Anatomy- Le2

Front 1

Sacral Plexus

Back 1

Sacral plexus
1. sciatic nerve divides into two branches common peroneal and tibial nerves

common peroneal (fibular) nerve
• wraps around the head of the fibula and then divides into superficial and deep peroneal nerves
• clinical: common site for nerve injury….fibular head fractures, direct blows to lateral leg
• superficial peroneal nerve
(i) supplies fibularis longus/brevis and skin on distal 1/3 of anterior surface of leg and dorsal foot
• deep peroneal nerve
(i) supplies anterior muscles of leg, dorsum along web of the foot (first interdigital cleft)

tibial nerve
• supplies posterior muscles of leg, knee joint and sensation along posterolateral leg & plantar surface of the foot
• divides in foot into
(i) medial plantar nerve
1. supplies intrinsic muscles of foot and sensation along medial plantar surface of the foot
(ii) lateral plantar nerve
1. supplies intrinsic muscles of foot and sensation along lateral plantar surface of the foot

• clinical: Morton’s neuroma…often neuroma develops in interdigital nerves in an anastomsis between the medial and lateral plantar nerves

Front 2

Back 2

Peroneal (fibular) portion of sciatic

Front 3

Back 3

Tibial Portion of Sciatic

Front 4

Back 4

Tibial Portion of Sciatic

Front 5

Superficial Nerves of the Leg

Back 5

Leg
a. three major cutaneous branches provide sensation of the skin of the leg
• Saphenous nerve
(i) branch of femoral nerve – supplies “medial” surfaces of the leg and foot
• Sural nerve
(i) branch of the sciatic nerve – supplies “posterior” regions down to the foot
• Superficial branch of peroneal (fibular) nerve
(i) supplies “anterior” surface of leg

Front 6

Back 6

Saphenous Nerve of Femoral Nerve

Front 7

Superficial Nerves of the Foot

Back 7

Foot
a. two major branches of the peroenal (fibular) nerve supplies the dorsum of the foot
• Superficial peroneal (fibular) nerve
(i) supplies most of the dorsum of the foot
• Deep peroneal (fibular) nerve
(i) Supplies web of the foot (1st interdigital cleft)
b. two major branches of the tibial nerve supply plantar surface of the foot
• medial plantar nerve
(i) supplies intrinsic muscles of foot and sensation along medial plantar surface of the foot
• lateral plantar nerve
(i) supplies intrinsic muscles of foot and sensation along lateral plantar surface of the foot

Front 8

Blood Supply of Leg/Ankle/Foot

Back 8

Overview of the Blood Supply of the Leg/Ankle/Foot
A. Femoral artery passes through adductor canal becomes popliteal artery
B. Popliteal artery descends in popliteal fossa and divides into anterior and posterior tibial arteries

1. anterior tibial artery
a. decends anterior to the interosseus membrane
b. terminates as the dorsalis pedis artery
• eventually forms anastomosis with plantar surface of the foot (communicates with the plantar arch)
• clinical: palpation of dorsalis pedis pulse

2. posterior tibial artery
a. descends 1/3 of the way down the leg and gives off a peroneal artery branch
• peroneal artery (travels posterior to lateral malleolus…can potentially palpate pulse here)

b. posterior tibial artery continues to descend
• continues to descend in the leg, passes posterior to the medial malleolus (palpate pulse here)
• splits into two arteries that supply the plantar surface of the foot
(i) medial plantar artery
(ii) lateral plantar artery
1. eventually forms plantar arch….
2. the plantar arch forms anastomosis to the dorsum of the foot
a. via communication to blood supply from the dorsalis pedis artery

Front 9

Back 9

Anterior Tibial Artery

Front 10

Back 10

Front 11

Back 11

Dorsalis Pedis Artery

Front 12

Back 12

Front 13

Back 13

Medial and Lateral Plantar Artery

On right- lateral plantar artery forms plantar arch

Front 14

Bones of Leg

Back 14

Tibia
a. wt bearing of the lower leg
b. clinical: tibia stress fractures
Fibula
a. minimal wt bearing role
b. provides structure/function for ankle joint
c. provide leverage for muscle attachments

Front 15

+text

Back 15

Proximal Tibiofibular joint (p632) planar type of synovial joint
a. Articular surfaces
• Head of fibula
• Lateral condyle of tibia
b. Movement
• slight movement occurs during ankle dorsiflexion/plantarflexion

Front 16

Back 16

Distal Tibiofibular joint (p632) essential for ankle joint stability
a. Articular surfaces
• medial surface of inferior end of fibula articulates with facet on inferior end of tibia
b. Ligaments
• interosseous ligament is continuous with interosseous membrane
• anterior and posterior inferior tibiofibular ligament
• inferior transverse tibiofibular ligament (contacts talus)
c. Movement
• movement occurs during ankle plantar flexion/dorsiflexion to accommodate talus

Front 17

+ Text

Back 17

Foot and Ankle Joints
1. Foot is divided into three regions
a. Hindfoot
• Talus
• Calcaneus
b. Midfoot
• Navicular
• Cuboid
• Cuneiforms
c. Forefoot
• Metatarsals
• Phalanges

Front 18

Function of Ankle/Foot

Back 18

Function of the ankle/foot complex
a. Provide stability and mobility
b. provide stable base for weight bearing forces
c. absorb shock as foot hits the ground
d. provide lever system for gait (acts as rigid lever for push off)
e. permit foot to conform to different surfaces
f. absorb rotational forces of LE (ER forces foot into supination, IR forces foot into pronation)

Front 19

Movement of Ankle/Foot Joints

Back 19

Movement of the ankle/foot joints
a. Planar movement in foot/ankle region
• Motion in the sagittal plane – dorsiflexion/plantarflexion
• Motion in the frontal plane, longitudinal axis through the foot. eversion/inversion
• Motion in the transverse plane, vertical axis – abduction/adduction

Front 20

Supination of Foot

Back 20

Supination
(i) inversion of hindfoot
(ii) adduction of forefoot
(iii) plantarflexion of ankle

Front 21

Pronation

Back 21

Pronation
(i) Eversion of hindfoot
(ii) abduction of forefoot
(iii) dorsiflexion of ankle

Front 22

+ Ankle Osteology and Motion

Back 22

Osteology…(mortise and tenon joint)
• Tibia, fibula form the mortise
• Talus (trochlea) forms the tenon

Motion of ankle joint (p635)
• primarily dorsiflexion and plantarflexion
• ankle is more stable in dorsiflexion

Front 23

+ Text

Back 23

Deltoid (Medial Collateral) (p635 fig 5.65)
(i) Protects against eversion of ankle in different degrees of plantarflexion/dorsiflexion
(ii) 4 sections named after the each bone that they attach to
1. Tibionavicular
2. Anterior tibiotalar
3. posterior tibiotalar
4. Tibiocalaneal

Front 24

+ Text

Back 24

Lateral Collateral (p634 fig 5.64)
(i) generally opposes inversion of ankle)
(ii) 3 sections named after the bony attachments
1. Anterior talofibular
a. clinical: classic site of “ankle sprain”
2. Posterior talofibular
3. Calcaneofibular

Front 25

Back 25

a. Subtalar Joint (talocalcaneal jt)
• critical for damping rotational forces of the leg and foot

Front 26

+ Text

Back 26

Talocalcaneonavicular (TCN) Joint
• TCN jt is critical for foot movement…acts as a ball bearing
• movement of the talus and calcaneus will force the forefoot to move via the TCN jt
• Technically the TCN is part of the Transverse Tarsal Joint

Front 27

Back 27

Transverse Tarsal Joint
• S shaped line that divides the hindfoot and midfoot
• TCN motion controls the Transverse Tarsal Joint
• NOTE: the TCN and Transverse Tarsal Joint divide the hindfoot and midfoot

Front 28

Back 28

Tarsal Metatarsal Joint
• divides the midfoot and forefoot
• similar action as Transverse Tarsal Joint (not much motion needed unless the transverse tarsal joint can’t compensate for extreme hindfoot)
• site of Lisfranc…amputation or sprain

Front 29

Back 29

Metatarsalphalangeal (MTP) Joints
• primarily flexion/extension motion of phalanges but can abduct/adduct

Front 30

Back 30

Muscles and Structures of the Leg
A. Fascia divides leg is divided into compartments
1. anterior, lateral and posterior compartments

Front 31

+ Text

Back 31

A. Anterior Crural Compartment (p579) (dorsiflexor extensor compartment;
1. Borders of anterior crural compartment
a. Anterior – tibia, lateral surface
b. Lateral – anterior crural Intermuscular septum
c. Posterior – interosseous membrane

Front 32

Back 32

Front 33

Back 33

PT

Front 34

+ Text

Back 34

Nerve and blood Supply of the anterior compartment
a. deep fibular nerve descends in the anterior copmpartment and supplies the muscles of the anterior compartment (p579) (p581, fig5.35)(p582, table5.10)

b. anterior tibial artery(p579) (p574, fig 5.33A; p581, fig5.35B; p583, Table 5.11) descends in the anterior compartment, cross the ankle joint and becomes the dorsalis pedis artery

Front 35

Tibialis Anterior

Back 35

Tibialis anterior (p579)
P = lateral condyle and superior half of lateral surface of tibia and interosseous membrane
D = Medial and inferior surfaces of medial cuneiform and base of 1st metatarsal
N = deep fibular (peroneal) nerve (L4, L5)
A = Dorsiflexes ankle and +/- inverts foot (depends on where tendon pulls relative to axis of subtalar joint)

Front 36

Extensor Digitorum Longus

Back 36

Extensor digitorum longus (p579)
P = Lateral condyle of tibia and superior threequarters of medial surface of the fibula and interosseous membrane
D = Middle and distal phalanges of lateral four digits
N = Deep fibular (peroneal) nerve (L5, S1)
A = Extends lateral four digits and dorsiflexes ankle

Front 37

Extensor Hallucis Longus

Back 37

Extensor hallucis longus (p579)
P = Middle part of anterior surface of fibula and interosseous membrane
D = Dorsal aspect of base of distal phalanx of great toe
N = Deep fibular (peroneal) nerve (L5, S1)
A = Extends great toe and dorsiflexes ankle

Front 38

Fibularis (peroneus) Tertius

Back 38

Fibularis (peroneus) Tertius (p579)
P = Inferior third of anterior surface of fibula and interosseous membrane
D = Dorsum fo base of 5th metatarsal
N = Deep fibular (peroneal) nerve (L5, S1)

Front 39

Back 39

Anterior Tibialis

Front 40

Lateral Crural Compartment

Back 40

Lateral Crural Compartment (p584)
1. Borders of the lateral crural compartment
a. Medial – lateral surface of the fibula
b. Anteromedial – anterior crural Intermuscular septum
c. Lateral – deep (crural) fascia
d. Posterior – posterior crural Intermuscular septum

Front 41

Back 41

Front 42

Back 42

Superficial Peroneal Nerve

Front 43

Back 43

Peroneal Artery

Front 44

Fibularis (peroneus) Longus

Back 44

Fibularis (peroneus) Longus
P = Head and superior 2/3 of lateral surface of fibula
D = Base of 1st metatarsal and medial cuneiform
N = Superficial fibular (peroneal) nerve (L5, S1, S2)
A = Everts foot and plantarflexes 1st ray; weakly plantarflexes ankle

Front 45

Fibularis (peroneus) Brevis

Back 45

Fibularis (peroneus) Brevis
P = Inferior 2/3 of lateral surface of fibula
D = Dorsal surface of tuberosity on lateral side of base of 5th metatarsal
N = Superficial fibular (peroneal) nerve (L5, S1, S2)
A = Everts foot and plantarflexes, weakly plantarflexes ankle

Front 46

Nerve and Blood Supply of Lateral Compartment

Back 46

nerve supply
• superficial fibular nerve (p580, fig 5.35A; p582 table 5.10) supplies muscles of the lateral compartment skin on distal part of anterior surface of leg and nearly all the dorsum of the foot.

blood supply (THERE IS NO ARTERY IN THE LATERAL COMPARTMENT)
• The muscles in the compartment are supplied by superiorly and inferiorly perforating branches of the peroneal (fibular) artery (p576, fig 5.33A; p583, table 5.11

Front 47

Back 47

Front 48

Back 48

Achille's Tendon

Front 49

Back 49

Popliteus

Front 50

Back 50

Front 51

Back 51

Front 52

Back 52

Tibial Nerve

Front 53

Back 53

Front 54

Posterior Compartment

Back 54

Posterior Crural Compartment (p586) (largest of the three leg compartments)
1. Borders of the lateral crural compartment (p574, fig 5.33A)
a. posterior – (medial to lateral) posterior crural fascia)
b. anterior – (medial to lateral)posterior tibia, interosseous membrane, fibula, posterior intermuscular septum

Front 55

Superficial Group of Posterior

Back 55

Gastrocnemius (fabella p587)
P = Lateral head: lateral aspect of femoral condyle; Medial head: popliteal surface of femur (superior to medial condyle)
D = Posterior surface of calcaneus via calcaneal tendon
N = Tibial nerve (S1 and S2)
A = plantaflexes ankle with knee extended, raises heel during walking and flexes leg at knee joint

Soleus
P = Posterior aspect fibular head, superior ¼ of posterior surface of fibula soleal line and medial border of tibia
D = Posterior surface of calcaneus via calcaneal tendon
N = Tibial nerve (S1 and S2)
A = Plantarflexes ankle independent of knee position and steadies leg on foot
•
Plantaris (maybe a proprioceptive organ p586)
P = Inferior end of lateral supracondylar line of femur and oblique popliteal ligament
D = Posterior surface of calcaneus via calcaneal tendon
N = Tibial nerve (S1 and S2)
A = Weakly assists gastronemius in PF ankle and flexing knee

Front 56

Deep Group of Posterior

Back 56

• Popliteus
P = Lateral surface o lateral condyle of femur and lateral meniscus
D = Posterior surface of tibia, superior to soleal line
N = Tibial N. (L4-S1)
A = Weakly flexes knee and unlocks it; in NWB it medially rotates tibia on femur; in WB it laterally rotates femur on tibia

• Flexor Hallucis Longus
P = Inferior 2/3 of posterior surface of fibula and inferior part of interosseous membrane
D = Base of distal phalanx of great toe
N = Tibial N. (S2, S3)
A = Flexes great toe at all joints and weakly plantarflexes ankle; supports medial longitudinal arches of foot

• Flexor Digitorum Longus
P = Medial part of posterior surface of tibia inferior to soleal line and by a broad tendon to fibula
D = Bases of distal phalanges of lateral four digits
N = Tibial N. (S2, S3)
A = Flexes lateral four digits and plantarflexes ankle; supports longitudinal arches of foot

• Tibialis Posterior
P = Interosseous membrane, posterior surface of tibia inferior to soleal line, and posterior surface of fibula
D = Tuberosity of navicular, cuneiform, and cuboid and bases of 2nd, 3rd, 4th metatarsals
N = Tibial nerve (L4, L5)
A = plantarflexes ankle and inverts (supinates) foot

Front 57

Nerve and Blood Supply to Posterior Compartment

Back 57

2. Nerve and blood supply of the posterior compartment – (p582, table 5.10)
a. tibial nerve (L4-S3) descends in median plane of the fibula, deep to the soleus; in ankle it lies between the FHL and FDL; posterior-inferior to medial malleolus the nerve divides into medial and lateral plantar nerves; the medial sural cutaneous usually unites with the communicating branch of common fibula nerve to form the sural nerve; articular branches supply the knee joint and medial calcaneal branches supply the skin of the heel.

b. (p583 table 5.11) posterior tibial artery (largest terminal branch of popliteal artery provides main blood supply to foot, ) and fibular artery (supplies lateral compartment of leg through perforating branches)

Front 58

+ Text

Back 58

Longitudinal Arch
a. Blend of connective tissue and bone that extends from the calcaneus to metatarsal heads
• 2 portions of arch…medial and lateral arch
b. Muscular sling provides support for the arch
• fibularis longus and tibialis posterior

Front 59

+ Text

Back 59

Transverse Arch
a. Anterior tarsals and base of metatarsals
b. Perpendicular to longitudinal arches
c. Extend to level of metatarsal heads
d. Muscular sling also provides support for the arch
• fibularis longus and tibialis posterior

Front 60

Arches of the Foot Function

Back 60

Function
a. contribute to balance
b. provide shock absorption
c. propulsion
d. space for blood vessels, nerves, muscles to pass under foot
e. transfer weight forward

Front 61

Back 61

Front 62

Ligaments that Provide Arch Support

Back 62

Ligaments that provide support for the arch
• Long plantar ligament
• Short plantar ligament
• Spring ligament
(i) navicular bone to sustentaculum tali (calcaneus)
• Plantar aponeurosis (bears most of the load in maintaining the arch)
(i) attachment at medial calcaneus
(ii) “windlass” effect
1. MCP flexes during gait the aponeurosis pulls on the calcaneus
2. This increases the arch height…maintains supination
(iii) Clinical: attachment on calcaneus is site for plantar fasciitis
1. excessive forces contribute to development of bone spur (“heel spur”)

PL and PT support as ligaments

Front 63

Back 63

Plantar Aponeurosa

Front 64

+ Text

Back 64

Dorsum of the foot (p599, fig 5.34)
a. Extensor Hallucis Brevis
P = Dorsal aspect of calcaneus
D = lateral side of base of proximal phalanx of great toe
N = deep fibular (L5, S1)
A = helps extend proximal phalanx of great toe

b. Extensor Digitorum Brevis
P = dorsal and lateral aspect of calcaneus
D = lateral side of tendons of EDL muscle for 2nd, 3rd, and 4th toes
N = deep fibular (L5, S1)
A = helps extend proximal phalanges of 2nd, 3rd, and 4th toes

Front 65

+ Text

Back 65

First Layer (“flexor digitorum surrounded by two abductors”)
• Abductor hallucis
P = medial tubercle of tuberosity of calcaneus, flexor retinaculum, and plantar aponeurosis
D = medial side of base of proximal phalanx of 1st digit
N = medial plantar nerve (S2 and S3)
A = abducts and flexes great toe (hullux) (mtp joints)

• Flexor digitorum brevis
P = medial tubercle of tuberosity of calcaneus, plantar aponeurosis, and intermuscular septa
D = both sides of middle phalanges of lateral four toes
N = medial plantar nerve (S2 and S3)
A = flexes lateral four digits (pip and mtp joints)

• Abductor digiti minimi
P = medial and lateral tubercles of tuberosity of calcaneus, plantar aponeurosis, and intermuscular septa
D = lateral side of base of proximal phalanx of 5th digit
N = lateral plantar (S2 and S3)
A = abducts and flexes 5th digit (mtp joint)

Front 66

+ Text

Back 66

Second Layer
• Quadratus plantae
P = medial surface of lateral margin of plantar surface of calcaneus
D = posterior-lateral margin of tendon of FDL
N = lateral plantar (S2 and S3)
A = assists FDL in flexing lateral four toes; actually helps to keep pull of FDL tendons pulling straight

• Lumbricals
P = tendons of FDL
D = medial aspect of expansion over lateral four digits
N = 1st = MPN; #2-4 = LPN
A = flex pip joints and extends pip and dip joints of lateral four toes

Front 67

Third Layer (not on practical)

Back 67

Third Layer
• Flexor hallucis brevis
P = plantar surfaces of cuboid and lateral cuneiforms
D = both sides of base of proximal phalanx of great toe
N = MPN (S2 and S3)
A = flexes mtp joint great toe

• Adductor hallucis
P = oblique head: bases of metatarsals #2-4; transverse head: plantar ligaments of MTP joints
D = tendons of both heads attach to lateral side of base of proximal phalanx of 1st digit
N = deep branch of lateral plantar nerve (S2 and S3)
A = adducts 1st digit at MTP joint; assists in maintaining transverse arch of foot

• Flexor digiti minimi brevis
P = base of 5th metatarsal
D = base of proximal phalanx of 5th digit
N = superficial branch of lateral plantar nerve (S3 and S3)
A = flexes proximal phalanx of 5th digit at MTP joint

Front 68

Fourth Layer (not on practical)

Back 68

• Plantar Interossei
P = bases of medial sides of metatarsals
D = medial sides of bases of proximal phalanges of 3rd to 5th digits
N = lateral plantar nerve (S2 and S3)
A = adducts digits (2-4) and flex MTP joints

• Dorsal Interossei – (LPN)
P = adjacent sides of metatarsals #1-5)
D = First: medial side of proximal phalanx of 2nd digit; Second to fourth: lateral sides of 2nd to 4th digits
N = lateral plantar nerve (S2 and S3)
A = abducts digits (2-4) and flex MTP joints

Front 69

Back 69

Front 70

Back 70

Front 71

Back 71

Front 72

Back 72

Arcuate Artery

Front 73

Medial Plantar Nerve

Back 73

1. Medial Plantar Nerve
a. larger of two terminal tibial branches
b. 3 sensory branches (sensation to lateral 3 ½ digits, (plantar surface)
c. motor branches (ABD Hal, FDB, FHB, and most medial lumbrical muscle)

Front 74

Lateral Plantar Nerve

Back 74

a. Superficial Branch
• cutaneous to lateral 1 ½ digits (plantar surface)
• motor supply: quadratus plantae, abd dig min, flex dig min,
b. Deep Branch
• motor supply: plantar and dorsal interossei, lateral three lumbricles, add hal

Front 75

Deep Peroneal (Fibular) Nerve

Back 75

1. Deep Peroenal (Fibular)
a. Motor suuply to foot: supplies dorsal intrinsic muscles of the foot (EDB, EHB)
b. Sensory supply to the foot: web if first interdigital space

Front 76

Superficial Peroneal (Fibular) Nerve

Back 76

2. Superficial Peroneal (Fibular)
a. Supplies most of the skin along dorsum of the foot

Front 77

Continuation of Anterior Tibial Artery

Back 77

1. Continuation of Anterior Tibial Artery
a. Dorsalis Pedis Artery
• continuation of the anterior tibial artery (palpate the pulse between the EHL and EDL)
b. Deep plantar artery
• joins lateral plantar artery to form deep plantar arch
c. Arcuate artery
• gives rise to dorsal digital arteries

Front 78

Continuation of Posterior Tibial Artery

Back 78

Continuation of Posterior Tibial Artery
a. Medial Plantar Artery
• most plantar digital vessels arise from these vessel

b. Lateral Plantar Artery
• larger than medial plantar artery,
• continues to form deep plantar arch with connection to medial plantar artery