Snell Lower Limb

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157

Lower Limb55

C H A P T E R

The primary func tion of the lower limb is to suppo rt the

weight of the bo dy and to provide a stable foundation when

standing, walking, or running. Each lower limb may be d i-

vided into the gluteal region, the thigh, the knee , the leg, the

ankle, and the foot.

It is suggested that the lower limb be reviewed in the

following order:

1. A brief overview of the bo nes and the major joints, prefer-

ably with use o f an articulated skeleton.

2. A consideration of the more important muscles, concen-

trating on their actions and their nerve supply.3. A brief review of the b lood supply and the lymphatic

drainage.

4. A detailed overview of the nerves and their distribution.

To assist students, tables are used extensively in this

chapter.

BONES

Bones o f the Pelvic Girdle

The pelvic girdle consists of four b ones: the two hip bones,

the sacrum, and the coccyx (see Fig. 3-1). The pelvic girdle

pro vides a stron g co nn ec tion be tween the trun k an d the

lower limbs.

HIP BONE

In ch ildren, ea ch h ip bone co nsists of the ilium, the ischium,

and the pub is (Fig. 5-1). At pub erty, these three bones fuse

together to form one large, irregular bon e. The acetabulum

is a cup-shaped depression on the outer surface of the hip

bo ne , and it articulates with the head of the femur. The ar-

ticular surface of the acetabulum is limited to a horseshoe-

shaped area and is covered with hyaline cartilage. The ac-

etabular fossa is the floor of the acetabulum, which is

nonarticular. The acetabular notch is situated on the

inferior margin of the acetabu lum.

The iliac crest runs between the anterior and poste-

rior superior iliac spines. Below these spines are the cor-

responding inferior iliac spines.

The ischium possesses an ischial spine and an ischial

tuberosity (Fig. 5-1).

The pubis has a body and a superior and an inferior

pubic rami. The b ody of the pubis has the pubic crest an dthe pubic tubercle, and it articulates with the pubic bone

of the oppo site side at the symphysis pubis.

The obturator foramen is a large opening that is

bo unde d b y the p arts of the isch ium an d pub is (Fig. 5-1).

Bones o f the Thigh

The b one s of the thigh consist of the femu r and the pa tella

(Fig. 5-2).

FEMUR

The head of the femur is hemispheric in sha pe and fits intothe acetabulum to form the hip joint. The fovea capitis is

a small depression in the center of the head for the attach-

ment of the ligament of the head. Part of the blood sup-

ply to the head of the femur from the ob tura tor artery is

conveyed along this ligament and enters the bone at the

fovea.

The neck connects the head to the shaft (Fig. 5-2). The

greater and the lesse r trochanters are large e minences at

the junction of the neck and the shaft. Connecting the two

trochanters are the intertrochanteric line anteriorly

(where the iliofemoral ligament is attached) and a promi-


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158 CHAPTER5 Lower Limb

iliac crestrough surface for attachment of interosseous ligament

posterior superior iliac spine

auricular surface

posterior inferior iliac spine

greater sciatic notch

ischial spine

lesser s ciatic notch

obturator membrane

ischial tuberosity

ischial ramusinferior ramus of pubis

obturator canal

pubic crest

pubic tubercle

body of pubis

superior ramus of pubis

iliopectineal line

anterior inferior iliac spine

anterior superior iliac spine

iliac fossa

ilium tubercle of ilium

line of fusion of bones

acetabulum

obturator foramen

ischium

A

B

pubis

Figure 5-1 Right h ip bone . A. Medial surface. B. Lateral surface. Note the lines of fusion b etwee nthe ilium, the ischium , and the pub is.


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nent intertrochanteric crest posteriorly (on which is thequadrate tubercle) .

The shaft is smooth on its anterior surface but has a

ridge posteriorly (the linea aspera) to which are attached

muscles and intermuscular septa. The medial margin of

the linea aspera continues below (as the medial supra-

condylar ridge) to the adductor tubercle (Fig. 5-2) on

the medial condyle. The lateral margin becomes continu-

ous below with the lateral supracondy lar ridge. On the

posterior surface of the sha ft below the greater trochante r

is the gluteal tuberosity for the insertion of the gluteus

maximus muscle. A flat, triangular area on the posterior surface of the lower end of the shaft is called the popliteal

surface.

The lower end of the femur has a lateral and a medial

condyle, which are separated posteriorly by the inter-

condylar notch. The anterior surface s of the con dyles are

join ed by an ar ticula r surfac e for the patella. The two

condyles take p art in the formation of the knee joint. Above

the condyles are the medial and the lateral epicondyles.

The adductor tubercle is continuous with the medial epi-

condyle.

CHAPTER5 Lower Limb 159

greater trochanter

intertrochanteric line

lateral condyle

patellar surface

head fovea capitis

neck

lesser trochanter

shaft

adductor tubercle

medial epicondyle

medial condyle

for attachment

of rectus femoris

for attachment

of vastus lateralis

for attachment

of vastus medialis

patella

for attachment of ligamentum patellae

lateral condyle

head of fibula

neck

shaft

lateral malleolus

medial malleolus

shaft of tibia

lateral border

anterior border

tibial tuberosity

medial condyle

intercondylar eminence

A

C

B

Figure 5-2 A. Anterior su rface of the right femu r. B. Anterior surface of the right patella. C.Anterior surface o f the righ t tibia an d fibu la.


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PATELLA

The pa tella is the largest sesamoid bo ne ( a bone that de vel-

ops within a tendon), and it lies within the tendon of the

quadriceps femoris muscle in front of the knee joint. It is tri-

angular in shape. Its apex lies inferiorly and is conne cted to

the tub erosity of the tibia b y the ligame ntum patellae. The

posterior surface articulates with the cond yles of the femu r.

Bones of the Leg

The bon es of the leg a re the tibia a nd the fibula (Fig. 5-2).

TIBIAThe tibia is the large, weight-bearing, med ial bone of the leg.

At the upper end are the lateral and medial condyles,

which articulate with the lateral and med ial condyles of the

femur with the lateral and medial menisci intervening.

Separating the upper articular surfaces of the tibial cond yles

is the intercondylar e minence. The lateral condyle pos-

sesses an oval articular facet for the h ead of the fibula

on its lateral aspect.

At the upper en d o f the anterior border of the shaft of the

tibia is the tuberosity (Fig. 5-2), which receives the attach-

men t of the ligamentum p atellae. The anterior border is pro-

longed downward and medially to form the medial malle-

olus below. The lateral border of the tib ia provide s

attachment to the interosseous me mbrane, which b inds to-

gether the tibia and the fibula. The lower end of the tibia

shows a wide, rough dep ression on its lateral surface for ar-

ticulation with the fibula.

FIBULA

The fibula provides attachmen t for muscles. It takes no pa rt

in articulation at the knee joint, but below, it forms part of

the an kle joint.

The head forms the upper end of the fibula (Fig. 5-2). It

has a styloid process, and it possesses an articular sur-

face for articula tion with the latera l cond yle of the tibia. The

shaft is attache d to the tibia by the interosseous memb rane.

The lower end of the fibula forms the lateral malleolus.


BLOOD SUPPLY TO THE FEMORAL HEAD AND

FRACTURES OF THE FEMORAL NECK

In the young, the epiphysis of the he ad is supp lied bya small branch o f the obturator artery, which passes to

the head along the ligament to the femoral head. The

upper part of the neck of the femur rece ives a profuse

bloo d supp ly from the med ial femoral circum flex

artery. In the adu lt, after the epiphyseal cartilage dis-

appears, an anastomosis between the two sources of

blood supply is established . Frac tures o f the femo ral

neck interfere with or completely interrupt the main

blood supply from the root of the femora l neck to the

femo ral head . Avascular necrosis of the femoral head

is a commo n com plication of femoral neck fractures.

CLINICAL NOTES

FRACTURES OF THE NECK OF THE FIBULA ANDINJURY TO THE COMMON PERONEAL NERVE

The common peroneal nerve is in an exposed posi-

tion as it winds around the neck of the fibula. The

nerve can be injured in fractures of the neck of the

fibula an d b y pressure from casts or splints.

CLINICAL NOTES

Bones o f the Foot

The bones of the foot are the tarsal bones, the metatarsal

bone s, and the pha langes (Fig. 5-3).

TARSAL BONES

The tarsal bone s are the calcaneum, the talus, the navicular,

the cuboid, and the three cuneiform bones.

Calcaneum

The calcaneum is the largest bone of the foot. It articulates

abo ve with the talus and in front with the cuboid b one . The

po sterior surface forms the pro min en ce of the he el, an d

the med ial surface possesses a large, shelflike ridge (the

sustentaculum tali) that assists in supporting of the talus.

Talus

The talus articulates ab ove at the ankle joint with the tibia

and the fibula, be low with the calca neum, and in front with

the navicular bone (Fig. 5-3). It possesses a head, neck, an d

body. Nume rous important ligame nts are attach ed to the

talus, but no muscles are attached to this bone.

Navicular

The navicular lies between the head of the talus and the

three cuneiform bones (Fig. 5-3). The tuberosity lies in

front of and below the medial malleolus, and it attaches to

the ma in part of the tibialis posterior tend on.

Cuboid

The cuboid articulates with the anterior end of the calca-

neum ( Fig. 5-3). It has a dee p groove on its inferior aspec t for

the tendon of the peroneus longus muscle.

Cuneiform Bones

The three cuneiform bones are small, wedge-shaped bones

that articulate proximally with the navicular bone and dis-

tally with the first three metatarsal bon es. Their wedge shape

contributes to the formation and maintenance of the

transverse arch of the foot.


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METATARSAL BONES AND PHALANGES

The metatarsal bones and the phalanges resemble the

metacarpal bones and the phalanges of the hand; each pos-

sesses a distal head, shaft, and proximal base (Fig. 5-3).

There are five metatarsal bones, and they are numbered

from the med ial to the lateral side. The fifth metatarsal has

a prominent tubercle on its base, which can be easily pal-

pa ted along the la tera l borde r of the foot. The tub erc le pro-

vides attachment to the peroneus brevis tendon.

Except for the b ig toe, each toe h as three phalanges. The

big toe possesses only two.

JOINTS

Hip Joint

ARTICULATION

Articulation is between the head of the femur and the ac-

etabu lum of the hip bone (Fig. 5-4). The articular surface of


extensor digitorum longus tendons

extensor hallucis longus

insertions of dorsal interossei

extensor digitorum brevis(extensor hallucis brevis)

second dorsal interosseous

first dorsal interosseous

first metatarsal bone

medial cuneiform

intermediate cuneiform

lateral cuneiform

navicular

talus

tendo calcaneus

calcaneum

extensor digitorum brevis

cuboid

peroneus brevis

peroneus tertius

fourth dorsal interosseous

third dorsal interosseous

Figure 5-3 Dorsal view o f the b one s of the right foot. Note the m uscle attachm ents.


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acetabular labrum

capsule

head of femur

synovial membrane

acetabulum

acetabular fossa

pad of fat

ligamentof headof femur

epiphyseal line

synovial sheath

synovial membrane

articular surface

acetabular labrum

transverseacetabular ligament

obturator artery

small branchof obturator artery


synovial sheath

arterial supplyfrom circumflexfemoral arteries

arterial supplyfrom obturator artery


A

B

Figure 5-4 A. Corona l se ction o f the righ t hip joint. B. Articular su rfaces o f the righ t hip joint andthe arterial supply of the fem ur.


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the acetabulum is horseshoe shaped and is deficient inferi-

orly at the acetabular notch. The cavity of the ace tabulum

is deepened by the fibrocartilaginous rim called the ac-

etabular labrum. The labrum b ridges the ace tabular notch

and is called the transverse acetabular ligament.

TYPE

The hip is a synovial ball-and-socke t joint.

CAPSULE

The capsule encloses the joint and is attached medially to

the acetabular labrum (Fig. 5-4). It is attached late rally to the

intertrochanteric line of the femur in front of and halfway

along the posterior aspect of the neck of the bone be hind. It

is reinforced b y the iliofemo ral, the pub ofemoral, and the is-

chiofemoral ligaments.

LIGAMENTSIliofemoral Ligament

The iliofemoral ligament is the strongest and most important

ligament of the hip joint (Fig. 5-5). It is shaped like an in-

verted Y. Its base is attached to the anteroinferior iliac spine

abo ve, and the two limbs of the Y are attached to the up per

and the lower parts of the intertrochanteric line o f the femur


anterior inferior iliac s pineopening for bursa

superior ramus of pubis

pubofemoral ligament

intertrochanteric line

iliofemoral ligament

capsule

A

ischiumiliofemoral ligament

ischiofemoral ligament

intertrochanteric crest

area of loose attachment

of capsule

B

Figure 5-5 Anterior (A) and poste rior (B) views of the right hip joint.


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below. This ligamen t resists hype rextension and latera l

rotation of the hip joint.

Pubofemoral Ligament

The pubofemoral ligament is triangular in shape (Fig. 5-5).

The base is attached above to the superior ramus of the pubis, and the apex is a ttached be low to the lower en d o f the

intertrochanteric line. This ligament limits abduction and

lateral rotation of the h ip joint.

Ischiofemoral Ligament

The ischiofemoral ligame nt is spiral in shape and is attached

to the body of the ischium and laterally to the greater

trochanter of the femur (Fig. 5-5). This ligament limits me-

dial rotation of the h ip joint.

Ligament of the Head of the Femur

The ligament of the head of the femur is flat and triangular

in shape (Fig. 5-4). It is attache d by its apex to the fovea c ap i-tis of the femu r and by its base to the transverse ac etabu lar

ligament and to the margins of the acetabular notch. This

ligament lies within the joint and is ensheathed b y synovial

membrane . It has a slight limiting action on add uction of the

hip joint.

SYNOVIAL MEMBRANE

The synovial membrane lines the capsule (Fig. 5-4) an d cov-

ers the portion of the femoral neck that lies within the joint

capsule. It enshea thes the ligame nt of the head of the femur

and covers the floor of the acetabular fossa. It frequently

communicates with the psoas bursa.

NERVE SUPPLY

The femoral, the obturator, and the sciatic nerves and the

nerve to the quadratus femoris supp ly the joint.

MOVEMENTS AND THE MUSCLES THAT PRODUCE

MOVEMENT

The h ip joint has a wide ran ge of movement.

• Flexion: Iliopsoas, rectus femoris, sartorius, and add uctor

muscles.

• Extension (posterior movement of the flexed thigh):

Gluteus maximus an d hamstring muscles.• Abduction: Gluteus medius and minimus, sartorius, ten-

sor fasciae latae, an d piriformis muscles.

• Adduction: Adductor longus and brevis, adductor fibers

of adduc tor magnus, pectineus, and gracilis muscles.

• Lateral rotation: Piriformis, obturator internus and exter-

nus, superior an d inferior gemelli, qua dratus femoris, and

gluteus ma ximus muscles.

• Medial rotation: Anterior fibers of the gluteus medius

and minimus and the tensor fasciae latae muscles.

• Circumduction: A combination of all the previously

described movements.

IMPORTANT RELATIONS

• Anteriorly: Femoral vessels and nerve.

• Posteriorly: Sciatic nerve.


HIP JOINT STABILITY AND

TRENDELENBURG’S SIGN

The stability of the hip joint when a person stands on

one leg with the foot of the op posite leg raised above

the ground de pends o n three factors:

• The gluteus medius and m inimus must be function-

ing normally.

• The hea d of the femur must be located normally

within the acetabulum.

• The nec k of the femur must be intact and must have

a normal an gle with the shaft of the femur.

If one of these factors is defective, then the pelvis

will sink downward on the o pposite, unsupported

side. The patient is then said to exhibit a positive

Trendelenburg’s sign.

CLINICAL NOTES

Knee Joint

ARTICULATION

Above are the co ndyles of the femur; below are the c ond yles

of the tibia and their menisci (Fig. 5-6). In front is the articu-

lation between the lower end of the femur and the patella.

TYPE

Between the femur and the tibia is a synovial joint of the

hinge variety. Between the patella and the femur is a

synovial gliding joint.

CAPSULE

The capsule encloses the knee joint, except anteriorly,

where the capsule is deficient. Here, the synovial mem-

brane pouches upwa rd benea th the quadriceps ten do n an d

forms the sup rapatellar bursa.

LIGAMENTS

Extracapsular

Ligamentum Patellae

The ligamentum patellae is a continuation of the tendon of the

quadriceps femoris muscle. It is attached above to the lower

border of the patella and b elow to the tubercle of the tibia.

Lateral Collateral Ligament

The lateral collateral ligament is cordlike; it is attached

above to the lateral condyle of the femur and below to the

head o f the fibula (Fig. 5-6). It is separated from the lateral

meniscus by the tendon of the popliteus muscle.


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Medial Collateral Ligament

The medial co llateral ligamen t is a flat band that is attach ed

above to the medial condyle of the femur and below to

the med ial surface of the shaft of the tibia (Fig. 5-6). It is

strongly attached to the med ial meniscus.

Oblique Popliteal Ligament

The oblique po pliteal ligame nt is a tend inous expan sion of

the semimembranosus muscle. It strengthens the back

of the capsule.

Intracapsular

Cruciate Ligaments

The cruciate ligaments are two very strong ligaments that

cross each other within the knee joint (Fig. 5-6). They are

termed anterior and posterior, according to their tibial at-

tachments.

The anterior cruciate ligament is attached below to

the a nterior intercondylar area of the tibia ( Fig. 5-7), and it

passes upwa rd, backwa rd, and latera llyto b e atta ched to thelateral femoral cond yle.

The posterior cruciate ligament is attached below to

the posterior intercondylar area of the tibia (Fig. 5-7), and it

passes upwa rd, forward, and medially to b e attached to the

medial femoral condyle.

MENISCI

The menisci are C-shaped shee ts of fibrocartilage (Fig. 5-7).

The peripheral convex border of each meniscus is thick

and a ttached to the capsule, and the inner conc ave border

is thin and forms a free edge. The upper surfaces are in


suprapatellar bursa

lateral femoral condyle

infrapatellar fold of

synovial membrane

lateral meniscus

capsule (cut open)

shaft of fibula

shaft of femur

medial femoral condyle

posterior cruciate ligament

anterior cruciate ligament

medial meniscus

patellar

shaft of tibia

medial femoral condyle

medial collateral ligament

medial meniscus

medial tibial condyle

shaft of tibia

femur


lateral femoral condyle

lateral meniscuslateral collateral ligament

lateral tibial condyle

shaft of fibula

A

B

Figure 5-6 A. Anterior view of the internal asp ect of the right knee joint. Note that the capsu le has been cu t a nd th e pa te lla tu rn ed downward . B. Posterior view of the internal aspe ct of the right

knee joint. Note that the capsule and the synovial mem brane ha ve been removed.


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contact with the femoral condyles and the lower surfaces

with the tibial condyles. Each meniscus is attached to the

upper surface of the tibia by the anterior and the posterior

horns. Because the medial meniscus is also attached to

the medial collateral ligame nt, it is relatively immo bile and

is very susceptible to injury. The function of these menisci

is to deepen the articular surfaces of the tibial condyles to

receive the convex femoral condyles.

BURSAE RELATED TO THE KNEE JOINT

Suprapatellar Bursa

The suprapatellar bursa lies beneath the quadriceps muscle.

It is the largest bursa , and it always communicates with the

knee joint.

Prepatellar Bursa

The p repatellar bursa lies between the pa tella and the skin.

Infrapatellar Bursae

The superficial infrapatellar bursa lies be tween the liga-

mentum patellae and the skin. The deep infrapatellar

bursa lies between the ligamentum patellae and the tibia.

Popliteal Bursa

The p opliteal bursa surrounds the tendo n of the popliteus. It

always communicates with the joint cavity.

Semimembranosus Bursa

The semime mbran osus bursa lies between the ten don o f the

semimembranosus muscle and the medial condyle of the

tibia. It may communicate with the joint cavity.

NERVE SUPPLY

Femoral, obturator, common peroneal, and tibial nerves

supply the joint.


MOVEMENT

• Flexion: Biceps femoris, semitendinosus, and semi-

memb ranosus muscles.



medial meniscus

medial collateral ligament

semimembranosus

medial head of gastrocnemius

prepatellar bursa

ligamentum patellae

capsule

lateral meniscus

lateral collateral ligament

tendon of popliteus

deep fascia

popliteal artery

posterior cruciate ligament

Figure 5-7 Cross-section of the right knee joint as se en from a bove. Note the po sitions o f the ligam ents a nd the me nisci.

INJURIES TO THE LIGAMENTS AND MENISCI

The ligaments and menisci are commonly injured in

active sports. The medial men iscus is damaged m uch

more frequen tly than the lateral, probab ly bec ause of

its strong attachment to the medial collateral liga-

ment, which restricts its mobility.

CLINICAL NOTES

SYNOVIAL MEMBRANE

The synovial membrane lines the capsule. Anteriorly, itforms a pouch that extends up beneath the quadriceps

femoris muscle to form the suprapatellar bursa. Posteri-

orly, it is prolonged downward on the tendo n of the popliteus

muscle to form the popliteal bursa. The synovial mem-

bra ne is also re flected forward and around the front of the

cruciate ligaments; as a result, the c ruciate ligaments lie be-

hind the synovial cavity.

In the anterior part of the lower region of the joint, the

synovial membrane is reflected backward from the liga-

mentum patellae to form the infrapatellar fold. The ed ges

of this fold are called the alar folds.


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• Extension: Quadriceps femo ris muscle.

• Medial rotation: Sartorius, gracilis, and semitendinosus

muscles.

• Lateral rotation: Biceps femoris mu scle.

The knee joint is most stable when in full extension. As

the knee joint assumes this position, med ial rotation of thefemur results in a twisting and tightening of all the major lig-

aments of the joint. During flexion, the ligaments are un-

twisted by contraction of the popliteus muscle, which

laterally rotates the femur on the tibia.

The inferior transverse tibiofibular ligament deepens

the socket into which the b ody of the talus fits snugly.

TYPE

The ankle is a synovial hinge joint.

CAPSULE

The c apsule en closes the joint.

LIGAMENTS

Medial (Deltoid) Ligament

The medial ligament is very strong and is attached by its

apex to the tip of the medial malleolus ( Fig. 5-8). Below, the

dee p fibers are attache d to the me dial surface of the body of

the talus. The superficial fibers are attached to the medial

side of the talus, the sustentaculum tali, the plantar calca-

neonavicular ligament, and the tuberosity of the navicular

bo ne .

Late ral Ligament

The lateral ligament is weaker than the medial ligament

(Fig. 5-8) an d has three b and s.

Anterior Talofibular Ligament

The anterior talofibular ligame nt runs from the lateral malle-

olus to the lateral surface of the talus.


fibula

lateral malleolus

posterior talofibular ligament

calcaneofibular ligament

tibia

talus

anterior talofibular ligament

bifurcated ligament

tibia

navicular

medial malleolus

medial (deltoid) ligament

calcaneum

sustentaculum tali

A

B

Figure 5-8 Right ankle joint. A. Late ral view. B. Med ial view.

STRENGTH OF THE K NEE JOINT

The strength of the kne e joint depen ds on the strength

of the ligaments that bind the femur to the tibia and o n

the tone of the muscles acting on the joint. The most

important muscle group is the quadriceps femoris;

provided tha t this is we ll d eveloped , it is capable of

stabilizing the knee in the p resence of torn ligaments.

CLINICAL NOTES

Ankle Joint

ARTICULATION

The articulation is between the lower end of the tibia, the

malleoli above, and the body of the talus below (Fig. 5-8).


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Calcaneofibular Ligament

The calcaneofibular ligament runs from the lateral malleo-

lus to the lateral surface of the calcane um.

Posterior Talofibular Ligament

The posterior talofibular ligament runs from the lateral

malleolus to the p osterior tubercle of the talus.

SYNOVIAL MEMBRANE

The synovial membrane lines the capsule.

NERVE SUPPLY

Deep peron eal and tibial nerves supp ly the joint.


MOVEMENT

• Dorsiflexion (toes pointing upward): Tibialis anterior, ex-tensor ha llucis longus, extensor digitorum longus, and p er-

one us tertius muscles.

• Plantar flexion (toes pointing downward): Gastrocne-

mius, soleus, plantaris, peroneu s longus, peroneu s brevis,

tibialis posterior, flexor digitorum longus, and flexor hal-

lucis longus muscles.

IMPORTANT RELATIONS

• Anteriorly: Anterior tibial vessels and the dee p pe ronea l

nerve (Fig. 5-9).

• Posteriorly: Tendo calcaneus (Fig. 5-10).

• Behind the lateral malleolus: Tendons of peroneus

longus a nd brevis (Fig. 5-10).• Behind the medial malleolus:Posterior tibial vessels, tib-

ial nerve, and the long flexor ten dons of the foot (Fig. 5-10).

Intertarsal Joints

SUBTALAR JOINT

Articulation

The articulation is between the concave inferior surface of

the bod y of the talus and the convex face t on the uppe r sur-

face of the c alcaneum.

Type

The subta lar joint is a synovial gliding joint.

TALOCALCANEONAVICULAR J OINT

Articulation

Articulation is between the rounde d head o f the talus, upper

surface o f the sustentaculum tali of the calcaneum, and pos-

terior concave surface of the navicular bone.

Type

The talocalcaneonavicular joint is a synovial joint.

Ligaments

Plantar Calcaneonavicular (Spring) Ligament

The p lantar calcan eonavicular ligame nt runs from the ante-

rior border o f the sustentaculum tali to the inferior surface

and the tuberosity of the navicular bone. It supports the

head of the talus.

CALCANEOCUBOID JOINT

Articulation

Articulation is between the anterior end of the calcaneum

and posterior surface of the cu boid.

Type

The calcan eocubo id joint is a synovial gliding joint.

Ligaments

Long Plantar Ligament

The long plantar ligame nt is strong and connec ts the under-

surface of the c alcaneum to the cub oid and the bases of the

third, the fourth, and the fifth me tatarsal bones.

Short Plantar Ligament

The short plantar ligament is wide and strong and conne cts

the undersurface of the calcaneum to the adjoining part

of the cuboid.


MOVEMENT

The movements of the subtalar, the talocalcaneonavicular,

and the calcaneocuboid joints are inversion and eversion.Inversion is more extensive than eversion.

• Inversion (movement of the foot so that the sole faces

medially): Tibialis anterior, extensor hallucis longus, me-

dial tendo ns of extensor digitorum longus, and tibialis pos-

terior muscles.

• Eversion (op posite movement of the foot so that the sole

faces laterally): Peroneus longus, peroneus brevis, per-

oneus tertius, and lateral tendons of extensor digitorum

longus muscles.

CUNEONAVICULAR J OINT

ArticulationArticulation is between the three cuneiform bones and the

navicular bo ne.

Type

This is a synovial gliding joint.

CUBOIDEONAVICULAR JOINT

The cub oideon avicular joint is a fibrous joint. The bon es are

connected by dorsal, plantar, and interosseous ligaments,

and a small amoun t of moveme nt is possible.


13/44


Figure 5-9 Structures of the anterior and lateral right leg and o f the do rsum of the foot.


14/44


flexor hallucis longus

peroneal artery

tendocalcaneus

abductor digiti minimi

inferior peroneal retinaculum

fifth metarsal bone

inferior extensor retinaculum

synovial sheath

superior peroneal retinaculum

lateral malleolus

peroneus longus

peroneus brevis

tibia

tibialis posterior

flexor digitorum longus

posterior tibial artery

tibial nerveflexor hallucis longus

medial malleolus

tibialis anterior


medial plantar nerve

medial plantar artery

lateral plantar artery

lateral plantar nerve

abductor hallucisflexor digitorum brevis

medial calcanealnerve and artery

tendo calcaneus

flexor retinaculum

A

B

Figure 5-10 Structures pa ssing be hind the lateral ma lleolus (A) and the m edial malleolus (B). Notethe p osition o f the retinacula.


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INTERCUNEIFORM AND CUNEOCUBOID JOINTS

Intercuneiform and cuneocubo id joints are synovial gliding

join ts. The bon es are con nec ted by dorsal, plan tar, an d

interosseous ligaments.

TARSOMETATARSAL AND INTERMETATARSAL JOINTS

Tarsometatarsal and intermetatarsal joints are synovial glid-

ing joints. The b ones are connec ted by dorsal, plantar, and

interosseous ligaments.

METATARSOPHALANGEAL AND INTERPHALANGEAL

JOINTS

Metatarsopha langeal and interphalangeal joints are similar

to those of the hand ( see p. 123 and 124). Abduction an d ad-

duction of the toes, which are performed by the interossei

muscles, are small in amount and occur from the midline

of the second digit (and no t the third digit, as in the hand) .

MUSCLES OF THE LOWER LIMB

Gluteal Region

The gluteal region is bounded superiorly by the iliac crest

and inferiorly by the fold of the buttock (Fig. 5-11). This re-

gion consists largely of the gluteal muscles and a thick layer

of superficial fascia.

The m uscles of the gluteal region are described in Table

5-1.

Sacrotuberous Ligament

The sacrotuberous ligamen t conn ects the p osteroinferior il-

iac spine, the lateral part of the sacrum, and the coccyx to

the ischial tuberosity (Fig. 5-11).

Sacrospinous Ligament

The sacrospinous ligament connects the lateral part of the

sacrum and the coccyx to the spine of the ischium (Fig. 5-

11).

IMPORTANT FORAMINA

Greater Scia tic Foramen

The greater sciatic foramen is formed by the c onversion of

the greater sciatic notch of the hip bone into a foramen

by the presence of the sac rotube rous an d th e sacrospinous

ligaments.

The following structures pass through the foramen:

• Piriformis muscle.• Sciatic nerve.

• Posterior cutaneou s nerve o f the thigh.

• Superior and inferior gluteal nerves.

• Nerves to obturator internus and q uadratus femoris

muscles.

• Pudendal nerve.

• Superior and inferior gluteal arteries and veins.

• Internal puden dal artery and vein.

Lesser Sciatic Foramen

The lesser sciatic foramen is formed by the conversion of

the lesser sciatic notch of the hip bo ne into a foramen by

the presence of the sacrotuberous and the sacrospinousligaments.

The following structures pass through the foramen:

• Tendo n of the ob turator internus muscle.

• Nerve to the o bturator internus muscle.

• Pudendal nerve.

• Internal puden dal artery and vein.

Thigh

The muscles of the anterior fascial compartment (Fig. 5-12)

are d escribed in Table 5-2. The muscles of the med ial fascial

compartmen t are described in Table 5-3, and the muscles of

the p osterior fascial compa rtment ( Fig. 5-13) are d escribedin Tab le 5-4.

DEEP FASCIA OF THE THIGH (FASCIA LATA)

The deep fascia encloses the thigh as a trouser leg would.

The upper end is attached to the pelvis and its associated

ligaments.

ILIOTIBIAL TRACT

The iliotibial tract is a thickening of the fascia lata on its lat-

eral side. It is attached ab ove to the iliac tubercle and b elow

GLUTEUS MAXIMUS ANDINTRAMUSCULAR INJECTIONS

The great thickness of the gluteus maximus muscle

makes it ideal for intramuscular injections. To avoid

injury to the underlying sciatic nerve, the injection

should be given well forward on the upper outer

quadrant of the b uttock.

CLINICAL NOTES

FASCIA

Superficial Fascia

The superficial fascia is thick (especially in women) and isimpregnated with large q uan tities of fat.

Deep Fascia

The d eep fascia is continuous below with the fascia lata of the

thigh, and it splits to enclose the gluteus ma ximus muscle.

IMPORTANT LIGAMENTS

The sac rotuberou s and the sacrospinous ligaments stabilize

the sacrum and prevent its rotation by the weight of the

vertebral column.


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posterior superior iliac spine

sacrotuberous ligament

superior gluteal artery

inferior gluteal arteryand nerve

spine of ischium

nerve toobturator internus

pudendal nervesacrospinous ligamentinternal pudendal artery

coccyx

ischiorectal fossa

anus

fat

semimembranosus

gracilis

nerve to hamstrings

adductor magnus

semitendinosus biceps femoris

gluteus maximus

sciatic nerve

iliotibial tract

adductor magnus

quadratus femoris

posterior cutaneous nerve

of thigh

greater trochanter

gemellus superior

piriformis

superior gluteal nerve

tensor fasciae latae

gluteus minimus

superior gluteal artery

gluteus medius

iliac crest

gemellus inferior

oburator internus

Figure 5-11 Structures of the right gluteal region. Note that the g reater pa rt of the gluteus m ax-imus and part of the gluteus med ius m uscles have be en remo ved.


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Table 5-1 Muscles of the Gluteal Region of the Lower Limb

Muscle Origin Insertion Nerve Supply Action

Gluteus maximus Outer surface of the Iliotibial tract and Inferior gluteal nerve Extends and laterally

ilium, sacrum, gluteal tuberosity of rotates the thigh at the

coccyx, and the femur hip joint; it extends knee

sacrotuberous joint through the iliotibialligament tract

Gluteus medius Outer surface of the Greater trochanter of Superior gluteal Abducts the thigh at the hip

ilium the femur nerve joint; tilts the pelvis when

walking

Gluteus minimus Outer surface of the Greater trochanter of Superior gluteal Abducts the thigh at the hip

ilium the femur nerve joint; tilts the pelvis when

walking; anterior fibers

med ially rotate the thigh

Tensor fasciae latae Iliac crest Iliotibial tract Superior gluteal Assists the gluteus maximus

nerve in extending

the knee joint

Piriformis Anterior surface of the Greater trochanter of First and second Laterally rotates the thigh at

sacrum the femur sacral nerves the hip joint

Ob tu ra tor in te rn us Inn er su rfa ce o f th e Gre ate r tro ch ante r of Sa cra l p le xus La te ra lly rota te s the th igh a t

obturator membrane the femur the hip jointGemellus superior Spine of the ischium Greater trochanter of Sacral plexus Laterally rotates the thigh at

the femur the hip joint

Gemellus inferior Ischial tuberosity Greater trochanter of Sacral plexus Laterally rotates the thigh at

the femur the hip joint

Quadratus femoris Ischial tuberosity Quadrate tubercle on the Sacral plexus Laterally rotates the thigh at

upper end of the femur the hip joint

to the lateral condyle of the tibia. It rece ives the insertion of

the greater part of the gluteus maximus and the tensor

fasciae latae m uscles.

SAPHENOUS OPENING

The saphenous opening is a gap in the deep fascia in the

front of the thigh and just below the inguinal ligament. It al-

lows passage of the great saphenous vein, some small

branche s of the femoral ar tery, and lymp h vessels. The

opening is filled with loose connective tissue called the

cribriform fascia.

FASCIAL COMPARTMENTS OF THE THIGH

Three fascial septa pass from the inner aspect of the deep

fascial sheath of the thigh to the linea aspera of the femur.

By this means, the thigh is divided into three co mpa rtments,

with each having muscles, nerves, and arteries. The com-

pa rtme nts are as follows:

• Anterior with the femoral nerve.

• Medial (adduc tor) with the obturator nerve.

• Posterior with the sciatic nerve.

FEMORAL TRIANGLE

The femoral triangle is situated in the u pper part of the front

of the thigh. Its boundaries are as follows:

• Superiorly: The inguinal ligament.

• Laterally: The sartorius muscle.

• Medially: The adductor longus muscle.

The femoral triangle contains the terminal part of the

femoral nerve and its branches, the femoral sheath, the

femoral artery and its branches, the femoral vein and its

tributaries, and the inguinal lymph no des.

FEMORAL SHEATHThe femoral sheath is a downward protrusion from the ab-

domen into the thigh of the fascia transversalis and the fas-

cia iliaca. The sheath surrounds the femoral blood vessels

and lymph vessels for approximately 1 in. (2.5 cm) below

the inguinal ligament. As the femoral artery enters the

thigh benea th the inguinal ligament, it occupies the lateral

compartment of the sheath. The femoral vein occupies

the intermediate compartment, and the lymph vessels

(and usually one lymph node) occupy the most medial

compartment.


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anterior superior iliac spine

lateral cutaneous nerve of thigh

sartorius

femoral nerve

lateral femoralcircumflex artery

intermediate cutaneous nerveof thigh

nerve to vastus medialis

vastus intermedius

vastus lateralis

vastus medialis

shaft of femur

iliotibial tract

rectus femoris

ligamentum patellae

saphenous nerve

saphenous nerve

femoral artery

gracilis

adductor magnus

adductor longus

medial cutaneous nerve of thigh

pectineus

spermatic cord

deep external pudendal artery

pubic tubercle

inguinal ligamentfemoral canal

femoral sheath

femoral vein

psoas

iliacus

profunda femoris artery

tensor fasciae latae

medial femoralcircumflex artery

femoral artery

Figure 5-12 Femora l triang le and the a dductor (subs artorial) cana l in the right lower limb.


19/44


Table 5-2 Muscles of the Anterior Fasc ial Compartment of the Thigh


Sartorius Anterior superior Upper medial surface Femoral nerve Flexes, abducts, and laterally

iliac spine of the shaft of the tibia rotates the thigh at the hip

joint; flexes a nd media lly

rotates the leg at the knee joint

Iliacus Iliac fossa of the With psoas into the lesser Femoral nerve Flexes the thigh on the trunk; if

hip bone trochanter of the femur the thigh is fixed, it flexes the

trunk on the thigh ( as in

sitting up from lying down)

Psoas Twelfth thoracic With the iliacus into the Lumbar plexus Flexes the thigh on the trunk; if

vertebral body; lesser trochanter of the the thigh is fixed, it flexes the

transverse processes, femur trunk on the thigh (as in

bo die s, and sitting up from lying down )

intervertebral discs

of the five lumb ar

vertebae

Pectineus Superior ramus of Upper end of the shaft of Femoral nerve Flexes and adducts the thigh at

the pubis the femur the hip joint

Quadratus femorisRectus femoris Straight head; anterior Quadriceps tendon Femoral nerve Extends the leg at the knee

inferior iliac spine; into the patella joint; flexes the thigh at the

reflected head: ilium hip joint

above the

acetabulum

Vastus lateralis Upper e nd and shaft Quad rice ps te ndon Femoral n erve Exte nd s the leg at the knee joint

of the femur into the patella

Vastus med ialis Upper e nd and shaft Quad rice ps te ndon Femoral n erve Exte nd s the leg at the kn ee

of the femur into the patella joint

Vastus intermedius Shaft of femur Quadriceps tendon Femoral nerve Extends the leg at the knee

into the patella joint

Table 5-3 Muscles of the Medial Fascial Compartment of the Thigh


Gracilis Inferior ramus of the Upper part of the shaft Obturator nerve Adducts the thigh at the hip

pubis and ram us of the of the tibia joint; flexes th e leg at the

ischium knee joint

Adductor longus Body of the pubis Posterior surface of the Obturator nerve Adducts the thigh at the hip

shaft of the femur joint, assists in lateral

rotation

Adductor brevis Inferior ramus of the Posterior surface of the Obturator nerve Adducts the thigh at the hip

pubis sha ft of the fem ur joint, assists in lateral

rotationAd duc to r ma gn us In fe rio r ra mu s o f th e Po ste rio r su rfa ce o f th e Ob tu ra to r n erve Ad du cts th e thigh a t the h ip

pubis, ramus of the sha ft of the fem ur, ad du cto r pa rt; joint, assists in lateral

ischium, and ischial adductor tubercle sciatic nerve: rotation,

tuberosity of the femur hamstring part hamstring part

extend s the thigh at the

hip joint

Obturator externus Outer surface of the Greater trochanter Obturator nerve Laterally rotates the thigh at

obturator of the femur the hip joint

membrane


20/44


gluteus maximus

ischial spine

sacrotuberous ligament

ischial tuberosity

adductor magnus

(hamstring part)

semimembranosus

semitendinosus

gracilis

tibial nerve

semimembranosus

popliteus

oblique popliteal ligament

common peroneal nerve

biceps femoris(long head)

gluteus maximus

sciatic nerve

nerve to hamstrings

adductor magnus

qaudratus femoris

greater trochanter

gemellus inferior

obturator internus

gemellus superior

piriformis

gluteus minimus

gluteus medius

iliac crest

Figure 5-13 Structures of the p osterior aspe ct of the right thigh.


21/44


FEMORAL CANALThe femoral canal is the small, medial compartment of the

femoral sheath occupied by the lymphatics. It is approxi-

mately 0.5 in. (1.3 cm) in len gth. It is also a poten tially weak

area in the wall of the abdomen; a protrusion of peritoneum

could be forced down the femoral canal to form a femoral

hernia.

FEMORAL RING

The femoral ring is the up per op ening of the femoral canal.

It is filled by a plug of extra pe ritonea l fat ca lled the femoral

septum.

Important Relations

• Anteriorly: Inguinal ligament.

• Posteriorly: Superior ramus of the pubis and the

pe ctinea l ligament.

• Laterally: Femoral vein.

• Medially: Lacu nar ligame nt (an extension of the inguinal

ligament; see p age 39).

ADDUCTOR (SUBSARTORIAL) CANALThe adductor cana l is an intermuscular cleft on the medial as-

pect of the midd le third of the thigh beneath the sartorius mus-

cle. The posterior wall is formed by the adductor magnus

muscle, the lateral wall by the vastus medialis, and the an tero-

med ial wall by the sartorius muscle and fascia. The cana l con-

tains the femoral artery and vein, the deep lymph vessels, the

saphenous nerve, and the nerve to the vastus med ialis muscle.

Knee Region

POPLITEAL FOSSA

The popliteal fossa is a diamond-shaped, intermuscular

space at the back of the knee (Fig. 5-14). It contains the

po pliteal vessels, the sma ll sap he no us vein , the co mmon

peronea l and tibia l nerves, the poste rior cu taneo us ne rve of

the thigh, con nec tive tissue, and lymph nodes.

BOUNDARIES

• Laterally:The b iceps femo ris muscle above and the lateralhead of the gastrocnemius and plantaris muscles below.

• Medially: The semimembranosus and semitendinosusmuscles above and the med ial head of the gastrocnemius

muscle below.

Leg

The muscles of the anterior fascial compartment (Fig. 5-9)are described in Table 5-5. The muscles of the lateral fascial

compartment (Fig. 5-9) a re de scribed in Table 5-6, and the

muscles of the posterior fascial compartment (Fig. 5-15) are

described in Table 5-7. The m uscle on the dorsum of the foot

is described in Table 5-8.

FASCIAL COMPARTMENTS OF THE LEG

The deep fascia surrounds the leg and is continuous above

with the dee p fascia of the thigh. It is attache d to the anterior

and the medial borders of the tibia, and two intermuscular

septa pass from its deep aspect to be attached to the fibula.

Together with the interosseous membrane, the septa divide

Table 5-4 Muscles of the Posterior Fascial Compartment of the Thigh


Biceps femoris Long head: ischial Head of the fibula Sciatic nerve (long Flexes and laterally rotates

tuberosity; short head: tibial nerve; the leg at the knee joint;

head: shaft of the short head: common the long head also

femur peroneal nerve) extends the thigh at thehip joint

Semiten dinosus Ischial tub erosity Uppe r part of the med ia l Scia tic ne rve (tibia l Flexes a nd media lly rotates

surface of the shaft of portion) the leg at the knee joint

the tibial and extends the thigh at

the hip joint

Semimemb ra nosus Ischial tub erosity Med ial c ond yle of the Scia tic ne rve (tibia l Flexes a nd media lly rotates

tibia, forms the oblique portion) the leg at the knee joint

po plitea l ligament an d exten ds the th igh at

the hip joint

Ad du ctor m agn us Isc hia l tu be ro sity Ad du ctor tu be rc le of the Sc ia tic n erve ( tib ia l Exte nd s th e thigh a t the h ip

(hamstring portion) femur portion) joint

FEMORAL HERNIA

• A protrusion o f the a bdominal parietal peritoneum

down through the femoral canal to form the hernial

sac.

• More common in women than in men.

• The n eck of the hernial sac lies below and lateral to

the pubic tube rcle.

• The ne ck of the hernial sac lies at the femoral ring

and is related anteriorly to the inguinal ligament,

posteriorly to the pectinea l ligament, latera lly to the

femoral vein, and med ially to the sha rp, free ed ge of

the lacunar ligament.

CLINICAL NOTES


22/44


Figure 5-14 Boundaries an d conten ts of the right pop liteal fossa .


23/44


Table 5-5 Muscles of the Anterior Fascial Compartment of the Leg

Muscle Origin Insertion Nerve Supply Actiona

Tib ia lis a nte rior Sh aft of the tib ia a nd the Me dia l c un eifo rm a nd De ep p eron ea l n erve Exte nd s th e fo ot a t th e

interosseous base of the first ankle joint, inverts the

membrane metatarsal bone foot at the subtalar and

the transverse tarsal joints, and ho lds up the

med ial longitudinal

arch o f the foot

Exte nso r d igito ru m Sh aft of the fib ula an d Exte nso r e xpa nsio n of De ep p ero ne al ne rve Exte nd s th e to es a nd

longus the interosseous the lateral four toes dorsiflexes the foot at

membrane the ankle joint

Peroneus tertius Shaft of the fibula and Base of the fifth Deep peroneal nerve Dorsiflexes the foot at the

the interosseous metatarsal bone ankle joint and everts

membrane foot at the subtalar and

the transverse tarsal

joints

Exte nso r h alluc is lo ngus Sh aft of the fib ula an d Ba se of th e d ista l De ep pe ro ne al ne rve Exte nd s th e b ig to e,

the interosseous phalanx of the dorsiflexes the foot at

membrane great toe the ankle joint, and

inverts the foot at thesubtalar and the

transverse tarsal joints

aExtens ion (or dors iflexion) of the ankle is the move ment o f the foot away from the grou nd.

Table 5-6 Muscles of the Lateral Fascial Compartment of the Leg


Pe ro ne us lo ngu s Sh aft of fib ula Ba se of first me ta ta rsa l Su pe rfic ia l p ero ne al Pla nta r fle xe s th e fo ot a t th e a nkle

bo ne an d th e med ial ne rve joint, everts the foot a t the

cuneiform subtalar and the transversetarsal joints, holds up the lateral

longitudina l arch o f the foot,

and supports the transverse arch

Pe roneus b re vis Shaft of the fib ula Base of the fifth Superfic ial perone al Plantar flexe s the foot a t the ankle

metatarsal bone nerve joint, everts the foot at the

subtalar and the transverse

tarsal joints, and ho lds up the

lateral longitudinal arch o f the

foot


24/44


Figure 5-15 Structures of the p osterior aspe ct of the right leg. A. The gastrocnemius muscle issho wn in full. B. Part of the gas trocnem ius m uscle has b een rem oved.


25/44


Table 5-7 Muscles of the Posterior Fasc ial Compartment of the Leg


Superficial Grou p

Gastrocnemius Medial and lateral Via tendo calcaneus Tibial nerve Plantar flexes the foot at the

condyles of the femur (Achilles tendon) ankle joint, flexes the knee

into the calcaneum jointPlantaris Lateral supracondylar Calcaneum Tibial nerve Plantar flexes the foot at the

ridge of the femur ankle joint, flexes the knee

joint

Soleus Shafts of the tibia Via tendo calcaneus Tibial nerve Together with the

and the fibula (Achilles tendon) gastrocnemius and

into the calcaneum the plantaris, it is a powerful

flexor of the ankle joint;

pro vides the ma in

pro pu lsive force in walking

and running

Deep Grou p

Popliteus Lateral condyle of Shaft of the tibia Tibial nerve Flexes the leg at the knee joint;

the femur unlocks the knee joint by

laterally rotating the femur

on the tibia, thus slackeningthe ligaments of the joint

Flexor digitorum Shaft of the tibia Bases of the distal Tibial nerve Flexes the distal phalanges

longus phalanges of of the lateral four toes,

the lateral four toes plantar flexes the foot, and

supports the medial and the

lateral longitudinal arche s

of the foot

Flexor hallucis Shaft of the fibula Base of the distal Tibial nerve Flexes the distal phalanx of the

longus phalanx of the big toe big toe, plantar flexes the

foot at the ankle joint, and

supports the medial

longitudina l arch o f the foot

Tibialis posterior Shafts of the tibia Tuberosity of the Tibial nerve Plantar flexes the foot at the

and the fibula and navicular and other ankle joint, inverts the foot

the interosseous neighboring bones at the subtalar and themembrane transverse tarsal joints, and

supports the medial

longitudinal a rch o f the foot

Table 5-8 Muscle on the Dorsum of the Foot


Exte nso r d igito ru m Ca lc an eu m By fo ur te nd on s in to th e p roxima l De ep pe ro ne al n erve Exte nd s th e first, se co nd ,

bre vis phalanx o f the b ig toe (sometimes third , an d fou rth toescalled the extensor ha llucis brevis)

and long extensor tendons to the

second, third, and fourth toes


26/44


the leg into three compartments, with each having its own

muscles, blood supply, and nerve supply. The compart-

ments are as follows:

• Anterior with the deep peroneal nerve.

• Lateral (peroneal) with the superficial peroneal nerve.

• Posterior with the tibial nerve.

INTEROSSEOUS MEMBRANE

The interosseous membrane binds the tibia and the fibula

together and p rovides attachmen t for the muscles.

Ankle

RETINACULA

The retinacula are thickenings of the deep fascia that keep

the long tendons around the ankle joint in position and act

as pulleys (Fig. 5-10).

Superior Extensor Retinaculum

The superior extensor retinaculum is attached to the distal

end s of the a nterior borders of the fibula and the tibia (Fig.

5-9).

Inferior Extensor Retinaculum

The inferior extensor retinaculum is a Y-shaped band

located in front of the ankle joint (Fig. 5-9).

Flexor Retinaculum

The flexor retinaculum extends from the medial malleolus

to the med ial surface of the ca lcaneum (Fig. 5-10). It binds

the deep muscles of the back of the leg to the back of themed ial malleolus as they pass forward to en ter the sole.

Superior Peroneal Retinaculum

The superior peroneal retinaculum connects the lateral

malleolus to the lateral surface of the calcane um (Fig. 5-10).

It binds the tendo ns of the peroneus longus and brevis mus-

cles to the ba ck of the lateral malleolus.

Inferior Peroneal Retinaculum

The inferior peroneal retinaculum binds the ten don s of the

pe roneus longus and b revis musc les to the latera l side o f the

calcaneum (Fig. 5-10).

Sole of Foot

The muscles of the sole (Figs. 5-16 and 5-17) are usua lly de -

scribed in four layers (from inferior to superior). These

muscles are listed in Table 5-9.

DEEP FASCIA

Plantar Aponeurosis

The plantar aponeurosis is a triangular thickening of the

deep fascia that protects the underlying nerves, blood ves-

sels, and muscles. Its apex is attached to the me dial and the

lateral tubercles of the calcaneum. The base of the aponeu-

rosis divides into five slips that pass into the toes.

ARCHES OF THE FOOT

There a re three bon y arches in the sole.

Medial Longitudinal Arch

The medial longitudinal arch is formed by the calcaneum,

the talus, the navicular bone, three cuneiform bones,

and the first (medial) three metatarsal bones.

• Muscular support: Medial part of the flexor digitorum

bre vis, a bd uc tor ha llucis, flexor ha llucis longus, me dia l

pa rt of the flexor digitoru m longus, flexor hallucis b revis,

tibialis anterior, and ten dinous e xtensions of the insertion

of the tibialis posterior.

• Ligamentous support: Plantar and dorsal ligaments, in-

cluding the important calcaneonavicular (spring) liga-

men t, the medial ligament of the ankle joint, and the p lan-

tar aponeurosis.

Lateral Longitudina l Arch

The lateral longitudinal arch is formed by the calcaneum,

the cub oid, and the fourth and the fifth metatarsal bones.

• Muscular support: Abductor digiti minimi, lateral part of

the flexor digitorum longus and brevis, and peroneus

longus and brevis.

• Ligamentous support: Long and short plantar ligame nts

and plantar aponeurosis.

Transverse ArchThe transverse arch is formed by the b ases of the me tatarsal

bon es, the cu boid , an d the three cun eifo rm bon es. The

wedge shape of the cuneiform bones and the bases of

the metatarsal bone s play a large role in the support of the

transverse arch .

• Muscular support: Dorsal interossei, transverse he ad of

the adductor hallucis, and peroneus longus and brevis.

• Ligamen tous support: Deep transverse ligaments and

very strong plantar ligaments.

ARTERIES OF THE LOWER LIMB

Femoral Artery

The femo ral artery is a con tinuation o f the external iliac a rtery

(Fig. 5-18). It begins behind the inguinal ligament, where it

lies midway between the an terior superior iliac spine an d the

symphysis pubis (the site for taking a femoral pulse). The

artery descends through the femoral triangle (Fig. 5-12) and

the adduc tor canal, and it leaves the front of the thigh by pass-

ing through the opening in the add uctor magnus and then e n-

tering the popliteal space as the po pliteal artery (Fig. 5-14).

In the femora l triangle, the artery is related latera lly to the

femo ral nerve and med ially, in the upper part of its course,

to the femo ral vein and the femoral cana l.


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third lumbrical

fourth lumbrical

digital nerve

plantar arch

deep branch of lateral plantar nerve

lateral plantar nerve

lateral plantar artery

flexor digitorum

accessorius

(quadratus plantae)

medial plantar artery


medial plantar nerve


digital nerves

second lumbrical

first lumbrical

Figure 5-16 Secon d layer of the plantar m uscles of the right foot. Note the m edial and the lateral

p lanta r a rt erie s and ne rves .


28/44


184

fibrous flexor sheath of second toe

digital synovial sheaths


synovial sheathof peroneus brevis

synovial sheathof peroneus longus

synovial sheathof flexor hallucis longus

tibialis posterior

synovial sheathof flexor digitorum

longus

flexor hallucislongus

Figure 5-17 Synovial she aths of tendo ns on the so le of the right foot.


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Table 5-9 Muscles of the Sole


First Laye r

Ab ductor Medial tub erc le of the Me dia l side of the ba se Media l plantar nerve Fle xes and abd uc ts the big toe ,

hallucis calcaneum, flexor of the proximal phalanx supports the medial longitudinal

retinaculum of the big toe arch

Flexor d igito rum Medial tuberc le of the Media l phalanx of the Media l p lan tar nerve Flexes the la tera l four toes,

bre vis ca lcane um four la tera l toes sup ports the media l and th e

lateral longitudinal arche sAb du cto r d igiti Me dia l a nd la te ra l La te ra l sid e o f th e b ase La te ra l p la nta r n erve Fle xe s a nd ab duc ts the fifth to e,

minimi tubercles of the of the proximal phalanx supports the lateral longitudinal

calcaneum of the fifth toe arch

Second Layer

Fle xor d igitoru m Me dia l a nd la te ra l Te nd on of th e fle xo r La te ra l p la nta r n erve Assists th e lon g fle xo r te nd on s

accessorius sides of the digitorum longus to flex the lateral four toes

calcaneum

Flexor digitorum Shaft of the tibia Base of the distal phalanx Tibial nerve Flexes the distal phalanges of

longus of the lateral four toes the lateral four toes, plantar

flexes the foot, and supp orts

the longitudinal arches

Lumbricals (4) Tendons of the flexor Dorsal extensor expansion First lumbrical: medial Extends the toes at the

digitorum longus of the lateral four toes plantar nerve; interphalangeal joints

remainder: deep

bra nch of the la tera l planta r ne rve

Flexor hallucis Shaft of the fibula Base of the distal phalanx Tibial nerve Flexes the distal phalanx of the big

longus of the big toe toe, plantar flexes the foot, and

supports the med ial longitudinal

arch

Third Layer

Fle xor ha llu cis Cub oid a nd la te ra l Me dia l a nd la te ra l sid es Me dia l p la nta r n erve Fle xe s th e me ta ta rso ph ala nge al

bre vis cu ne iform b on es; of the ba se o f the joint o f the b ig toe, supports

tibialis posterior proximal phalanx of the medial longitudinal arch

insertion the big toe

Addu ctor hallucis

Ob liq ue he ad Ba se s of th e se co nd , La te ra l sid e o f th e b ase De ep bra nc h o f th e Fle xe s th e b ig toe , sup po rts the

third, and fourth of the proximal pha la nx la te ra l plantar nerve transverse arc h

metatarsal bones of the big toe

Transverse Plantar ligaments Lateral side of the base Deep branch of the Flexes the big toe, supports the

head of the proximal phalanx lateral plantar nerve transverse arch

of the big toe

Flexor digiti Base of the fifth Lateral side of the base Lateral plantar nerve Flexes the little toe

minimi brevis metatarsal bone of the proximal phalanx

of the little toe

Fourth Layer

Interossei

Dorsa l ( 4) Ad ja ce nt sid es o f th e Ba se s o f th e p ha la nge s La te ra l p la nta r n erve Ab du ct th e to es from th e se co nd

metatarsal bones and the dorsal expansion toe, flex the metatarsophalangeal

of the corresponding toes joints, and extend the

interphalangea l joints

Planta r (3) In fe rio r su rfaces o f th e Bases o f th e p ha langes La te ra l p lanta r n erve Ad du ct th e to es to th e seco nd to e,

third, fourth, and and the dorsal expansion flex the metatarsophalangeal

fifth metatarsal of the corresponding toes joints, and extend the

bo nes interph alangeal joints

Peroneus longus Shaft o f the fibula Base of the first meta tarsa l Superfic ia l peroneal Plantar flexes the foot a t the ankle

bo ne an d th e med ial ne rve joint, everts the foot a t the

cuneiform subtalar and the transverse tarsal

joints, and ho lds up the la tera l

longitudinal and the transverse

arche s of the foot

Tib ia lis p oste rio r Sh afts o f th e tib ia an d Tu be ro sity o f th e n avicula r Tib ia l n erve Planta r flexes th e fo ot a t th e ankle

the fibula and the and other neighboring joint, inverts the foot at the

interosseous bones subtalar and the transverse tarsal

membrane joints, and supports the medial

longitudinal a rch o f the foot


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inguinal ligament

profunda artery

lateral femoralcircumflex

artery

anterior tibial

artery

dorsalis pedis artery

arcuate artery

peroneal artery

posterior tibial artery

popliteal artery

perforating branchesof profunda femoris

artery

femoral artery

medial femoralcircumflex artery

femoral artery

external iliac artery

Figure 5-18Major arteries of the lower limb .

BRANCHES

• Superficial circumflex iliac artery, which a rises just be-

low the inguinal ligame nt and runs laterally toward the an-

terior superior iliac spine.

• Superficial epigas tric artery, which a rises just below the

inguinal ligame nt and runs upward to the abd omina l wall.

• Superficial e xternal puden dal artery.

• Deep external pudendal artery and the superficial ex-

ternal pudendal artery arise just below the inguinal liga-

ment and run medially to supply the skin of the scrotum

(or labium majus).

• Profunda femoris artery, which is a large branch that

arises from the femo ral artery approximately 1.5 in. (4 c m)

be low the inguin al ligament ( Fig. 5-12). It sup plies struc-

tures in the anterior, medial, and posterior fascial com-

pa rtme nts of the thigh via the following branche s: medial

and lateral femoral circumflex arteries and four per-

forating arteries.

• Descend ing genicular artery.


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TROCHANTERIC ANASTOMOSIS

The trocha nteric anastomo sis provides the ma in blood sup-

ply to the head of the femur (in ad ults) via the following

arteries:

• Supe rior gluteal artery.

• Inferior gluteal artery.• Medial femoral circumflex artery.

• Lateral femoral circumflex artery.

CRUCIATE ANASTOMOSIS

Together with the trochanteric anastomosis, the cruciate

anastomosis provides the important connection between

the internal iliac and the femoral arteries. The following

arteries are involved:

• Inferior gluteal artery.

• Medial femoral circumflex artery.

• Lateral femoral circumflex artery.

• First perforating artery, which is a branch of the profundaartery.

Popliteal Artery

The popliteal artery (Fig. 5-18) is a continuation of the

femo ral artery. It extends from the op ening in the a ddu ctor

magnus to the lower border of the pop liteus muscle, where

it divides into the anterior and the posterior tibial arteries. It

is deeply placed in the popliteal fossa and lies close to the

posterior surface o f the femur and the kne e joint.

BRANCHES

• Muscular branches.

• Articular branches to the knee joint.

• Terminal branches: Anterior and posterior tibial

arteries.

ANASTOMOSIS AROUND THE KNEE JOINT

The a rteries involved in ana stomosis aroun d the knee joint

are as follows:

• The descending genicu lar artery from the femoral artery.

• The lateral femoral circumflex artery from the profunda

femoris.

• The articular branches from the pop liteal artery.

• The b ranche s from the anterior and the po sterior tibial

arteries.

Anterior Tibial Artery

The anterior tibial artery arises at the bifurcation of the

popliteal artery in the pop liteal fossa ( Fig. 5-18). It passes for-

ward between the tibia and the fibula through the upper

pa rt of the inte rosseus me mb rane an d en ters the an terior

compartment of the leg. It then d escends with the deep p er-

oneal nerve to the front of the ankle joint, where it becomes

the dorsalis pedis artery (Fig. 5-9).

At the ankle, the anterior tibial artery lies midway be-

tween the malleoli and has the tendon of the extensor hal-

lucis longus muscle on its med ial side and the tendon s of ex-

tensor digitorum longus muscle o n its lateral side (the site

for taking an anterior tibial pulse).

BRANCHES


• Anastomotic branches, which anastomose with

branch es of other arteries aroun d the knee an d an kle

joints.

Dorsalis Pedis Artery

The dorsalis pedis artery begins in front of the ankle joint

midway between the malleoli and is a continuation of the

anterior tibial artery (Figs. 5-9 and 5-18). The dorsalis pedis

artery end s by entering the sole through the proximal part of

the space between the first and second metatarsal bones.Having passed between the two he ads o f the first dorsal in-

terosseous muscle, it joins the lateral plantar artery and

completes the plantar a rch (Fig. 5-16).

At first, the a rtery is supe rficial, having the tend ons of the

extensor digitorum longus mu scle on its lateral side an d the

tendon of the extensor hallucis longus muscle on its med ial

side (the site for taking a dorsalis pedis pulse ).

BRANCHES

• Lateral tarsal artery, which supplies the dorsum of the

foot.

• Arcuate artery, which runs laterally across the bases of

the me tatarsal bones and gives off branc hes to the toes.• First dorsal metatarsal artery, which supplies both

sides o f the big toe.

Posterior Tibial Artery

The posterior tibial artery arises at the bifurcation of the

popliteal artery in the po plitea l fossa ( Fig. 5-18). It descen ds

in the posterior compartment of the leg and is accompanied

by the tibia l nerve. The artery terminates beh ind the me dia l

malleolus by dividing into the med ial and the lateral plantar

arteries. The pulse may be felt midway between the med ial

malleolus and the hee l.

BRANCHES

• Peroneal artery, which is a large artery that arises close

to the origin of the posterior tibial artery. It descends in

close association with the flexor hallucis longus muscle

to the region o f the a nkle, and it gives off muscular

branches, a nutrient artery to the fibula, and anasto-

motic branches around the ankle joint.


• Nutrient artery to the tibia.

• Anastomotic branche s around the ankle joint.

• Medial and lateral plantar arteries.



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Medial Plantar Artery

The medial plantar artery is the smaller of the terminal

branches of the posterior tibial artery (Fig. 5-16). It runs forward

along the medial border of the foot with the medial plantar

nerve, and it gives off many muscular and cutaneous branches.

Lateral Plantar Artery

The lateral plantar artery is the larger of the terminal

branc hes of the posterior tibia l arte ry (Fig. 5-16). It run s for-

ward dee p to the abd uctor hallucis and the flexor digitorum

brevis musc les with th e latera l plan tar nerve, and it end s by

curving medially to form the plantar arch through anasto-

mosis with the dorsalis pedis artery. The plantar arch gives

off perforating an d metatarsal arteries; the metatarsal arter-

ies give rise to digital arteries.

VEINS OF THE LOWER LIMB

The superficial veins lie in the superficial fascia and are of

great clinical importance. The deep veins acc ompan y the

main arteries.

Superficial Veins

DORSAL VENOUS NETWORK

The dorsal venous network lies on the dorsum of the foot

(Fig. 5-19). It is drained on the medial side by the great

saphenous vein and on the lateral side by the small saphe-

nous vein.

GREAT SAPHENOUS VEIN

The great saphenous vein arises from the med ial side of the

dorsal venous network of the foot ( Fig. 5-19), and it ascend s

directly in front of the medial malleolus. Accompanied by

the sapheno us nerve, it ascends the leg in the superficial fas-

cia, passes beh ind the knee, and c urves forward around the

medial side of the thigh. It then passes through the saphe-

nous opening in the deep fascia and joins the femoral vein

approximately 1.5 in. (4 cm) b elow and lateral to the pu bic

tubercle. The great saphenous vein possess numerous

valves, and it is connected to the small saphenous vein by

bra nc hes tha t pass be hind the kne e. Several perforating

veins conne ct the great saphenous vein with the de ep veins

along the me dial side of the c alf.

The great saphenous vein receives the following small

tributaries near its termination:

• Th e superficial circumflex iliac ve in.

• The superficial epigastric ve in.

• Th e superficial external pudendal vein.


COMPRESSION OF ARTERIES OF THE

LOWER LIMB

Medica l personal should know the precise position of

the main arteries within the lower limb.

• Femo ral artery: This enters the thigh behind the in-

guinal ligament at a point midway between the an-

terior superior iliac spine an d the symphysis pub is.

• Popliteal artery: This artery can be felt by gentle

pa lpation in the de pths of the popliteal space , pro-

vided that the deep fascia is fully relaxed by pas-

sively flexing the knee joint.

• Dorsalis pe dis artery: This artery lies between the

tendons of the extensor hallucis longus and the ex-tensor digitorum longus, midway between the me-

dial and lateral malleoli on the front of the a nkle.

• Posterior tibial artery: This artery passes behind

the medial malleolus, beneath the flexor retinacu-

lum, and lies between the tendons of flexor digito-

rum longus and the flexor hallucis longus. The

pulsation s of the a rtery ca n be felt midway between

the medial malleolus and the heel.

CLINICAL NOTES

LIGATION OF ARTERIES OF THE LOWER LIMB

Sudd en occ lusion of the femoral artery by ligature is

usually followed by gangrene. However, gradual oc-

clusion , such as occurs in atherosc lerosis, is less likely

to be followed by necrosis because the collateral

blood vessels have time to dilate fully. The co llateral

circulation for the proximal part of the femoral artery

is through the cruciate and troch anteric anastomoses;

for the femoral artery in the adductor canal, it is

through the perforating branches of the profunda

femoris artery and the articular and muscular

bra nches of the femoral and popliteal arteries.

CLINICAL NOTES

THE CLINICAL IMPORTANCE OF THE GREATSAPHENOUS VEIN

• Blood transfusions: The constant position of the

great saphenous vein in front of the medial malleo-

lus should be remembered for patients requiring

emergency blood transfusion.• Bypass operations: The insertion of a graft of a por-

tion of the great saphenous vein can be used in oc-

clusive coronary artery disease and also to bypass

obstructions of the brachial or femoral arteries.

CLINICAL NOTES

SMALL SAPHENOUS VEIN

The small saphenous vein a rises from the lateral side o f the

dorsal venous network of the foot (Fig. 5-19). It ascends

behind the lateral malleolus in company with the sural

nerve, passes up the back of the leg, and pierces the deep


33/44


saphenous opening

femoral vein

femoral artery

great saphenous vein

accessory vein

dorsal venous arch

medial malleolus

smallsaphenous vein

great saphenous vein

superficial external pudendal vein

pubic tubercle

superficial epigastric vein

superficial circumflex iliac vein

popliteal vein

lateralmalleolus

perforating vein

muscle

superficialfascia

skin

saphenous veindeep fascia

"Venous pump"

venae comitantes

Figure 5-19 Sup erficial veins of the right lowe r limb . Note the imp ortance of the valved p erforatingveins in the “venou s pum p.”


34/44

fascia to e nter the p opliteal fossa. It drains into the pop liteal

vein. The small saphenous vein communicates with the

deep veins and with the great saphenous vein.

The superficial veins of the lower limbs are common sites

for varicosities.

Deep Veins

VENAE COMITANTES

The deep veins accomp any the respective arteries as vena e

comitantes. The venae comitantes of the anterior and the

posterior tibia l a rteries un ite in the popliteal fossa to form

the po pliteal vein.

POPLITEAL VEIN

The popliteal vein is formed by the union of the venae comi-

tantes of the anterior and the p osterior tibial arteries (Fig. 5-

14). It end s by passing through the open ing in the ad duc tor

magnus muscle to become the femoral vein. The poplitealvein receives numerous tributaries, including the small

saphenous vein.

FEMORAL VEIN

The femoral vein is a continuation of the popliteal vein at

the ope ning in the addu ctor magnus muscle. It ascends

through the adductor canal and the femoral triangle and is

accomp anied by the femoral artery. In the femoral sheath, it

lies on the me dial side of the femoral artery and on the lat-

eral side to the femoral canal. As it ascends behind the in-

guinal ligament, it become s continuous with the external il-

iac vein. The femoral vein receives the great saphe nous veinand the veins that correspond to branches of the femoral

artery.

LYMPHATIC DRAINAGE OF THELOWER LIMB

The superficial lymph vessels ascend the limb in the su-

pe rficia l fascia with th e superficial veins. The deep lymph

vessels lie deep to the deep fascia and follow the deep ar-

teries and veins. All the lymph vessels of the lowe r limb ulti-

mately drain into the dee p inguinal group of nodes that are

situated in the groin.

Superficial Inguinal Nodes

The superficial inguinal nodes lie in the superficial fascia

just be low the inguinal ligamen t and d rain into the de ep in-

guinal nodes. The superficial inguinal nodes may be

divided into a horizontal and a vertical group .

HORIZONTAL GROUP

The horizontal group receives lymph from the superficial

lymph vessels of the anterior abdominal wall below the

level of the umbilicus, the p erineum, the external genitalia

in both sexes (but not the testes), and the lower half of

the anal canal. It also receives lymph from the skin of the

bu ttocks.

VERTICAL GROUP

The vertical group lies alongside the terminal part of the

great saphenous vein and receives most of the superficial

lymph vessels of the lower limb (except from the bac k and

lateral side of the ca lf and the lateral side o f the foot, which

drain into the popliteal nodes).

Deep Inguinal Node s

The deep inguinal nod es are usually three in number and lie

along the me dial side of the femoral vein and in the femoral

canal. They receive all the lymph from the superficial in-

guinal nodes and the dee p structures of the lower limb . The

efferent lymph vessels pass upward through the femoral

canal into the abdominal cavity, and they drain into theexternal iliac nodes.

Popliteal Lymph Node s

Situated in the pop liteal fossa, the popliteal lymph node s re-

ceive the superficial lymph vessels that accompany the

small saphenous vein from the lateral side of the foot and

from the bac k and the lateral side of the calf. They also re-

ceive lymph from the deep structures of the leg below the

knee. The efferent vessels from the se nodes d rain upward to

the deep inguinal nodes.

NERVES OF THE LOWER LIMBFemoral Nerve

The femo ral nerve arises from the lumba r plexus (L2, 3, and

4). It enters the thigh behind the inguinal ligament, and it

lies lateral to the femoral vessels and the femoral shea th in

the femoral triangle (Fig. 5-12). It quickly terminates by di-

viding into the anterior and the posterior divisions.

BRANCHES OF THE FEMORAL NERVE IN THE THIGH

• Cutaneous branches: Medial cutaneous ne rve of the

thigh, which supplies the skin on the medial side of the

thigh. Intermediate cutaneous nerve of the thigh,

which supplies the skin on the anterior surface of thethigh. Saphenous nerve, which descends through the

femoral triangle and the adductor canal and crosses the

femoral artery. The nerve emerges on the medial side of

the knee joint between the tendo ns of the sartorius and the

gracilis muscles, and it accompanies the great saphe nous

vein down the med ial side of the leg and in front of the me-

dial malleolus. It passes along the medial border of the

foot a s far as the ball of the b ig toe.

• Muscular branches to the sartorius, the pectineus, and

the qua driceps femo ris muscles.

• Articular branches to the hip and knee joints.



35/44

The branches of the femoral nerve are summarized in

Figure 5-20. Dermatomal charts for the anterior and poste-

rior surfaces of the b ody are shown in Figures 2-3 and 2-4.

Obturator Nerve

The obturator nerve arises from the lumbar plexus (L2, 3,

and 4) and runs forward on the lateral wall of the pelvis to

reach the o bturator canal ( the uppe r part of the obturator foramen) . The obturator nerve divides into the an terior and

the posterior divisions.

BRANCHES OF THE OBTURATOR NERVE IN THE THIGH

The anterior division descends into the thigh anterior to

the obturator externus and the adductor brevis muscles.

• Muscular branches: Gracilis, adductor b revis, addu ctor

longus, and sometimes the pectineus muscles.

• Cutaneous branch: Skin on the med ial side of the thigh.

• Articular branch: Hip joint.

The posterior division descends through the ob turator

externus muscle and passes behind the adduc tor brevis and

in front of the ad duc tor magnus muscles.

• Muscular branches: Obturator externus, adductor mag-

nus (ad ductor part), and sometimes the add uctor brevis

muscles.

• Articular branch: Knee joint.

The branches of the obturator nerve are summarized inFigure 5-21. Dermatomal charts for the anterior and the pos-

terior surfaces o f the bo dy are shown in Figures 2-3 and 2-4.

Sciatic Nerve

The sciatic nerve arises from the sacral plexus (L4 and 5 and

S1, 2, and 3). It passes out of the pelvis and into the gluteal

region through the greater sciatic foramen (Fig. 5-11). The

nerve appears below the piriformis muscle and is covered

by the glute us ma ximus mu scle . It d esc en ds thro ugh the

gluteal region, and it enters the posterior compartment of

Documents

Snell Lower Limb