distributed

Cutaneous:

(Fig. 10.44)

branches to the peroneus longus and brevis

Muscular

Branches

cutaneous (Figs. 10.47 and 10.50).

brevis muscles, and in the lower part of the leg it becomes

and 10.50). It descends between the peroneus longus and

the lateral side of the neck of the fibula (Figs. 10.44, 10.46,

487

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The Back of the Leg

Skin

■

Contents of the Posterior Fascial

Compartment of the Leg

■

fibers of the soleus or partial tearing of the tendo calcaneus is

gastrocnemius and soleus muscles retract proximally, leaving

tion. A sudden, sharp pain is felt, with immediate disability. The

Tearing of the gastrocnemius or soleus muscles will produce

Gastrocnemius and Soleus Muscle Tears

severe localized pain over the damaged muscle. Swelling may

be present.

Ruptured Tendo Calcaneus

Rupture of the tendo calcaneus is common in middle-aged

men and frequently occurs in tennis players. The rupture

occurs at its narrowest part, about 2 in. (5 cm) above its inser-

a palpable gap in the tendon. It is impossible for the patient to

actively plantar flex the foot. The tendon should be sutured as

soon as possible and the leg immobilized with the ankle joint

plantar flexed and the knee joint flexed.

Rupture of the Plantaris Tendon

Rupture of the plantaris tendon is rare, although tearing of the

frequently diagnosed as such a rupture.

Plantaris Tendon and Autografts

The plantaris muscle, which is often missing, can be used for

tendon autografts in repairing severed flexor tendons to the

fingers; the tendon of the palmaris longus muscle can also be

used for this purpose.

C L I N I C A L N O T E S

488

CHAPTER 10

The Lower Limb

popliteal artery

semitendinosus

semimembranosus

gracilis

tibial nerve

gastrocnemius

soleus

tendo calcaneus

gastrocnemius

soleus

biceps femoris

lateral head of
gastrocnemius

plantaris

tibial nerve

popliteal artery

semitendinosus

gracilis

semimembranosus

gastrocnemius

plantaris

biceps femoris

FIGURE 10.53

Structures in the posterior aspect of the right leg. In

The posterior tibial artery is one of the terminal branches

Posterior Tibial Artery

Artery of the Posterior Fascial Compartment

knee joint.

The popliteus muscle is responsible for “unlocking” the

of the femur and the tibia.

is freer to move and adapt to the surfaces of the condyle

so that the meniscus is not tethered to the ligament and

eral ligament of the knee joint from the lateral meniscus

terior surface of the tibia. The tendon separates the lat

knee joint and is inserted into the upper part of the pos

The popliteus muscle arises inside the capsule of the

Note the following:

10.49 and are described in Table 10.7.

The muscles are seen in Figures 10.43, 10.45, 10.48, and

of the Leg: Deep Group

Muscles of the Posterior Fascial Compartment

part of the gastrocnemius has been removed.

■

-
-

■

of the Leg

of the popliteal artery (see page 477). It begins at the level

form the popliteal vein.

those of the anterior tibial artery in the popliteal fossa to

of the posterior tibial artery join

Venae comitantes

(see page 495).

Medial and lateral plantar arteries

around the ankle joint.

which join other arteries

Anastomotic branches,

Nutrient artery to the tibia.

posterior compartment of the leg.

are distributed to muscles in the

Muscular branches

of the leg.

seous membrane to reach the lower part of the front

pierces the interos

perforating branch

ankle joint. A

and ends by taking part in the anastomosis around the

nutrient artery to the fibula

muscular branches

posterior to it. The peroneal artery gives off numerous

the substance of the flexor hallucis longus muscle or

10.44). It descends behind the fibula, either within

close to the origin of the posterior tibial artery (Fig.

which is a large artery that arises

Peroneal artery,

Branches

dividing into medial and lateral plantar arteries (Fig. 10.49).

malleolus deep to the flexor retinaculum and terminates by

by skin and fascia. The artery passes behind the medial

below. In the lower part of the leg, the artery is covered only

rior muscle above and on the posterior surface of the tibia

10.44). It lies on the posterior surface of the tibialis poste

deep transverse fascia of the leg (Figs. 10.41, 10.42, and

downward deep to the gastrocnemius and soleus and the

of the lower border of the popliteus muscle and passes

■

and a

■

Basic Anatomy

489

Muscles of the Posterior Fascial Compartment of the Leg

T A B L E 1 0 . 7

Tibial nerve

Tuberosity of

Tibialis posterior

supports medial longitudinal

plantar flexes foot at ankle joint;

Flexes distal phalanx of big toe;

Tibial nerve

Together with gastrocnemius and

Tibial nerve

Via tendo calcaneus

Tibial nerve

Via tendo

Muscle

Origin

Insertion

Nerve Supply

Nerve Root

Action

Superficial Group
Gastrocnemius

Lateral head from

lateral condyle of

femur and medial

head from above

medial condyle

calcaneus into

posterior surface

of calcaneum

S1, 2

Plantar flexes foot at ankle joint;

flexes knee joint

Plantaris

Lateral

supracondylar

ridge of femur

Posterior surface of

calcaneum

S1, 2

Plantar flexes foot at ankle joint;

flexes knee joint

Soleus

Shafts of tibia and

fibula

into posterior

surface of

calcaneum

S1, 2

plantaris is powerful plantar

flexor of ankle joint; provides

main propulsive force in

walking and running

Deep Group
Popliteus

Lateral surface of

lateral condyle of

femur

Posterior surface

of shaft of tibia

above soleal line

L4, 5; S1

Flexes leg at knee joint; unlocks

knee joint by lateral rotation

of femur on tibia and slackens

ligaments of joint

Flexor digitorum

longus

Posterior surface of

shaft of tibia

Bases of distal

phalanges of

lateral four toes

S2, 3

Flexes distal phalanges of lateral

four toes; plantar flexes foot

at ankle joint; supports medial

and lateral longitudinal arches

of foot

Flexor hallucis

longus

Posterior surface of

shaft of fibula

Base of distal

phalanx of big toe

S2, 3

arch of foot

Posterior surface

of shafts of tibia

and fibula and

interosseous

membrane

navicular bone

and other

neighboring

bones

L4, 5

Plantar flexes foot at ankle

joint; inverts foot at subtalar

and transverse tarsal joints;

supports medial longitudinal

arch of foot

The predominant nerve root supply is indicated by boldface type.

lum and divides into the medial and lateral plantar nerves.

longus (Fig. 10.50). It is covered here by the flexor retinacu

tendons of the flexor digitorum longus and the flexor hallucis

the artery, passes behind the medial malleolus, between the

terior to it, and finally lies on its lateral side. The nerve, with

tibial artery and lies at first on its medial side, then crosses pos

of the tibia (Fig. 10.43). The nerve accompanies the posterior

posterior and, lower down the leg, on the posterior surface

10.43 and 10.53). It lies on the posterior surface of the tibialis

passes deep to the gastrocnemius and soleus muscles (Figs.

(see page 467). It descends through the popliteal fossa and

nerve (Fig. 10.17) in the lower third of the back of the thigh

The tibial nerve is the larger terminal branch of the sciatic

Tibial Nerve

Nerve of the Posterior Fascial Compartment
of the Leg

Deep Vein Thrombosis and Long-Distance Air

often fatal. Preventative measures include stretching of the

the heart and lungs, causing pulmonary embolism, which is

Should the thrombus become dislodged, it passes rapidly to

vein thrombosis can also occur with no signs or symptoms.

ness in the calf and calf muscle tenderness. However, deep

of the veins of the soleus muscle gives rise to mild pain or tight

are very prone to deep vein thrombosis in the legs. Thrombosis

Passengers who sit immobile for hours on long-distance flights

Travel

legs every hour to improve the venous circulation.

C L I N I C A L N O T E S

490

CHAPTER 10

to absorb shocks, such as in jumping.

shape to uneven surfaces. It also serves as a resilient spring

structed in the form of arches, which enable it to adapt its

age for walking and running. It is unique in that it is con

The foot supports the body weight and provides lever

(see Fig. 10.48).

The fat and the large tendo calcaneus lie behind the ankle

Structures That Lie Directly behind the Ankle

rate sheaths.

beneath the inferior peroneal retinaculum, they have sepa

10.59) share a common synovial sheath. Lower down,

The peroneus longus and brevis tendons (Figs. 10.48 and

Malleolus beneath the Superior Peroneal

Structures That Pass behind the Lateral

Small saphenous vein (see Fig. 10.48)

The sural nerve

Malleolus Superficial to the Superior Peroneal

Structures That Pass behind the Lateral

lum, it is surrounded by a synovial sheath.

As each of these tendons passes beneath the flexor retinacu

Flexor hallucis longus (Figs. 10.48 and 10.49)

Tibial nerve

Posterior tibial artery with venae comitantes

Flexor digitorum longus

Tibialis posterior tendon

From Medial to Lateral

Malleolus beneath the Flexor Retinaculum

Structures That Pass behind the Medial

Saphenous nerve (Figs. 10.48 and 10.51)

Great saphenous vein

Structures That Pass in Front of the Medial

oneus tertius share a common synovial sheath.

The tendons of extensor digitorum longus and the per

extensor retinacula, it is surrounded by a synovial sheath.

As each of the above tendons passes beneath or through the

Peroneus tertius (Fig. 10.48)

Extensor digitorum longus tendons

Deep peroneal nerve

Anterior tibial artery with venae comitantes

Extensor hallucis longus tendon

Tibialis anterior tendon

Extensor Retinacula from Medial to Lateral

Structures That Pass Beneath or Through the

(Fig. 10.48)

Superficial peroneal nerve (medial and lateral branches)

the medial malleolus)

(in front of

Saphenous nerve and great saphenous vein

Retinacula from Medial to Lateral

Structures That Pass Anterior to the Extensor

identify as many of the structures as possible.

to lateral. At the same time, examine your own ankle and

in Figure 10.48; on it, identify the structures from medial

A transverse section through the ankle joint is shown

site for fractures, sprains, and dislocations.

joint. From the clinical standpoint, the ankle is a common

the tendons, arteries, and nerves in the region of the ankle

a student have a sound knowledge of the arrangement of

Before learning the anatomy of the foot, it is essential that

See pages 496 and

Medial and lateral plantar nerves:

to the ankle joint.

Articular branch

skin over the medial surface of the heel (Fig. 10.49).

supplies the

medial calcaneal branch

The

Cutaneous:

gus, flexor hallucis longus, and tibialis posterior.

to the soleus, flexor digitorum lon

Muscular branches

Branches in the Leg (Below the Popliteal Fossa)

The Lower Limb

■

497.

The Region of the Ankle

Anterior Aspect of the Ankle

■

Malleolus

■

Posterior Aspect of the Ankle

■

Retinaculum

■

Retinaculum

The Foot

-
-

plantar aponeurosis

The

Deep Fascia

the sole (Figs. 10.1 and 10.54).

which innervate the lateral third of

lateral plantar nerve,

the medial two thirds of the sole; and branches from the

which innervate

medial plantar nerve,

branches from the

tibial nerve, which innervates the medial side of the heel;

of the

medial calcaneal branch

foot is derived from the

to the skin of the sole of the

sensory nerve supply

The

large numbers.

the sites of skin movement. Sweat glands are present in

ous fibrous bands. The skin shows a few flexure creases at

firmly bound down to the underlying deep fascia by numer

The skin of the sole of the foot is thick and hairless. It is

The Sole of the Foot

Skin

is a triangular thickening of the

into the toes.

base of the aponeurosis divides into five slips that pass

the medial and lateral tubercles of the calcaneum. The

vessels, and muscles (Fig. 10.54). Its apex is attached to

deep fascia that protects the underlying nerves, blood